A track walking unit lifting system for an amphibious vehicle and method of use

Abstract

The application relates to the technical field of amphibious vehicle suspensions, in particular to a track walking unit lifting system for an amphibious vehicle and a use method thereof, which comprises an oil-gas spring upper support, a double-cylinder oil-gas spring, a limiting lock, a pull rod, a track walking unit, a balance elbow assembly, a balance elbow auxiliary seat, a limiting rod, a rocker arm and a vehicle body. When the vehicle runs on soft road surface, oil is filled into the main oil cavity of the oil-gas spring through a hydraulic control system, the rocker arm is pushed and the balance elbow swings until the track walking unit is in contact with the ground. Under this use condition, the track walking unit can bear part of the load of the vehicle, the contact area between the vehicle and the ground is increased, the ground pressure of the whole vehicle is reduced, and the passing performance of the vehicle on the soft road surface is improved. When the vehicle runs on water, oil is filled into the annular cavity of the oil-gas spring through the hydraulic control system, the piston rod is contracted to drive the rocker arm and the balance elbow to swing, and finally the track walking unit is lifted into the wheel cabin.

Description

Technical Field

[0001] This invention relates to the field of amphibious vehicle suspension technology, specifically to a tracked walking unit lifting system and its usage method for amphibious vehicles. Background Technology

[0002] For amphibious vehicles, to improve overall off-road capability, it is crucial to address their ability to traverse soft terrain such as mudflats and deserts, reducing ground pressure and preventing wheels from sinking into soft surfaces that could impede normal vehicle operation. However, due to the inherent limitations of the tracked drive unit, it is difficult to meet high-speed requirements. Therefore, for amphibious vehicles, while improving off-road capability on soft surfaces, it is also necessary to consider the vehicle's speed on off-road terrain and waterways.

[0003] Therefore, it is urgent to solve the problem of adding a tracked running unit lifting system, which extends the tracked running unit out of the wheel well to contact the ground when traveling on soft ground to reduce the ground pressure of the vehicle, and retracts the tracked running unit into the wheel well to increase the vehicle speed when traveling on off-road roads and waterways. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] The technical problem to be solved by this invention is: how to solve the passability problem of amphibious vehicles, especially wheeled amphibious vehicles, when driving on soft surfaces, and the problem of high-speed driving on water.

[0006] (II) Technical Solution

[0007] To solve the above technical problems, the present invention provides a tracked walking unit lifting system for an amphibious vehicle. The system includes: an upper support for a gas spring (1), a double-cylinder gas spring (2), a limit lock (3), a pull rod (4), a tracked walking unit (5), a balance elbow assembly (6), a balance elbow sub-seat (7), a limit rod (8), a rocker arm (9), and a vehicle body (10).

[0008] The double-cylinder hydropneumatic spring (2) includes: a connecting body (204), a hydraulic cylinder (207), a pneumatic cylinder (205), and a main piston rod (206); and is provided with a main oil chamber port (201), an annular chamber port (203), and a locking port (202) for the hydropneumatic spring (2); the ports on the hydropneumatic spring (2) are connected to the corresponding functional valve group ports through pipelines, and under the control of the hydraulic control system, the extension and retraction of the track walking unit and the rigid locking function of the hydropneumatic spring (2) are realized.

[0009] The splined shaft of the balance elbow assembly (6) passes through the outside of the vehicle body (10) into the balance elbow sub-seat (7) and the inner splined hole of the rocker arm (9), and aligns the pin (604) installed on the balance elbow splined shaft (601) with the missing tooth of the inner spline of the rocker arm (9), thereby fixing the angle between the balance elbow body and the rocker arm (9); finally, adjust the position of the balance elbow assembly (6) and fix the balance elbow assembly (6) on the balance elbow sub-seat (7) with bolts; the balance elbow optical shaft (603) and the track walking unit mounting through hole are connected to the metal The bushing is hinged to realize the rotation and support of the tracked walking unit; the mounting holes at both ends of the tie rod (4) are fitted with metal bushings and are respectively hinged to the shafts welded on the vehicle body and the tracked walking unit, so that the four hinge points of the balance elbow assembly (6) and the tie rod (4) with the vehicle body (10) and the tracked walking unit assembly (5) form a parallelogram structure, wherein the balance elbow body (602) and the tie rod (4) are parallel sides, ensuring that the tracked walking unit maintains a horizontal state during the rising and falling process;

[0010] The balance elbow assembly (6) has a pin hole machined on its spline shaft. The center line of the pin hole is located at the center line of the bottom of the outer involute spline tooth groove and the center line is located on the center surface of the balance elbow body. A positioning pin is installed at the pin hole.

