Suspension cylinder hydraulic control system, adaptive oil-gas suspension system, and method for adjusting the balance position of the suspension cylinder

Abstract

The present invention belongs to the field of vehicle suspension, specifically relating to a suspension cylinder hydraulic control system, an adaptive hydro-pneumatic suspension system, and a method for adjusting the balance position of a suspension cylinder. The suspension cylinder hydraulic control system includes a suspension cylinder, an adjustment mechanism, a cylinder pump, and a valve. The adjustment mechanism is connected to the oil chamber of the suspension cylinder. The cylinder barrel of the cylinder pump is provided with an upper oil port and an oil inlet, both of which are connected to the oil chamber of the cylinder pump. An oil outlet is provided in the middle of the cylinder barrel of the cylinder pump. When the piston of the cylinder pump extends outward to a position below the oil outlet, the oil outlet is connected to the oil chamber of the cylinder pump. Both the oil inlet and the oil outlet are designed to be unidirectional. The present invention can achieve dynamic return of the suspension cylinder piston position of the front, center, and rear axles and dynamic adjustment of the vehicle body posture in both empty and fully loaded states, thereby improving vehicle ride comfort and smoothness. The present invention can also recover vibration energy through the oil outlet of the cylinder pump, thereby improving energy utilization efficiency.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle suspension, and in particular relates to a suspension cylinder hydraulic control system, an adaptive oil-gas suspension system, and a method for adjusting the equilibrium position of a suspension cylinder. Background Art

[0002] Mining dump trucks, with their heavy loads and high hauling efficiency, are widely used in small mines. However, due to the harsh road conditions and severe overloading in mining areas, mining dump trucks offer poor ride comfort and are prone to frame fatigue cracking. Suspension, the primary force transmission component between the vehicle body and axles, plays a crucial role in vehicle ride comfort and smoothness. Currently, small-tonnage mining dump trucks operating in my country's mining areas mostly utilize leaf springs and riveted frames. However, with increasing demand for transportation capacity, market demand for larger-tonnage dump trucks is growing. Large-tonnage dump trucks generally utilize hydro-pneumatic suspension, which significantly improves load-bearing capacity and reliability, but still leaves room for improvement in shock absorption performance.

[0003] Currently, most dump trucks use passive hydro-pneumatic suspension, including hybrid front axle suspension and hydro-pneumatic balanced suspension for the center and rear axles. These suspensions offer advantages such as high load capacity and long life. This approach typically adjusts the charging pressure and accumulator volume to improve operating characteristics under empty and fully loaded conditions. However, this approach fails to dynamically match the damping performance of the front, center, and rear axles and ensures piston position return under varying load conditions. Consequently, it struggles to balance damping performance under empty and fully loaded conditions, and across the front, center, and rear axles. This is specifically manifested in three key aspects:

[0004] 1. The telescopic travel of the hydro-pneumatic suspension is determined by the amount of air in the accumulator chamber, which is a fixed value. The significant difference in equilibrium position between the empty and fully loaded states limits its dynamic travel, creating a trade-off between the two. This makes it difficult to achieve a balanced damping performance under both empty and fully loaded conditions.

[0005] 2. The center of gravity of the vehicle changes under empty and fully loaded conditions, and the load distribution between the front, middle and rear axles changes accordingly, resulting in different extension and contraction amounts of the front, middle and rear oil-gas suspensions, causing the vehicle body posture to change under empty and fully loaded conditions, which is not conducive to the vehicle's smooth driving.

[0006] 3. Mining dump trucks operate in extremely harsh road conditions. The energy consumed by vehicle vibration is far greater than the energy consumed by braking. Current suspension structures usually do not recover this vibration energy, resulting in reduced energy efficiency of mining dump trucks. Summary of the Invention

[0007] To overcome the shortcomings of the aforementioned prior art, the present invention provides a suspension cylinder hydraulic control system, an adaptive hydro-pneumatic suspension system, and a suspension cylinder balance position adjustment method. These systems dynamically adjust the suspension cylinder piston positions of the front, center, and rear axles, both in empty and fully loaded states, and dynamically adjust the vehicle's body posture, improving ride comfort and smoothness. Furthermore, the system recycles vibration energy, improving the energy efficiency of mining dump trucks.

[0008] The present invention is achieved through the following technical solution: a suspension cylinder hydraulic control system, comprising:

[0009] Suspension cylinder;

[0010] an adjusting mechanism connected to the oil chamber of the suspension cylinder and used to control the piston position of the suspension cylinder;

[0011] An oil cylinder pump, wherein an upper oil port and an oil inlet are provided on the cylinder barrel of the oil cylinder pump, and both the upper oil port and the oil inlet are connected to the oil chamber of the oil cylinder pump, and an oil outlet is provided in the middle of the cylinder barrel of the oil cylinder pump, and when the piston of the oil cylinder pump extends outward to a position below the oil outlet, the oil outlet is connected to the oil chamber of the oil cylinder pump, the oil inlet can only flow oil into the oil chamber of the oil cylinder pump in one direction, and the oil outlet can only discharge oil from the oil chamber of the oil cylinder pump in one direction; and

[0012] A valve is provided in the oil circuit between the upper oil port and the regulating mechanism, and includes a first station and a second station;

[0013] The valve is in the first working position, and the oil circuit on the upper oil port side is unidirectionally connected to the oil circuit on the regulating mechanism side;

[0014] The valve is in the second working position, and the oil path between the upper oil port and the regulating mechanism is connected to each other.

[0015] In some embodiments, the valve includes a first control end and a second control end;

[0016] The first control end is connected to the oil circuit between the oil chamber of the suspension cylinder and the regulating mechanism, and the first control end is used to control the valve to be in the first position;

[0017] The second control end is provided with a spring, and the second control end is used to control the valve to be in the second position.

