Oil and gas suspension control valve and oil and gas suspension hydraulic control system

Abstract

The present invention belongs to the field of construction machinery, and discloses an oil-gas suspension control valve and an oil-gas suspension hydraulic control system. The oil-gas suspension control valve includes an oil inlet valve port, a rod chamber connection oil port, a rodless chamber connection oil port, and a rod chamber oil return port which is internally connected to the rod chamber connection oil port and is used for controllable oil return of the rod chamber; an internal oil inlet oil path which connects the oil inlet valve port and the rodless chamber connection oil port and is provided with a rising valve for controlling the on-off of the internal oil inlet oil path; and an oil port connection oil path which is connected between the rod chamber connection oil port and the rodless chamber connection oil port and is provided with a rigid-flexible switching valve for controlling the on-off of the oil port connection oil path. In the suspension cylinder hydraulic control system of the present invention, when switched to the rigid mode, the vehicle crane can directly adjust the vehicle body attitude under the heavy load state, improving the load transfer capacity during transfer. Moreover, under the heavy load state, the vehicle body attitude is adjustable, realizing the function that the vehicle crane can automatically adjust the vehicle body attitude under the heavy load state.

Description

Technical Field

[0001] The present invention belongs to the technical field of construction machinery hydraulics, and particularly relates to an oil-gas suspension control valve and an oil-gas suspension hydraulic control system. Background Art

[0002] Figure 1 As shown in the oil-gas suspension system of a truck crane, a frame 100 and an axle 200 are connected by dedicated suspension cylinders (including a left suspension cylinder 1 and a right suspension cylinder 8), and the load of the frame 100 and the working device thereon is borne by the suspension cylinders. The truck crane has the working conditions of transferring between different construction sites. After the crane completes the lifting task, it needs to transfer to another construction site with as many working devices (such as a full boom, superlift, and counterweight, etc.) as possible to reduce the transfer costs of operations such as disassembly, assembly, and transportation of the working devices. In the above-mentioned transfer working conditions, the truck crane is generally in a heavy-load state. That is, considering factors such as driving safety, the truck crane must complete the above transfer in a rigid mode. Before the transfer, the truck crane needs to complete the leveling of the whole vehicle in a flexible mode.

[0003] In the prior art, the system pressure of the truck crane in the rigid mode is high, while the load capacity is low. Moreover, during the transfer, due to being in the rigid mode, the truck crane is prohibited from directly adjusting the body attitude, which on the one hand restricts the adjustment function of the suspension system in the heavy-load state; on the other hand, weakens the passability of the whole vehicle through complex roads. Summary of the Invention

[0004] In view of the above defects or deficiencies, the present invention provides an oil-gas suspension control valve and an oil-gas suspension hydraulic control system to enable the truck crane to directly adjust the body attitude in the heavy-load state and improve the transfer load capacity.

[0005] According to one aspect of the present invention, an oil-gas suspension control valve is disclosed, including:

[0006] An oil inlet valve port, a rod chamber connection oil port, and a rodless chamber connection oil port:

[0007] A rod chamber oil return port, which is internally connected to the rod chamber connection oil port and is used for controllable oil return of the rod chamber;

[0008] An internal oil inlet oil path, which connects the oil inlet valve port and the rodless chamber connection oil port and is provided with a rising valve for controlling the on / off of the internal oil inlet oil path; and

[0009] An oil port connection oil path, which is connected between the rod chamber connection oil port and the rodless chamber connection oil port and is provided with a rigid-flexible switching valve for controlling the on / off of the oil port connection oil path.

[0010] In some embodiments, the oil-gas suspension control valve further includes:

[0011] The rod-end oil return circuit connects the rod-end oil return port to an external oil tank, and a heavy-duty control valve for controlling the on / off of the rod-end oil return circuit is provided in the rod-end oil return circuit.