[0011] The nut (16) passes through the through hole on the vehicle body and connects to the threaded hole (105) of the upper support of the gas spring. The reamed bolt (11) is connected to the reamed hole (104) of the upper support of the gas spring to ensure the installation position and angle of the upper support of the gas spring on the vehicle body. The pin (12) passes through the through hole (102) of the gas spring and the bearing hole (208) of the gas spring connector and then passes into the blind hole (103) of the pin of the upper support of the gas spring. The right-angle pin (17) passes through the locking hole (101) of the upper support of the gas spring. After the round hole at the front end of the right-angle pin (17) passes through the locking hole at the far end of the upper support of the gas spring, the cotter pin (18) passes through the round hole on the right-angle pin (17) to prevent the right-angle pin from falling off.

[0012] The balance elbow seat (7) is fixedly connected to the bottom plate of the vehicle body (10) by welding;

[0013] The pin (12) passes through the round hole on the rocker arm (9) and the bearing hole (209) of the lower hinge of the double-cylinder oil spring in sequence until the pin (12) is completely pressed on the rocker arm (9). Then the right-angle pin (17) passes through the two locking holes (901) of the rocker arm. After the round hole at the front end of the right-angle pin (17) passes through the locking hole at the far end of the rocker arm, the cotter pin (18) passes through the round hole on the right-angle pin (17) to prevent the right-angle pin from falling off.

[0014] The limit lock (3) has an oil port (14). By injecting oil into the oil port through the hydraulic control system, the lock hook (15) can be retracted into the limit lock. When the oil injection into the oil port (14) is stopped, the rebound device inside the limit lock can pop out the lock hook (15) and restore it to the locked state.

[0015] The tracked walking unit (5) is placed on the ground under the action of the hydraulic control system. The pump motor on the tracked walking unit (5) is driven by the hydraulic system to realize the walking function of the tracked walking unit (5) in the forward and backward directions.

[0016] The limiting rod (8) is riveted to the balance elbow. After the track walking unit is retracted into the wheel well, the limiting rod is locked in the locking hook to form a mechanical protection device to prevent the track walking unit from falling due to internal leakage of the hydraulic system.

[0017] The rocker arm (9) needs to have its splines milled off at specific locations so that it can be positioned and installed when assembled with the balance elbow assembly.

[0018] In the case of soft road surface, hydraulic oil is filled into the main oil chamber of the oil-air spring (2) through the hydraulic control system. The piston rod of the oil-air spring (2) extends and drives the pull arm and balance elbow to rotate, so that the track walking unit is extended outside the wheel chamber until it contacts the ground. Under this condition, the track walking unit can bear part of the load of the whole vehicle, increase the contact area between the whole vehicle and the ground, reduce the ground pressure of the whole vehicle, and improve the passability of the vehicle on soft road surface. In the case of water, the oil-air spring (2) is controlled to retract through the hydraulic control system, so that the track walking unit is completely retracted into the vehicle body, reducing the water resistance during the whole vehicle's driving process and increasing the vehicle speed in the case of water.

[0019] The limiting rod (8) is riveted to the balance elbow body. By operating the lifting wheel key on the control panel, the hydraulic system can fill the annular cavity of the gas spring (2) with oil, driving the pull arm (9) and the balance elbow assembly (6) to rotate around the central axis of the balance elbow spline, thus retracting the track walking unit (5) into the wheel well; at the same time, the hydraulic system fills the oil port (301) on the limiting lock (3) with oil, retracting the locking hook (302) of the limiting lock into the limiting lock, at which time the limiting lock is in the unlocked state; when the gas spring (2) is retracted to its shortest position... After positioning, the limit rod (8) is located at the center of the limit lock hook. After releasing the lifting wheel key, the hydraulic system stops filling the annular cavity of the gas spring (2) and the limit lock with oil. The annular cavity of the gas spring (2) forms a high-pressure cavity, which prevents the piston rod of the gas spring (2) from extending, ensuring that the tracked walking unit remains in the retracted wheel chamber state. At the same time, the rebound device set inside the limit lock can eject the lock hook and lock the limit rod inside the lock hook, forming a mechanical protection device to prevent the tracked walking unit from falling due to internal leakage of the hydraulic system.