[0018] In some embodiments, further comprising a first one-way valve and a second one-way valve;

[0019] The first one-way valve is connected to the oil circuit between the oil inlet of the oil cylinder pump and the oil tank, the oil inlet of the first one-way valve is connected to the oil tank, and the oil outlet of the first one-way valve is connected to the oil inlet of the oil cylinder pump;

[0020] The second one-way valve is connected to the oil circuit between the oil outlet of the cylinder pump and the oil tank, the oil inlet of the second one-way valve is connected to the oil outlet of the cylinder pump, and the oil outlet of the second one-way valve is connected to the oil tank.

[0021] In some embodiments, the regulating mechanism includes an accumulator and an air storage cylinder;

[0022] The accumulator comprises an oil chamber, a first air chamber and a second air chamber in sequence. The oil chamber and the first air chamber of the accumulator and the first air chamber and the second air chamber of the accumulator are separated by pistons. The oil chamber of the accumulator is connected to the oil chamber of the suspension cylinder.

[0023] The air storage cylinder includes an oil chamber and an air chamber, the oil chamber and the air chamber of the air storage cylinder are separated by a piston, the oil chamber of the air storage cylinder is connected to a valve, and the air chamber of the air storage cylinder is connected to the second air chamber of the accumulator.

[0024] Some embodiments of the present invention provide an adaptive hydro-pneumatic suspension system for an engineering vehicle, comprising a vehicle frame, suspension links, wheels, and the suspension cylinder hydraulic control system as described above;

[0025] The cylinder bottom of the suspension cylinder and the cylinder bottom of the cylinder pump of the suspension cylinder hydraulic control system are both hinged to the vehicle frame, and the piston rod of the suspension cylinder is hinged to the wheel axle or to the axle connected to the wheel axle;

[0026] One end of the suspension link is hinged to the vehicle frame; the other end of the suspension link is hinged to the axle of the wheel or to the axle connected to the axle of the wheel, and the middle part of the suspension link is hinged to the piston rod of the cylinder pump, or the other end of the suspension link is hinged to the piston rod of the cylinder pump, and the middle part of the suspension link is hinged to the axle of the wheel or to the axle connected to the axle of the wheel.

[0027] In some embodiments, the regulating mechanism includes an accumulator and an air storage cylinder;

[0028] The upper end of the accumulator is hinged to the vehicle frame. The accumulator includes an oil chamber, a first air chamber, and a second air chamber from top to bottom. The oil chamber and the first air chamber of the accumulator and the first air chamber and the second air chamber of the accumulator are separated by pistons. The oil chamber of the accumulator is connected to the oil chamber of the suspension cylinder.

[0029] The upper end of the air storage cylinder is hinged to the frame, and the air storage cylinder includes an oil chamber and an air chamber. The oil chamber and the air chamber of the air storage cylinder are separated by a piston. The oil chamber of the air storage cylinder is connected to the valve, and the air chamber of the air storage cylinder is connected to the second air chamber of the accumulator.

[0030] In some embodiments, the oil circuit between the oil inlet of the cylinder pump of the suspension cylinder hydraulic control system and the oil tank is further connected to a power generation device.

[0031] In some embodiments, the power generation device includes a hydraulic motor, which is arranged in the oil circuit between the oil inlet of the cylinder pump of the suspension cylinder hydraulic control system and the oil tank, and the output shaft of the hydraulic motor is connected to the generator through an overrunning clutch.

[0032] In some embodiments, the engineering vehicle is a mining dump truck, which includes a front axle, a middle axle and a rear axle, wherein the front axle is located under the cab, and the middle axle and the rear axle are both located under the cargo compartment; the front axle, the middle axle and the rear axle are each provided with a set of the adaptive oil-gas suspension system, and the adaptive oil-gas suspension system at the middle axle and the adaptive oil-gas suspension system at the rear axle share a set of adjustment mechanisms.

[0033] Some embodiments of the present invention provide a method for adjusting the equilibrium position of a suspension cylinder, including the above-mentioned adaptive hydro-pneumatic suspension system for an engineering vehicle. The method for adjusting the equilibrium position of the suspension cylinder is as follows:

[0034] When the vehicle is unloaded and stationary, the first air chamber of the accumulator is first inflated. Under the action of gas pressure, the upper piston of the accumulator moves upward to squeeze the hydraulic oil in the oil chamber of the accumulator into the oil chamber of the suspension cylinder. The piston of the suspension cylinder extends, and the piston rod of the suspension cylinder drives the piston rod of the cylinder pump to extend through the suspension connecting rod until the piston of the cylinder pump moves to a position below the oil outlet. Then, the inflation of the first air chamber of the accumulator stops. At this time, the piston of the suspension cylinder is stable in the middle position of the stroke.

[0035] Then the air cavity of the air storage cylinder is inflated, and the piston of the air storage cylinder moves to the limit position close to the inner wall of the air storage cylinder under the action of gas pressure until the gas pressure in the air storage cylinder approaches the gas pressure of the first air cavity in the accumulator, and the inflation of the air cavity of the air storage cylinder is stopped.

