Hydro-pneumatic suspension system and vehicle

Abstract

A hydro-pneumatic suspension system, comprising an oil pump (1) and a hydraulic oil tank as well as suspension cylinders (1-3), lifting reversing valves (4), lowering reversing valves (5), elastic-rigid switching valves (7), and integral lifting reversing valves (3) that are symmetrically arranged on the two sides of each axle. P ports of the lifting reversing valves (4) and the integral lifting reversing valves (3) are respectively connected to a pressure oil path of the hydro-pneumatic suspension system, the other end of each lifting reversing valve (4) is connected to a rodless cavity of a suspension cylinder (1-3), and the other end of each integral lifting reversing valve (3) is connected to a rod cavity of the suspension cylinder (1-3); and a T port of each lowering reversing valve (5) is connected to the hydraulic oil tank, and the other end of the lowering reversing valve (5) is connected to the rodless cavity of the suspension cylinder (1-3). Also disclosed is a vehicle. The hydro-pneumatic suspension system enables simultaneous lifting and lowering of cylinders on one single side or two sides of a vehicle body, allows for overall lifting of axles between one group of suspensions when support legs are in a supporting state, and also allows the vehicle to lift only one axle to enable the vehicle to travel in a one-less-axel state and realize lifting of a single axle when the vehicle is supported by the support legs.

Description

Oil-gas suspension system and vehicle Technical Field

[0001] The present invention relates to the technical field of engineering vehicles, in particular to an oil-gas suspension system and a vehicle, and in particular to an oil-gas suspension system and a multi-axis crane equipped with the oil-gas suspension system. Background Art

[0002] Some multi-axle construction vehicles, especially all-terrain wheeled cranes, feature a hydro-pneumatic suspension system. This system is typically located between the vehicle's body 1-2 and axle 1-1 and consists of a suspension cylinder 1-3, a suspension valve assembly, an accumulator, an oil pump, and a fuel tank. The upper hinge of the suspension cylinder 1-3 connects to the body 1-2, and the lower hinge connects to the axle 1-1. The axle 1-1 supports the suspension cylinder 1-3, which uses oil as a force transmission medium to support the body 1-2. The body 1-2, in turn, supports components such as the cab, engine, and boom. As shown in Figure 1, most crane bodies 1-2 also have outriggers 1-4.

[0003] The connection between the oil ports of suspension cylinders 1-3 and the accumulators mitigates and attenuates ground-induced impact and vibration. Suspension cylinders 1-3 are connected to other hydraulic components, such as the suspension valve block, oil pump, and oil tank. The valve block controls the extension and retraction of the suspension cylinders, thereby controlling the lifting and lowering of vehicle body 1-2 and its load.

[0004] When the vehicle is unloaded, the middle axle can be raised to reduce vehicle resistance and tire wear. When the vehicle is heavily loaded, the middle axle is lowered to support body 1-2, sharing the load on the other axles and preventing overloading of axle 1-1. When the body 1-2 of an all-wheel-steer vehicle is longer, the last axle can be raised, making the second-to-last axle the last axle. If the second-to-last axle is turned at the same steering angle as the last axle, the vehicle's minimum turning radius can be significantly reduced, making it easier for the vehicle to pass through narrow areas. These two requirements necessitate the development of a lifting and lowering function within the multi-axle hydro-pneumatic suspension system that can lift individual axles (a lifting and lowering function refers to the ability of engineering vehicles to lift, raise, and lower axles).

[0005] To balance axle loads and improve vehicle handling, the hydropneumatic suspension system of a multi-axle vehicle is generally divided into front and rear suspension groups. For example, on a five-axle all-terrain crane, the front two axles (axles 1 and 2) are usually grouped together, while the rear three axles (axles 3, 4, and 5) are grouped together. In most cases, the rodless chambers of the suspension cylinders 1-3 on the same side of all axles in each suspension group are connected to each other, and the rod chambers are connected to each other. The rodless chambers are then connected to the rod chambers of the suspension cylinders 1-3 on the opposite side. This balances the axle loads on both sides while also enhancing the vehicle's anti-roll capability.

[0006] When the vehicle is traveling with a light load, the third bridge in a five-bridge vehicle can be lifted, and the vehicle can travel with one bridge less; when the vehicle is traveling in order to reduce the turning radius, the last bridge (the fifth bridge) can be lifted, and the vehicle can also travel with one bridge less.

[0007] Utility model patent CN203655745U discloses a hydro-pneumatic suspension hydraulic system and engineering vehicle. The hydro-pneumatic suspension system can simultaneously raise or lower a vehicle body on one side or both sides: when the second switch valve is energized, oil enters the rodless chamber of the oil cylinder, lifting the vehicle body; when the second switch valve and the first switch valve are energized simultaneously, the oil cylinder differentially extends, enabling rapid lifting of the vehicle body; when the third switch valve is energized, the rodless chamber connects to the T-port, that is, to the fuel tank, allowing the vehicle body to fall back under the action of gravity; when the first switch valve and the third switch valve are energized simultaneously, pressurized oil enters the rod chamber of the oil cylinder, allowing the vehicle body to fall back without relying on gravity. When a vehicle equipped with outriggers is in the outrigger-supported vehicle state, if the first switch valve and the third switch valve are energized simultaneously, all axles within a suspension group can be lifted as a whole.

[0008] Invention patent application CN 115159350 A discloses a hydro-pneumatic suspension control valve and a hydro-pneumatic suspension hydraulic control system. This system can simultaneously raise or lower one or both sides of the vehicle body. When the left and right axle lift valves are energized simultaneously on a vehicle equipped with outriggers and supported by the outriggers, pressurized oil flows into the rod chamber and returns oil to the rodless chamber, enabling the overall lifting of all axles within a suspension group.