[0012] In some embodiments, the hydro-pneumatic suspension control valve further includes:

[0013] A branch oil inlet circuit is connected between the oil inlet valve port and the rod-end connection oil port, and a bridge lift valve for controlling the on / off of the branch oil inlet circuit is provided.

[0014] In some embodiments, the hydro-pneumatic suspension control valve further includes:

[0015] An oil return valve port; and

[0016] An internal oil return circuit is connected between the oil return valve port and the rodless-end connection oil port, and a lowering valve for controlling the on / off of the internal oil return circuit is provided.

[0017] In some embodiments, the hydro-pneumatic suspension control valve further includes:

[0018] An oil inlet flow regulating valve is serially arranged with the rising valve in the internal oil inlet circuit and is closer to the oil inlet valve port than the rising valve.

[0019] In some embodiments, the rising valve, the bridge lift valve, and the lowering valve are all electromagnetic directional control valves, and the oil inlet flow regulating valve is an electromagnetic proportional valve.

[0020] In some embodiments, the rigid-flexible switching valve is a pneumatically controlled stop valve, and the hydro-pneumatic suspension control valve is further provided with a gas source control port connected to an external gas source.

[0021] In some embodiments, the hydro-pneumatic suspension control valve further includes:

[0022] An accumulator connection oil port internally communicates with the rod-end connection oil port and is used for externally connecting an accumulator.

[0023] According to another aspect of the present invention, a hydro-pneumatic suspension hydraulic control system is disclosed, which includes the above-mentioned hydro-pneumatic suspension control valve.

[0024] In some embodiments, the hydro-pneumatic suspension hydraulic control system includes:

[0025] A left suspension cylinder and a right suspension cylinder; and

[0026] A left suspension valve and a right suspension valve, both of which are the above-mentioned hydro-pneumatic suspension control valves;

[0027] Among them, the rod-end chamber connection oil port of the left suspension valve is connected to the rod-end chamber of the left suspension cylinder, and the rodless chamber connection oil port of the left suspension valve is connected to the rodless chamber of the right suspension cylinder; the rod-end chamber connection oil port of the right suspension valve is connected to the rod-end chamber of the right suspension cylinder, and the rodless chamber connection oil port of the right suspension valve is connected to the rodless chamber of the left suspension cylinder.

[0028] In the oil-gas suspension control valve of the present invention, the rodless chamber connection oil port is used to connect to the rodless chamber of the suspension cylinder on the same side, that is, the pressure oil enters the oil inlet valve port, passes through the internal oil inlet oil path provided with the rising valve to reach the rodless chamber connection oil port, and then directly reaches the rodless chamber of the left suspension cylinder to drive the left suspension cylinder to rise. Moreover, an oil port connection oil path is provided between the rod-end chamber connection oil port and the rodless chamber connection oil port, and rigid-flexible switching can be performed through the rigid-flexible switching valve. Additionally, a rod-end chamber oil return port for controllable oil return of the rod-end chamber is added, and the inside of the rod-end chamber oil return port is connected to the rod-end chamber connection oil port. In this way, in the suspension cylinder hydraulic control system of the present invention, when switching to the rigid mode, the rodless chamber of the left suspension cylinder is filled with oil, and the rod-end chamber of the left suspension cylinder returns oil, so that the pressure oil can smoothly lift the left suspension cylinder to complete the attitude adjustment operation of the vehicle body rising. Through the suspension valve and hydraulic control system of the present invention, it is possible to directly adjust the vehicle body attitude under the heavy load state of the truck crane and improve the load capacity during transfer. When the whole vehicle rises and adjusts its attitude, the suspension load capacity is also very strong. Moreover, under the heavy load state, by controlling the suspension cylinder, the vehicle body attitude can be adjusted, realizing the function that the truck crane can automatically adjust the vehicle body attitude under the heavy load state. Since the vehicle body attitude can be automatically adjusted under heavy load conditions, on the one hand, the workload of operations such as disassembly, installation, and transportation of the working device is reduced, and the transfer efficiency is improved; on the other hand, the passability of the whole vehicle on complex roads is improved.