[0036] The beneficial effects of the present invention are: it can achieve dynamic return of the suspension cylinder piston position of the axle and dynamic adjustment of the vehicle body posture in both empty and fully loaded vehicle states, thereby improving the vehicle's ride comfort and driving smoothness. At the same time, it recovers vibration energy to improve energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic diagram of the hydraulic control system of the suspension cylinder of the present invention;

[0038] Figure 2 It is a structural diagram of the oil cylinder pump of the present invention;

[0039] Figure 3 is a schematic diagram of the adaptive oil-gas suspension system of the present invention;

[0040] Figure 4 This is a schematic diagram of an embodiment of the adaptive oil-gas suspension system of the present invention applied to the center axle and rear axle of a mining dump truck;

[0041] Figure 5 Schematic diagram of the state after loading the cargo;

[0042] Figure 6 This is a schematic diagram of the state of starting to travel with full load;

[0043] Figure 7 This is a schematic diagram of the state of full load and stable driving;

[0044] Figure 8 This is a schematic diagram of the state during unloading;

[0045] Figure 9 This is a schematic diagram of a vehicle traveling without load;

[0046] In the figure, 1, vehicle frame, 2, suspension cylinder, 2-1, suspension cylinder 1, 2-2, suspension cylinder 2, 3, second one-way valve, 3-1, second one-way valve 1, 3-2, second one-way valve 2, 4, suspension link, 4-1, suspension link 1, 4-2, suspension link 2, 5, cylinder pump, 5-1, oil inlet, 5-2, oil inlet, 5-3, oil outlet, 5-4, cylinder pump 1, 5-5, cylinder pump 2, 6, valve, 6-1. Valve 1, 6-2. Valve 2, 7. First one-way valve, 7-1. First one-way valve 1, 7-2. First one-way valve 2, 8. Accumulator, 8-1. Accumulator 1, 9. Air cylinder, 9-1. Air cylinder 1, 10. Hydraulic motor, 11. Fuel tank, 12. Overrunning clutch, 13. Generator, 14. Rubber shock-absorbing pad, 15. Wheel, 15-1. Middle wheel, 15-2. Rear wheel, 16. Road surface. DETAILED DESCRIPTION

[0047] The present invention will be further described below with reference to the accompanying drawings and examples.

[0048] like Figure 1 As shown, a suspension cylinder hydraulic control system includes: a suspension cylinder 2, an adjustment mechanism, a cylinder pump 5 and a valve 6.

[0049] The suspension oil cylinder 2 is a single-rod hydraulic cylinder, and its rodless chamber is the oil chamber of the hydraulic cylinder.

[0050] The regulating mechanism is connected to the oil chamber of the suspension cylinder 2 and is used to control the piston position of the suspension cylinder 2.

[0051] In some embodiments, the regulating mechanism includes an accumulator 8 and an air storage cylinder 9. The accumulator 8 includes an oil chamber, a first air chamber, and a second air chamber in sequence. The first air chamber is located between the oil chamber and the second air chamber of the accumulator 8. The oil chamber and the first air chamber of the accumulator 8 are separated by an upper piston, and the first air chamber and the second air chamber are separated by a lower piston. The oil chamber of the accumulator 8 is connected to the oil chamber of the suspension cylinder 2. The air storage cylinder 9 includes an oil chamber and an air chamber. The oil chamber and the air chamber of the air storage cylinder 9 are separated by a piston. The oil chamber of the air storage cylinder 9 is connected to the valve 6, and the air chamber of the air storage cylinder 9 is connected to the second air chamber of the accumulator 8. The regulating mechanism adjusts the piston position of the suspension cylinder 2 by changing the gas pressure in the first air chamber of the accumulator 8.

[0052] like Figure 1 and Figure 2 As shown, the cylinder pump 5 is a single-rod hydraulic cylinder, whose rodless chamber serves as the hydraulic cylinder's oil chamber. The cylinder barrel of the cylinder pump 5 is provided with an upper oil port 5-1 and an oil inlet 5-2, both of which are connected to the oil chamber of the cylinder pump 5. An oil outlet 5-3 is provided in the middle of the cylinder barrel of the cylinder pump 5. When the piston of the cylinder pump 5 extends outward to a position below the oil outlet 5-3, the oil outlet 5-3 communicates with the oil chamber of the cylinder pump 5. The oil inlet 5-2 allows only one-way oil flow into the oil chamber of the cylinder pump 5, while the oil outlet 5-3 allows only one-way oil flow from the oil chamber of the cylinder pump 5. When the oil inlet 5-2 and the oil outlet 5-3 are connected, hydraulic oil entering the oil chamber of the cylinder pump 5 via the oil inlet 5-2 can be discharged through the oil outlet 5-3. When the oil inlet 5-2 and the oil outlet 5-3 are cut off, the hydraulic oil in the oil chamber of the oil cylinder pump 5 can be squeezed by the piston of the oil cylinder pump 5, and the oil is replenished to the oil chamber of the air storage cylinder 9 through the upper oil port 5-1, thereby increasing the gas pressure in the air chamber of the air storage cylinder 9.

[0053] In some embodiments, a first one-way valve 7 and a second one-way valve 3 are also included. The first one-way valve 7 is connected to the oil circuit between the oil inlet 5-2 of the cylinder pump 5 and the fuel tank. The oil inlet of the first one-way valve 7 is connected to the fuel tank, and the oil outlet of the first one-way valve 7 is connected to the oil inlet 5-2 of the cylinder pump 5. When the piston of the cylinder pump 5 extends, the cylinder pump 5 draws oil from the fuel tank through the oil inlet 5-2 and the first one-way valve 7. The second one-way valve 3 is connected to the oil circuit between the oil outlet 5-3 of the cylinder pump 5 and the fuel tank. The oil inlet of the second one-way valve 3 is connected to the oil outlet 5-3 of the cylinder pump 5, and the oil outlet of the second one-way valve 3 is connected to the fuel tank. When the piston of the cylinder pump 5 moves below the oil outlet 5-3, the oil inlet 5-2 and oil outlet 5-3 of the cylinder pump 5 are connected, and the oil drawn by the cylinder pump 5 flows back to the fuel tank 11 through the second one-way valve 3.

