A variable damping and variable stiffness oil-pneumatic spring device for heavy vehicles

Abstract

The present application belongs to the technical field of vehicle shock absorption, and specifically relates to a variable damping and variable stiffness oil-gas spring device for heavy-duty vehicles. The present patent proposes a variable damping and variable stiffness oil-gas spring device for heavy-duty vehicles, which is designed with an electrically controlled proportional throttle valve with continuously adjustable damping port opening, so as to realize continuous, real-time and stepless adjustment of the damping characteristics of the suspension device, and is designed with a nitrogen chamber with variable pressure to balance the stiffness characteristics of the heavy-duty vehicle under different load conditions, thereby ensuring the comfort and stability of the heavy-duty vehicle under different load conditions and road conditions.

Description

Technical Field

[0001] The present application belongs to the technical field of vehicle body shock absorption under uncertain road conditions, and specifically designs a variable damping and variable stiffness oil-pneumatic spring device for heavy vehicles. Background Art

[0002] The gas spring is an elastic buffer device that integrates gas and oil. It has good shock absorption effect and support capacity and is widely used in various heavy-duty special vehicles. Traditional fixed damping and fixed stiffness gas spring devices are mostly designed for fixed load conditions. When facing changing road conditions and vehicle loads, their vibration reduction and stability are prone to drift, which restricts the comfort and safety of the vehicle. For example, the gas spring designed for urban conditions has a smaller stiffness and damping to ensure comfort, but when facing heavy loads and mountainous roads, it is easy to have rigid impact between the piston rod and the rigid body, which greatly reduces the comfort and safety of the vehicle. Summary of the invention

[0003] In response to the above problems, this patent proposes a variable damping and variable stiffness oil-pneumatic spring device for heavy vehicles, which is designed with an electronically controlled proportional throttle valve with continuously adjustable damping port opening, so as to achieve continuous, real-time and stepless adjustment of the damping characteristics of the suspension device. A nitrogen chamber with variable pressure is designed to balance the stiffness characteristics of heavy vehicles under different load conditions. The technical solution is as follows:

[0004] A variable damping and variable stiffness oil-gas spring device for heavy vehicles comprises an upper connecting tube, an integrated end cover, an outer cylinder, an air storage bag, an isolation piston, an air pump module, a lower connecting ring, a hydraulic accumulator and a proportional throttle valve; the upper connecting tube is connected to the outer cylinder through an integrated end cover, and the lower connecting ring is connected to the piston rod or is an integrated structure; the air storage bag, the air pump module, the hydraulic accumulator and the proportional throttle valve are all arranged on the upper part of the integrated end cover, the air pump module is connected to the air storage bag, and is connected to the nitrogen chamber through the integrated end cover; the hydraulic accumulator is respectively connected to the upper oil chamber and the lower oil chamber through the integrated end cover, and the proportional throttle valve is respectively connected to the upper oil chamber and the lower oil chamber through the integrated end cover.

[0005] Preferably, the integrated end cover includes an air pump mounting port, an air cavity flow channel, an oil cavity flow channel and a throttle valve mounting port; the air pump mounting port is connected to the air pump module and connected to the nitrogen cavity through the air cavity flow channel; the throttle valve mounting port is connected to the proportional throttle valve and connected to the upper oil cavity and the lower oil cavity respectively through the oil cavity flow channel. A piston thread is provided at the bottom of the integrated end cover for connecting and sealing the integrated end cover with the isolation piston.

[0006] Preferably, the air storage bag is provided with an air storage cavity, which adopts a rubber bladder with variable volume; and is an air storage device for inflating or exhausting the A4 nitrogen cavity.

[0007] Preferably, the air pump module is connected in series between the air pump installation port and the air storage bag, and is used to inflate or exhaust air from the air storage cavity into the nitrogen cavity, thereby changing the pressure of the nitrogen cavity and thus changing the stiffness characteristics of the device.

[0008] Preferably, the hydraulic accumulator is connected in parallel to the middle of the oil chamber flow channel to supplement or absorb the flow difference between the upper oil chamber and the lower oil chamber caused by the unequal areas.

[0009] Preferably, the piston rod and the connecting ring are relatively moving parts; dynamic sealing and static sealing devices are provided at the mutual moving parts and the threaded connection parts.

[0010] Preferably, the proportional throttle valve changes the valve core position and the valve port area under the drive of external current, thereby changing the damping coefficient of the suspension system.