[0029] Other features and advantages of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings are used to provide an understanding of the present invention and form a part of the specification, and are used together with the following specific implementation to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0031] Figure 1 is a schematic structural diagram of the oil-gas suspension system of the truck crane;

[0032] Figure 2 is a schematic structural principle diagram of the oil-gas suspension control valve according to the specific implementation of the present invention; and

[0033] Figure 3 is a hydraulic schematic diagram of the oil-gas suspension hydraulic control system according to the specific implementation of the present invention.

[0034] Description of the Attached Drawing Reference Numerals

[0035] 1 Left suspension oil cylinder 2 Left accumulator

[0036] 3 Left heavy-duty control valve 4 Left rigid-flexible switching valve

[0037] 5 Left axle lift valve 6 Left rising valve

[0038] 7 Left lowering valve 8 Right suspension oil cylinder

[0039] 9 Right heavy-duty control valve 10 Right accumulator

[0040] 11 Right rigid-flexible switching valve 12 Right rising valve

[0041] 13 Right axle lift valve 14 Right lowering valve

[0042] 15 Right inlet flow regulating valve 16 Left inlet flow regulating valve

[0043] 100 Frame 200 Axle

[0044] 101 Left suspension valve 201 Right suspension valve

[0045] A1 Rod chamber connection oil port A2 Rodless chamber connection oil port

[0046] P Inlet oil valve port T Return oil valve port

[0047] T1 Rod chamber return oil port X Pneumatic source control port

[0048] SP Accumulator connection oil port L1 Internal inlet oil path

[0049] L2 Oil port connection path L3 Branch inlet oil path

[0050] L4 Internal return oil path L5 Rod chamber return oil path Detailed Embodiment

[0051] The following is a detailed description of the specific embodiments of the present invention with reference to the attached drawings. It should be understood that the specific embodiments described herein are only for explaining and illustrating the present invention and are not used to limit the present invention.

[0052] The following describes an oil-gas suspension control valve and an oil-gas suspension hydraulic control system according to the present invention with reference to the attached drawings.

[0053] Figure 2 Shown is an oil-gas suspension control valve according to a specific embodiment of the present invention, namely the left suspension valve 101, which includes:

[0054] Inlet oil valve port P, rod chamber connection oil port A1, and rodless chamber connection oil port A2:

[0055] The rod chamber oil return port T1 is internally connected to the rod chamber connecting oil port A1 and is used for controllable oil return of the rod chamber;

[0056] The internal oil inlet oil path L1 connects the oil inlet valve port P and the rodless chamber connecting oil port A2 and is provided with a left rising valve 6 for controlling the on / off of the internal oil inlet oil path L1; and

[0057] The oil port connecting oil path L2 is connected between the rod chamber connecting oil port A1 and the rodless chamber connecting oil port A2 and is provided with a left rigid-flexible switching valve 4 for controlling the on / off of the oil port connecting oil path L2.

[0058] The oil-gas suspension control valve of the present invention is different from the conventional suspension valve in that the rodless chamber connecting oil port A2 is used to connect to the rodless chamber of the suspension cylinder on the same side, that is, the pressure oil enters the oil inlet valve port P, passes through the internal oil inlet oil path L1 provided with the left rising valve 6 to reach the rodless chamber connecting oil port A2, and then directly reaches the rodless chamber of the left suspension cylinder to drive the left suspension cylinder to rise. Moreover, an oil port connecting oil path L2 is provided between the rod chamber connecting oil port A1 and the rodless chamber connecting oil port A2, and rigid-flexible switching can be performed through the left rigid-flexible switching valve 4.