[0054] like Figure 1As shown, valve 6 is disposed in the oil circuit between the upper oil port 5-1 and the regulating mechanism, and includes a first position and a second position. In the first position, the oil circuit on the upper oil port 5-1 side is unidirectionally connected to the oil circuit on the regulating mechanism side. When the valve 6 is in the first position, the cylinder pump 5 can replenish oil to the oil chamber of the air storage cylinder 9 through the first position of the valve 6. In the second position, the oil circuit between the upper oil port 5-1 and the regulating mechanism is interconnected. When the valve 6 is in the second position, the oil chamber of the air storage cylinder 9 can be unloaded.

[0055] In some embodiments, the valve 6 includes a first control end and a second control end. The first control end is connected to the oil circuit between the oil chamber of the suspension cylinder 2 and the regulating mechanism, and the first control end is used to control the valve 6 to be in the first position. The second control end is provided with a spring, and the second control end is used to control the valve 6 to be in the second position. When the oil pressure in the oil chamber of the suspension cylinder 2 is less than the preset pressure of the valve 6, the valve 6 is in the second position; the piston of the suspension cylinder 2 moves upward, and the oil pressure in the oil chamber of the suspension cylinder 2 gradually rises. After the oil pressure in the oil chamber of the suspension cylinder 2 is greater than the preset pressure of the valve 6, the valve 6 overcomes the spring resistance and switches the valve 6 from the second position to the first position.

[0056] like Figures 1 to 3 As shown, some embodiments of the present invention provide an adaptive oil-gas suspension system for an engineering vehicle, including a vehicle frame 1, a suspension link 4, a wheel 15, a rubber shock-absorbing pad 14 and the above-mentioned suspension cylinder hydraulic control system.

[0057] The bottoms of the suspension cylinder 2 and the cylinder pump 5 of the suspension cylinder hydraulic control system are both hinged to the vehicle frame 1. The piston rod of the suspension cylinder 2 is hinged to the axle of the wheel 15 (the piston rod of the suspension cylinder 2 may also be hinged to the axle connected to the axle of the wheel 15). One end of the suspension link 4 is hinged to the vehicle frame 1, and the other end of the suspension link 4 is hinged to the axle of the wheel 15 (the other end of the suspension link 4 may also be hinged to the axle connected to the axle of the wheel 15). The middle portion of the suspension link 4 is hinged to the piston rod of the cylinder pump 5. However, this application is not limited to the above-mentioned connection method of the suspension link 4 and other components. Any method that can achieve the functions of extending the piston rod of the suspension cylinder 2 and driving the piston rod of the cylinder pump 5 to extend via the suspension link 4, and retracting the piston rod of the cylinder pump 5 via the suspension link 4 when the piston rod of the suspension cylinder 2 is retracted will suffice. As another solution of this embodiment: one end of the suspension link 4 is hinged to the vehicle frame 1, the other end of the suspension link 4 is hinged to the piston rod of the oil cylinder pump 5, and the middle part of the suspension link 4 is hinged to the axle of the wheel 15 (the middle part of the suspension link 4 can also be hinged to the axle connected to the axle of the wheel 15). This connection form of the suspension link 4 and other components can also meet the requirements of this application. Figure 3As shown, this embodiment provides a suspension link 4 with one end hinged to the vehicle frame 1, the other end hinged to the axle of the wheel 15 (the other end of the suspension link 4 can also be hinged to the axle connected to the axle of the wheel 15), and the middle portion of the suspension link 4 hinged to the piston rod of the cylinder pump 5. A rubber shock-absorbing pad 14 is installed between the vehicle frame 1 and the cab, or between the vehicle frame 1 and the cargo compartment. Initially, when the engineering vehicle is unloaded and stationary, the suspension cylinder hydraulic control system must be adjusted to ensure that the suspension cylinder 2 is in a balanced position, that is, the piston of the suspension cylinder 2 is at the mid-stroke position.

[0058] In some embodiments, the regulating mechanism includes an accumulator 8 and an air cylinder 9. The upper end of the accumulator 8 is hinged to the vehicle frame 1. From top to bottom, the accumulator 8 includes an oil chamber, a first air chamber, and a second air chamber. The oil chamber and the first air chamber of the accumulator 8 are separated by an upper piston, and the first air chamber and the second air chamber are separated by a lower piston. The oil chamber of the accumulator 8 is connected to the oil chamber of the suspension cylinder 2. The upper end of the air cylinder 9 is hinged to the vehicle frame 1. The air cylinder 9 includes an oil chamber and an air chamber. The oil chamber and the air chamber of the air cylinder 9 are separated by a piston. The oil chamber of the air cylinder 9 is connected to the valve 6, and the air chamber of the air cylinder 9 is connected to the second air chamber of the accumulator 8.

[0059] When the above adjustment mechanism is used, the method for adjusting the balance position of the suspension cylinder is as follows:

