Variable damping hydro-pneumatic suspension device and method

Abstract

This invention belongs to the field of hydropneumatic suspension and discloses a variable damping hydropneumatic suspension device and method. The device balances the pressure of the rodless chamber and the pressure rod cavity through a core tube. A sliding valve core is installed inside the hydraulic rod cavity. The upper cavity of the valve core in the annular cavity and the hydraulic rod cavity is filled with oil. Several damping orifices and several one-way valves are formed on the wall of the hydraulic rod. When the stroke of the hydraulic rod changes, the volume of the annular cavity changes, causing a change in the volume of the hydraulic rod cavity. The valve core slides accordingly, resulting in a change in the number of damping orifices blocked by the valve core. The number of damping orifices participating in the damping effect increases or decreases, thus adjusting the size of the damping orifices to change with the stroke of the hydraulic cylinder. This allows the device to automatically change the damping effect according to the magnitude of vibration energy to meet vehicle ride comfort requirements.

Description

Technical Field

[0001] This invention belongs to the field of hydropneumatic suspension, specifically relating to a variable damping hydropneumatic suspension device and method. Background Technology

[0002] Hydro-pneumatic suspension is a widely used suspension technology. It utilizes the change in suspension stiffness caused by the volume change of inert gas in an accumulator, instead of the springs found in traditional suspensions. The shock absorbers are replaced by damping orifices and one-way valves between the suspension hydraulic cylinders and the accumulator. This structural improvement allows the suspension to integrate both cushioning and damping characteristics, reducing the installation space required in the vehicle layout. The non-linear characteristics of hydro-pneumatic suspension also offer irreplaceable advantages over traditional suspensions in improving the performance of mining trucks, which is a crucial reason for its widespread application in mining vehicles.

[0003] Hydro-pneumatic suspensions come in various structures. Traditional fixed-damping hydro-pneumatic suspensions cannot meet the cushioning and vibration reduction requirements under multiple operating conditions. The size of the damping orifice in traditional hydro-pneumatic suspensions is fixed after design and production. Since the amplitude of vibration after excitation varies under different vehicle loads, the requirements for cushioning and vibration reduction also differ. Therefore, fixed-damping hydro-pneumatic suspensions can no longer meet the cushioning and vibration reduction needs under different load conditions. Furthermore, current active suspension control systems that achieve damping variations through electro-hydraulic control technology are complex to control, and their reliability is difficult to guarantee. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a variable damping hydropneumatic suspension device and method, which can change with the suspension travel, and achieve the purpose of automatically matching damping characteristics under different load conditions.

[0005] To achieve the above objectives, a variable damping hydropneumatic suspension device includes a cylinder, a hydraulic rod disposed inside the cylinder, a guide sleeve disposed at the end of the cylinder that contacts the outer wall of the hydraulic rod, and a sliding sleeve disposed at the end of the hydraulic rod that contacts the inner wall of the cylinder. An annular cavity is formed between the cylinder and the hydraulic rod through the guide sleeve and the sliding sleeve. A hydraulic rod cavity is disposed inside the hydraulic rod cavity, and a core tube is disposed inside the hydraulic rod cavity. One end of the core tube is connected to the sliding sleeve, and the other end is connected to the hydraulic rod. A valve core is sleeved on the core tube and contacts the inner wall of the hydraulic rod cavity. A plurality of damping holes and a plurality of one-way valves are disposed on the wall of the hydraulic rod. The damping holes and the one-way valves connect the hydraulic rod cavity and the annular cavity. The flow direction of the one-way valves is from the hydraulic rod cavity to the annular cavity. When the valve core slides in the core tube, it can block and open the damping holes.

[0006] The sliding sleeve and the cylinder form a rodless cavity, which is filled with inert gas.

[0007] The rodless cavity is filled with oil for sealing the sliding sleeve and cylinder.

[0008] All damping orifices are arranged linearly or non-linearly on the wall of the hydraulic rod.

[0009] The cylinder is equipped with an oil filling valve and an oil filling and air filling valve. The oil filling valve is connected to the annular cavity, and the oil filling and air filling valve is connected to the rodless cavity.

[0010] The hydraulic rod and cylinder are equipped with spherical bearings.

[0011] A working method of a variable damping hydropneumatic suspension device:

[0012] After being stimulated by the road surface, the hydraulic rod begins to compress its stroke. The gas in the rodless chamber is compressed and its volume decreases. The oil in the annular chamber enters the annular chamber from the hydraulic rod cavity through the check valve and several damping holes to mitigate the impact.

[0013] When the excitation reaches its peak and then decreases, the hydraulic rod begins to extend its stroke. The energy of the compressed gas in the rodless chamber begins to be released, pushing the hydraulic rod to extend. The check valve is in the closed state, and the oil in the annular chamber is pressurized and enters the hydraulic rod cavity through the damping orifice to exert a damping effect.

[0014] When the stroke of the hydraulic rod changes, the volume of the annular cavity changes, and the valve core slides along the core tube, thereby blocking or opening the damping orifice.