[0020] The cylinder of the gas spring (2) is filled with high-pressure nitrogen. When the vehicle is driving normally, the tracked walking unit transmits the ground excitation to the gas spring (2) through the balance elbow assembly (6) and rocker arm (9). The piston rod compresses the high-pressure nitrogen to alleviate the ground impact. At this time, the tracked walking unit lifting system can be regarded as an elastic lifting system.

[0021] Driven by the hydraulic system, the oil spring (2) can retract and extend the track walking unit through the rocker arm (9) and the balance elbow assembly (6); its oil filling circuit is equipped with a double overflow valve group, with two different overflow pressures, which can ensure that the extension length of the track walking unit can meet the ground clearance requirements of the vehicle under both unloaded and fully loaded conditions, thereby ensuring the normal posture of the vehicle body.

[0022] The gas spring (2) has a self-pressurizing locking device. Its locking oil circuit valve group consists of two normally closed solenoid valves and one check valve. Before the vehicle crosses the trench, after the track wheel travel unit is placed on the ground, press and hold the locking button on the control panel of the gas spring (2) for more than 10 seconds. The hydraulic oil enters the locking oil port of the gas spring (2) through the locking oil circuit, pushing the internal piston to move and realizing the separation of the hydraulic oil and high-pressure nitrogen inside the gas spring (2). In this state, the gas spring (2) is in a rigid state. When the vehicle travels to the point where the front axle tires are above the trench, the front axle tires are off the ground. At this time, the track travel unit provides rigid support to ensure that the vehicle passes through the trench smoothly in a stable posture.

[0023] The slide valve lifting wheel valve group, which is formed by two one-way valves interconnected and then connected in series with a three-position four-way valve, is set in the oil filling circuit of the annular cavity of the gas spring (2). When the hydraulic system is controlled by the operation panel to fill the main oil cavity of the gas spring (2) and release the track walking unit, all the solenoid valves of the return oil circuit valve group of the annular cavity of the gas spring (2) are opened. The hydraulic oil in the annular cavity flows through the slide valve lifting wheel valve group, which slows down the descent speed of the track walking unit and avoids the track walking unit from falling too fast and causing an impact with the ground.

[0024] The balance elbow assembly (6) extends into the vehicle body through the wheel well. The splined shaft of the balance elbow assembly (6) is provided with a sealing groove. The sealing groove is equipped with a sealing element, which forms a rotary sealing fit with the bearing seat and the inner surface of the through hole of the balance elbow support. Needle roller bearings are installed on both sides of the splined shaft to provide rotational support between the splined shaft and the balance elbow support.

[0025] The outer end of the balance elbow assembly (6) is an optical shaft, and a metal bushing is installed in the through hole of the track walking unit (5). The optical shaft (603) of the balance elbow is fitted with the metal bushing in the through hole of the track walking unit with clearance, so as to realize the hinged assembly of the output end of the balance elbow assembly (6) and the track walking unit. The through holes at both ends of the tie rod (4) are fitted with metal bushings. The through holes and the metal bushings are interference fit. The metal bushings are fitted with the shafts welded on the vehicle body and the track walking unit with clearance to form a hinged pair.

[0026] Under the action of the hydraulic control system, the hydraulic system's functional valve group charges and releases oil to different oil ports of the oil spring, which can realize the functions of slowly lowering, retracting, and rigidly locking the tracked travel unit, thus meeting the vehicle's usage requirements for the tracked travel unit under different operating conditions.

[0027] The present invention also provides a method of using the tracked walking unit lifting system:

[0028] a. Extension control function

[0029] When the vehicle is traveling on a soft road surface, the tracked walking unit needs to be extended out of the wheel well until it contacts the ground. The specific process is as follows: The controller receives the tracked walking unit extension command through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group, and the hydraulic oil is filled through the oil port (301) on the limit lock (3), which retracts the lock hook (302) of the limit lock into the limit lock, and the limit lock is in the open state. Then, the main oil chamber is filled with oil through the oil port (201) of the main oil chamber of the air spring (2), which drives the pull arm (9) and the balance elbow assembly (6) to rotate around the center line of the balance elbow spline shaft (601), and lowers the tracked walking unit (5) to contact the ground, completing the tracked walking unit extension process.

[0030] The main oil chamber of the gas spring (2) is equipped with a double overflow valve group. By setting two different overflow pressures, it can be ensured that the extension length of the tracked walking unit can meet the requirements of the vehicle bottom height under both no-load and full-load conditions, thereby ensuring the normal posture of the vehicle body. The annular cavity of the gas spring (2) is equipped with a sliding valve lifting wheel valve group. When the hydraulic system fills the main oil chamber of the gas spring (2) and lowers the tracked walking unit, the hydraulic oil in the annular cavity of the gas spring (2) is squeezed out. The squeezed hydraulic oil passes through the sliding valve lifting wheel valve, which can slow down the descent speed of the tracked walking unit and avoid the tracked walking unit from falling too fast and causing an impact with the ground.