[0060] When the vehicle is unloaded and stationary, the first air chamber of accumulator 8 is first inflated. The upper piston of accumulator 8, under the action of gas pressure, moves upward, squeezing the hydraulic oil in the oil chamber of accumulator 8 into the oil chamber of suspension cylinder 2. The piston of suspension cylinder 2 extends, and the piston rod of suspension cylinder 2 pushes the distance between frame 1 and wheel 15, thereby causing suspension link 4 to swing downward about its hinge with frame 1. During this process, suspension link 4 extends the piston rod of cylinder pump 5 until the piston of cylinder pump 5 moves below oil outlet 5-3, stopping inflation of the first air chamber of accumulator 8. At this point, according to the setting, the piston of suspension cylinder 2 stabilizes at the mid-stroke position. Since oil outlet 5-3 is already connected to the oil chamber of cylinder pump 5, the upper oil port 5-1 and oil inlet 5-2 are connected to oil outlet 5-3, respectively. The valve 6 includes a first control end and a second control end. The first control end is connected to the oil circuit between the oil chamber of the suspension cylinder 2 and the regulating mechanism. The first control end is used to control the valve 6 in the first position. The second control end is equipped with a spring and is used to control the valve 6 in the second position. Because the vehicle is unladen, the oil pressure in the suspension cylinder 2 is lower than the switching pressure of the valve 6. The spring at the second control end causes the valve 6 to be in the second position, and the oil chamber of the air reservoir cylinder 9 and the oil chamber of the cylinder pump 5 are in a bidirectional state of communication. The air chamber of the air reservoir cylinder 9 is inflated until the gas pressure in the air reservoir cylinder 9 approaches the gas pressure in the first air chamber of the accumulator 8, at which point inflation of the air chamber of the air reservoir cylinder 9 is stopped. Before the gas pressure in the air reservoir cylinder 9 approaches the gas pressure in the first air chamber of the accumulator 8, the piston of the air reservoir cylinder 9 has already moved to its limit position against the inner wall of the air reservoir cylinder 9 under the action of the gas pressure. The gas filling the accumulator 8 and the air reservoir cylinder 9 is dry nitrogen.

[0061] After adjusting the suspension cylinder hydraulic control system so that the suspension cylinder 2 is in a balanced position, the engineering vehicle can achieve dynamic return of the axle suspension cylinder piston position and dynamic adjustment of the vehicle body posture in both empty and fully loaded states during operation, thereby improving the vehicle's ride comfort and driving smoothness.

[0062] In some embodiments, the oil circuit between the oil inlet 5-2 of the cylinder pump 5 of the suspension cylinder hydraulic control system and the oil tank is also connected to a power generation device, so that when the vehicle is working, the surplus vibration energy is generated through the power generation device to improve energy utilization efficiency.

[0063] In some embodiments, the power generation device includes a hydraulic motor 10, which is disposed in the oil circuit between the oil inlet 5-2 of the cylinder pump 5 of the suspension cylinder hydraulic control system and the oil tank. The output shaft of the hydraulic motor 10 is connected to a generator 13 via an overrunning clutch 12. When the hydraulic motor 10 rotates, the overrunning clutch 12 drives the generator 13 to generate electricity. The overrunning clutch 12 effectively reduces speed fluctuations of the generator 13 caused by sudden changes in the speed of the hydraulic motor 10.

[0064] In some embodiments, the engineering vehicle is a mining dump truck, which includes a front axle, a middle axle, and a rear axle. The front axle is located below the cab, and the middle axle and the rear axle are both located below the cargo compartment. Each of the front axle, the middle axle, and the rear axle is provided with a set of the adaptive oil-gas suspension system. Since the middle axle and the rear axle are both located below the cargo compartment, the force conditions of the vehicle are very similar whether it is empty or fully loaded. Therefore, in actual application, the adaptive oil-gas suspension system at the middle axle and the adaptive oil-gas suspension system at the rear axle share a set of adjustment mechanisms (such as Figure 4 As shown, the air reservoir cylinder 9-1 of the adjustment mechanism contains two oil chambers and one air chamber, with the two oil chambers located on either side of the air chamber. Sharing a common adjustment mechanism reduces component usage, saves costs, and facilitates optimization of the vehicle chassis's spatial layout. The front axle is located below the cab. Therefore, when the vehicle is unloaded or fully loaded, the forces acting on it differ significantly from those on the center and rear axles. Therefore, the adaptive hydro-pneumatic suspension system at the front axle utilizes a separate adjustment mechanism. The following uses the adaptive hydro-pneumatic suspension systems for the center and rear axles as examples to illustrate the working principles of this invention.

[0065] 1. During loading: Figure 5As shown, as the weight of the cargo compartment increases, the piston of suspension cylinder 2-1 in the adaptive hydro-pneumatic suspension system of the center axle moves upward, causing the oil pressure in the oil chamber of suspension cylinder 2-1 to gradually increase. When the oil pressure in the oil chamber of suspension cylinder 2-1 exceeds the preset pressure of valve 6-1, valve 6-1 switches to the first position, unidirectionally conducting the flow. The height of the vehicle frame 1 relative to the center wheel 15-1 continuously decreases, causing suspension link 4-1 to swing upward. This movement of suspension link 4-1 drives the piston rod of cylinder pump 5-4 upward to a position above the oil outlet of cylinder pump 5-4, disconnecting the connection between the upper oil inlet of cylinder pump 5-4 and the oil outlet of cylinder pump 5-4. At the same time, hydraulic oil is continuously squeezed from the oil chamber of suspension cylinder 2-1 into the oil chamber of accumulator 8-1. The upper piston of accumulator 8-1 moves downward, and the nitrogen volume in the first air chamber of accumulator 8-1 is continuously compressed. While the adaptive hydro-pneumatic suspension system on the center axle is operating, the adaptive hydro-pneumatic suspension system on the rear axle undergoes similar actions. As the weight of the cargo compartment increases, the piston of suspension cylinder 2-2 moves upward, causing the oil pressure in the oil chamber of suspension cylinder 2-2 to gradually increase. When the oil pressure in the oil chamber of suspension cylinder 2-2 exceeds the preset pressure of valve 2-2, valve 2-2 switches to the first position, unidirectionally opening valve 2-2. The height of vehicle frame 1 relative to rear wheel 15-2 continuously decreases, causing suspension link 2-4-2 to swing upward. The movement of suspension link 2 4-2 drives the piston rod of cylinder pump 2 5-5 upward to a position above the oil outlet of cylinder pump 2 5-5, disconnecting the connection between the upper oil inlet of cylinder pump 2 5-5 and the oil outlet of cylinder pump 2 5-5. Simultaneously, hydraulic oil is continuously squeezed from the oil chamber of suspension cylinder 2 2-2 into the oil chamber of accumulator 1 8-1. The upper piston of accumulator 1 8-1 moves downward, continuously compressing the nitrogen volume in the first air chamber of accumulator 1 8-1.

