Suspension valve group, hydro-pneumatic suspension system and all-terrain crane

Abstract

This invention discloses a suspension valve assembly, a hydropneumatic suspension system, and an all-terrain crane. The suspension valve assembly includes suspension valve assembly ports A, B, and SP; a first electromagnetic directional valve connected between suspension valve assembly port B and hydraulic oil tank inlet P, controlling the flow of hydraulic fluid into the small chamber of the suspension cylinder; a second electromagnetic directional valve connected between suspension valve assembly port A and hydraulic oil tank inlet P, controlling the flow of hydraulic fluid into the large chamber of the suspension cylinder; a third electromagnetic directional valve connected between suspension valve assembly port A and hydraulic oil tank return port T, controlling the flow of hydraulic fluid from the large chamber of the suspension cylinder back to the hydraulic oil tank; a suspension spring stiffness switching valve connected between suspension valve assembly port A and hydraulic oil tank return port T, controlling the interaction between the hydraulic fluid in the large chamber of the suspension cylinder and the accumulator; and a fourth electromagnetic directional valve connected between suspension valve assembly ports B and SP, controlling the interaction between the hydraulic fluid in the small chamber of the suspension cylinder and the accumulator. This solution enables the vehicle to have a lifting suspension function after being supported by a crane.

Description

Technical Field

[0001] This invention belongs to the field of all-terrain cranes, specifically relating to a suspension valve group, a hydropneumatic suspension system, and an all-terrain crane. Background Technology

[0002] The hydropneumatic suspension is a connecting device between the frame and axle of an all-terrain crane, using hydraulic oil as the transmission medium and inert gas as the elastic medium. It consists of suspension cylinders, suspension valve groups, accumulators, thrust rods, and distribution systems, etc. It mitigates and attenuates the impacts and vibrations caused by the ground, while transmitting force and torque.

[0003] As a key technology for all-terrain cranes, hydropneumatic suspension technology enables the crane chassis to perform functions such as lifting, pitching, and tilting, effectively improving the vehicle's driving performance and allowing it to adapt to complex and harsh terrain environments.

[0004] As the market for all-terrain cranes grows, users' familiarity with the technology is also increasing. Because all-terrain cranes' hydraulic suspensions have a vehicle lifting function, after the crane enters the work area, users often first lower the vehicle suspension, fully retracting the suspension cylinders to bring the chassis to its lowest position, then locking the suspension, and finally extending the outriggers to lift the vehicle. This method shortens the vertical cylinder stroke, lowers the vehicle's center of gravity, and increases tire ground clearance, thereby improving the safety and stability of the crane's lifting operations. However, current technology lacks the function of raising and lowering the suspension after the vehicle is supported, causing inconvenience for users' vehicle operation and maintenance. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide a suspension valve group, a hydropneumatic suspension system, and an all-terrain crane that enable the vehicle to have a lifting suspension function after being supported by a vehicle.

[0006] Technical Solution: The suspension valve assembly of the present invention includes a suspension valve assembly A port for connecting to the large chamber of the suspension cylinder on the same side, a suspension valve assembly B port for connecting to the small chamber of the suspension cylinder on the opposite side, and a suspension valve assembly SP port for connecting to the accumulator; a first solenoid directional valve connected between the suspension valve assembly B port and the hydraulic oil tank inlet P, the first solenoid directional valve controlling the flow of oil into the small chamber of the suspension cylinder; and a second solenoid directional valve connected between the suspension valve assembly A port and the hydraulic oil tank inlet P, the second solenoid directional valve controlling the flow of oil into the large chamber of the suspension cylinder. The system includes: a third solenoid directional valve connected between port A of the suspension valve group and port T of the hydraulic oil tank, which controls the flow of oil from the large chamber of the suspension cylinder back to the hydraulic oil tank; a suspension spring rigidity switching valve connected between port A of the suspension valve group and port T of the hydraulic oil tank, which controls the interaction between the large chamber of the suspension cylinder and the accumulator oil; and a fourth solenoid directional valve connected between port B of the suspension valve group and port SP of the suspension valve group, which controls the interaction between the small chamber of the suspension cylinder and the accumulator oil.