[0031] b. Contraction function control

[0032] When the vehicle switches to water mode, in order to reduce water resistance, the tracked walking unit (5) needs to be retracted into the track wheel bay. The specific process is as follows: The controller receives the tracked walking unit retraction command through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group, and the hydraulic oil is filled through the oil port (301) on the limit lock (3), which retracts the lock hook (302) of the limit lock into the limit lock, and the limit lock is opened. Then, the annular cavity is filled with oil through the annular cavity oil port (203) of the oil spring (2), which drives the pull arm (9) and the balance elbow assembly (6) to rotate around the center line of the balance elbow spline shaft (601), and retracts the tracked walking unit (5) into the track wheel bay, completing the tracked walking unit retraction process. At this time, the limit rod (8) on the balance elbow assembly (6) stays at the center position of the lock hook. After the control system is powered off, the limit lock (3) can pop out the lock hook through the internal spring device to realize the mechanical locking function of the lock hook.

[0033] c. Rigid support function

[0034] When the vehicle crosses the trench, in order to ensure the vehicle's passability, the tracked walking unit (5) needs to be lowered to the ground and the hydraulic spring (2) needs to be rigidly locked, so that the tracked walking unit is rigidly supported. The specific operation is as follows: The controller receives the tracked walking unit's external release command through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group of the main oil chamber filling oil circuit of the hydraulic spring (2), and fills the main oil chamber of the hydraulic spring (2) with oil. After the tracked walking unit is lowered to the ground, the controller receives the hydraulic spring (2)'s rigid locking command through the CAN bus and locks it. The solenoid valve of the hydraulic valve group in the oil circuit opens, filling the oil port (202) of the oil-air spring (2) with oil, pushing the self-pressurizing device inside the oil-air spring (2) to isolate the hydraulic oil and high-pressure nitrogen inside the oil-air spring (2). In this state, the oil-air spring (2) is rigid, so the entire track walking unit is also in a rigid state. After the preparation work is completed, the driver drives the vehicle forward until the first axle tire of the vehicle is suspended in the air. Due to the rigid support of the track walking unit lifting system, the vehicle body posture can be kept consistent with the first axle tire when it is on the ground, so that the vehicle can pass through the trench smoothly.

[0035] d. Vibration reduction function

[0036] When the tracked walking unit (5) travels with the vehicle on a soft road surface, it will be impacted by the ground. Through the balance elbow assembly (6) and the pull arm (9), the impact force transmitted from the ground to the tracked walking unit can be transmitted to the oil-gas spring (2). The piston rod of the oil-gas spring (2) is compressed inward, and the hydraulic oil in the main oil chamber flows to the cylinder to push the floating piston to compress the high-pressure nitrogen gas, generating elastic force, buffering and suppressing the impact caused by uneven road surface, and improving the overall comfort of the vehicle.

[0037] Moreover, the damping valve installed inside the cylinder of the gas spring (2) can generate damping force, which can accelerate the attenuation of vibration.

[0038] e. Drive function

[0039] The tracked walking unit is equipped with a pump motor. With the addition of a hydraulic control system, the controller receives the command to drive the tracked walking unit via the CAN bus. The hydraulic system drives the pump motor to realize the forward and backward functions of the tracked walking unit.

[0040] Since the wheels and track travel unit (5) cannot achieve synchronous movement, especially when the wheel speed is greater than the track travel unit speed, the track travel unit will be dragged, that is, the hydraulic system oil supply cannot meet the pump motor demand. In this state, the pump motor will suck in air and dry run, causing damage to the internal structure. In order to avoid this problem, the return oil pipeline from the pump motor return port to the hydraulic oil tank is increased, which can ensure that the pump motor will not suck in air and dry run in this state, and extend the service life of the pump motor.

[0041] (III) Beneficial Effects

[0042] To address the problems of existing technologies, the beneficial effects of this invention are as follows: When the vehicle travels on soft surfaces, extending the tracked running unit to the ground increases the vehicle's ground contact area, reduces ground pressure, and improves the vehicle's passability. The tracked running unit has a separate hydraulic drive unit, which increases the vehicle's driving force on soft surfaces. When the vehicle travels on water, the tracked running unit retracts into the compartment, reducing water resistance and increasing the vehicle's speed on water. The tracked running unit provides rigid support, acting as a rigid support when the vehicle crosses trenches, improving the vehicle's stability during trench crossings.