[0066] It is not difficult to see that when the vehicle is fully loaded, the piston in the suspension cylinder is at a high position, and the dynamic stroke of the suspension cylinder is small when fully loaded.

[0067] 2. When driving with full load, if Figure 6 and Figure 7As shown, due to the unevenness of road surface 16, the road surface 16 exerts vertical displacement excitation on the vehicle's wheels during driving, causing vehicle vibration. For the adaptive hydro-pneumatic suspension system on the mid-axle, the center wheel 15-1 moves relative to the vehicle frame 1, and the suspension link 4-1 drives the piston rod of cylinder pump 5-4 to continuously extend and retract relative to the cylinder body of cylinder pump 5-4. When the piston rod of cylinder pump 5-4 extends, cylinder pump 5-4 draws oil from the fuel tank through its oil inlet and first check valve 7-1. When the piston rod of cylinder pump 5-4 retracts, cylinder pump 5-4 pressurizes hydraulic oil into the oil chamber of air reservoir 9-1 through its upper oil port and the first position of valve 6-1. This pushes the piston of air reservoir 9-1 to move, compressing the air chamber of air reservoir 9-1 and increasing the gas pressure in the air chamber of air reservoir 9-1. As cylinder pump 5-4 continuously expands and contracts, the volume of the air chamber in air reservoir 9-1 is continuously compressed, and the gas pressure continues to rise. The gas in air reservoir 9-1 is gradually pressed into the second chamber of accumulator 8-1. The lower piston of accumulator 8-1 moves upward, further compressing the volume of the first chamber of accumulator 8-1. The rising gas pressure in the first chamber of accumulator 8-1 forces the hydraulic fluid in accumulator 8-1's fluid chamber back into suspension cylinder 2-1. The piston of suspension cylinder 2-1 moves downward, continuously lifting the vehicle frame 1 relative to the center wheel 15-1. Suspension link 4-1 drives the piston of cylinder pump 5-4 downward. When the vehicle is fully loaded, the rear axle's adaptive hydro-pneumatic suspension system undergoes similar movements. Relative motion between the rear wheel 15-2 and the vehicle frame 1 causes the suspension link 2 4-2 to continuously extend and retract the piston rod of the oil pump 2 5-5 relative to the cylinder body of the oil pump 2 5-5. When the piston rod of the oil pump 2 5-5 extends, the oil pump 2 5-5 draws oil from the fuel tank through the oil inlet of the oil pump 2 5-5 and the first check valve 2 7-2. When the piston rod of the oil pump 2 5-5 retracts, the oil pump 2 5-5 pressurizes hydraulic oil into the oil chamber of the air reservoir 1 9-1 through the oil port of the oil pump 2 5-5 and the first position of the valve 2 6-2. This pushes the piston of the air reservoir 1 9-1 to move, compressing the air chamber of the air reservoir 1 9-1 and increasing the gas pressure in the air chamber of the air reservoir 1 9-1. As cylinder pump 2 (5-5) continuously expands and contracts, the volume of the air chamber in air reservoir 1 (9-1) is continuously compressed, and the gas pressure continues to rise. The gas in air reservoir 1 (9-1) is gradually pressed into the second chamber of accumulator 1 (8-1). The lower piston of accumulator 1 (8-1) moves upward, further compressing the volume of the first chamber of accumulator 1 (8-1). The rising gas pressure in the first chamber of accumulator 1 (8-1) forces the hydraulic fluid in accumulator 1 (8-1)'s fluid chamber back into suspension cylinder 2 (2-2). The piston of suspension cylinder 2 (2-2) moves downward, continuously lifting the vehicle frame 1 relative to the rear wheel 15-2. Suspension connecting rod 2 (4-2) drives the piston of cylinder pump 2 (5-5) downward.

[0068] When the piston of cylinder pump 1 5-4 moves to the vicinity of the oil outlet of cylinder pump 1 5-4 and the piston of cylinder pump 2 5-5 moves to the vicinity of the oil outlet of cylinder pump 2 5-5, the gas pressure in the air storage cylinder 1 9-1 stops rising, the piston of suspension cylinder 1 2-1 returns to the vicinity of the middle position when it is at rest without load, and the piston of suspension cylinder 2 2-2 returns to the vicinity of the middle position when it is at rest without load, so that the vehicle's fully loaded dynamic stroke is equivalent to the vehicle's unloaded dynamic stroke, and the vehicle enters a stable driving stage.

[0069] After the piston of suspension cylinder 2-1 returns to the middle position, Figure 7 As shown, the piston of the oil cylinder pump 5-4 vibrates slightly up and down near its oil outlet. When the piston of the oil cylinder pump 5-4 moves to a position below the oil outlet of the oil cylinder pump 5-4, the oil inlet and outlet of the oil cylinder pump 5-4 are connected, and the oil pumped by the oil cylinder pump 5-4 flows back to the oil tank 11 through the second one-way valve 3-1. Similarly, when the piston of the suspension oil cylinder 2-2 returns to the middle position, as shown in FIG. Figure 7 As shown, the piston of oil cylinder pump 2 (5-5) vibrates slightly up and down near its oil outlet. When the piston of oil cylinder pump 2 (5-5) moves to a position below the oil outlet, the oil inlet and outlet of oil cylinder pump 2 (5-5) are connected, and the oil pumped by oil cylinder pump 2 (5-5) flows back to the oil tank 11 through the second one-way valve (2) (3-2).