[0007] A damping valve is installed on the connecting pipeline between the first electromagnetic reversing valve and port B of the suspension valve group, and between the third electromagnetic reversing valve and port A of the suspension valve group. This valve can control the extension and retraction speed of the suspension cylinder and improve the smoothness of the extension and retraction of the suspension cylinder.

[0008] One-way valves are installed on the connecting pipelines between the oil outlet of the second solenoid directional valve and the oil inlet P of the hydraulic oil tank, and between the third solenoid directional valve and the oil return port T of the hydraulic oil tank, to prevent oil from flowing backward.

[0009] It also includes an overflow valve, whose inlet is connected to the suspension valve group B port and the fourth solenoid directional valve, and whose outlet is connected to the hydraulic oil tank return port T, thus playing a role in system safety protection.

[0010] The suspension spring rigidity switching valve adopts a two-position two-way pneumatic control valve or a two-position two-way solenoid control valve to control the on / off of the interaction between the large chamber of the suspension cylinder and the accumulator oil.

[0011] The present invention also includes a hydropneumatic suspension system, comprising four suspension valve assemblies: a right front suspension valve assembly, a left front suspension valve assembly, a right rear suspension valve assembly, and a left rear suspension valve assembly; and further comprising right front suspension cylinder assemblies and left front suspension cylinder assemblies symmetrically arranged on both sides of the vehicle frame, and right rear suspension cylinder assemblies and left rear suspension cylinder assemblies symmetrically arranged on both sides of the vehicle frame; the right front suspension valve assembly, left front suspension valve assembly, right rear suspension valve assembly, and left rear suspension valve assembly are used to control the extension and retraction movements of the right front suspension cylinder assembly, left front suspension cylinder assembly, right rear suspension cylinder assembly, and left rear suspension cylinder assembly.

[0012] The A ports of the right front suspension valve group, left front suspension valve group, right rear suspension valve group, and left rear suspension valve group are connected to the large chamber of the suspension cylinder in the suspension cylinder group on the same side as them. The B port of each suspension valve group is connected to the small chamber of the suspension cylinder in the suspension cylinder group on the opposite side. The SP port of each suspension valve group is connected to an accumulator.

[0013] The large and small chambers of the suspension cylinders in the right front suspension cylinder group, left front suspension cylinder group, right rear suspension cylinder group, and left rear suspension cylinder group are connected to each other.

[0014] The present invention also includes an all-terrain crane employing a hydropneumatic suspension system.

[0015] Beneficial effects: Compared with the prior art, the technical solution of the present invention has the following beneficial effects: it enables the vehicle to have the function of raising and lowering the suspension after the vehicle is supported, increases the tire ground clearance by power lifting the axle, improves the safety of crane lifting operations, and achieves the purpose of quick vehicle retrieval by power lowering the axle, which brings convenience to users in vehicle operation and maintenance. Attached Figure Description

[0016] Figure 1 This is a hydraulic schematic diagram of the suspension valve assembly in Example 1;

[0017] Figure 2 This is a hydraulic schematic diagram of the hydropneumatic suspension system described in this invention;

[0018] Figure 3 This is a hydraulic schematic diagram of the suspension valve assembly in Example 2. Detailed Implementation

[0019] The technical solution of the present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0020] Example 1:

[0021] like Figure 1As shown, the suspension valve assembly of the present invention includes a first electromagnetic directional valve 1, a first damping valve 2, a second electromagnetic directional valve 3, a second damping valve 4, a third electromagnetic directional valve 5, a suspension spring stiffness switching valve 6, a fourth electromagnetic directional valve 7, an overflow valve 8, a first check valve 9, a second check valve 10, a suspension valve assembly port A, a suspension valve assembly port B, and a suspension valve assembly port SP. The first electromagnetic directional valve 1 is a two-position, two-way electromagnetic directional valve. The connection method of each component is as follows: the normally closed ends of the first electromagnetic directional valve 1 are connected to the suspension valve assembly port B and the outlet of the second check valve 10, respectively, to control the flow of oil into the small chamber of the suspension cylinder. The first damping valve 2 is installed on the connecting pipeline between the first electromagnetic directional valve 1 and the suspension valve assembly port B, and is used to control the extension and retraction speed of the suspension cylinder, improving the smoothness of the suspension cylinder extension and retraction. The inlet of the second solenoid directional valve 3 is connected to the outlet of the second check valve 10, and the outlet is connected to port A of the suspension valve assembly, controlling the flow of hydraulic fluid into the large chamber of the suspension cylinder. The third solenoid directional valve 5 is connected between port A of the suspension valve assembly and the inlet of the first check valve 9, controlling the flow of hydraulic fluid from the large chamber of the suspension cylinder back to the hydraulic tank. The second damping valve 4 is installed on the connecting pipeline between the third solenoid directional valve 5 and port A of the suspension valve assembly, controlling the extension and retraction speed of the suspension cylinder and improving the smoothness of the extension and retraction. The outlet of the first check valve 9 is connected to the return port T of the hydraulic tank, serving as a reverse cutoff to prevent system backflow into the large chamber of the suspension cylinder; the inlet of the second check valve 10 is connected to the inlet P of the hydraulic tank, serving as a reverse cutoff to prevent hydraulic fluid from flowing back into the hydraulic power source. The suspension spring rigidity switching valve 6 is connected between the suspension valve group A port and the hydraulic oil tank return port T. In this embodiment, the suspension spring rigidity switching valve 6 is a two-position, two-way pneumatic control directional valve. Its normally closed position ports are connected to the suspension valve group A port and the suspension valve group SP port, respectively, controlling the on / off interaction between the large chamber of the suspension cylinder and the accumulator oil. The normally open position ports of the fourth solenoid directional valve 7 are connected to the suspension valve group B port and the suspension valve group SP port, respectively, controlling the on / off interaction between the small chamber of the suspension cylinder and the accumulator oil. The inlet of the relief valve 8 is connected to the suspension valve group B port and the normally open position of the fourth solenoid directional valve 7, respectively. The outlet of the relief valve 8 is connected to the hydraulic oil tank return port T via the first check valve 9, serving as a system safety protection function.

[0022] like Figure 2As shown, the present invention also includes a hydropneumatic suspension system, comprising four sets of the aforementioned suspension valve assemblies: a right front suspension valve assembly 11, a left front suspension valve assembly 12, a right rear suspension valve assembly 13, and a left rear suspension valve assembly 14; it also includes a right front suspension cylinder assembly 19 and a left front suspension cylinder assembly 20 symmetrically arranged on both sides of the vehicle frame, and a right rear suspension cylinder assembly 21 and a left rear suspension cylinder assembly 22 symmetrically arranged on both sides of the vehicle frame; the number of suspension cylinders in the same group varies depending on the vehicle model, and this embodiment uses three suspension cylinders in the same group as an example for description. The right front suspension valve assembly 11, left front suspension valve assembly 12, right rear suspension valve assembly 13, and left rear suspension valve assembly 14 control the extension and retraction of the right front suspension cylinder assembly 19, left front suspension cylinder assembly 20, right rear suspension cylinder assembly 21, and left rear suspension cylinder assembly 22.

[0023] The A ports of the right front suspension valve assembly 11, left front suspension valve assembly 12, right rear suspension valve assembly 13, and left rear suspension valve assembly 14 are connected to the large suspension cylinder chamber in the suspension cylinder assembly on the same side as them, and the B ports of each suspension valve assembly are connected to the small suspension cylinder chamber in the suspension cylinder assembly on the opposite side; specifically, the A port of the right front suspension valve assembly 11 is connected to the large suspension cylinder chamber in the right front suspension cylinder assembly 19, and the B port is connected to the small suspension cylinder chamber in the left front suspension cylinder assembly 20; the left front suspension valve assembly 1... Port A of valve group 2 is connected to the large chamber of the suspension cylinder in the left front suspension cylinder group 20, and port B is connected to the small chamber of the suspension cylinder in the right front suspension cylinder group 19. Port A of valve group 13 of the right rear suspension is connected to the large chamber of the suspension cylinder in the right rear suspension cylinder group 21, and port B is connected to the small chamber of the suspension cylinder in the left rear suspension cylinder group 22. Port A of valve group 14 of the left rear suspension is connected to the large chamber of the suspension cylinder in the left rear suspension cylinder group 22, and port B is connected to the small chamber of the suspension cylinder in the right rear suspension cylinder group 21. Port SP of each suspension valve group is connected to an accumulator. Specifically, port SP of the right front suspension valve group 11 is connected to the first accumulator 15, port SP of the left front suspension valve group 12 is connected to the second accumulator 16, port SP of the right rear suspension valve group 13 is connected to the third accumulator 17, and port SP of the left rear suspension valve group 14 is connected to the fourth accumulator 18. The large and small chambers of the suspension cylinders in the right front suspension cylinder group 19, left front suspension cylinder group 20, right rear suspension cylinder group 21, and left rear suspension cylinder group 22 are connected respectively.