[0011] Preferably, the compression process damping adjustment:

[0012] When the suspension is compressed, the piston rod moves upward relative to the outer cylinder, the volume of the upper oil chamber decreases, and the volume of the lower oil chamber increases. Therefore, the oil in the upper oil chamber flows through the proportional throttle valve and enters the lower oil chamber through the oil chamber flow channel. Since the cross-sectional areas of the upper and lower oil chambers are different but the axial displacements are the same, the volume change ΔV of the upper oil chamber is greater than the volume change ΔV of the lower oil chamber, so another part of the oil enters the hydraulic accumulator;

[0013] When the suspension is stretched, the piston rod moves downward relative to the outer cylinder, the volume of the lower oil chamber decreases, and the volume of the upper oil chamber increases. The oil in the lower oil chamber flows through the oil chamber flow channel and the oil released from the hydraulic accumulator through the proportional throttle valve into the upper oil chamber.

[0014] Preferably, the suspension stiffness increase mode:

[0015] The air pump module sucks air from the air storage bag and pumps it into the nitrogen chamber through the air chamber flow channel to increase the internal pressure;

[0016] When the suspension stiffness remains unchanged, the air pump module does not work. Since the built-in one-way valve completely blocks the nitrogen in the nitrogen chamber and the air storage bag from flowing, the gas mass in the nitrogen chamber remains unchanged, which is a fixed stiffness mode;

[0017] Suspension stiffness reduction mode: The air pump module runs in reverse, pumping the nitrogen cavity into the air storage bag through the air cavity flow channel, and the pressure inside the nitrogen cavity is reduced.

[0018] Similar to the prior art, the present invention has the following beneficial effects:

[0019] 1. Damping is continuously adjustable in real time. A proportional throttle valve is set between the two oil chambers. According to the size of the command value issued by the upper controller, the proportional throttle valve controls the valve opening at the hardware level, realizing the two-way damping adjustment function of the suspension device tension and compression, so that the suspension system can adapt to different road conditions and improve vehicle comfort.

[0020] 2. The stiffness is continuously adjustable in real time. The air pump module is set to inflate or exhaust the nitrogen chamber according to the instructions of the upper controller, increase or decrease the nitrogen chamber pressure, and realize the system stiffness adjustment function.

[0021] 3. The load of the suspension system of heavy vehicles changes greatly before and after loading / unloading, and the suspension system with fixed stiffness cannot provide sufficient support stiffness during the vehicle's cornering process. The variable stiffness function of the present invention can overcome the above defects. In scenarios with high stiffness requirements such as loading (or roll side), the air pump module inflates the nitrogen chamber to increase the nitrogen chamber pressure to increase the stiffness of the suspension system. In scenarios with low stiffness requirements such as unloading (or the opposite side of roll), the air pump module exhausts air into the air storage bag to reduce the nitrogen chamber pressure to reduce the stiffness of the suspension system, so that the vehicle body maintains a stable posture, further improving the vehicle's anti-roll capability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the device structure.

[0023] Figure 2 This is a structural diagram of the integrated end cover.

[0024] Figure 3 It is an isolation piston structure.

[0025] Figure 4 It is a piston rod structure.

[0026] In the figure, 1-upper connecting tube 2-air storage bag 3-air pump module 4-hydraulic accumulator 5-integrated end cover 6-proportional throttle valve 7-piston rod 8-isolating piston 9-outer cylinder 10-lower connecting ring;

[0027] 5-1 air pump installation port 5-2 throttle valve installation port 5-3 oil chamber flow channel 5-4 air chamber flow channel 5-5 piston thread;

[0028] A1-air storage chamber, A2-upper oil chamber, A3-lower oil chamber and A4-nitrogen chamber. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] A variable damping and variable stiffness oil-gas spring device for heavy vehicles, comprising an upper connecting tube 1, an integrated end cover 5, an outer cylinder 9, an air storage bag 2, an isolation piston 8, an air pump module 3, a lower connecting ring 10, a hydraulic accumulator 4 and a proportional throttle valve 6; the upper connecting tube 1 is connected to the outer cylinder 9 through the integrated end cover 5, and the lower connecting ring 10 is connected to the piston rod 7 or is an integral structure; the air storage bag 2, the air pump module 3, the hydraulic accumulator 4 and the proportional throttle valve 6 are all arranged on the upper part of the integrated end cover 5, the air pump module 3 is connected to the air storage bag 2, and is connected to the nitrogen chamber A4 through the integrated end cover 5; the hydraulic accumulator 4 is connected to the upper oil chamber A2 and the lower oil chamber A3 respectively through the integrated end cover 5, and the proportional throttle valve 6 is connected to the upper oil chamber A2 and the lower oil chamber A3 respectively through the integrated end cover 5.

[0031] The upper connecting tube 1, the integrated end cover 5, and the outer cylinder 9 are connected as a whole by threads or welding during assembly, and an earring connected to the vehicle body is provided above the upper connecting tube 1;

[0032] The air storage bag 2, the air pump module 3, the hydraulic accumulator 4 and the proportional throttle valve 6 are all arranged on the upper part of the integrated end cover 5 and fixed by a mechanical structure.