[0070] 3. When unloading a vehicle, if Figure 8As shown, as the weight of the cargo compartment decreases, the oil pressure in the oil chamber of suspension cylinder 2-1 in the center axle's adaptive hydro-pneumatic suspension system continuously decreases. The high-pressure gas in accumulator 8-1 and air reservoir 9-1 begins to expand, pushing the piston of suspension cylinder 2-1 downward to a position slightly below the vehicle's unloaded static center position. The height of vehicle frame 1 continuously rises relative to center wheel 15-1, causing suspension link 4-1 to swing downward. This movement of suspension link 4-1 extends the piston rod of cylinder pump 5-4 downward, which in turn drives the piston of cylinder pump 5-4 downward to a position slightly below the oil outlet of cylinder pump 5-4, connecting the passage between the upper oil inlet and the oil outlet of cylinder pump 5-4. When the oil pressure in suspension cylinder 2-1 falls below the switching pressure of valve 6-1, the oil chamber of air reservoir 9-1 and cylinder pump 5-4 return to a two-way flow state. As a result, the oil passages between reservoir cylinder 9-1, cylinder pump 5-4, and fuel tank 11 are reconnected, and the gas in accumulator 8-1 and reservoir cylinder 9-1 further expands, forcing the hydraulic oil in the oil chamber connecting reservoir cylinder 9-1 to valve 6-1 back into tank 11 via the upper oil port of cylinder pump 5-4 and the oil outlet of cylinder pump 5-4. Similarly, the oil pressure in the oil chamber of suspension cylinder 2-2 in the rear axle's adaptive hydro-pneumatic suspension system continues to decrease. The high-pressure gas in accumulator 8-1 and reservoir cylinder 9-1 begins to expand, pushing the piston of suspension cylinder 2-2 downward to a position slightly below the vehicle's unloaded static neutral position. The height of vehicle frame 1 continues to rise relative to rear wheel 15-2, causing suspension link 2-4-2 to swing downward. The movement of suspension link 2 4-2 drives the piston rod of cylinder pump 2 5-5 downward, which in turn drives the piston of cylinder pump 2 5-5 downward to a position slightly below the oil outlet of cylinder pump 2 5-5. This connects the passage between the upper oil inlet of cylinder pump 2 5-5 and the oil outlet of cylinder pump 2 5-5. When the oil pressure in suspension cylinder 2 2-2 falls below the switching pressure of valve 2 6-2, the oil chamber of air reservoir 1 9-1 and cylinder pump 2 5-5 return to a two-way conductive state. Consequently, the oil passages between air reservoir 1 9-1, cylinder pump 2 5-5, and fuel tank 11 are once again connected. The gas in accumulator 1 8-1 and air reservoir 1 9-1 further expands, forcing the hydraulic oil in the oil chamber connecting air reservoir 1 9-1 and valve 2 6-2 to flow back to fuel tank 11 through the upper oil inlet of cylinder pump 2 5-5 and the oil outlet of cylinder pump 2 5-5.

[0071] The piston of the air storage cylinder 9-1 returns to the two side positions, the lower piston of the accumulator 8-1 returns to the bottom position, the piston of the suspension cylinder 2-1 moves slightly upward and returns to near the middle position, and the piston of the suspension cylinder 2-2 moves slightly upward and returns to near the middle position.

[0072] 4. When the vehicle is running without load, Figure 9As shown, the piston motion pattern is similar to that of a fully loaded vehicle during stable driving. After the piston of suspension cylinder 2-1 returns to near neutral, the piston of cylinder pump 5-4 vibrates slightly near its outlet. When the piston of cylinder pump 5-4 moves below its outlet, the inlet and outlet of cylinder pump 5-4 connect, and the oil pumped by cylinder pump 5-4 flows back to the fuel tank 11 through the second one-way valve 3-1. After the piston of suspension cylinder 2-2 returns to near neutral, the piston of cylinder pump 2-5 vibrates slightly near its outlet. When the piston of cylinder pump 2-5 moves below its outlet, the inlet and outlet of cylinder pump 2-5 connect, and the oil pumped by cylinder pump 2-5 flows back to the fuel tank 11 through the second one-way valve 3-2.

[0073] The layout structure of the adaptive oil-gas suspension system of the front axle of the mining dump truck is as follows: Figure 3 As shown, its working principle is the same as that of the adaptive oil-gas suspension system of the above-mentioned middle and rear axles, and will not be repeated here.

[0074] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A suspension cylinder hydraulic control system, characterized in that: include: Suspension cylinder (2); An adjusting mechanism connected to the oil chamber of the suspension oil cylinder (2) and used to control the piston position of the suspension oil cylinder (2); An oil cylinder pump (5), wherein an upper oil port (5-1) and an oil inlet (5-2) are provided on the cylinder barrel of the oil cylinder pump (5), and both the upper oil port (5-1) and the oil inlet (5-2) are communicated with the oil cavity of the oil cylinder pump (5); an oil outlet (5-3) is provided in the middle of the cylinder barrel of the oil cylinder pump (5); when the piston of the oil cylinder pump (5) extends outward to a position below the oil outlet (5-3), the oil outlet (5-3) is communicated with the oil cavity of the oil cylinder pump (5); the oil inlet (5-2) can only flow oil into the oil cavity of the oil cylinder pump (5) in one direction, and the oil outlet (5-3) can only discharge oil from the oil cavity of the oil cylinder pump (5) in one direction; and A valve (6), the valve (6) is provided in the oil path between the upper oil port (5-1) and the regulating mechanism, and the valve (6) includes a first station and a second station; The valve (6) is in the first working position, and the oil circuit on the upper oil port (5-1) side is unidirectionally connected to the oil circuit on the regulating mechanism side; The valve (6) is in the second working position, and the oil path between the upper oil port (5-1) and the regulating mechanism is in communication with each other; The regulating mechanism includes an accumulator (8) and an air storage cylinder (9); The accumulator (8) comprises an oil chamber, a first air chamber, and a second air chamber in sequence. The oil chamber and the first air chamber of the accumulator (8) and the first air chamber and the second air chamber are separated by pistons. The oil chamber of the accumulator (8) is connected to the oil chamber of the suspension cylinder (2). The air storage cylinder (9) comprises an oil chamber and an air chamber, the oil chamber and the air chamber of the air storage cylinder (9) are separated by a piston, the oil chamber of the air storage cylinder (9) is connected to the valve (6), and the air chamber of the air storage cylinder (9) is connected to the second air chamber of the accumulator (8).

