Suspension valve group, vehicle suspension system and control method

Abstract

The invention relates to the technical field of vehicle suspensions, in particular to a suspension valve group, a vehicle suspension system and a control method. The first reversing valve is arranged between the rod cavity of the suspension oil cylinder and the oil tank, switching-on and switching-off between the rod cavity and the hydraulic oil tank can be achieved through reversing of the first reversing valve, when the rod cavity communicates with the oil tank, the rod cavity relieves pressure, and therefore under the same load bearing state (a rodless cavity of the suspension oil cylinder communicates with the first energy accumulator), the hydraulic oil tank can be opened or closed. The cylinder diameter of the oil cylinder of the suspension can be designed to be smaller, and the interactive flow between the oil cylinder and the energy accumulator is reduced, so that the purpose of damping reduction is achieved. When the vehicle is supported and after the vehicle is supported, and the first reversing valve is switched to a stop position, the rod cavity of the suspension oil cylinder is disconnected from the oil tank and can be closed, the suspension oil cylinder cannot be lengthened when the vehicle is supported and after the vehicle is supported, tires can be separated from the ground, and the tires are separated from the ground, so that safe operation of the vehicle is facilitated.

Description

Technical Field

[0001] This invention relates to the field of vehicle suspension technology, specifically to a suspension valve assembly, a vehicle suspension system, and a control method. Background Technology

[0002] Hydropneumatic suspension systems are commonly used in wheeled cranes, especially all-terrain cranes. Basic components include suspension cylinders, accumulators, and control valves. The upper end of the suspension cylinder connects to the frame, boom, and other sprung supports, while the lower end connects to the axle. Suspension cylinders are typically double-acting, containing both rodless and rod-driven chambers. Generally, when the axle is on the ground and the outriggers are off the ground, lifting the suspension involves extending the suspension cylinders, raising the frame; lowering the suspension involves shortening the suspension cylinders (sometimes by gravity, sometimes by hydraulic power), lowering the frame. Typically, when the outriggers support the vehicle, lifting the axle involves shortening the suspension cylinders (at this point, shortening by force is not possible), lifting the axle off the ground; lowering the axle involves extending the suspension cylinders (when the axle is heavy, it can be extended by the axle's weight or shortened by hydraulic power), bringing the axle closer to the ground. After the outriggers extend to support the vehicle, the axle may fall to the ground due to gravity and internal leakage in the hydraulic system after a period of time. If there is no power to lift the axle, the outriggers can only be retracted again, and the suspension cylinders can be compressed by the weight of the vehicle frame. Then the outriggers can be extended again, and the shortened suspension cylinders will lift off the ground as the outriggers extend, thus indirectly lifting the axle. This process is time-consuming, labor-intensive, and may cause safety accidents.

[0003] There is an urgent need for a suspension system that can reduce damping during vehicle operation and maintain the extension and retraction of the suspension cylinders when and after the vehicle is supported. Summary of the Invention

[0004] The purpose of this invention is to provide a suspension valve assembly, a vehicle suspension system, and a control method. By installing a first directional valve between the rod chamber of the suspension cylinder and the hydraulic tank, the switching of the first directional valve can achieve the connection and disconnection between the rod chamber and the hydraulic tank. When the rod chamber is connected to the tank, the rod chamber is depressurized. Thus, under the same load conditions (with the rodless chamber of the suspension cylinder connected to the first accumulator), the cylinder diameter of the suspension cylinder can be designed to be smaller, and the flow rate between the cylinder and the accumulator is reduced, thereby achieving the purpose of reducing damping. Furthermore, when the vehicle is supported and after being supported, when the first directional valve switches to the cut-off position, the rod chamber of the suspension cylinder is disconnected from the tank, which can close the rod chamber. During and after vehicle support, the suspension cylinder can maintain its extension and retraction state, keeping the tires off the ground to aid in safe vehicle operation.

[0005] In a first aspect, the present invention provides a suspension valve assembly, comprising: a valve assembly body, the valve assembly body including an A1 port for connecting to the rodless chamber of a suspension cylinder via a main directional valve, an SP port for connecting to a first accumulator, an A2 port for connecting to the rod chamber of the suspension cylinder, and a T port for connecting to a hydraulic oil tank, wherein the SP port and the A1 port are connected; the valve assembly body includes a first directional valve, wherein a first end and a second end of the first directional valve are respectively connected to the T port and the A2 port of the valve assembly body; both the main directional valve and the first directional valve have a shut-off position and a through position.

[0006] Optionally, it also includes: The second directional valve has its first end connected to port A2 of the valve assembly body and its second end connected to port SP of the valve assembly body. The second directional valve is used to keep the main directional valve in the closed state before the vehicle is supported or the axle is lifted. The second directional valve is de-energized to the connected position, and the rod chamber of the suspension cylinder is connected to the first accumulator. When the vehicle is in motion, the second directional valve is kept in the energized closed state.

[0007] Optionally, it also includes: The second overflow valve has its inlet connected to port A2 of the valve assembly body and its outlet connected to port T of the valve assembly body.

[0008] Optionally, it also includes: The third relief valve has its oil inlet connected to the SP port of the valve assembly body via a damping orifice.

[0009] Optionally, the valve assembly body also has an M1 port for connecting to the SP port, the M1 port being used to connect to a pressure sensor.