[0009] Although the above technical solutions can simultaneously extend or shorten all the cylinders on the same side or both sides of a group of axles under the premise that the outriggers support the vehicle, thereby realizing the overall lifting function of all axles in a group of suspensions, it is impossible to lift a single axle in a group of suspensions when the outriggers are supporting the vehicle; when the vehicle's outriggers are off the ground or the axle without outriggers supports the vehicle, the above solutions are also unable to lift a single axle, and it is impossible to drive with one axle less.

[0010] Summary of the Invention

[0011] In view of the fact that in the prior art, it is impossible to lift a single axle in a group of suspensions of a multi-axle oil-gas suspension vehicle, the present invention provides an oil-gas suspension system and a vehicle, which can not only realize the simultaneous lifting of the oil cylinders on one or both sides of the vehicle body, but also realize the overall lifting of the axles in a group of suspensions under the support of the outriggers.

[0012] To achieve the above object, the present invention provides the following technical solutions:

[0013] In the first aspect, the present invention proposes an oil-gas suspension system, including an oil pump and a hydraulic oil tank, and also includes a suspension oil cylinder, a lifting reversing valve, a lowering reversing valve, a spring-rigidity switching valve and an integral lifting reversing valve symmetrically arranged on both sides of the vehicle axle; the P ports of the lifting reversing valve and the integral lifting reversing valve are respectively connected to the pressure oil circuit of the oil-gas suspension system, the other end of the lifting reversing valve is connected to the rodless cavity of the suspension oil cylinder; the other end of the integral lifting reversing valve is connected to the rod cavity of the suspension oil cylinder; the T port of the lowering reversing valve is connected to the hydraulic oil tank, and the lowering reversing valve is connected to the rod cavity of the suspension oil cylinder. The other end of the directional valve is connected to the rodless chamber of the suspension cylinder; the elastic-rigidity switching valve is respectively connected to the rodless chamber of the suspension cylinder on one side and the rod chamber of the suspension cylinder on the opposite side; the lifting reversing valve is used to realize the connection and disconnection of the rodless chamber of the suspension cylinder and the oil pump. When the lifting reversing valve is energized, all the suspension cylinders on the same side are lengthened; the lowering reversing valve is used to realize the connection and disconnection of the rodless chamber of the suspension cylinder and the hydraulic oil tank. When the lowering reversing valve is energized, all the suspension cylinders on the same side are shortened; when the lifting reversing valve or the lowering reversing valve on both sides are energized at the same time, the overall lifting or lowering of the vehicle body can be realized.

[0014] In combination with the first aspect, further, the oil-gas suspension system of the present invention also includes two through-reversing valves, which are symmetrically arranged on both sides of the axle; the suspension cylinder includes a lifting and lowering bridge suspension cylinder and a non-lifting and lowering bridge suspension cylinder, and the lifting and lowering bridge suspension cylinder can lift and lower the corresponding connected axle while the non-lifting and lowering bridge suspension cylinder is stationary; the through-reversing valve is arranged on the rodless chamber of the lifting and lowering bridge suspension cylinder and the rodless chamber of the non-lifting and lowering bridge suspension cylinder, and is used to close the rodless chamber of the non-lifting and lowering bridge suspension cylinder.

[0015] When the through-reversing valve is in a two-way connected state, the lifting reversing valve in the oil-gas suspension system is energized, which can realize the simultaneous lifting of the oil cylinders on one side or both sides of the vehicle body; the lowering reversing valve is energized, which can realize the simultaneous lowering of the oil cylinders on one side or both sides of the vehicle body.

[0016] When the through-reversing valve is in a two-way connected state, the overall lifting reversing valve and the lowering reversing valve in the oil-gas suspension system are electrically connected, which can realize the overall lifting of a group of axles in the suspension when the outriggers support the vehicle body; when the overall lifting reversing valve and the raising reversing valve in the system are electrically connected, which can realize the overall lowering of a group of axles in the suspension when the outriggers support the vehicle body.

[0017] When the through-type reversing valve is in a one-way cut-off state and the elastic-rigidity switching valve is in a two-way cut-off state, the overall lifting reversing valve and the lowering reversing valve in the oil-gas suspension system are electrically connected, so that the vehicle can lift only one axle to complete driving with one axle less.

[0018] When the through-direction reversing valve is in the one-way cut-off state, the overall lifting reversing valve is electrically connected, and the lowering reversing valve is electrically connected, and a single axle can also be lifted when the outriggers are supporting the vehicle.

[0019] In the second aspect, the present invention proposes an oil-gas suspension system, including an oil pump and a hydraulic oil tank, and also includes a suspension cylinder, a lifting reversing valve, a lowering reversing valve, a spring-rigid switching valve, a lifting and lowering reversing valve and a hydraulically controlled one-way valve symmetrically arranged on both sides of the vehicle axle; the P ports of the lifting reversing valve and the lifting and lowering reversing valve are respectively connected to the pressure oil circuit of the oil-gas suspension system, and the other end of the lifting reversing valve is connected to the rodless cavity of the suspension cylinder; the T port of the lowering reversing valve is connected to the hydraulic oil tank, and the other end of the lowering reversing valve is connected to the rodless cavity of the suspension cylinder; the spring-rigid switching valve is respectively connected to the rodless cavity of the suspension cylinder on one side and the rod of the suspension cylinder on the opposite side cavity; the T-port of the lifting and lowering reversing valve is connected to the hydraulic oil tank; there are two hydraulically controlled one-way valves, which are arranged in parallel. After the two hydraulically controlled one-way valves are arranged in parallel, they are connected in series between the rod cavity of each suspension cylinder and the lifting and lowering reversing valve, sharing a control oil circuit; the lifting reversing valve is used to realize the connection and disconnection between the rodless cavity of the suspension cylinder and the oil pump. When the lifting reversing valve is energized, all the suspension cylinders on the same side are lengthened; the lowering reversing valve is used to realize the connection and disconnection between the rodless cavity of the suspension cylinder and the hydraulic oil tank. When the lowering reversing valve is energized, all the suspension cylinders on the same side are shortened; when the lifting reversing valve or the lowering reversing valve on both sides are energized at the same time, the entire vehicle body can be raised or lowered.