2. The suspension cylinder hydraulic control system according to claim 1, characterized in that: The valve (6) comprises a first control end and a second control end; The first control end is connected to the oil circuit between the oil chamber of the suspension oil cylinder (2) and the regulating mechanism, and the first control end is used to control the valve (6) to be in the first working position; The second control end is provided with a spring, and the second control end is used to control the valve (6) to be in the second position.

3. The suspension cylinder hydraulic control system according to claim 1, characterized in that: Also includes a first one-way valve (7) and a second one-way valve (3); The first one-way valve (7) is connected to the oil circuit between the oil inlet (5-2) of the oil cylinder pump (5) and the oil tank, the oil inlet of the first one-way valve (7) is connected to the oil tank, and the oil outlet of the first one-way valve (7) is connected to the oil inlet (5-2) of the oil cylinder pump (5); The second one-way valve (3) is connected to the oil circuit between the oil outlet (5-3) of the oil cylinder pump (5) and the oil tank, the oil inlet of the second one-way valve (3) is connected to the oil outlet (5-3) of the oil cylinder pump (5), and the oil outlet of the second one-way valve (3) is connected to the oil tank.

4. An adaptive oil-gas suspension system for an engineering vehicle, characterized in that: It comprises a vehicle frame (1), a suspension link (4), a wheel (15) and a suspension cylinder hydraulic control system according to any one of claims 1 to 3; The cylinder bottom of the suspension cylinder (2) and the cylinder bottom of the cylinder pump (5) of the suspension cylinder hydraulic control system are both hinged to the vehicle frame (1), and the piston rod of the suspension cylinder (2) is hinged to the axle of the wheel (15) or to the axle connected to the axle of the wheel (15); One end of the suspension link (4) is hinged to the vehicle frame (1); the other end of the suspension link (4) is hinged to the axle of the wheel (15) or to the axle connected to the axle of the wheel (15); the middle part of the suspension link (4) is hinged to the piston rod of the oil cylinder pump (5); or the other end of the suspension link (4) is hinged to the piston rod of the oil cylinder pump (5); the middle part of the suspension link (4) is hinged to the axle of the wheel (15) or to the axle connected to the axle of the wheel (15).

5. The adaptive oil-pneumatic suspension system for an engineering vehicle according to claim 4, characterized in that: The upper end of the accumulator (8) is hinged to the vehicle frame (1), and the accumulator (8) comprises an oil chamber, a first air chamber, and a second air chamber from top to bottom; The upper end of the gas storage cylinder (9) is hinged to the vehicle frame (1).

6. The adaptive oil-pneumatic suspension system for an engineering vehicle according to claim 4 or 5, characterized in that: The oil circuit between the oil inlet (5-2) of the oil cylinder pump (5) of the suspension oil cylinder hydraulic control system and the oil tank is also connected to a power generation device.

7. The adaptive oil-pneumatic suspension system for an engineering vehicle according to claim 6, characterized in that: The power generation device includes a hydraulic motor (10), which is arranged in the oil circuit between the oil inlet (5-2) of the oil cylinder pump (5) of the suspension oil cylinder hydraulic control system and the oil tank, and the output shaft of the hydraulic motor (10) is connected to the generator (13) through an overrunning clutch (12).

8. The adaptive oil-pneumatic suspension system for an engineering vehicle according to claim 4 or 5, characterized in that: The engineering vehicle is a mining dump truck, which includes a front axle, a middle axle and a rear axle. The front axle is located under the cab, and the middle axle and the rear axle are both located under the cargo compartment. The front axle, the middle axle and the rear axle are each provided with a set of the adaptive oil-gas suspension system, and the adaptive oil-gas suspension system at the middle axle and the adaptive oil-gas suspension system at the rear axle share a set of adjustment mechanisms.

9. A method for adjusting the balance position of a suspension cylinder, characterized in that: The adaptive oil-gas suspension system for engineering vehicles according to claim 5 is used; the method for adjusting the equilibrium position of the suspension cylinder is as follows: When the vehicle is unloaded and stationary, the first air chamber of the accumulator (8) is first inflated. The upper piston of the accumulator (8) moves upward under the action of gas pressure to squeeze the hydraulic oil in the oil chamber of the accumulator (8) into the oil chamber of the suspension cylinder (2). The piston of the suspension cylinder (2) extends, and the piston rod of the suspension cylinder (2) drives the piston rod of the cylinder pump (5) to extend through the suspension connecting rod (4) until the piston of the cylinder pump (5) moves to a position below the oil outlet (5-3). The inflation of the first air chamber of the accumulator (8) is stopped. At this time, the piston of the suspension cylinder (2) is stable at the middle position of the stroke. Then, the air chamber of the air storage cylinder (9) is inflated, and the piston of the air storage cylinder (9) moves to the limit position close to the inner wall of the cylinder of the air storage cylinder (9) under the action of the gas pressure, until the gas pressure in the air storage cylinder (9) approaches the gas pressure of the first air chamber in the accumulator (8), and the inflation of the air chamber of the air storage cylinder (9) is stopped.

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