[0010] Secondly, the present invention provides a vehicle suspension system, comprising a left front suspension system, a left rear suspension system, a right front suspension system, and a right rear suspension system, wherein each of the left front suspension system, left rear suspension system, right front suspension system, and right rear suspension system includes the aforementioned suspension valve assembly and suspension cylinder, and the vehicle suspension system further includes: Hydraulic oil pump, The inlet and outlet valve assembly includes ports P3, P4, P5, and P6 connected in parallel with the outlet of the hydraulic oil pump; ports T3, T4, T5, and T6 connected to the hydraulic oil tank; ports A3 and B3 connected to the rod-side and rodless-side chambers of the suspension cylinder of the right front suspension system, respectively; ports A4 and B4 connected to the rod-side and rodless-side chambers of the suspension cylinder of the left front suspension system, respectively; ports A5 and B5 connected to the rod-side and rodless-side chambers of the suspension cylinder of the right rear suspension system, respectively; and ports A6 and B6 connected to the rod-side and rodless-side chambers of the suspension cylinder of the left rear suspension system. The inlet and return oil valve assembly includes: The third directional valve is used to control the P3 port of the inlet and return oil valve group to supply oil to the A3 port or the B3 port. The fourth directional valve is used to control the oil supply from port P4 of the inlet and return valve assembly to port A4 or port B4. The fifth directional valve is used to control the oil supply from port P5 of the inlet and return valve assembly to port A5 or port B5. The sixth directional valve is used to control the oil supply from port P6 of the inlet and return valve assembly to port A6 or port B6.

[0011] Optionally, the third, fourth, fifth and sixth directional valves each include a directional valve body, and a hydraulic lock is provided between each directional valve body and the corresponding A port and B port of the inlet and return oil valve group. When the reversing valve body is in the left position, the corresponding P port supplies oil to the corresponding A port. When the reversing valve body is in the right position, the corresponding P port supplies oil to the corresponding B port. When the reversing valve body is in the neutral position, both port A and port B are connected to port T.

[0012] Optionally, the left rear suspension system and the right rear suspension system further include: The second accumulator is connected to the rodless chamber of the suspension cylinder through the tenth directional valve and is connected in parallel with the first accumulator; The seventh reversing valve has an inlet connected to the first air source, and a first outlet and a second outlet connected to the first control port and the second control port of the tenth reversing valve, respectively. The opening or closing of the tenth directional valve can be controlled by switching the valve position of the seventh directional valve.

[0013] Optionally, it also includes: The eighth reversing valve has an inlet connected to the second air source and an outlet connected in parallel to the first control port of the main reversing valve of the left front suspension system, left rear suspension system, right front suspension system and right rear suspension system. The ninth directional valve has its inlet connected to the third air source and its outlet connected in parallel to the second control port of the main directional valves of the left front suspension system, left rear suspension system, right front suspension system and right rear suspension system. When the eighth directional valve is energized and switched to the through position, the output pressure of the second air source acts on the first control port of each main directional valve to make the main directional valve switch to the cut-off position; When the ninth directional valve is energized and switched to the through position, the output pressure of the third air source acts on the second control port of each main directional valve to switch the main directional valve to the through position.

[0014] Thirdly, the present invention provides a control method for a vehicle suspension system, which is based on the vehicle suspension system, the control method comprising: During vehicle operation, the main directional valves of the left front suspension system, left rear suspension system, right front suspension system and right rear suspension system are in the open position, the first accumulator is connected to the rodless chamber of the suspension cylinder, the first directional valve is in the open position, and the rod chamber of the suspension cylinder is connected to the hydraulic oil tank through the first directional valve. When the axle is carrying the vehicle, the suspension system that needs to be lifted or lowered among the left front suspension system, left rear suspension system, right front suspension system and right rear suspension system is identified as the target suspension system. For a target suspension system that needs to be raised, the main directional valve of the corresponding suspension valve group is in the off position. The hydraulic oil output by the hydraulic oil pump flows in through the corresponding P port of the inlet and return valve group and enters the rodless chamber of the suspension cylinder through the corresponding B port on the inlet and return valve group. The rod chamber returns through the corresponding A port on the inlet and return valve group. If the first directional valve is in the open position, the rod chamber also returns through the A2 port of the suspension valve group and the first directional valve. The suspension cylinder extends to achieve the raising of the target suspension system. For the target suspension system that needs to be lowered, the main directional valve and the first directional valve of the corresponding suspension valve group are in the cut-off position. The hydraulic oil output by the hydraulic oil pump flows in through the corresponding P port of the inlet and return valve group and enters the rod chamber of the suspension cylinder through the corresponding A port of the inlet and return valve group. The rodless chamber returns oil through the corresponding B port of the inlet and return valve, and the suspension cylinder shortens to achieve the suspension lowering of the target suspension system. In the case of a vehicle with a non-load-bearing axle, the suspension system that requires suspension lifting or lowering among the left front suspension system, left rear suspension system, right front suspension system, and right rear suspension system is identified as the target suspension system. For the target suspension system that needs to be lowered, the main directional valve is switched to the cut-off position. The hydraulic oil output by the hydraulic pump flows in through the corresponding P port of the inlet and return valve group and enters the rodless chamber of the corresponding suspension cylinder through the corresponding B port of the inlet and return valve group. The rod chamber returns through the corresponding A port of the inlet and return valve group. If the first directional valve is in the open position, the rod chamber also returns through the A2 port of the suspension valve group and the first directional valve. The suspension cylinder extends to realize the suspension lowering of the target suspension system. After the suspension lowering is completed, the first directional valve needs to be in the cut-off position to close the rod chamber of the suspension cylinder. For a target suspension system that requires suspension bridge lifting, the main directional valve and the first directional valve are in the off position. The hydraulic oil output by the hydraulic pump flows in through the corresponding P port of the inlet and return valve group and enters the rod chamber of the corresponding suspension cylinder through the corresponding B port of the inlet and return valve group 11. The rodless chamber returns oil through the corresponding B port of the inlet and return valve group. The suspension cylinder shortens to achieve suspension bridge lifting of the target suspension system.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. The suspension valve assembly of the present invention includes a first directional valve, which is disposed between the rod chamber of the suspension cylinder and the hydraulic oil tank. The switching of the first directional valve can realize the connection and disconnection between the rod chamber and the hydraulic oil tank. When the rod chamber is connected to the oil tank, the rod chamber is depressurized. Thus, under the same load condition (the rodless chamber of the suspension cylinder is connected to the first accumulator 4), the cylinder diameter of the suspension cylinder can be designed to be smaller, and the flow rate between the cylinder and the accumulator is reduced, thereby achieving the purpose of reducing damping. Furthermore, when the first directional valve is switched to the cut-off position during and after vehicle support, the rod chamber of the suspension cylinder is disconnected from the oil tank, which can close the rod chamber. During and after vehicle support, the suspension cylinder will not be stretched, and the tire can be lifted off the ground. Tire lifting off the ground helps the vehicle operate safely.