[0033] An air storage chamber A1 is provided inside the air storage bag 2, which is an air storage device for inflating or exhausting air into the nitrogen chamber A4.

[0034] The integrated end cover 5 includes an air pump installation port 5-1, an air cavity flow channel 5-4, an oil cavity flow channel 5-3 and a throttle valve installation port 5-2; the air pump installation port 5-1 is connected to the air pump module 3, and is connected to the nitrogen cavity A4 through the air cavity flow channel 5-4; the throttle valve installation port 5-2 is connected to the proportional throttle valve 6, and is respectively connected to the upper oil cavity A2 and the lower oil cavity A3 through the oil cavity flow channel 5-3. A piston thread 5-5 is provided at the bottom of the integrated end cover 5 for connecting and sealing the integrated end cover 5 with the isolation piston 8.

[0035] The air pump module 3 is connected in series between the air pump installation port 5-1 and the air storage bag 2, and is used to inflate / exhaust air from the air storage chamber A1 into the nitrogen chamber A4, change the pressure of the nitrogen chamber A4, and thus change the stiffness characteristics of the device. The air pump module 3 integrates a two-way air pump and a one-way valve with a self-locking function at both ends of the air port.

[0036] The hydraulic accumulator 4 is connected in parallel to the middle of the oil chamber flow channel 5-3 to supplement or absorb the flow difference between the upper oil chamber A2 and the lower oil chamber A3 caused by the unequal areas.

[0037] The 5-integrated end cover is an integrated structure of the end cover and the piston rod, and a 5-1 air pump mounting port is provided on the upper surface, a 5-2 throttle valve mounting port is provided with a 5-3 oil chamber flow channel and a 5-4 air chamber flow channel inside, and a 5-5 piston thread is provided for the connection and sealing of the 5-integrated end cover and the isolation piston 8.

[0038] The proportional throttle valve 6 is on the upper end surface of the integrated end cover 5, connected in parallel to the middle of the oil chamber flow channel 5-3, and converts the control signal into a change in the valve opening.

[0039] The piston rod 7 and the lower connecting ring 10 are connected as a whole and are relatively moving parts. Dynamic and static sealing devices are provided at the mutual moving parts and the threaded connection parts.

[0040] The proportional throttle valve 6 changes the valve core position and the valve port area under the drive of external current, thereby changing the damping coefficient of the suspension system.

[0041] Compression damping adjustment:

[0042] When the suspension is compressed, the piston rod 7 moves upward relative to the outer cylinder 9, the volume of the upper oil chamber A2 decreases, and the volume of the lower oil chamber A3 increases. Therefore, the oil in the upper oil chamber A2 flows through the proportional throttle valve 6 and enters the lower oil chamber A3 through the oil chamber flow channel 5-2. Since the cross-sectional areas of A2 and A3 are different but the axial displacement is the same, the volume change ΔV(A2) of the upper oil chamber A2 is greater than the volume change ΔV(A3) of the lower oil chamber A3, so another part of the oil enters the hydraulic accumulator 4. The proportional throttle valve 6 changes the valve core position and the valve port area under the drive of the external current, thereby changing the compression damping coefficient of the suspension system.

[0043] When the suspension is stretched, the piston rod 7 moves downward relative to the outer cylinder 9, the volume of the lower oil chamber A3 decreases, the volume of the upper oil chamber A2 increases, and the oil in the lower oil chamber A3 enters the upper oil chamber A2 through the oil chamber flow channel 5-3 and the oil released by the hydraulic accumulator 4 through the proportional throttle valve 6. The proportional throttle valve 6 changes the valve core position and the valve port area under the drive of the external current, thereby changing the tensile damping coefficient of the suspension system.

[0044] The variable stiffness adjustment process of the oil-gas spring device:

[0045] According to the gas state equation, the higher the pressure in the nitrogen chamber during inflation, the greater the stiffness of the suspension system.

[0046] Suspension stiffness increase mode: the air pump module 3 draws air from the air storage bag 2 and pumps it into the nitrogen chamber A4 through the air chamber flow channel 5-4 to increase the internal pressure.

[0047] When the suspension stiffness remains unchanged, the air pump module 3 does not work. Since the built-in one-way valve completely blocks the nitrogen in the nitrogen chamber A4 and the air storage bag 2 from flowing, the gas mass in the nitrogen chamber A4 remains unchanged, which is a fixed stiffness mode.