[0020] In combination with the second aspect, further, the oil-gas suspension system of the present invention also includes two through-reversing valves, which are symmetrically arranged on both sides of the axle; the suspension cylinder includes a lifting and lowering bridge suspension cylinder and a non-lifting and lowering bridge suspension cylinder, and the lifting and lowering bridge suspension cylinder is capable of lifting and lowering the correspondingly connected axle while the non-lifting and lowering bridge suspension cylinder is stationary; the through-reversing valve is arranged on the rodless chamber of the lifting and lowering bridge suspension cylinder and the rodless chamber of the non-lifting and lowering bridge suspension cylinder, and is used to close the rodless chamber of the non-lifting and lowering bridge suspension cylinder.

[0021] When the through-reversing valve is in a two-way connected state, the lifting reversing valve in the oil-gas suspension system is energized, which can realize the simultaneous lifting of the oil cylinders on one side or both sides of the vehicle body; the lowering reversing valve is energized, which can realize the simultaneous lowering of the oil cylinders on one side or both sides of the vehicle body.

[0022] When the through-reversing valve is in a two-way connected state, the overall lifting reversing valve and the lowering reversing valve in the oil-gas suspension system are electrically connected, which can realize the overall lifting of a group of axles in the suspension when the outriggers support the vehicle body; when the overall lifting reversing valve and the raising reversing valve in the system are electrically connected, which can realize the overall lowering of a group of axles in the suspension when the outriggers support the vehicle body.

[0023] When the through-type reversing valve is in a one-way cut-off state and the elastic-rigidity switching valve is in a two-way cut-off state, the lifting and lowering reversing valve in the oil-gas suspension system is electrically switched to the lower position and the lowering reversing valve is electrically connected, so that the vehicle can lift only one axle to complete driving with one axle less.

[0024] When the through-direction reversing valve is in the one-way cut-off state, the lifting and lowering reversing valve is electrically switched to the lower position, and the lowering reversing valve is electrically connected, and a single axle can also be lifted when the outriggers are supporting the vehicle.

[0025] In combination with the first aspect or the second aspect, further, the oil-gas suspension system of the present invention also includes a first overflow valve, the oil inlet of the first overflow valve is connected to the oil outlet of the oil pump, and the oil outlet is connected to the hydraulic oil tank, for stabilizing the pressure of the oil-gas suspension system.

[0026] In combination with the first aspect or the second aspect, further, the oil-gas suspension system of the present invention also includes two second overflow valves, which are symmetrically arranged on both sides of the axle. The second overflow valve on each side is arranged between the T-port of the lowering reversing valve on this side and the accumulator on this side, for realizing overflow protection of the liquid chamber of the accumulator on this side.

[0027] In combination with the first aspect or the second aspect, further, the oil-gas suspension system of the present invention also includes two accumulators, which are symmetrically arranged on both sides of the axle. The accumulator on each side is normally connected to the rod chamber of the suspension cylinder on the opposite side, and is mainly used to absorb the vibration brought to the suspension system by the road surface, alleviate pressure shock, play a role in vibration reduction and protection of the suspension system, and provide cab comfort and suspension system reliability; secondly, when the axle leaves the ground, it plays a role in maintaining pressure and keeping the axle off the ground.

[0028] In combination with the first aspect or the second aspect, further, the through-flow reversing valve is a high-flow, two-position, two-way reversing valve with one-way cutoff and no potential loss, specifically a two-position, two-way pneumatic-controlled reversing valve or a two-position, two-way hydraulic-controlled reversing valve or a two-position, two-way electromagnetic reversing valve.

[0029] In combination with the first or second aspect, further, the raising reversing valve and the lowering reversing valve are two-position, two-way electromagnetic reversing valves with one-way or two-way cutoff, and the elastic-rigid switching valve is a two-position, two-way air-controlled reversing valve with two-way cutoff. Preferably, the raising reversing valve and the lowering reversing valve are two-position, two-way electromagnetic reversing valves with one-way cutoff when de-energized.

[0030] In combination with the first aspect, further, the integral lifting reversing valve is a two-position, two-way electromagnetic reversing valve with bidirectional cutoff when the potential is lost.

[0031] In combination with the second aspect, further, the lifting and lowering reversing valve is a three-position four-way reversing valve with a mid-position Y function, preferably a three-position four-way electromagnetic reversing valve.

[0032] In combination with the second aspect, further, the hydraulically controlled one-way valve can be replaced with an electromagnetic reversing valve or an air-controlled valve, a one-way shut-off electromagnetic reversing valve, or a two-way shut-off electromagnetic reversing valve.

[0033] In a third aspect, a vehicle includes the above-mentioned oil-gas suspension system.