[0016] 2. To delay the axle's descent, this invention allows the rod chamber of the suspension cylinder to be connected to the first accumulator via a second directional valve during the vehicle support phase. When the vehicle needs to be supported, before support or axle lifting, the main directional valve remains in the closed position, and the second directional valve is de-energized to the connected position. This connects the rod chamber of the suspension cylinder to the first accumulator, thus enabling the first accumulator to maintain pressure in the rod chamber of the suspension cylinder. Attached Figure Description

[0017] Figure 1 A hydraulic schematic diagram of a suspension valve assembly provided in an embodiment of the present invention; Figure 2 A hydraulic schematic diagram of a suspension valve assembly with another structure provided in an embodiment of the present invention; Figure 3 for Figure 1 A hydraulic schematic diagram of a vehicle suspension system used in the suspension valve assembly; Figure 4 for Figure 2 A hydraulic schematic diagram of a vehicle suspension system used in the suspension valve assembly; Figure 5 for Figure 3 Hydraulic schematic diagram of the inlet and outlet oil valve assembly; Figure 6 for Figure 3 The hydraulic schematic diagram of the main directional valve in the system is a solenoid valve. Figure 7 for Figure 1 Hydraulic schematic diagram of the suspension valve group working in coordination with the second valve group; Figure 8 for Figure 7 Hydraulic schematic diagram of the second valve group.

[0018] The following are the labeling elements in the diagram: 1. Suspension valve assembly; 101. First directional control valve; 102. Second relief valve; 103. Third relief valve; 104. Damping orifice; 105. Second directional control valve; 2. Suspension cylinder; 3. Main directional control valve; 4. First accumulator; 5. Hydraulic pump; 6. Hydraulic oil tank; 7. First relief valve; 8. Eighth directional control valve; 9. Ninth directional control valve; 10. Seventh directional control valve; 11. Inlet and return valve assembly; 1101. Third directional valve 1102, fourth directional valve 1103, fifth directional valve 1104, sixth directional valve; 12, tenth directional valve; 13, second accumulator; 14, second valve group; 1401, eleventh directional valve; 1402, first damping orifice; 1403, twelfth directional valve; 1404, first check valve; 1405, second damping orifice; 1406, thirteenth directional valve; 15, third accumulator. Detailed Implementation

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention 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, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0021] Combination Figure 1This embodiment provides a suspension valve assembly 1, which includes: a valve assembly body, the valve assembly body including an A1 port for connecting to the rodless chamber of the suspension cylinder 2 via a main directional valve 3, an SP port for connecting to a first accumulator 4, an A2 port for connecting to the rod chamber of the suspension cylinder 2, and a T port for connecting to a hydraulic oil tank 6, wherein the SP port and the A1 port are connected; the valve assembly body includes a first directional valve 101, the first end and the second end of the first directional valve 101 are respectively connected to the T port and the A2 port of the valve assembly body; both the main directional valve 3 and the first directional valve 101 have a shut-off position and a through position.

[0022] The suspension valve assembly 1 of the present invention includes a first directional valve 101, which is disposed between the rod chamber of the suspension cylinder 2 and the hydraulic tank. The first directional valve 101 can switch the connection between the rod chamber of the suspension cylinder 2 and the hydraulic tank 6. When the rod chamber of the suspension cylinder 2 is connected to the hydraulic tank 6, the rod chamber of the suspension cylinder 2 is depressurized. Thus, under the same load condition (with the rodless chamber of the suspension cylinder 2 connected to the first accumulator 4), the cylinder diameter of the suspension cylinder 2 can be designed to be smaller, and the flow rate between the suspension cylinder 2 and the first accumulator 4 is reduced, thereby achieving the purpose of reducing damping. When the first directional valve 101 is switched to the cut-off position, the rod chamber of the suspension cylinder 2 is disconnected from the hydraulic tank, which can close the rod chamber. During and after vehicle support, the suspension cylinder will not be stretched, allowing the tire to leave the ground. Tire lift-off contributes to safe vehicle operation.

[0023] In addition, combined Figure 2 To compensate for the impact of internal leakage in the suspension cylinder 2 on maintaining tire ground clearance, this embodiment allows the first accumulator 4 to connect with the rod-side chamber of the suspension cylinder 2 during vehicle support, and to connect with the rodless chamber of the suspension cylinder 2 during driving. The suspension valve assembly also includes a second directional valve 105, with its first end connected to port A2 of the valve assembly body and its second end connected to port SP. Considering factors such as internal leakage in the suspension cylinder, the axle may still drop after prolonged vehicle support. To delay axle drop, the second directional valve 105 connects the rod-side chamber of the suspension cylinder 2 to the first accumulator 4 during vehicle support. When the vehicle needs to be supported, before support or axle lifting, the main directional valve 3 remains in the closed state, and the second directional valve 105 is de-energized to the connected position, connecting the rod-side chamber of the suspension cylinder 2 to the first accumulator 4, thus achieving the pressure-holding effect of the first accumulator 4 on the rod-side chamber of the suspension cylinder 2. When the vehicle is in motion, the second directional valve 105 remains in the energized and cut-off state, thereby preventing the oil in the first accumulator 4 and the rodless chamber from flowing into the rod chamber through the second directional valve 105, or even into the oil tank through the first directional valve 101.