[0043] Furthermore, the beneficial effects of the present invention are: by adopting the structure of the gas spring (2), the balance elbow assembly (6), and the rocker arm (9), under the same lifting height of the tracked walking unit (5), compared with the vertical lifting method described in patent CN203372314U, the height of the wheel well of the tracked walking unit is greatly reduced, the lateral space in the vehicle compartment is increased, and the overall layout of the vehicle is more conducive to the overall arrangement of the vehicle.

[0044] Furthermore, the beneficial effects of the present invention are as follows: a slide valve lifting wheel valve group is added to the oil circuit of the annular cavity of the oil spring (2). When the main oil chamber of the oil spring (2) is filled with oil and the track walking unit (5) is lowered, the hydraulic oil in the annular cavity is squeezed out and flows through the slide valve lifting wheel valve group, which can ensure that the track walking unit descends smoothly and will not cause the track walking unit to fall rapidly and hit the ground, thus protecting the track walking unit and its associated pump motor and other components.

[0045] Furthermore, the beneficial effects of the present invention are: a double overflow valve group is provided on the oil circuit of the main oil chamber of the gas spring (2). By setting two different overflow pressures, the lowering height of the track walking unit can be satisfied under both no-load and full-load conditions of the vehicle, and the height and posture of the vehicle body are not affected.

[0046] Furthermore, the beneficial effects of the present invention are as follows: a pump motor is provided on the tracked walking unit (5), which, driven by the hydraulic system, can independently realize the bidirectional rotation of the tracked walking unit. When the vehicle is traveling on a soft road surface, the tracked walking unit, after being lowered, not only increases the ground contact area of ​​the entire vehicle and reduces the ground contact specific pressure, but also provides additional driving force for the vehicle, improving the vehicle's passability.

[0047] Furthermore, the beneficial effects of the present invention are: by assembling the spline shaft of the balance elbow assembly (6) with the rocker arm (9), the assembly accuracy and product stability can be guaranteed, preventing axial and radial loosening after long-term use, and providing stable and effective support for the tracked walking unit when it is working.

[0048] Furthermore, the beneficial effects of the present invention are as follows: In the structure connecting the balance elbow assembly (6) to the vehicle body, a sealing structure and a needle roller bearing support structure are provided from the outer side to the inner side of the vehicle body. The sealing structure can effectively prevent the influence of external mud and sand impurities when driving on land, and can also prevent seawater from entering the vehicle body and causing corrosion of the components inside the vehicle compartment after entering water. The needle roller bearings on both sides can support the spline shaft, and can also reduce the friction force during rotation when the balance elbow assembly (6) rotates. Attached Figure Description

[0049] Figure 1 General layout of the tracked walking unit lifting system;

[0050] Figure 2 This is a structural diagram of a limit lock;

[0051] Figure 3 This is a structural diagram and installation general drawing of the upper support structure for the gas spring.

[0052] Figure 4 A schematic diagram showing the installation of parts at the upper support of the gas spring;

[0053] Figure 5 Diagram of the balance elbow structure;

[0054] Figure 6 Here is a diagram of the rocker arm structure;

[0055] Figure 7 A schematic diagram showing the position of the locating pin on the balancing elbow spline shaft (601);

[0056] Figure 8 This is a structural diagram of a gas spring;

[0057] Figure 9 This is a schematic diagram showing the installation of the balance elbow assembly, balance elbow sub-seat, and bearing housing.

[0058] Figure 10 A schematic diagram showing the installation of the rocker arm, gas spring, and pin.

[0059] Figure 11 Schematic diagram of the lifting drive control principle for the tracked walking unit;

[0060] Figure 12 Schematic diagram of the drive control principle for the lifting wheel lock of the tracked walking unit;

[0061] Figure 13 This is a schematic diagram of the hydraulic spring interlocking drive control principle for the tracked walking unit;

[0062] Figure 14 A schematic diagram showing the tracked walking unit being lowered to the ground;

[0063] Figure 15 A schematic diagram showing the tracked walking unit retracting into the wheel well.

[0064] Figure 16 A schematic diagram illustrating the rigid support provided by the tracked walking unit to assist the vehicle in crossing a trench.