[0059] In particular, an additional rod chamber oil return port T1 for controllable oil return of the rod chamber is provided, and the rod chamber oil return port T1 is internally connected to the rod chamber connecting oil port A1. In this way, when switching to the rigid mode, the oil port connecting oil path L2 is controlled to be disconnected, and the internal oil inlet oil path L1 is conducted. The rodless chamber of the left suspension cylinder is filled with oil, and the oil in the rod chamber of the left suspension cylinder returns oil through the rod chamber oil return port T1, so that the pressure oil can smoothly lift the left suspension cylinder to complete the vehicle body lifting operation. As will be described below, through the suspension valve of the present invention, the vehicle body attitude can be directly adjusted under the heavy load state of the truck crane, and the transfer load capacity can be improved.

[0060] Furthermore, the oil-gas suspension control valve of this embodiment may further include:

[0061] The rod chamber oil return oil path L5 connects the rod chamber oil return port T1 and an external fuel tank, and a left heavy-duty control valve 3 for controlling the on / off of the rod chamber oil return oil path L5 is provided in the rod chamber oil return oil path L5.

[0062] When lifting the vehicle body under the heavy load state of the truck crane, pressure oil is pumped into the rodless chamber through the internal oil inlet oil path L1, and at the same time, the left heavy-duty control valve 3 is opened to conduct the rod chamber oil return oil path L5, so that the oil in the rod chamber of the suspension cylinder returns to the fuel tank through the rod chamber connecting oil port A1, the rod chamber oil return port T1, and the left heavy-duty control valve 3. In this way, the pressure in the rod chamber is small, which facilitates lifting with load.

[0063] Moreover, the oil-gas suspension control valve may further include:

[0064] The branch inlet oil circuit L3 is connected between the inlet valve port P and the rod chamber connection oil port A1 and is provided with a left bridge lifting valve 5 for controlling the on / off of the branch inlet oil circuit L3.

[0065] When the left bridge lifting valve 5 is turned on, the pressure oil at the inlet valve port P can simultaneously lead to the rod chamber connection oil port A1 and the rodless chamber connection oil port A2, thereby realizing the flexible mode of the suspension valve group.

[0066] In addition, Figure 2 The shown oil-gas suspension control valve further includes:

[0067] An oil return valve port T; and

[0068] An internal oil return oil circuit L4 is connected between the oil return valve port T and the rodless chamber connection oil port A2 and is provided with a left lowering valve 7 for controlling the on / off of the internal oil return oil circuit L4.

[0069] In this way, when the left lowering valve 7 is turned on, the oil return of the rodless chamber can return oil through the rodless chamber connection oil port A2 and the internal oil return oil circuit L4, causing the piston rod of the suspension cylinder to retract.

[0070] Particularly, the oil-gas suspension control valve further includes:

[0071] A left inlet oil flow regulating valve 16 is serially arranged with the left rising valve 6 in the internal inlet oil circuit L1 and is closer to the inlet valve port P than the left rising valve 6.

[0072] Through the inlet oil flow regulating valve, the flow rate of the pressure oil flowing from the inlet valve port P into the internal inlet oil circuit L1, the rodless chamber connection oil port A2, and / or the rod chamber connection oil port A1 can be controlled, thereby controlling the rising or falling speed of the piston rod of the suspension cylinder, etc.

[0073] It should be noted that in this embodiment, the left rising valve 6, the left bridge lifting valve 5, and the left lowering valve 7 are all electromagnetic reversing valves, and the left inlet oil flow regulating valve 15 is an electromagnetic proportional valve, so that it can be conveniently integrated into the vehicle electronic control system for vehicle control or independent electronic control.

[0074] See Figure 3 , the left rigid-flexible switching valve 4 is a pneumatic cut-off valve, and the oil-gas suspension control valve is also provided with a gas source control port X connected to an external gas source. When pressure gas is introduced into the gas source control port X, the left rigid-flexible switching valve 4 switches to the on position, conducting the oil port connection oil circuit L2 between the rod chamber connection oil port A1 and the rodless chamber connection oil port A2. In addition, the inlet valve port P is connected with a pressure source oil circuit, and the oil return valve port T is connected with the system oil return port.