[0024] In addition, the suspension valve assembly 1 also includes a second relief valve 102 and a third relief valve 103. The second relief valve 102 has its inlet connected to port A2 of the valve assembly body and its outlet connected to port T of the valve assembly body. The inlet of the third relief valve 103 is connected to port SP of the valve assembly body through a damping orifice 104.

[0025] The second relief valve 102 and the third relief valve 103 can limit the pressure of the hydraulic system and provide pressure limiting protection for the suspension valve group 1, the rodless chamber of the suspension cylinder 2, the rod chamber of the suspension cylinder 2, and the first accumulator 4.

[0026] The valve body also has an M1 port for connecting to the SP port. The M1 port is used to connect to a pressure sensor. The pressure sensor can trigger an early warning to remind the operator to handle the situation when the pressure of the first accumulator 4 is abnormal.

[0027] Combination Figure 3 In another specific embodiment, a vehicle suspension system is provided, which is a five-axle crane chassis suspension system. The front two axles are considered as the front suspension group, divided into left front and right front positions; the rear three axles are considered as the rear suspension group, also divided into left rear and right rear positions. The vehicle suspension system includes a left front suspension system, a left rear suspension system, a right front suspension system, and a right rear suspension system. The left front suspension system, left rear suspension system, right front suspension system, and right rear suspension system all include the suspension valve assembly 1 (the suspension valve assembly 1 includes a second reversing valve 105, as shown in the attached figure). Figure 4 As shown in the figure, the vehicle suspension system also includes a hydraulic pump 5 and an inlet / outlet valve assembly 11.

[0028] Combination Figure 5 The inlet and return valve assembly 11 includes ports P3, P4, P5, and P6 connected in parallel to the outlet of the hydraulic pump 5; ports T3, T4, T5, and T6 connected to the hydraulic tank 6; ports A3 and B3 connected to the rod-side and rodless-side chambers of the suspension cylinder 2 of the right front suspension system, respectively; ports A4 and B4 connected to the rod-side and rodless-side chambers of the suspension cylinder 2 of the left front suspension system, respectively; ports A5 and B5 connected to the rod-side and rodless-side chambers of the suspension cylinder 2 of the right rear suspension system, respectively; and ports A6 and B6 connected to the rod-side and rodless-side chambers of the suspension cylinder 2 of the left rear suspension system, respectively. By controlling the inlet and return valve assembly 11, the suspension can be raised / lowered individually or simultaneously in multiple directions at 1 / 4 of the vehicle's position. A first relief valve 7 is connected to the outlet of the hydraulic pump 5 to protect the system safety.

[0029] Specifically, the inlet and return oil valve assembly 11 includes: a third directional valve 1101, used to control the P3 port of the inlet and return oil valve assembly 11 to supply oil to the A3 port or the B3 port; a fourth directional valve 1102, used to control the P4 port of the inlet and return oil valve assembly 11 to supply oil to the A4 port or the B4 port; a fifth directional valve 1103, used to control the P5 port of the inlet and return oil valve assembly 11 to supply oil to the A5 port or the B5 port; and a sixth directional valve 1104, used to control the P6 port of the inlet and return oil valve assembly 11 to supply oil to the A6 port or the B6 port. The third directional valve 1101, fourth directional valve 1102, fifth directional valve 1103, and sixth directional valve 1104 all include a directional valve body. A hydraulic lock is provided between each directional valve body and the corresponding A and B ports of the inlet / return valve assembly 11. The hydraulic lock significantly reduces oil leakage from the suspension cylinder 2 back to the oil tank, preventing abnormal vehicle posture changes caused by cylinder retraction or extension due to external leakage after a period of vehicle driving or operation. When the directional valve body is in the left position, the corresponding P port supplies oil to the corresponding A port; when the directional valve body is in the right position, the corresponding P port supplies oil to the corresponding B port; when the directional valve body is in the middle position, both the corresponding A and B ports are connected to the corresponding T port.

[0030] Because the rear suspension has more axles, the number of accumulators required is increased. In this embodiment, the left and right rear suspension systems also include a second accumulator 13 and a seventh directional valve 10. The second accumulator 13 is connected to the rodless chamber of the suspension cylinder 2 through the tenth directional valve 12 and is connected in parallel with the first accumulator 4. The air inlet of the seventh directional valve 10 is connected to a first air source, and the first and second air outlets are respectively connected to the first and second control ports of the tenth directional valve 12. By switching the valve position of the seventh directional valve 10, the opening or closing of the tenth directional valve 12 can be controlled.

[0031] In this embodiment, the main directional valve 3 is a pneumatically controlled hydraulic directional valve. The control air pressure is generally generated by an air compressor driven by the vehicle engine, and the directional valve 3 is switched via the eighth directional valve 8 and the ninth directional valve 9. Other types of directional valves can also be used, such as solenoid valves or hydraulically controlled directional valves. The main directional valve 3 uses a solenoid valve with the following structure: Figure 6 As shown.