[0015] When the load is at its maximum, only the damping hole at the top connects the hydraulic rod cavity and the annular cavity.

[0016] When the compression is at its minimum, all damping orifices connect the hydraulic rod cavity and the annular cavity.

[0017] Compared with the prior art, the device of the present invention balances the pressure of the rodless cavity and the pressure rod cavity through the core tube. A sliding valve core is set in the hydraulic rod cavity, and the upper cavity of the valve core in the annular cavity and the hydraulic rod cavity is filled with oil. Several damping holes and several one-way valves are opened on the wall of the hydraulic rod. When the stroke of the hydraulic rod changes, the volume of the annular cavity changes, causing the volume of the hydraulic rod cavity to change. The valve core will slide accordingly, thereby changing the number of damping holes blocked by the valve core. The number of damping holes participating in the damping effect will increase or decrease, thus adjusting the size of the damping holes to change with the stroke of the hydraulic cylinder. This allows the device to automatically change the damping effect according to the magnitude of vibration energy to meet the vehicle ride comfort requirements.

[0018] Furthermore, the present invention fills the rodless chamber with inert gas and adds a small amount of oil to the bottom of the rodless chamber to prevent gas from entering the annular cavity through the gap between the piston and the cylinder.

[0019] When fully loaded, the hydraulic rod has a large initial compression stroke due to the high gravitational potential energy, resulting in a large amplitude of vertical vibration and high vibration energy. This leads to a small average number of damping holes participating in each reciprocating motion, resulting in a large damping force, perfectly matching the damping requirements under heavy vehicle loads. Conversely, when unloaded, the average number of damping holes participating in each reciprocating motion is large, resulting in a small damping force, ensuring the vehicle's buffering needs are met. The gas in the rodless chamber plays a buffering role, and the varying damping holes match the different damping effects under different load conditions. Attached Figure Description

[0020] Figure 1 This is a longitudinal sectional view of the present invention;

[0021] Figure 2 This is a schematic diagram of the hydraulic rod in this invention;

[0022] Among them, 1. Spherical bearing; 2. Hydraulic rod; 3. Guide sleeve; 4. Oil filling valve; 5. Core tube; 6. Cylinder; 7. Valve core; 8. Damping orifice; 9. Oil filling and air filling valve; 10. Sliding sleeve; 11. Check valve. Detailed Implementation

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] See Figure 1 and Figure 2 A variable damping hydropneumatic suspension device includes a cylinder 6, a hydraulic rod 2 disposed inside the cylinder 6, a guide sleeve 3 disposed at the end of the cylinder 6 in contact with the outer wall of the hydraulic rod 2, and a sliding sleeve 10 disposed at the end of the hydraulic rod 2 in contact with the inner wall of the cylinder 6. The cylinder 6 and the hydraulic rod 2 are sealed to form an annular cavity through the guide sleeve 3 and the sliding sleeve 10. A hydraulic rod cavity is disposed inside the hydraulic rod 2, and a core tube 5 is disposed inside the hydraulic rod cavity. One end of the core tube 5 is connected to the sliding sleeve 10, and the other end is connected to the hydraulic rod 2. A valve core 7 is sleeved on the core tube 5 and contacts the inner wall of the hydraulic rod cavity. A plurality of damping holes 8 and a plurality of one-way valves 11 are disposed on the wall surface of the hydraulic rod 2. The damping holes 8 and the one-way valves 11 connect the hydraulic rod cavity and the annular cavity. The flow direction of the one-way valves 11 is from the hydraulic rod cavity to the annular cavity. When the core tube 5 slides, the valve core 7 can block and open the damping holes 8. The sliding sleeve 10 and the cylinder 6 form a rodless cavity, which is filled with inert gas. The rodless cavity is also filled with oil for sealing the sliding sleeve 10 and the cylinder 6. The cylinder 6 is equipped with an oil filling valve 4 and an oil filling / air filling valve 9; the oil filling valve 4 connects to the annular cavity, and the oil filling / air filling valve 9 connects to the rodless cavity. A spherical bearing 1 is installed on the hydraulic rod 2 and the cylinder 6.

[0025] Preferably, all damping holes 8 are arranged at equal intervals on the wall surface of the hydraulic rod 2.

[0026] A working method of a variable damping hydropneumatic suspension device:

[0027] After being stimulated by the road surface, the hydraulic rod 2 begins to compress, the gas in the rodless chamber is compressed and its volume decreases, and the oil in the annular chamber enters the annular chamber from the hydraulic rod cavity through the one-way valve 11 and several damping holes 8, giving full play to the advantage of the large unit energy storage ratio of the gas and mitigating the impact.

[0028] When the excitation reaches its peak and then decreases, the hydraulic rod 2 begins to extend its stroke. The energy of the compressed gas in the rodless chamber begins to be released, pushing the hydraulic rod 2 to extend. The one-way valve 11 is in the closed state, and the oil in the annular chamber is subjected to great pressure. It is squeezed into the hydraulic rod cavity through the damping hole 8 to exert a damping effect and make the vibration of the vehicle body quickly decay.