[0075] Specifically, the hydro-pneumatic suspension control valve also includes an accumulator connection port SP, which is internally connected to the rod chamber connection port A1 and externally connected to the left accumulator 2. The left accumulator 2 is connected to the rod chamber via the rod chamber connection port A1. This allows the left accumulator 2 to store pressurized oil in the rod chamber as energy when the cylinder piston rod extends, ensuring system stability. When the cylinder piston rod retracts, the pressurized oil is quickly replenished to the rod chamber.

[0076] It should be noted that Figure 2 Only the left suspension valve 101 is used as an example for explanation. Figure 3 The right suspension valve 201 has the same components and structure as the left suspension valve 101. The right suspension valve 201 also includes the right heavy-duty control valve 9, the right rigid-flexible switching valve 11, the right rising valve 12, the right axle lift valve 13, the right lowering valve 14, the right oil inlet flow control valve 15, and is also connected to the right accumulator 10, etc., which will not be detailed here.

[0077] The above oil-gas suspension control valve can be applied to the oil-gas suspension hydraulic control system. Figure 3 As shown, the oil-gas suspension hydraulic control system includes:

[0078] Left suspension cylinder 1 and right suspension cylinder 8; and

[0079] The left suspension valve 101 and the right suspension valve 201 are both the above-mentioned oil and gas suspension control valves;

[0080] Among them, the rod chamber connecting oil port A1 of the left suspension valve 101 is connected to the rod chamber of the left suspension cylinder 1, and the rodless chamber connecting oil port A2 of the left suspension valve 101 is connected to the rodless chamber of the right suspension cylinder 8; the rod chamber connecting oil port A1 of the right suspension valve 201 is connected to the rod chamber of the right suspension cylinder 8, and the rodless chamber connecting oil port A2 of the right suspension valve 201 is connected to the rodless chamber of the left suspension cylinder 1.

[0081] It can be seen that in the oil-gas suspension hydraulic control system of the present invention, on the one hand, the left suspension cylinder 1 and the right suspension cylinder 8 still adopt an X-type cross connection, but the rodless chamber connection oil port A2 of the suspension valve on the same side (for example, the left suspension valve 101) is connected to the rodless chamber of the opposite cylinder (for example, the right suspension cylinder 8), and the A1 port is connected to the rod chamber of the cylinder on the same side (for example, the left suspension cylinder 1), and the A1 port and the A2 port are connected through an air-controlled stop valve.

[0082] On the other hand, see Figure 3 A two-position, two-way electromagnetic switching valve (i.e., left heavy-load control valve 3 and right heavy-load control valve 9) is added to the hydraulic control system of the present invention. The valve works in the right position when energized, so that the rod chamber oil return port T1 on the valve group returns oil.

[0083] In addition, a two-position two-way electromagnetic switching valve (i.e. bridge lifting valve, seeFigure 3 The left bridge lift valve 5 and the right bridge lift valve 13) in it. When the valve is energized and works in the left position, the oil inlet valve port P communicates with the rod chamber connecting oil port A1 connected to the rod chamber, allowing the pressure oil source to directly enter the rod chamber of the oil cylinder, realizing the lifting operation of the axle when the whole vehicle is supported by outriggers.

[0084] In particular, an additional rod chamber oil return port T1 is added. This oil port communicates with the rod chamber connecting oil port A1 connected to the rod chamber of the oil cylinder. By controlling the energization of the heavy-duty control valves (i.e., the left heavy-duty control valve 3 and the right heavy-duty control valve 9), the rod chamber of the suspension oil cylinder communicates with the rod chamber oil return port T1 under heavy-duty conditions.