[0032] The suspension system includes an eighth directional valve 8 and a ninth directional valve 9. The eighth directional valve 8 has an inlet connected to a second air source and an outlet connected in parallel to the first control port of the main directional valves 3 of the left front suspension system, left rear suspension system, right front suspension system, and right rear suspension system. The ninth directional valve 9 has an inlet connected to a third air source and an outlet connected in parallel to the second control port of the main directional valves 3 of the left front suspension system, left rear suspension system, right front suspension system, and right rear suspension system. When the eighth directional valve 8 is energized and switched to the through position, the output pressure of the second air source acts on the first control port of each main directional valve 3, causing the main directional valve 3 to switch to the cut-off position. When the ninth directional valve 9 is energized and switched to the through position, the output pressure of the third air source acts on the second control port of each main directional valve 3, causing the main directional valve 3 to switch to the through position.

[0033] The working principle of damping reduction in the suspension system is explained below. For a hydropneumatic suspension system, road excitation is transmitted to the suspension cylinder 2 through the axle, causing the cylinder to extend and retract. The hydraulic fluid in the suspension cylinder 2 interacts rapidly and frequently with the first accumulator 4. This interaction requires a suitable damping state; damping is needed to reduce vibrations caused by road excitation, while excessive damping can lead to excessive dynamic stiffness and reduced comfort. Damping is generally improved by changing the interaction flow rate and altering the damping state of the connection between the hydraulic fluid interaction components. To address excessive suspension damping, on the one hand, with the vehicle load remaining constant, when the rod chamber of the suspension cylinder 2 is depressurized (when the first directional valve 101 is open, the rod chamber of the suspension cylinder 2 connects back to the oil tank), the cylinder diameter of the suspension cylinder 2 can be designed to be smaller. A smaller cylinder diameter reduces the interaction flow rate with the first accumulator 4, thus achieving the purpose of damping reduction. On the other hand, when there are multiple accumulators in the same group (the left and right rear suspension systems in this embodiment also include a second accumulator 13), the accumulators can be distributed and designed closer to the suspension cylinder 2 to reduce the length of the connecting pipes and achieve the purpose of reducing damping. Specifically, when the vehicle is moving, the main directional valve 3 is in the through position, the rodless chamber of the suspension cylinder 2 is connected to the first accumulator 4, the first directional valve 101 is in the through position, and the rod chamber of the suspension cylinder 2 is connected to the T port of the suspension valve group through the first directional valve 101 and is in a depressurized state. In this way, the cylinder diameter of the suspension cylinder 2 can be designed to be smaller and the interactive flow is also smaller, thereby achieving the purpose of reducing damping. The rear suspension group has three axles, and the last axle is far from the suspension valve group. An accumulator and a directional valve can be added near the last axle to reduce the pipe length between the flow interaction elements.

[0034] In another specific embodiment, a control method for a vehicle suspension system is provided, which is based on the vehicle suspension system, the control method comprising: During vehicle operation, the main directional valves 3 of the left front suspension system, left rear suspension system, right front suspension system, and right rear suspension system are in the through position. The first accumulator 4 is connected to the rodless chamber of the suspension cylinder 2, and the first directional valve 101 is in the through position. The rod chamber of the suspension cylinder 2 is connected to the hydraulic oil tank 6 through the first directional valve 101. The first directional valve 101 is located between the rod chamber of the suspension cylinder 2 and the hydraulic oil tank 6. The switching of the first directional valve 101 can realize the connection and disconnection between the rod chamber and the hydraulic oil tank 6. When the rod chamber of the suspension cylinder 2 is connected to the oil tank, the rod chamber is depressurized. In this way, under the same load conditions (the rodless chamber of the suspension cylinder 2 is connected to the first accumulator 4), the cylinder diameter of the suspension cylinder 2 can be designed to be smaller, and the interaction flow between the suspension cylinder 2 and the first accumulator 4 is reduced, thereby achieving the purpose of damping reduction.

[0035] When the axle is carrying the vehicle, the suspension system that needs to be lifted or lowered among the left front suspension system, left rear suspension system, right front suspension system and right rear suspension system is identified as the target suspension system. For the target suspension system that needs to be lifted, the main directional valve 3 of the corresponding suspension valve group is in the off position. The hydraulic oil output by the hydraulic pump flows in through the corresponding P port of the inlet and return valve group 11 and enters the rodless chamber of the suspension cylinder 2 through the corresponding B port on the inlet and return valve group. The rod chamber returns through the corresponding A port on the inlet and return valve group. If the first directional valve 101 is in the open position, the rod chamber also returns through the A2 port of the suspension valve group 1 and the first directional valve 101. The suspension cylinder 2 extends to achieve the lifting of the target suspension system. For the target suspension system that needs to be lowered, the main directional valve 3 and the first directional valve 101 of the corresponding suspension valve group are in the cut-off position. The hydraulic oil output by the hydraulic oil pump 5 flows in through the corresponding P port of the inlet and return valve group 11 and enters the rod chamber of the suspension cylinder 2 through the corresponding A port of the inlet and return valve group 11. The rodless chamber returns oil through the corresponding B port of the inlet and return valve group 11. The suspension cylinder 2 shortens to achieve the suspension lowering of the target suspension system. In the case of a vehicle with a non-load-bearing axle, the suspension system that requires suspension lifting or lowering among the left front suspension system, left rear suspension system, right front suspension system, and right rear suspension system is identified as the target suspension system. For the target suspension system that needs to be lowered, the main directional valve 3 is switched to the cut-off position. The hydraulic oil output by the hydraulic pump flows in through the corresponding P port of the inlet and return valve group 11 and enters the rodless chamber of the corresponding suspension cylinder through the corresponding B port of the inlet and return valve group 11. The rod chamber returns through the corresponding A port of the inlet and return valve group 11. If the first directional valve 101 is in the open position, the rod chamber also returns through the A2 port of the suspension valve group 1 and the first directional valve 101. The suspension cylinder 2 extends to realize the suspension lowering of the target suspension system. After the suspension lowering is completed, the first directional valve 101 needs to be in the cut-off position to close the rod chamber of the suspension cylinder 2. For the target suspension system that requires suspension bridge lifting, the main directional valve 3 and the first directional valve 101 are in the off position. The hydraulic oil output by the hydraulic oil pump flows in through the corresponding P port of the inlet and return valve group 11 and enters the rod chamber of the corresponding suspension cylinder through the corresponding B port of the inlet and return valve group 11. The rodless chamber returns oil through the corresponding B port of the inlet and return valve group 11. The suspension cylinder 2 is shortened to realize the suspension bridge lifting of the target suspension system.