[0034] Compared with the prior art, the present invention provides an oil-gas suspension system and a vehicle, which have the following beneficial effects:

[0035] (1) The oil-gas suspension system of the present invention can not only realize the simultaneous lifting of the oil cylinders on one or both sides of the vehicle body, but also realize the overall lifting of a group of axles in the suspension under the support of the outriggers.

[0036] (2) The oil-gas suspension system of the present invention can further enable the vehicle to travel in a state where one axle is missing by lifting only one axle, and can also achieve the lifting of a single axle when the vehicle is supported by the outriggers, thereby meeting the user's demand for lifting and lowering a single axle and improving product satisfaction.

[0037] (3) The oil-gas suspension system of the present invention realizes the lifting and lowering bridge function through a lifting and lowering reversing valve or an integral lifting and lowering reversing valve, and utilizes a lifting and lowering bridge oil cylinder; in addition, a universal control valve is provided for each control valve position in the oil-gas suspension system of the present invention, which has strong versatility, is easy to implement, and has obvious cost advantages.

[0038] (4) The vehicle of the present invention can realize the lifting and lowering bridge function through the oil-gas suspension system of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a schematic structural diagram of a vehicle in the prior art;

[0040] FIG2 is a schematic structural diagram of the oil-gas suspension system provided in Example 1 of the present invention;

[0041] FIG3 is a schematic structural diagram of an oil-gas suspension system provided in Example 2 of the present invention;

[0042] FIG4 is a schematic structural diagram of the oil-gas suspension system provided in Example 3 of the present invention.

[0043] The meanings of the reference numbers in the figure are: 1-1, axle; 1-2, vehicle body; 1-3, suspension cylinder; 1-4, support leg; 1-oil pump; 2-first overflow valve; 3-integral lifting reversing valve; 4-lifting reversing valve; 5-lowering reversing valve; 6-second overflow valve; 7-elastic-rigidity switching valve; 8-accumulator; 9-non-lifting and lowering axle suspension cylinder; 10-through reversing valve; 11-hydraulic-controlled one-way valve, 12-lifting and lowering reversing valve; 13-lifting and lowering axle suspension cylinder. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. Technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may also include different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0046] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0047] The present invention takes the suspension hydraulic system of a five-axle vehicle with three rear axles as a group as an example to illustrate the technical solution of the present invention. It should be noted that the present invention is also applicable to multi-axle vehicles with other numbers of axles.

[0048] Example 1

[0049] As shown in Figure 2, the oil-gas suspension system proposed by the present invention includes an oil pump 1 and a hydraulic oil tank, and also includes a suspension cylinder, a lifting reversing valve 4, a lowering reversing valve 5, a spring-rigidity switching valve 7 and an integral lifting reversing valve 3 symmetrically arranged on both sides of the vehicle axle; the P ports of the lifting reversing valve 4 and the integral lifting reversing valve 3 are respectively connected to the pressure oil circuit of the oil-gas suspension system, the other end of the lifting reversing valve 4 is connected to the rodless cavity of the suspension cylinder; the other end of the integral lifting reversing valve 3 is connected to the rod cavity of the suspension cylinder; the T port of the lowering reversing valve 5 is connected to the hydraulic oil tank, and the lowering reversing valve The other end of 5 is connected to the rodless chamber of the suspension cylinder; the elastic-rigidity switching valve 7 is respectively connected to the rodless chamber of the suspension cylinder on one side and the rod chamber of the suspension cylinder on the opposite side; the lifting reversing valve 4 is used to realize the on-off connection between the rodless chamber of the suspension cylinder and the oil pump 1. When the lifting reversing valve 4 is energized, all the suspension cylinders on the same side are lengthened; the lowering reversing valve 5 is used to realize the on-off connection between the rodless chamber of the suspension cylinder and the hydraulic oil tank. When the lowering reversing valve 5 is energized, all the suspension cylinders on the same side are shortened; when the lifting reversing valve 4 or the lowering reversing valve 5 on both sides are energized at the same time, the entire vehicle body can be raised or lowered.

[0050] In Figure 1, A, B, P, T, A1, B1 and B2 are the codes for the oil ports of the valve block, and the letters A and B near each suspension cylinder are also the codes for the oil ports of the cylinder.

[0051] In this embodiment, the oil-gas suspension system can realize simultaneous raising or lowering of one or both sides of the vehicle body. The specific control method is as follows:

[0052] When the vehicle does not need to raise or lower one or several suspension cylinders separately, the through-reversing valve 10 is always in the power-off and connected position. At this time, if the raising reversing valve 4 is energized, all the suspension cylinders on the same side are lengthened; if the lowering reversing valve 5 is energized, all the suspension cylinders on the same side are shortened; when the raising reversing valves 4 or the lowering reversing valves 5 on both sides are energized at the same time, the entire vehicle body can be raised or lowered.

[0053] When a vehicle equipped with outriggers is in the outrigger-supported vehicle state, when the overall lifting reversing valve 43 and the lowering reversing valve 5 are energized at the same time, the pressure oil enters the rod chamber of all suspension cylinders, and the rodless chamber is connected to the return oil, which can also realize the overall lifting of the axle.