[0085] When the crane is in heavy-duty conditions and performs the operation of lifting the vehicle body in place, such as Figure 3 As shown, the rising valve in the suspension valve is energized to conduct the oil circuit, and the lowering valve is de-energized to close the oil circuit. The oil inlet valve port P communicates with the rodless chamber connecting oil port A2, and the pressure oil source enters the rodless chamber of the suspension oil cylinder. Under the action of the return spring, the pneumatic switching valve in the suspension valve closes the connecting oil circuit between the rod chamber connecting oil port A1 and the rodless chamber connecting oil port A2. The rod chambers and rodless chambers of the left and right suspension oil cylinders are in a non-connected state, that is, a rigid state. In this rigid state, the bridge lift valve on the suspension valve is de-energized, and the oil inlet valve port P and the rod chamber connecting oil port A1 are in a non-connected state, and the pressure oil source cannot enter the rod chamber of the suspension oil cylinder.

[0086] When the heavy-duty control valve in the hydraulic control system is energized and works in the right position, it can make the rod chamber connecting oil port A1 on the valve group return oil through the rod chamber oil return port T1, and the rod chamber of the suspension oil cylinder communicates with the return oil tank.

[0087] In summary, during the operation of lifting the vehicle body under heavy-duty conditions, the pressure oil source enters the rodless chamber of the suspension oil cylinder, the rod chamber communicates with the oil return oil circuit, and the suspension oil cylinder extends under the action of the hydraulic pressure in the rodless chamber to complete the lifting operation of the vehicle body.

[0088] It can be seen that in the oil-gas suspension hydraulic control system of the present invention, under heavy-duty conditions, when the suspension system performs a rising action, the effective pressure-bearing area of the oil cylinder is the piston area, and the suspension system only requires a system pressure of about 15 MPa, for example. Compared with the suspension systems of the prior art, the suspension system designed in the present invention has a lower pressure. The lower pressure of the heavy-duty suspension system can, on the one hand, be compatible with the pressures of other hydraulic systems of the truck crane chassis, facilitating the sharing of the pressure oil source and improving the cost performance of the hydraulic system; on the other hand, the lower suspension adjustment pressure is beneficial to improving the performance reliability and service life of hydraulic components.

[0089] Secondly, it has a strong hanging load capacity. Since the working pressure of the suspension system is low under heavy load conditions, after the crane completes the hoisting task, it is allowed to carry as many working devices as possible (such as full boom, superlift, and counterweight, etc.) and transfer to another construction site, greatly enhancing the hanging load capacity of the truck crane. With a strong hanging load capacity, it is allowed to carry more working devices, significantly reducing the workload and transfer costs of operations such as the disassembly, assembly, and transportation of working devices.

[0090] In particular, the newly added heavy-duty suspension is adjustable. In the prior art, the pressure oil source is connected to the rod chamber of the suspension cylinder through a rising valve. In the rigid mode, the rodless chamber of the suspension cylinder cannot be connected to the pressure oil source. Therefore, in the heavy-duty state, the suspension system cannot adjust the body attitude. However, as Figure 3 shown, through the optimized design of the suspension valve and suspension control system of the present invention, the function of automatically adjusting the body attitude of the truck crane in the heavy-duty state is realized. Since the body attitude can be automatically adjusted under heavy load conditions, on the one hand, it reduces the workload of operations such as the disassembly, assembly, and transportation of working devices, improving the transfer efficiency; on the other hand, it improves the passability of the whole vehicle on complex road surfaces.

[0091] Comparably, in a conventional oil-gas suspension hydraulic control system, the suspension cylinders on both sides generally also adopt an X-shaped cross-connection. However, compared with the Figure 3 embodiment of the present invention shown, the A1 port of the same-side suspension valve (for example, the left suspension valve) in the prior art is connected to the rodless chamber of the same-side cylinder (i.e., the left suspension cylinder), and the A2 port is connected to the rod chamber of the opposite-side cylinder (i.e., the right suspension cylinder). In this way, when the truck crane needs to perform a body lifting operation, the A1 port and the A2 port are connected, so that the rodless chamber of the left suspension cylinder is connected to the rod chamber of the right suspension cylinder, and the rodless chamber of the right suspension cylinder is connected to the rod chamber of the left suspension cylinder, respectively, forming a differential connection, that is, the flexible mode.