[0024] The invention also includes an all-terrain crane that employs the above-mentioned hydropneumatic suspension system.

[0025] The following is the specific control strategy for raising and lowering the suspension after the vehicle is supported. After the vehicle is supported, the hydropneumatic suspension is in a rigid locked state, and the suspension spring rigidity switching valve 6 in the suspension valve group is cut off from air supply, operating in its normally closed position.

[0026] The following control strategy is used to control the retraction of the suspension cylinders, thereby raising the axle and increasing the tire ground clearance. The first solenoid directional valve 1 is energized and positioned in the through position; the second solenoid directional valve 3 is de-energized and positioned in the one-way valve position; the third solenoid directional valve 5 is energized and positioned in the through position; and the fourth solenoid directional valve 7 is energized and positioned in the cut-off position. The hydraulic power source injects high-pressure oil sequentially through the second one-way valve 10, the through position of the first solenoid directional valve 1, and the first damping valve 2 into the small chamber of the suspension cylinder. Simultaneously, the hydraulic oil in the large chamber of the suspension cylinder flows back to the hydraulic tank sequentially through the second damping valve 4, the through position of the third solenoid directional valve 5, and the first one-way valve 9.

[0027] The following control strategy is adopted to control the extension of the suspension cylinder, thereby lowering the axle and achieving the purpose of rapid vehicle retraction. The first solenoid directional valve 1 is energized and put into the through position; the second solenoid directional valve 3 is energized and put into the through position; the third solenoid directional valve 5 is de-energized and put into the one-way valve position; the fourth solenoid directional valve 7 is energized and put into the cut-off position. The hydraulic power source injects high-pressure oil sequentially through the second one-way valve 10 and the through position of the second solenoid directional valve 3 into the large chamber of the suspension cylinder. Simultaneously, hydraulic oil in the small chamber of the suspension cylinder sequentially passes through the first damping valve 2, the through position of the first solenoid directional valve 1, and the through position of the second solenoid directional valve 3 into the large chamber of the suspension cylinder, forming differential control of the suspension cylinder.

[0028] During the aforementioned power-lift suspension process, the suspension spring stiffness switching valve 6 is in the normally closed position, the fourth electromagnetic reversing valve 7 is in the cut-off position, and the accumulator connected to the SP port of the suspension valve group is isolated from the outside world, preventing oil interaction. This achieves the accumulator pressure holding function, effectively preventing the risk of vehicle sinking or rebounding when the vehicle suspension state switches from rigid to elastic after the vehicle is lifted, thus improving the product's suspension handling stability.

[0029] Example 2:

[0030] like Figure 3 As shown, the suspension spring rigidity switching valve 6 can also be replaced by a two-position two-way solenoid directional valve. The suspension spring rigidity switching valve 6 is replaced by a two-position two-way pneumatic directional valve. Its normally closed position oil ports are connected to the suspension valve group A port and the suspension valve group SP port respectively, controlling the on and off of the interaction between the large chamber of the suspension cylinder and the accumulator oil, and can achieve the same function.