[0054] In a specific implementation of this embodiment, the oil-gas suspension system of the present invention also includes two through-reversing valves 10, which are symmetrically arranged on both sides of the axle; the suspension cylinder includes a lifting and lowering bridge suspension cylinder 13 and a non-lifting and lowering bridge suspension cylinder 9, and the lifting and lowering bridge suspension cylinder 13 is a correspondingly connected axle and can be lifted and lowered when the non-lifting and lowering bridge suspension cylinder 9 is a correspondingly connected axle and remains stationary; the through-reversing valve 10 is arranged on the rodless cavity of the lifting and lowering bridge suspension cylinder 13 and the rodless cavity of the non-lifting and lowering bridge suspension cylinder 9 connecting the pipeline, and is used to close the rodless cavity of the non-lifting and lowering bridge suspension cylinder 9.

[0055] When the through-reversing valve 10 is in a two-way connected state, the lifting reversing valve 4 in the oil-gas suspension system is energized, which can realize the simultaneous lifting of the oil cylinders on one side or both sides of the vehicle body; the lowering reversing valve 5 is energized, which can realize the simultaneous lowering of the oil cylinders on one side or both sides of the vehicle body.

[0056] When the through-reversing valve 10 is in a two-way connected state, the overall lifting reversing valve 3 and the lowering reversing valve 5 in the oil-gas suspension system are electrically connected, which can realize the overall lifting of a group of axles in the suspension when the outriggers support the vehicle body; the overall lifting reversing valve 3 and the raising reversing valve 4 in the system are electrically connected, which can realize the overall lowering of a group of axles in the suspension when the outriggers support the vehicle body.

[0057] When the through-type reversing valve 10 is in a one-way cut-off state and the elastic-rigidity switching valve 7 is in a two-way cut-off state, the overall lifting reversing valve 3 and the lowering reversing valve 5 in the oil-gas suspension system are electrically connected, so that the vehicle can lift only one axle to complete driving with one axle less.

[0058] When the through-reversing valve 10 is in the one-way cut-off state, the overall lifting reversing valve 3 is electrically connected, and the lowering reversing valve 5 is electrically connected, and a single axle can also be lifted in the state of the outriggers supporting the vehicle.

[0059] A vehicle including the oil-gas suspension system of the present invention can achieve driving with one axle missing by lifting only one axle, and can also achieve single axle lifting with the outriggers supporting the vehicle. The specific control method is as follows:

[0060] When the vehicle needs to lift a single axle, first, the through-reversing valve 10 is energized and in the upper position, so that the rodless chamber of the non-lifting and lowering axle suspension cylinder 9 is closed, the rodless chamber of the non-lifting and lowering axle suspension cylinder 9 is disconnected from the rodless chamber of the lifting and lowering axle suspension cylinder 13, and is also disconnected from the suspension lifting and lowering oil circuit. Secondly, the lowering reversing valve 5 is energized and the valve core is in the connecting position, so that the rodless chamber of the lifting and lowering axle suspension cylinder 13 is connected to the hydraulic oil tank. Finally, the overall lifting reversing valve 3 is switched to the connecting position, and the pressure oil provided by the oil pump 1 enters the rod chambers of all suspension cylinders through the overall lifting reversing valve 43. At the same time, the elastic rigidity switching valve 7 is switched to the cut-off position to prevent the pressure oil from flowing back to the hydraulic oil tank, so that the lifting and lowering axle suspension cylinder 13 is retracted, the lifting and lowering axle is lifted, and the tire is off the ground. When the bridge is lifted, the lowering reversing valve 5 and the overall lifting reversing valve 43 are de-energized; in order to keep the tire off the ground, the through reversing valve 10 needs to be in the upper position all the time.

[0061] When the vehicle needs to lower a single axle that has been lifted, first, the integral lift reversing valve 3 and the lifting reversing valve 4 are energized and switched to the connecting position. Pressurized oil enters the rodless chamber of the lifting and lowering axle suspension cylinder 13. The oil in the rod chamber of the lifting and lowering axle suspension cylinder 13 is squeezed out and flows through the integral lift reversing valve 3 into the rodless chamber of the opposite lifting and lowering axle suspension cylinder 13. The lifting and lowering axle suspension cylinder 13 is smoothly extended, and the axle falls back to the ground. When the lifting and lowering axle falls to the ground, the through-flow reversing valve 10 switches to the connected state, and the rodless chamber of the lifting and lowering axle suspension cylinder 13 is connected with the rodless chamber of the other axle on the same side, completing the axle lowering operation.

[0062] In a specific implementation of this embodiment, the oil-gas suspension system of the present invention also includes a first overflow valve 2, the oil inlet of the first overflow valve 2 is connected to the oil outlet of the oil pump 1, and the oil outlet is connected to the hydraulic oil tank, which is used to stabilize the pressure of the oil-gas suspension system.

[0063] In a specific implementation of this embodiment, the oil-gas suspension system of the present invention also includes two second overflow valves 6, which are symmetrically arranged on both sides of the axle. The second overflow valve 6 on each side is arranged between the T port of the lowering reversing valve 5 on this side and the accumulator 8 on this side, for realizing overflow protection of the liquid chamber of the accumulator 8 on this side.

[0064] In a specific implementation of this embodiment, the oil-gas suspension system of the present invention also includes two accumulators 8, which are symmetrically arranged on both sides of the axle. The accumulator 8 on each side is normally connected to the rod chamber of the suspension cylinder on the opposite side. It is mainly used to absorb the vibration brought to the suspension system by the road surface, alleviate pressure shock, play a role in vibration reduction and protection of the suspension system, and provide cab comfort and suspension system reliability; secondly, it plays a role in maintaining pressure and keeping the axle off the ground when the axle leaves the ground.

[0065] In a specific implementation of this embodiment, the through-flow reversing valve 10 is a high-flow, two-position, two-way reversing valve with one-way cutoff and no-potential function, specifically a two-position, two-way pneumatic-controlled reversing valve, a two-position, two-way hydraulic-controlled reversing valve, or a two-position, two-way electromagnetic reversing valve.