[0048] Suspension stiffness reduction mode: the air pump 3 runs in reverse to pump the nitrogen chamber A4 into the air storage bag 2 through the air chamber flow channel 5-4, and the internal pressure of the nitrogen chamber A4 is reduced.

[0049] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A variable damping and variable stiffness oil-gas spring device for heavy vehicles, characterized in that: It includes an upper connecting tube, an integrated end cover, an outer cylinder, an air storage bag, an isolation piston, an air pump module, a lower connecting ring, a hydraulic accumulator and a proportional throttle valve; the upper connecting tube is connected to the outer cylinder through the integrated end cover, and the lower connecting ring is connected to the piston rod or is an integrated structure; the air storage bag, the air pump module, the hydraulic accumulator and the proportional throttle valve are all arranged on the upper part of the integrated end cover, the air pump module is connected to the air storage bag, and is connected to the nitrogen chamber through the integrated end cover; the hydraulic accumulator is connected to the upper oil chamber and the lower oil chamber respectively through the integrated end cover, and the proportional throttle valve is connected to the upper oil chamber and the lower oil chamber respectively through the integrated end cover; The integrated end cover includes an air pump mounting port, an air cavity flow channel, an oil cavity flow channel and a throttle valve mounting port; the air pump mounting port is connected to the air pump module, and is connected to the nitrogen cavity through the air cavity flow channel; the throttle valve mounting port is connected to the proportional throttle valve, and is respectively connected to the upper oil cavity and the lower oil cavity through the oil cavity flow channel, and a piston thread is provided at the bottom of the integrated end cover for connecting and sealing the integrated end cover and the isolation piston.

2. A heavy-duty vehicle variable damping and variable stiffness oil-gas spring device according to claim 1, characterized in that: The air storage bag is provided with an air storage cavity, which adopts a rubber bladder with variable volume; and is an air storage device used for inflating or exhausting the A4 nitrogen cavity.

3. A heavy-duty vehicle variable damping and variable stiffness oil-gas spring device according to claim 1, characterized in that: The air pump module is connected in series between the air pump installation port and the air storage bag, and is used to inflate or exhaust air from the air storage cavity into the nitrogen cavity, change the pressure of the nitrogen cavity, and thus change the stiffness characteristics of the device.

4. A heavy-duty vehicle variable damping and variable stiffness oil-gas spring device according to claim 1, characterized in that: The hydraulic accumulator is connected in parallel to the middle of the oil chamber flow channel to supplement or absorb the flow difference between the upper oil chamber and the lower oil chamber caused by the unequal areas.

5. The heavy-duty vehicle variable damping and variable stiffness oil-gas spring device according to claim 1, characterized in that: The piston rod and the connecting ring are relatively moving parts; dynamic sealing and static sealing devices are provided at the mutual moving parts and the threaded connection parts.

6. A heavy-duty vehicle variable damping and variable stiffness oil-gas spring device according to claim 1, characterized in that: The proportional throttle valve changes the position of the valve core and the valve port area under the drive of external current, thereby changing the damping coefficient of the suspension system.

7. A heavy-duty vehicle variable damping and variable stiffness oil-gas spring device according to any one of claims 2 to 6, characterized in that: Compression damping adjustment: When the suspension is compressed, the piston rod moves upward relative to the outer cylinder, the volume of the upper oil chamber decreases, and the volume of the lower oil chamber increases. Therefore, the oil in the upper oil chamber flows through the proportional throttle valve and enters the lower oil chamber through the oil chamber flow channel. Since the cross-sectional areas of the upper and lower oil chambers are different but the axial displacements are the same, the volume change ΔV of the upper oil chamber is greater than the volume change ΔV of the lower oil chamber, so another part of the oil enters the hydraulic accumulator; When the suspension is stretched, the piston rod moves downward relative to the outer cylinder, the volume of the lower oil chamber decreases, and the volume of the upper oil chamber increases. The oil in the lower oil chamber flows through the oil chamber flow channel and the oil released from the hydraulic accumulator through the proportional throttle valve into the upper oil chamber.

8. A heavy-duty vehicle variable damping and variable stiffness oil-gas spring device according to any one of claims 2 to 6, characterized in that: Suspension stiffness increase mode: The air pump module sucks air from the air storage bag and pumps it into the nitrogen chamber through the air chamber flow channel to increase the internal pressure; When the suspension stiffness remains unchanged, the air pump module does not work. Since the built-in one-way valve completely cuts off the nitrogen in the nitrogen chamber and the air storage bag, the gas mass in the nitrogen chamber remains unchanged, which is a fixed stiffness mode. Suspension stiffness reduction mode: The air pump module runs in reverse, pumping the nitrogen cavity into the air storage bag through the air cavity flow channel, and the pressure inside the nitrogen cavity is reduced.

Images