[0036] In another specific embodiment, the suspension valve group 1 also works in conjunction with the second valve group. The A2 and A3 ports of the second valve group are respectively connected to the rodless chamber and the rod chamber of the suspension cylinder 2, and the SP port is connected to the third accumulator 15. The second valve group 14 includes an eleventh directional valve 1401, a twelfth directional valve 1403, and a thirteenth directional valve 1406. The first end of the eleventh directional valve 1401 is connected to the A3 port, and the second end is connected in parallel to the A2 port and the first end of the thirteenth directional valve 1406. The eleventh directional valve 1401 is used to control the opening or closing of the rodless chamber and the rod chamber of the suspension cylinder 2, which can realize the differential function of the suspension cylinder 2 and increase the effective stroke of the suspension cylinder 2 to improve the ground contact performance of the suspension. The first end of the twelfth directional valve 1403 is connected to port A1, and the second end is connected in parallel to port SP and the second end of the thirteenth directional valve 1406. The thirteenth directional valve 1406 is used to control the opening and closing of the rodless chamber of the third accumulator 15 and the suspension cylinder 2, so as to realize the adaptive adjustment of suspension stiffness under different axle load driving conditions. Among them, the eleventh directional valve 1401, the twelfth directional valve 1403 and the thirteenth directional valve 1406 are all two-position two-way solenoid directional valves (or two-position two-way pneumatic directional valves can be used instead), and the normally closed position function is a bidirectional cut-off state.

[0037] In addition, the first suspension valve assembly 14 also includes a first damping orifice 1402, a second damping orifice 1405, and a first check valve 1404; the first damping orifice 1402 is located between the A1 port of the second valve assembly 14 and the twelfth directional valve 1403; the first damping orifice 1402 and the twelfth directional valve 1403 work together to gradually balance the pressure of the first accumulator 4 and the third accumulator 15, prevent system pressure shocks, and improve vehicle handling stability.

[0038] The working principle of the suspension valve group 1 working in conjunction with the second valve group is explained as follows: The working pressure of the rodless chamber of the suspension cylinder 2 is detected by the pressure sensor. The actual axle load can be calculated by multiplying the piston area of ​​the rodless chamber of the suspension cylinder 2 by the working pressure. In this embodiment, the suspension stiffness and damping can be adaptively adjusted in three axle load ranges. The three axle load ranges are: actual axle load ≤ first axle load G1, first axle load G1 < actual axle load ≤ second axle load G2, and actual axle load > second axle load G2. The first axle load G1 and the second axle load G2 are both preset axle loads.

[0039] Specifically, when the vehicle is in motion and not steer or brake, for the left front suspension system, left rear suspension system, right front suspension system and right rear suspension system, the A1 port and B1 port of suspension valve group 1 are kept closed, the working pressure of the rodless chamber of suspension cylinder 2 detected by the pressure sensor is obtained, and the actual axle load is calculated by multiplying the working pressure of the rodless chamber of suspension cylinder 2 by the piston area.

[0040] When the actual axle load is less than or equal to the first axle load G1, combined with Figure 1 , Figure 7 and Figure 8 This positions the main directional valve 3 and the eleventh directional valve 1401 of the second valve group 14 in the through position, and positions the twelfth directional valve 1403 and the thirteenth directional valve 1406 of the second valve group 14 and the first directional valve 101 of the suspension valve group 1 in the cut-off position. In this state, the rodless chamber of suspension cylinder 2 is connected to the first accumulator 4 via the main directional valve 3 and the A2 and SP ports of suspension valve group 1. Under light axle load conditions (actual axle load less than or equal to the first axle load G1), the working pressure of the suspension system is effectively increased. The oil volume of the first accumulator 4 is sufficient to replenish the oil required by the rodless chamber when suspension cylinder 2 extends during vehicle operation, increasing the stroke of suspension cylinder 2 and improving suspension contact performance. At the same time, when suspension cylinder 2 is compressed during vehicle operation, the rodless chamber and rod chamber of suspension cylinder 2 are connected to form a differential cylinder through the A3 port of the second valve group 14, the eleventh directional valve 1401, and the A2 port of the second valve group 14. This reduces the hydraulic oil exchange flow between suspension cylinder 2 and the first accumulator 4, thereby reducing suspension damping and improving vehicle ride comfort.