[0065] In the diagram: 1. Upper support of the gas spring; 2. Gas spring; 3. Limit lock; 4. Tie rod; 5. Track travel unit; 6. Balance elbow assembly; 7. Balance elbow sub-seat; 8. Limit rod; 9. Tie arm; 10. Vehicle body; 11. Reaming hole bolt; 12. Pin; 13. Dust cover; 16. Nut; 17. Right angle pin; 18. Cotter pin; 19. Plug; 20. Dust ring; 21. Bearing housing; 22. Balance elbow sub-seat; 23. Steel ball; 24. Elastic retaining ring; 25. O-ring; 26. Needle roller bearing; 27. Limit ring.

[0066] 101: Locking hole of upper support for gas spring; 102: Through hole of pin of upper support for gas spring; 103: Blind hole of pin of upper support for gas spring; 104: Reaming hole of upper support for gas spring; 105: Threaded hole of upper support for gas spring; 201: Oil port of main oil chamber; 202: Locking oil port; 203: Oil port of annular cavity; 204: Connecting body; 205: Cylinder; 206: Main piston rod; 207: Oil cylinder; 208: Bearing hole of connecting body; 209: Bearing hole; 601: Splined shaft of balance elbow; 602: Elbow body of balance elbow; 603: Plain shaft of balance elbow; 604: Pin; 901: Locking hole; Detailed Implementation

[0067] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0068] To solve the above technical problems, the present invention provides a tracked walking unit lifting system for an amphibious vehicle. The system includes: an upper support for a gas spring (1), a double-cylinder gas spring (2), a limit lock (3), a pull rod (4), a tracked walking unit (5), a balance elbow assembly (6), a balance elbow sub-seat (7), a limit rod (8), a rocker arm (9), and a vehicle body (10).

[0069] The double-cylinder hydropneumatic spring (2) includes: a connecting body (204), a hydraulic cylinder (207), a pneumatic cylinder (205), and a main piston rod (206); and is provided with a main oil chamber port (201), an annular chamber port (203), and a locking port (202) for the hydropneumatic spring (2); the ports on the hydropneumatic spring (2) are connected to the corresponding functional valve group ports through pipelines, and under the control of the hydraulic control system, the extension and retraction of the track walking unit and the rigid locking function of the hydropneumatic spring (2) are realized.

[0070] The splined shaft of the balance elbow assembly (6) passes through the outside of the vehicle body (10) into the balance elbow sub-seat (7) and the inner splined hole of the rocker arm (9), and aligns the pin (604) installed on the balance elbow splined shaft (601) with the missing tooth of the inner spline of the rocker arm (9), thereby fixing the angle between the balance elbow body and the rocker arm (9); finally, adjust the position of the balance elbow assembly (6) and fix the balance elbow assembly (6) on the balance elbow sub-seat (7) with bolts; the balance elbow optical shaft (603) and the track walking unit mounting through hole are connected to the metal The bushing is hinged to realize the rotation and support of the tracked walking unit; the mounting holes at both ends of the tie rod (4) are fitted with metal bushings and are respectively hinged to the shafts welded on the vehicle body and the tracked walking unit, so that the four hinge points of the balance elbow assembly (6) and the tie rod (4) with the vehicle body (10) and the tracked walking unit assembly (5) form a parallelogram structure, wherein the balance elbow body (602) and the tie rod (4) are parallel sides, ensuring that the tracked walking unit maintains a horizontal state during the rising and falling process;

[0071] The balance elbow assembly (6) has a pin hole machined on its spline shaft. The center line of the pin hole is located at the center line of the bottom of the outer involute spline tooth groove and the center line is located on the center surface of the balance elbow body. A positioning pin is installed at the pin hole.

[0072] The nut (16) passes through the through hole on the vehicle body and connects to the threaded hole (105) of the upper support of the gas spring. The reamed bolt (11) is connected to the reamed hole (104) of the upper support of the gas spring to ensure the installation position and angle of the upper support of the gas spring on the vehicle body. The pin (12) passes through the through hole (102) of the gas spring and the bearing hole (208) of the gas spring connector and then passes into the blind hole (103) of the pin of the upper support of the gas spring. The right-angle pin (17) passes through the locking hole (101) of the upper support of the gas spring. After the round hole at the front end of the right-angle pin (17) passes through the locking hole at the far end of the upper support of the gas spring, the cotter pin (18) passes through the round hole on the right-angle pin (17) to prevent the right-angle pin from falling off.