[0066] In a specific implementation of this embodiment, the raising reversing valve 4 and the lowering reversing valve 5 are two-position, two-way solenoid reversing valves with one-way or two-way shutoff, and the elastic-rigid switching valve 7 is a two-position, two-way pneumatic reversing valve with two-way shutoff. Preferably, the raising reversing valve 4 and the lowering reversing valve 5 are two-position, two-way solenoid reversing valves with one-way shutoff when de-energized.

[0067] In a specific implementation of this embodiment, the integral lifting reversing valve 43 is a two-position, two-way electromagnetic reversing valve with bidirectional cutoff when de-energized.

[0068] Example 2

[0069] For vehicles that partially rely on gravity to lower their bodies or do not require the overall lifting bridge function after the outriggers support the vehicle, the oil-gas suspension system no longer has the overall lifting reversing valve 3. In view of this situation, Example 2, based on Example 1, removes the overall lifting reversing valve 3 and adds a lifting reversing valve 12 and a hydraulically controlled one-way valve 11 in the pipeline. The specific solution is as follows:

[0070] As shown in Figure 3, another oil-gas suspension system proposed by the present invention includes an oil pump 1 and a hydraulic oil tank, and also includes a suspension cylinder, a lifting reversing valve 4, a lowering reversing valve 5, an elastic rigidity switching valve 7, a lifting and lowering reversing valve 12 and a hydraulically controlled one-way valve 11 symmetrically arranged on both sides of the vehicle axle; the P ports of the lifting reversing valve 4 and the lifting and lowering reversing valve 12 are respectively connected to the pressure oil circuit of the oil-gas suspension system, and the other end of the lifting reversing valve 4 is connected to the rodless cavity of the suspension cylinder; the T port of the lowering reversing valve 5 is connected to the hydraulic oil tank, and the other end of the lowering reversing valve 5 is connected to the rodless cavity of the suspension cylinder; the elastic rigidity switching valve 7 is respectively connected to the rodless cavity of the suspension cylinder on one side and the rodless cavity of the suspension cylinder on the opposite side. Rod chamber; the T port of the lifting and lowering reversing valve 12 is connected to the hydraulic oil tank; there are two hydraulically controlled one-way valves 11, which are arranged in parallel. After the two hydraulically controlled one-way valves 11 are arranged in parallel, they are connected in series between the rod chamber of each suspension cylinder and the lifting and lowering reversing valve 12, sharing a control oil circuit; the lifting reversing valve 4 is used to realize the connection and disconnection between the rodless chamber of the suspension cylinder and the oil pump 1. When the lifting reversing valve 4 is energized, all the suspension cylinders on the same side are lengthened; the lowering reversing valve 5 is used to realize the connection and disconnection between the rodless chamber of the suspension cylinder and the hydraulic oil tank. When the lowering reversing valve 5 is energized, all the suspension cylinders on the same side are shortened; when the lifting reversing valve 4 or the lowering reversing valve 5 on both sides are energized at the same time, the entire vehicle body can be raised or lowered.

[0071] In a specific implementation of this embodiment, a one-way valve is provided in the descending reversing valve 5 .

[0072] In a specific implementation of this embodiment, the oil-gas suspension system of the present invention also includes two through-reversing valves 10, which are symmetrically arranged on both sides of the axle; the suspension cylinder includes a lifting and lowering bridge suspension cylinder 13 and a non-lifting and lowering bridge suspension cylinder 9, and the lifting and lowering bridge suspension cylinder 13 is a correspondingly connected axle and can be lifted and lowered when the non-lifting and lowering bridge suspension cylinder 9 is a correspondingly connected axle and remains stationary; the through-reversing valve 10 is arranged on the rodless cavity of the lifting and lowering bridge suspension cylinder 13 and the rodless cavity of the non-lifting and lowering bridge suspension cylinder 9, and is used to close the rodless cavity of the non-lifting and lowering bridge suspension cylinder 9.

[0073] When the through-reversing valve 10 is in a two-way connected state, the lifting reversing valve 4 in the oil-gas suspension system is energized, which can realize the simultaneous lifting of the oil cylinders on one side or both sides of the vehicle body; the lowering reversing valve 5 is energized, which can realize the simultaneous lowering of the oil cylinders on one side or both sides of the vehicle body.

[0074] When the through-reversing valve 10 is in a two-way connected state, the overall lifting reversing valve 43 and the lowering reversing valve 5 in the oil-gas suspension system are electrically connected, which can realize the overall lifting of a group of axles in the suspension when the support legs support the vehicle body; the overall lifting reversing valve 43 and the raising reversing valve 4 in the system are electrically connected, which can realize the overall lowering of a group of axles in the suspension when the support legs support the vehicle body.

[0075] When the through-type reversing valve 10 is in a one-way cut-off state and the elastic-rigidity switching valve 7 is in a two-way cut-off state, the lifting and lowering reversing valve 12 in the oil-gas suspension system is electrically switched to the lower position and the lowering reversing valve 5 is electrically connected, so that the vehicle can lift only one axle to complete driving with one axle less.

[0076] When the through-reversing valve 10 is in the one-way cut-off state, the lifting and lowering reversing valve 12 is electrically switched to the lower position, and the lowering reversing valve 5 is electrically connected, and a single axle can also be lifted in the state of the outriggers supporting the vehicle.