[0041] When the actual axle load is greater than the first axle load G1 and less than or equal to the second axle load G2, combined with Figure 1 , Figure 7 and Figure 8This positions the main directional valve 3 and the first directional valve 101 of the suspension valve group 1 in the through position, and positions the eleventh directional valve 1401, twelfth directional valve 1403 and thirteenth directional valve 1406 of the second valve group 14 in the cut-off position. In this state, the rod chamber of suspension cylinder 2 is connected to the hydraulic oil tank 6 through port B2 of suspension valve group 1, the first directional valve 101 of suspension valve group 1, and port T2 of suspension valve group 1. The rodless chamber of suspension cylinder 2 is connected to the first accumulator 4 through the main directional valve 3, port A2 and port SP of suspension valve group 1. In this state, the sprung weight of the suspension only establishes pressure in the rodless chamber of suspension cylinder 2. Compared with the prior art where the sprung weight of the suspension establishes pressure in both the rodless and rod chambers of suspension cylinder 2, this state can effectively reduce the technical parameters such as cylinder diameter, rod diameter, and weight of suspension cylinder 2 while maintaining the consistent working pressure of the suspension system. It further reduces the hydraulic oil interaction flow between suspension cylinder 2 and first accumulator 4, thereby reducing suspension damping and improving vehicle ride comfort.

[0042] When the actual axle load is greater than the second axle load G2, combined with Figure 1 , Figure 7 and Figure 8 This positions the main directional valve 3, the twelfth directional valve 1403 and the thirteenth directional valve 1406 of the second valve group 14, and the first directional valve 101 of the suspension valve group 1 in the through position, and positions the eleventh directional valve 1401 of the second valve group 14 in the cut-off position. In this state, the rod-side chamber of suspension cylinder 2 is connected to the hydraulic oil tank 6 through port B2 of suspension valve group 1, the first directional valve 101, and port T2 of suspension valve group 1. The rodless chamber of suspension cylinder 2 is connected to the first accumulator 4 through the main directional valve 3, port A2 of suspension valve group 1, and port SP. The rodless chamber of suspension cylinder 2 is also connected to the third accumulator 15 through parallel first and second oil circuits. The first oil circuit is connected to the third accumulator 15 through the main directional valve 3, port A1 of second valve group 14, twelfth directional valve 1403, and port SP of second valve group 14. The second oil circuit is connected to the third accumulator 15 through port A2 of second valve group 14, thirteenth directional valve 1406, and port SP of second valve group 14. At this time, the rodless chamber of the suspension cylinder 2 is simultaneously connected to the first accumulator 4 and the third accumulator 15. This state reduces the stiffness of the suspension system by increasing the effective volume of the accumulator, thereby improving the ride comfort of the vehicle.

[0043] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A suspension valve group, characterized by, Comprising: a valve group body, the valve group body comprising an A1 port for connecting a rodless chamber of a suspension cylinder (2) through a main reversing valve (3), an SP port for connecting a first accumulator (4), an A2 port for connecting a rod chamber of the suspension cylinder (2), and a T port for connecting a hydraulic oil tank (6), the SP port and the A1 port being in communication; the valve group body comprising a first reversing valve (101), a first end and a second end of the first reversing valve (101) being connected to the T port and the A2 port of the valve group body respectively; the main reversing valve (3) and the first reversing valve (101) each having a cut-off position and a through position.

2. A suspension valve group according to claim 1, wherein Further comprising: a second reversing valve (105), a first end of the second reversing valve (105) being connected to the A2 port of the valve group body, and a second end of the second reversing valve (105) being connected to the SP port of the valve group body; the second reversing valve (105) being used for, before the vehicle on which the suspension valve group is installed is lifted or before the bridge on which the vehicle is installed is lifted, the main reversing valve (3) being kept in a cut-off state, the second reversing valve (105) being de-energized to a communication position, and the rod chamber of the suspension cylinder (2) being in communication with the first accumulator (4); when the vehicle is running, the second reversing valve (105) is kept in an energized cut-off state.

3. A suspension valve group according to claim 1, wherein Further comprising: a second overflow valve (102), an oil inlet of the second overflow valve (102) being connected to the A2 port of the valve group body, and an oil outlet of the second overflow valve (102) being connected to the T port of the valve group body.

4. A suspension valve group according to claim 1, wherein Further comprising: a third overflow valve (103), an oil inlet of the third overflow valve (103) being connected to the SP port of the valve group body through a damping hole (104).

5. A suspension valve group according to claim 1, wherein the valve group body further comprising an M1 port connected to the SP port, the M1 port being used for connecting a pressure sensor.

6. A vehicle suspension system characterized by, comprising a left front suspension system, a left rear suspension system, a right front suspension system, and a right rear suspension system, each of the left front suspension system, the left rear suspension system, the right front suspension system, and the right rear suspension system comprising the suspension valve group according to any one of claims 1-5 and a suspension cylinder, the vehicle suspension system further comprising: a hydraulic oil pump (5), an inlet and return valve group (11), comprising P3, P4, P5, and P6 ports connected in parallel to an oil outlet of the hydraulic oil pump (5), T3, T4, T5, and T6 ports connected to the hydraulic oil tank (6), A3 and B3 ports connected to a rod chamber and a rodless chamber of the suspension cylinder (2) of the right front suspension system respectively, A4 and B4 ports connected to a rod chamber and a rodless chamber of the suspension cylinder (2) of the left front suspension system respectively, A5 and B5 ports connected to a rod chamber and a rodless chamber of the suspension cylinder (2) of the right rear suspension system respectively, and A6 and B6 ports connected to a rod chamber and a rodless chamber of the suspension cylinder (2) of the left rear suspension system respectively; the inlet and return valve group (11) comprising: a third reversing valve (1101) for controlling the P3 port of the inlet and return valve group (11) to supply oil to the A3 port or the B3 port; a fourth reversing valve (1102) for controlling the P4 port of the inlet and return valve group (11) to supply oil to the A4 port or the B4 port; a fifth reversing valve (1103) for controlling the P5 port of the inlet and return valve group (11) to supply oil to the A5 port or the B5 port; a sixth reversing valve (1104) for controlling the P6 port of the inlet and return valve group (11) to supply oil to the A6 port or the B6 port.