[0073] The balance elbow seat (7) is fixedly connected to the bottom plate of the vehicle body (10) by welding;

[0074] The pin (12) passes through the round hole on the rocker arm (9) and the bearing hole (209) of the lower hinge of the double-cylinder oil spring in sequence until the pin (12) is completely pressed on the rocker arm (9). Then the right-angle pin (17) passes through the two locking holes (901) of the rocker arm. After the round hole at the front end of the right-angle pin (17) passes through the locking hole at the far end of the rocker arm, the cotter pin (18) passes through the round hole on the right-angle pin (17) to prevent the right-angle pin from falling off.

[0075] The limit lock (3) has an oil port (14). By injecting oil into the oil port through the hydraulic control system, the lock hook (15) can be retracted into the limit lock. When the oil injection into the oil port (14) is stopped, the rebound device inside the limit lock can pop out the lock hook (15) and restore it to the locked state.

[0076] The tracked walking unit (5) is placed on the ground under the action of the hydraulic control system. The pump motor on the tracked walking unit (5) is driven by the hydraulic system to realize the walking function of the tracked walking unit (5) in the forward and backward directions.

[0077] The limiting rod (8) is riveted to the balance elbow. After the track walking unit is retracted into the wheel well, the limiting rod is locked in the locking hook to form a mechanical protection device to prevent the track walking unit from falling due to internal leakage of the hydraulic system.

[0078] The rocker arm (9) needs to have its splines milled off at specific locations so that it can be positioned and installed when assembled with the balance elbow assembly.

[0079] In the case of soft road surface, hydraulic oil is filled into the main oil chamber of the oil-air spring (2) through the hydraulic control system. The piston rod of the oil-air spring (2) extends and drives the pull arm and balance elbow to rotate, so that the track walking unit is extended outside the wheel chamber until it contacts the ground. Under this condition, the track walking unit can bear part of the load of the whole vehicle, increase the contact area between the whole vehicle and the ground, reduce the ground pressure of the whole vehicle, and improve the passability of the vehicle on soft road surface. In the case of water, the oil-air spring (2) is controlled to retract through the hydraulic control system, so that the track walking unit is completely retracted into the vehicle body, reducing the water resistance during the whole vehicle's driving process and increasing the vehicle speed in the case of water.

[0080] The limiting rod (8) is riveted to the balance elbow body. By operating the lifting wheel key on the control panel, the hydraulic system can fill the annular cavity of the gas spring (2) with oil, driving the pull arm (9) and the balance elbow assembly (6) to rotate around the central axis of the balance elbow spline, thus retracting the track walking unit (5) into the wheel well; at the same time, the hydraulic system fills the oil port (301) on the limiting lock (3) with oil, retracting the locking hook (302) of the limiting lock into the limiting lock, at which time the limiting lock is in the unlocked state; when the gas spring (2) is retracted to its shortest position... After positioning, the limit rod (8) is located at the center of the limit lock hook. After releasing the lifting wheel key, the hydraulic system stops filling the annular cavity of the gas spring (2) and the limit lock with oil. The annular cavity of the gas spring (2) forms a high-pressure cavity, which prevents the piston rod of the gas spring (2) from extending, ensuring that the tracked walking unit remains in the retracted wheel chamber state. At the same time, the rebound device set inside the limit lock can eject the lock hook and lock the limit rod inside the lock hook, forming a mechanical protection device to prevent the tracked walking unit from falling due to internal leakage of the hydraulic system.

[0081] The cylinder of the gas spring (2) is filled with high-pressure nitrogen. When the vehicle is driving normally, the tracked walking unit transmits the ground excitation to the gas spring (2) through the balance elbow assembly (6) and rocker arm (9). The piston rod compresses the high-pressure nitrogen to alleviate the ground impact. At this time, the tracked walking unit lifting system can be regarded as an elastic lifting system.

[0082] Driven by the hydraulic system, the oil spring (2) can retract and extend the track walking unit through the rocker arm (9) and the balance elbow assembly (6); its oil filling circuit is equipped with a double overflow valve group, with two different overflow pressures, which can ensure that the extension length of the track walking unit can meet the ground clearance requirements of the vehicle under both unloaded and fully loaded conditions, thereby ensuring the normal posture of the vehicle body.

[0083] The gas spring (2) has a self-pressurizing locking device. Its locking oil circuit valve group consists of two normally closed solenoid valves and one check valve. Before the vehicle crosses the trench, after the track wheel travel unit is placed on the ground, press and hold the locking button on the control panel of the gas spring (2) for more than 10 seconds. The hydraulic oil enters the locking oil port of the gas spring (2) through the locking oil circuit, pushing the internal piston to move and realizing the separation of the hydraulic oil and high-pressure nitrogen inside the gas spring (2). In this state, the gas spring (2) is in a rigid state. When the vehicle travels to the point where the front axle tires are above the trench, the front axle tires are off the ground. At this time, the track travel unit provides rigid support to ensure that the vehicle passes through the trench smoothly in a stable posture.