[0092] At this time, in the flexible mode, when pressure oil enters the oil inlet of the suspension valve, control the A1 port and the A2 port to both enter pressure oil, that is, the pressure oil source is connected to the rod chamber and the rodless chamber of each suspension cylinder. Since the acting area of the rodless chamber is larger than that of the rod chamber, the suspension cylinder extends under the differential action, and the vehicle body can be lifted. Therefore, in the flexible mode, the suspension cylinder is in a differential connection state, and the effective pressure-bearing area of the cylinder is the cross-sectional area of the piston rod. Compared with using the cross-sectional area of the piston as the pressure-bearing area in the rigid mode, under the same load condition, the pressure of the oil-gas suspension system in the flexible mode is higher. For example, in an extra-large tonnage truck crane with a single axle load exceeding 20 tons, the required pressure of the oil-gas suspension system will generally exceed 25 MPa. Frequent operation at such a high system pressure will seriously affect the performance reliability and service life of the hydraulic system components.

[0093] After completing the lifting task, the crane needs to transfer to another construction site with as many working devices as possible (such as full boom, superlift and counterweight, etc.) to reduce the workload of disassembling, assembling and transporting the working devices. Considering factors such as driving safety, the truck crane must complete the above-mentioned transfer in the rigid mode. At this time, since the whole vehicle is in the heavy-load state in the rigid mode, the rodless cavity of the suspension cylinder is a closed cavity, and the attitude of the whole vehicle cannot be adjusted. Due to the inability to adjust the vehicle body attitude in the heavy-load state, on the one hand, the adjustment function of the suspension system in the heavy-load state is restricted; on the other hand, the passability of the whole vehicle through complex roads is weakened. In the above-mentioned transfer working condition, the truck crane is generally in the heavy-load state. Therefore, before the transfer, the truck crane needs to complete the leveling of the whole vehicle in the flexible mode.

[0094] In a truck crane, the chassis hydraulic system generally also includes a steering and outrigger hydraulic system. Usually, the working pressure of these two systems is below 20 MPa. Considering the cost performance of the whole vehicle, a variable pump is generally used as the common oil source for the chassis suspension system, steering system, outrigger system and other systems. In an extra-large-tonnage truck crane with a single-axle load exceeding 20 tons, the required pressure of the oil-gas suspension system will generally exceed 25 MPa. As the suspension load continues to increase, the suspension system pressure will exceed the tolerance pressure of the common variable pump.

[0095] In summary, the existing suspension hydraulic control system has a low load capacity, which seriously restricts the weight of the working devices that the truck crane can carry during the transfer. The oil-gas suspension hydraulic control system of the present invention has a relatively low system pressure even in the heavy-load state, and because the rodless cavity of the cylinder directly enters the pressure oil and the rod cavity can return oil, the suspension load capacity is also very strong when the whole vehicle rises to adjust the attitude. Moreover, in the heavy-load state, by controlling the suspension cylinder, the vehicle body attitude can be adjusted, realizing the function that the truck crane can automatically adjust the vehicle body attitude in the heavy-load state. Because it can automatically adjust the vehicle body attitude under heavy-load working conditions, on the one hand, it reduces the workload of disassembling, assembling and transporting the working devices, etc., and improves the transfer efficiency; on the other hand, it improves the passability of the whole vehicle through complex roads.

[0096] It should be noted that the oil-gas suspension control valve and the oil-gas suspension hydraulic control system of the present invention are not limited to being applied to truck cranes, and can also be applied to any construction machinery with suspension cylinders. The present invention makes no limitation in this regard.