7. A vehicle suspension system as claimed in claim 6, wherein The third reversing valve (1101), the fourth reversing valve (1102), the fifth reversing valve (1103) and the sixth reversing valve (1104) each comprise a reversing valve body, and each reversing valve body is provided with a hydraulic lock between the A port and the B port corresponding to the inlet and return valve group (11); When the reversing valve body is located at the left position, the P port of the corresponding inlet and return valve group (11) is supplied with oil from the A port of the corresponding inlet and return valve group (11); When the reversing valve body is located at the right position, the P port of the corresponding inlet and return valve group (11) is supplied with oil from the B port of the corresponding inlet and return valve group (11); When the reversing valve body is located at the middle position, the A port and the B port of the corresponding inlet and return valve group (11) are both communicated with the T port of the corresponding inlet and return valve group (11).

8. A vehicle suspension system as claimed in claim 6, wherein The left rear suspension system and the right rear suspension system further comprise: A second accumulator (13) connected to the rodless chamber of the suspension cylinder (2) through a tenth reversing valve (12) and connected in parallel with the first accumulator (4); A seventh reversing valve (10) with an air inlet connected to a first air source, a first air outlet and a second air outlet connected to the first control port and the second control port of the tenth reversing valve (12) respectively; The through or cut-off of the tenth reversing valve (12) can be controlled by switching the valve position of the seventh reversing valve (10).

9. A vehicle suspension system as claimed in claim 6, wherein, Further comprising: An eighth reversing valve (8) with an air inlet connected to a second air source and an air outlet connected in parallel to the first control port of the main reversing valve (3) of the left front suspension system, the left rear suspension system, the right front suspension system and the right rear suspension system; A ninth reversing valve (9) with an air inlet connected to a third air source and an air outlet connected in parallel to the second control port of the main reversing valve (3) of the left front suspension system, the left rear suspension system, the right front suspension system and the right rear suspension system; When the eighth reversing valve (8) is switched to the through position, the second air source outputs pressure to the first control port of each main reversing valve (3) to make the main reversing valve (3) switch to the cut-off position; When the ninth reversing valve (9) is switched to the through position, the third air source outputs pressure to the second control port of each main reversing valve (3) to make the main reversing valve (3) switch to the through position.

10. A control method of a vehicle suspension system, characterized by, The vehicle suspension system based on any one of claims 6-9 is used to perform the control method, which comprises: During vehicle driving, the main reversing valve (3) of the left front suspension system, the left rear suspension system, the right front suspension system and the right rear suspension system is in the through position, the first accumulator (4) is communicated with the rodless chamber of the suspension cylinder (2), the first reversing valve (101) of the suspension valve group is in the through position, and the rod chamber of the suspension cylinder (2) is communicated with the hydraulic oil tank (6) through the first reversing valve (101); In the state of axle load bearing vehicle, the suspension system which needs to be lifted or lowered among the left front suspension system, the left rear suspension system, the right front suspension system and the right rear suspension system is determined as the target suspension system; For the target suspension system that needs to be lifted, the main reversing valve (3) of the corresponding suspension valve group is located at the cut-off position, the hydraulic oil output by the hydraulic oil pump (5) flows in through the corresponding P port of the inlet and return valve group (11) and makes the hydraulic oil enter the rodless chamber of the suspension cylinder (2) through the corresponding B port of the inlet and return valve group (11), the rod chamber returns through the corresponding A port of the inlet and return valve group (11), at this time, if the first reversing valve (101) is in the through position, the rod chamber also returns through the A2 port of the suspension valve group (1) and the first reversing valve (101), the suspension cylinder is elongated to realize the suspension lifting of the target suspension system; For the target suspension system that needs to be lowered, the main reversing valve (3) and the first reversing valve (101) of the corresponding suspension valve group (1) are located at the cut-off position, the hydraulic oil output by the hydraulic oil pump (5) flows in through the corresponding P port of the inlet and return valve group (11) and makes the hydraulic oil enter the rod chamber of the suspension cylinder (2) through the corresponding A port of the inlet and return valve group (11), the rodless chamber returns through the corresponding B port of the inlet and return valve (11), the suspension cylinder (2) is shortened to realize the suspension lowering of the target suspension system; In the state of the non-load-bearing vehicle, the suspension system that needs to be lifted or lowered among the left front suspension system, the left rear suspension system, the right front suspension system and the right rear suspension system is determined as the target suspension system; For the target suspension system that needs to be lowered, the main reversing valve (3) is reversed to the cut-off position, the hydraulic oil output by the hydraulic oil pump (5) flows in through the corresponding P port of the inlet and return valve group (11) and makes the hydraulic oil enter the rodless chamber of the corresponding suspension cylinder (2) through the corresponding B port of the inlet and return valve group (11), the rod chamber returns through the corresponding A port of the inlet and return valve group (11), at this time, if the first reversing valve (101) is in the through position, the rod chamber also returns through the A2 port of the suspension valve group (1) and the first reversing valve (101), the suspension cylinder 2 is elongated to realize the suspension lowering of the target suspension system, after the suspension lowering is completed, the first reversing valve (101) needs to be located at the cut-off position to close the rod chamber of the suspension cylinder (2); For the target suspension system that needs to be lifted, the main reversing valve (3) and the first reversing valve (101) are located at the cut-off position, the hydraulic oil output by the hydraulic oil pump flows in through the corresponding P port of the inlet and return valve group (11) and makes the hydraulic oil enter the rod chamber of the corresponding suspension cylinder (2) through the corresponding B port of the inlet and return valve group (11), the rodless chamber returns through the corresponding B port of the inlet and return valve group (11), the suspension cylinder (2) is shortened to realize the suspension lifting of the target suspension system.

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