[0077] In this embodiment, the oil-gas suspension system can realize simultaneous raising or lowering of one or both sides of the vehicle body. The specific control method is as follows:

[0078] When the vehicle needs to lift a single axle, first, the through-reversing valve 10 is energized and in the upper position, so that the rodless cavity of the non-lifting and lowering axle suspension cylinder 9 is closed, and the rodless cavity of the non-lifting and lowering axle suspension cylinder 9 is disconnected from the rodless cavity of the lifting and lowering axle suspension cylinder 13, and is also disconnected from the suspension lifting and lowering oil circuit. Secondly, the lowering reversing valve 5 is energized and the valve core is in the connecting position, so that the rodless cavity of the lifting and lowering axle suspension cylinder 13 is connected to the hydraulic oil tank. Finally, the lifting and lowering reversing valve 12 is energized and switched to the lower position, and the pressure oil provided by the oil pump 1 enters the rod cavity of all suspension cylinders respectively through the two hydraulically controlled one-way valves 11. At the same time, the elastic rigidity switching valve 7 is switched to the cut-off position to prevent the pressure oil from flowing back to the hydraulic oil tank, so that the lifting and lowering axle suspension cylinder 13 is retracted, the lifting and lowering axle is lifted, and the tire is off the ground. When the bridge is lifted, the lowering reversing valve 5 and the lifting and lowering reversing valve 12 are de-energized. To maintain the lift-off state, the through-reversing valve 10 must always be in the upper state. When the vehicle needs to lower the lifted single axle, the lifting and lowering reversing valve 12 is energized and switched to the upper state. The pressure oil reaches the pressure at which the hydraulic control one-way valve 11 can be reversely opened, and the hydraulic control one-way valve 11 is opened. At this time, the rod chamber of the lifting and lowering bridge suspension cylinder 13 is connected to the hydraulic oil tank. At the same time, the lifting reversing valves 4 on both sides are energized, and the pressure oil enters the large chamber of the lifting and lowering bridge suspension cylinder 13 through the lifting reversing valve, pushing this suspension cylinder down. After the lifting and lowering bridge falls to the ground, the lifting reversing valves 4 are de-energized, and the lifting and lowering reversing valve 12 is de-energized and reset to the middle state.

[0079] Next, the through-flow reversing valve 10 is switched to the on state, and the rodless chamber of the lifting and lowering bridge suspension cylinder 13 is connected with the rodless chamber of the other bridge on the same side, completing the bridge lowering operation.

[0080] In a specific implementation of this embodiment, the lifting and lowering reversing valve 12 is a three-position four-way reversing valve with a mid-position Y function, preferably a three-position four-way electromagnetic reversing valve.

[0081] In a specific implementation of this embodiment, the hydraulically controlled one-way valve 11 can be replaced with an electromagnetic reversing valve or an air-controlled valve, a one-way shut-off electromagnetic reversing valve, or a two-way shut-off electromagnetic reversing valve.

[0082] Example 3

[0083] By changing the connection position of the through-flow reversing valve 10 or the pipe connection mode in the oil-gas suspension system, the number of lifting and lowering bridges can be changed or the lifting and lowering bridge function can be transplanted to other axles. As shown in FIG4 , the difference between Example 3 and Example 2 is that: in Example 2, there is only one pair of lifting and lowering bridge suspension cylinders 13 (i.e., the leftmost suspension cylinder is the lifting and lowering bridge suspension cylinder 13, and the other two pairs are non-lifting and lowering bridge suspension cylinders 9.), while in Example 3, there are two pairs of lifting and lowering bridge suspension cylinders 13 (i.e., the leftmost suspension cylinder and the rightmost suspension cylinder are both lifting and lowering bridge suspension cylinders 13, and the middle suspension cylinder is the non-lifting and lowering bridge suspension cylinder 9.). The specific scheme is as follows:

[0084] The through-reversing valve 10 is provided on the connecting pipeline between the rodless chamber of the leftmost suspension cylinder and the rodless chamber of the middle suspension cylinder. The rodless chamber of the rightmost suspension cylinder is directly connected to the rodless chamber of the leftmost suspension cylinder through the pipeline.

[0085] Embodiments 1 to 3 all illustrate only a hydro-pneumatic suspension system with three axles, but the present invention is also applicable to multi-axle vehicles with other numbers of axles.

[0086] Example 4

[0087] The vehicle proposed in the present invention includes the above-mentioned oil-gas suspension system, which can not only realize the simultaneous lifting of the oil cylinders on one side or both sides of the vehicle body, and realize the overall lifting of a group of axles in the suspension under the support of the outriggers, but also realize the vehicle driving in a state of one axle less by lifting only one axle, and can also realize the lifting of a single axle in the state of outrigger supporting the vehicle, meeting the user's demand for lifting and lowering a single axle and improving product satisfaction.

[0088] It should be noted that, in this application, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article, or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0089] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A hydro-pneumatic suspension system, comprising an oil pump and a hydraulic oil tank, characterized in that: It also includes a suspension cylinder, a lifting reversing valve, a lowering reversing valve, a spring-rigidity switching valve and an integral lifting reversing valve symmetrically arranged on both sides of the vehicle axle; the P ports of the lifting reversing valve and the integral lifting reversing valve are respectively connected to the pressure oil circuit of the oil-gas suspension system, and the other end of the lifting reversing valve is connected to the rodless chamber of the suspension cylinder; the other end of the integral lifting reversing valve is connected to the rod chamber of the suspension cylinder; the T port of the lowering reversing valve is connected to the hydraulic oil tank, and the other end of the lowering reversing valve is connected to the rodless chamber of the suspension cylinder. connection; the elastic rigidity switching valve is respectively connected to the rodless chamber of the suspension cylinder on one side and the rod chamber of the suspension cylinder on the opposite side; the lifting reversing valve is used to realize the connection and disconnection of the rodless chamber of the suspension cylinder and the oil pump. When the lifting reversing valve is energized, all the suspension cylinders on the same side are lengthened; the lowering reversing valve is used to realize the connection and disconnection of the rodless chamber of the suspension cylinder and the hydraulic oil tank. When the lowering reversing valve is energized, all the suspension cylinders on the same side are shortened; when the lifting reversing valve or the lowering reversing valve on both sides are energized at the same time, the overall lifting or lowering of the vehicle body can be realized.