[0029] When the stroke of hydraulic rod 2 changes, the volume of the annular cavity changes, and valve core 7 slides along core tube 5, thereby blocking or opening damping orifice 8. When the load is at its maximum, only the top damping orifice 8 connects the hydraulic rod cavity and the annular cavity. When the compression is at its minimum, all damping orifices 8 connect the hydraulic rod cavity and the annular cavity.

[0030] This invention differs from fixed-damping hydropneumatic suspensions in that its hydraulic rod cavity and rodless cavity are not directly connected through damping holes 8, but rather through a core tube 5 to balance the pressure of the two cavities. The rodless cavity is filled with inert gas; simultaneously, a small amount of oil is added to the bottom of the rodless cavity to prevent gas from entering the annular cavity through the gap between the piston and cylinder. Furthermore, a sliding valve core is installed within the hydraulic rod cavity, and both the annular cavity and the valve core cavity of the hydraulic rod cavity are filled with oil. Linearly arranged damping holes are formed on the thin wall of the cavity, and a one-way valve 11 is installed at the top. When the stroke of the hydraulic rod changes, the volume of the annular cavity changes, causing a change in the volume of the upper cavity of the hydraulic rod. The valve core slides accordingly, resulting in a change in the number of damping holes blocked by the valve core. The number of damping holes participating in the damping effect increases or decreases, thus creating a variable-damping hydropneumatic suspension where the size of the damping holes can change with the stroke of the hydraulic cylinder. The working principle of the hydraulic rod and cylinder is similar to that of a fixed damping hydropneumatic suspension. The gas in the rodless chamber plays a buffering role, and the varying damping orifice matches the damping effect under different load conditions.

Claims

1. A variable-damping hydrogas suspension device, characterized by, The system includes a cylinder (6), a hydraulic rod (2) inside the cylinder (6), a guide sleeve (3) at the end of the cylinder (6) that contacts the outer wall of the hydraulic rod (2), and a sliding sleeve (10) at the end of the hydraulic rod (2) that contacts the inner wall of the cylinder (6). The cylinder (6) and the hydraulic rod (2) are sealed to form an annular cavity through the guide sleeve (3) and the sliding sleeve (10). A hydraulic rod cavity is provided inside the hydraulic rod (2), and a core tube (5) is provided inside the hydraulic rod cavity. One end of the core tube (5) is connected to the sliding sleeve (10). The sleeve (10) is connected, and the other end is connected to the hydraulic rod (2). A valve core (7) is sleeved on the core tube (5). The valve core (7) contacts the inner wall of the hydraulic rod cavity. Several damping holes (8) and several one-way valves (11) are provided on the wall of the hydraulic rod (2). The damping holes (8) and one-way valves (11) connect the hydraulic rod cavity and the annular cavity. The flow direction of the one-way valve (11) is from the hydraulic rod cavity to the annular cavity. When the valve core (7) slides in the core tube (5), it can block and open the damping holes (8). The sliding sleeve (10) and the cylinder (6) form a rodless cavity, which is filled with inert gas; The cylinder (6) is equipped with an oil filling valve (4) and an oil filling and air filling valve (9). The oil filling valve (4) is connected to the annular cavity, and the oil filling and air filling valve (9) is connected to the rodless cavity.

2. A variable-damping hydrogas suspension device according to claim 1, wherein The rodless cavity is filled with oil for sealing the sliding sleeve (10) and the cylinder (6).

3. A variable-damping hydrogas suspension device according to claim 1, wherein All damping holes (8) are arranged linearly or non-linearly on the wall of the hydraulic rod (2).

4. A variable-damping hydrogas suspension device according to claim 1, wherein The hydraulic rod (2) and the cylinder (6) are provided with spherical bearings (1).

5. A method for operating the variable damping hydropneumatic suspension device according to claim 1, characterized in that: After being stimulated by the road surface, the hydraulic rod (2) begins to compress, the gas in the rodless chamber is compressed and its volume decreases, and the oil in the annular chamber enters the annular chamber from the hydraulic rod cavity through the check valve (11) and several damping holes (8) to mitigate the impact; When the excitation reaches its peak and then decreases, the hydraulic rod (2) begins to extend its stroke. The energy of the compressed gas in the rodless chamber begins to be released, pushing the hydraulic rod (2) to extend. The check valve (11) is closed, and the oil in the annular chamber is pressurized and enters the hydraulic rod cavity through the damping hole (8) to exert a damping effect.

6. A method of operating a variable-damping hydrogas suspension device according to claim 5, wherein When the stroke of the hydraulic rod (2) changes, the volume of the annular cavity changes, and the valve core (7) slides along the core tube (5), thereby blocking or opening the damping orifice (8).

7. The operating method of a variable damping hydropneumatic suspension device according to claim 6, characterized in that, When the load is at its maximum, only the damping hole (8) at the top connects the hydraulic rod cavity and the annular cavity.

8. A method of operating a variable-damping hydrogas suspension device according to claim 6, wherein When the compression is at its minimum, all damping holes (8) are connected to the hydraulic rod cavity and the annular cavity.

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