[0097] In the description of the present invention, it should be understood that the terms "first" and "second" are used only for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0098] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or communicable with each other; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0099] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0100] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. An oil-gas suspension control valve, characterized in that, The oil-gas suspension control valve includes: An oil inlet valve port (P), a rod chamber connecting oil port (A1), and a rodless chamber connecting oil port (A2): A rod chamber oil return port (T1), which is internally connected to the rod chamber connecting oil port (A1) and is used for controllable oil return of the rod chamber; An internal oil inlet oil path (L1), which connects the oil inlet valve port (P) and the rodless chamber connecting oil port (A2) and is provided with a rising valve (6, 12) for controlling the on / off of the internal oil inlet oil path (L1); and An oil port connecting oil path (L2), which is connected between the rod chamber connecting oil port (A1) and the rodless chamber connecting oil port (A2) and is provided with a rigid-flexible switching valve (4, 11) for controlling the on / off of the oil port connecting oil path (L2); A rod chamber oil return oil path (L5), which connects the rod chamber oil return port (T1) and an external oil tank, and a heavy-duty control valve (3, 9) for controlling the on / off of the rod chamber oil return oil path (L5) is provided in the rod chamber oil return oil path (L5).

2. The oil-gas suspension control valve according to claim 1, wherein The oil-gas suspension control valve further includes: A bypass oil inlet oil path (L3), which is connected between the oil inlet valve port (P) and the rod chamber connecting oil port (A1) and is provided with a bridge lifting valve (5, 13) for controlling the on / off of the bypass oil inlet oil path (L3).

3. The oil-gas suspension control valve according to claim 2, wherein, The oil-gas suspension control valve further includes: An oil return valve port (T); and An internal oil return oil path (L4), which is connected between the oil return valve port (T) and the rodless chamber connecting oil port (A2) and is provided with a lowering valve (7, 14) for controlling the on / off of the internal oil return oil path (L4).

4. The oil-gas suspension control valve according to claim 3, characterized in that, The oil-gas suspension control valve further includes: An oil inlet flow regulating valve (15, 16), which is serially arranged with the rising valve (6, 12) in the internal oil inlet oil path (L1) and is closer to the oil inlet valve port (P) than the rising valve (6, 12).

5. The oil-gas suspension control valve according to claim 4, characterized in that, The rising valve (6, 12), the bridge lifting valve (5, 13), and the lowering valve (7, 14) are all electromagnetic reversing valves, and the oil inlet flow regulating valve (15, 16) is an electromagnetic proportional valve.

6. The oil-gas suspension control valve according to claim 1, wherein The rigid-flexible switching valve (4, 11) is a pneumatically controlled stop valve, and the oil-gas suspension control valve is further provided with a gas source control port (X) connected to an external gas source.

7. The oil-gas suspension control valve according to claim 1, wherein The oil-gas suspension control valve further includes: An accumulator connecting oil port (SP), which is internally connected to the rod chamber connecting oil port (A1) and is used for externally connecting an accumulator (2, 10).

8. An oil-gas suspension hydraulic control system, characterized in that, The oil-gas suspension hydraulic control system includes the oil-gas suspension control valve according to any one of claims 1 to 7.

9. The oil-gas suspension hydraulic control system according to claim 8, wherein, The oil-gas suspension hydraulic control system includes: A left suspension cylinder (1) and a right suspension cylinder (8); and A left suspension valve (101) and a right suspension valve (201), both of which are the oil-gas suspension control valves; Among them, the rod-end chamber connection oil port (A1) of the left suspension valve (101) is connected to the rod-end chamber of the left suspension cylinder (1), and the rodless chamber connection oil port (A2) of the left suspension valve (101) is connected to the rodless chamber of the right suspension cylinder (8); the rod-end chamber connection oil port (A1) of the right suspension valve (201) is connected to the rod-end chamber of the right suspension cylinder (8), and the rodless chamber connection oil port (A2) of the right suspension valve (201) is connected to the rodless chamber of the left suspension cylinder (1).

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