2. The oil-gas suspension system according to claim 1, characterized in that: It also includes two through-reversing valves, which are symmetrically arranged on both sides of the axle; the suspension cylinder includes a lifting and lowering axle suspension cylinder and a non-lifting and lowering axle suspension cylinder, and the lifting and lowering axle suspension cylinder can be lifted and lowered when the non-lifting and lowering axle suspension cylinder is stationary for the correspondingly connected axle; the through-reversing valve is arranged on the connecting pipeline between the rodless chamber of the lifting and lowering axle suspension cylinder and the rodless chamber of the non-lifting and lowering axle suspension cylinder, and is used to close the rodless chamber of the non-lifting and lowering axle suspension cylinder.

3. A hydro-pneumatic suspension system, comprising an oil pump and a hydraulic oil tank, characterized in that: It also includes a suspension cylinder, a lifting reversing valve, a lowering reversing valve, an elastic rigidity switching valve, a lifting and lowering reversing valve and a hydraulically controlled one-way valve symmetrically arranged on both sides of the vehicle axle; the P ports of the lifting reversing valve and the lifting and lowering reversing valve are respectively connected to the pressure oil circuit of the oil-gas suspension system, and the other end of the lifting reversing valve is connected to the rodless cavity of the suspension cylinder; the T port of the lowering reversing valve is connected to the hydraulic oil tank, and the other end of the lowering reversing valve is connected to the rodless cavity of the suspension cylinder; the elastic rigidity switching valve is respectively connected to the rodless cavity of the suspension cylinder on one side and the rod cavity of the suspension cylinder on the opposite side; the T port of the lifting and lowering reversing valve is connected to the rodless cavity of the suspension cylinder on one side and the rod cavity of the suspension cylinder on the opposite side; The port is connected to the hydraulic oil tank; there are two hydraulically controlled one-way valves, which are arranged in parallel. After the two hydraulically controlled one-way valves are arranged in parallel, they are connected in series between the rod chamber of each suspension cylinder and the lifting and lowering reversing valve; the lifting reversing valve is used to realize the connection and disconnection between the rodless chamber of the suspension cylinder and the oil pump. When the lifting reversing valve is energized, all the suspension cylinders on the same side are lengthened; the lowering reversing valve is used to realize the connection and disconnection between the rodless chamber of the suspension cylinder and the hydraulic oil tank. When the lowering reversing valve is energized, all the suspension cylinders on the same side are shortened; when the lifting reversing valve or the lowering reversing valve on both sides are energized at the same time, the overall lifting or lowering of the vehicle body can be realized.

4. The oil-gas suspension system according to claim 3, characterized in that: It also includes two through-reversing valves, which are symmetrically arranged on both sides of the axle; the suspension cylinder includes a lifting and lowering axle suspension cylinder and a non-lifting and lowering axle suspension cylinder, and the lifting and lowering axle suspension cylinder can be lifted and lowered when the non-lifting and lowering axle suspension cylinder is stationary for the correspondingly connected axle; the through-reversing valve is arranged on the connecting pipeline between the rodless chamber of the lifting and lowering axle suspension cylinder and the rodless chamber of the non-lifting and lowering axle suspension cylinder, and is used to close the rodless chamber of the non-lifting and lowering axle suspension cylinder.

5. The oil-gas suspension system according to claim 1 or 3, characterized in that: It also includes a first overflow valve, the oil inlet of the first overflow valve is connected to the oil outlet of the oil pump, and the oil outlet is connected to the hydraulic oil tank, so as to stabilize the pressure of the oil-gas suspension system.

6. The oil-gas suspension system according to claim 1 or 3, characterized in that: It also includes two second overflow valves, which are symmetrically arranged on both sides of the axle. The second overflow valve on each side is arranged between the T port of the lowering reversing valve on this side and the accumulator on this side, so as to realize overflow protection of the liquid chamber of the accumulator on this side.

7. The oil-gas suspension system according to claim 1 or 3, characterized in that: It also includes two accumulators, which are symmetrically arranged on both sides of the axle. The accumulator on each side is normally connected to the rod chamber of the suspension cylinder on the opposite side, and is used to absorb the vibration brought to the suspension system by the road surface, alleviate pressure shock, and maintain pressure and keep the axle off the ground after the axle leaves the ground.

8. The oil-gas suspension system according to claim 2 or 4, characterized in that: The through-type reversing valve is a two-position, two-way reversing valve with one-way cut-off when potential is lost.

9. The oil-gas suspension system according to claim 1 or 3, characterized in that: The raising reversing valve and the lowering reversing valve are two-position two-way electromagnetic reversing valves with one-way cutoff or two-way cutoff, and the elastic rigid switching valve is a two-position two-way air-controlled reversing valve with two-way cutoff.

10. A vehicle, characterized in that: The invention comprises the oil-gas suspension system as claimed in any one of claims 1 to 4.

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