Claims

1. A suspension valve assembly, characterized in that: It includes a suspension valve group A port for connecting to the large chamber of the suspension cylinder on the same side, a suspension valve group B port for connecting to the small chamber of the suspension cylinder on the opposite side, and a suspension valve group SP port for connecting to the accumulator. The first solenoid directional valve (1) is connected between the B port of the suspension valve group and the P port of the hydraulic oil tank. The first solenoid directional valve (1) controls the opening and closing of the oil entering the small chamber of the suspension cylinder. The second electromagnetic reversing valve (3) is connected between the suspension valve group A port and the hydraulic oil tank inlet P. The second electromagnetic reversing valve (3) controls the opening and closing of the oil entering the large chamber of the suspension cylinder. The third solenoid directional valve (5) is connected between the suspension valve group A port and the hydraulic oil tank return port T. The third solenoid directional valve (5) controls the flow of oil from the large chamber of the suspension cylinder back to the hydraulic oil tank. The suspension spring rigidity switching valve (6) is connected between the suspension valve group A port and the hydraulic oil tank return port T. The suspension spring rigidity switching valve (6) controls the on / off of the interaction between the large chamber of the suspension cylinder and the accumulator oil. The fourth solenoid directional valve (7) is connected between the B port of the suspension valve group and the SP port of the suspension valve group. The fourth solenoid directional valve (7) controls the opening and closing of the interaction between the small chamber of the suspension cylinder and the accumulator oil. During the retraction and extension of the suspension cylinder, the suspension spring stiffness switching valve (6) is in the normally closed working state, the fourth electromagnetic reversing valve (7) is in the cut-off working state, the accumulator connected to the SP port of the suspension valve group is isolated from the outside world and cannot perform oil-fluid interaction, thereby realizing the accumulator pressure holding function and avoiding the vehicle sinking or rebounding when the vehicle suspension state changes from rigid to elastic after the vehicle is withdrawn. A damping valve is installed on the connecting pipeline between the first electromagnetic directional valve (1) and the suspension valve group B port, and between the third electromagnetic directional valve (5) and the suspension valve group A port.

2. The suspension valve assembly according to claim 1, characterized in that: A check valve is installed on the connecting pipeline between the oil outlet of the second electromagnetic directional valve (3) and the oil inlet P of the hydraulic oil tank, and between the third electromagnetic directional valve (5) and the oil return T of the hydraulic oil tank.

3. The suspension valve assembly according to claim 1, characterized in that: It also includes an overflow valve (8), the oil inlet of which is connected to the suspension valve group B port and the fourth solenoid directional valve (7) respectively, and the oil outlet of the overflow valve (8) is connected to the hydraulic oil tank return port T.

4. The suspension valve assembly according to claim 1, characterized in that: The suspension spring rigidity switching valve (6) is a two-position two-way pneumatic control valve or a two-position two-way solenoid control valve.

5. A hydropneumatic suspension system, characterized in that: It includes four suspension valve groups as described in claim 1, namely, the right front suspension valve group (11), the left front suspension valve group (12), the right rear suspension valve group (13), and the left rear suspension valve group (14). It also includes the right front suspension cylinder group (19) and the left front suspension cylinder group (20) symmetrically arranged on both sides of the frame, and the right rear suspension cylinder group (21) and the left rear suspension cylinder group (22) symmetrically arranged on both sides of the frame. The right front suspension valve group (11), left front suspension valve group (12), right rear suspension valve group (13), and left rear suspension valve group (14) are used to control the extension and retraction of the right front suspension cylinder group (19), left front suspension cylinder group (20), right rear suspension cylinder group (21), and left rear suspension cylinder group (22).

6. The hydropneumatic suspension system according to claim 5, characterized in that: The A ports of the right front suspension valve group (11), left front suspension valve group (12), right rear suspension valve group (13), and left rear suspension valve group (14) are connected to the large chamber of the suspension cylinder in the suspension cylinder group on the same side. The B port of each suspension valve group is connected to the small chamber of the suspension cylinder in the suspension cylinder group on the opposite side. The SP port of each suspension valve group is connected to an accumulator.

7. The hydropneumatic suspension system according to claim 6, characterized in that: The large and small chambers of the suspension cylinders in the right front suspension cylinder group (19), left front suspension cylinder group (20), right rear suspension cylinder group (21), and left rear suspension cylinder group (22) are connected to each other.

8. An all-terrain crane, characterized in that: The hydropneumatic suspension system described in claim 5 is used.

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