[0084] The slide valve lifting wheel valve group, which is formed by two one-way valves interconnected and then connected in series with a three-position four-way valve, is set in the oil filling circuit of the annular cavity of the gas spring (2). When the hydraulic system is controlled by the operation panel to fill the main oil cavity of the gas spring (2) and release the track walking unit, all the solenoid valves of the return oil circuit valve group of the annular cavity of the gas spring (2) are opened. The hydraulic oil in the annular cavity flows through the slide valve lifting wheel valve group, which slows down the descent speed of the track walking unit and avoids the track walking unit from falling too fast and causing an impact with the ground.

[0085] The balance elbow assembly (6) extends into the vehicle body through the wheel well. The splined shaft of the balance elbow assembly (6) is provided with a sealing groove. The sealing groove is equipped with a sealing element, which forms a rotary sealing fit with the bearing seat and the inner surface of the through hole of the balance elbow support. Needle roller bearings are installed on both sides of the splined shaft to provide rotational support between the splined shaft and the balance elbow support.

[0086] The outer end of the balance elbow assembly (6) is an optical shaft, and a metal bushing is installed in the through hole of the track walking unit (5). The optical shaft (603) of the balance elbow is fitted with the metal bushing in the through hole of the track walking unit with clearance, so as to realize the hinged assembly of the output end of the balance elbow assembly (6) and the track walking unit. The through holes at both ends of the tie rod (4) are fitted with metal bushings. The through holes and the metal bushings are interference fit. The metal bushings are fitted with the shafts welded on the vehicle body and the track walking unit with clearance to form a hinged pair.

[0087] Under the action of the hydraulic control system, the hydraulic system's functional valve group charges and releases oil to different oil ports of the oil spring, which can realize the functions of slowly lowering, retracting, and rigidly locking the tracked travel unit, thus meeting the vehicle's usage requirements for the tracked travel unit under different operating conditions.

[0088] The present invention also provides a method of using the tracked walking unit lifting system:

[0089] a. Extension control function

[0090] When the vehicle is traveling on a soft road surface, the tracked walking unit needs to be extended out of the wheel well until it contacts the ground. The specific process is as follows: The controller receives the tracked walking unit extension command through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group, and the hydraulic oil is filled through the oil port (301) on the limit lock (3), which retracts the lock hook (302) of the limit lock into the limit lock, and the limit lock is in the open state. Then, the main oil chamber is filled with oil through the oil port (201) of the main oil chamber of the air spring (2), which drives the pull arm (9) and the balance elbow assembly (6) to rotate around the center line of the balance elbow spline shaft (601), and lowers the tracked walking unit (5) to contact the ground, completing the tracked walking unit extension process.

[0091] The main oil chamber of the gas spring (2) is equipped with a double overflow valve group. By setting two different overflow pressures, it can be ensured that the extension length of the tracked walking unit can meet the requirements of the vehicle bottom height under both no-load and full-load conditions, thereby ensuring the normal posture of the vehicle body. The annular cavity of the gas spring (2) is equipped with a sliding valve lifting wheel valve group. When the hydraulic system fills the main oil chamber of the gas spring (2) and lowers the tracked walking unit, the hydraulic oil in the annular cavity of the gas spring (2) is squeezed out. The squeezed hydraulic oil passes through the sliding valve lifting wheel valve, which can slow down the descent speed of the tracked walking unit and avoid the tracked walking unit from falling too fast and causing an impact with the ground.

[0092] b. Contraction function control

[0093] When the vehicle switches to water mode, in order to reduce water resistance, the tracked walking unit (5) needs to be retracted into the track wheel bay. The specific process is as follows: The controller receives the tracked walking unit retraction command through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group, and the hydraulic oil is filled through the oil port (301) on the limit lock (3), which retracts the lock hook (302) into the limit lock and opens the limit lock. Then, the annular cavity is filled with oil through the annular cavity oil port (203) of the oil spring (2), which drives the pull arm (9) and the balance elbow assembly (6) to rotate around the center line of the balance elbow spline shaft (601), retracting the tracked walking unit (5) into the track wheel bay and completing the tracked walking unit retraction process. At this time, the limit rod (8) on the balance elbow assembly (6) stays at the center position of the lock hook. After the control system is powered off, the limit lock (3) can pop out the lock hook through the internal spring device to realize the mechanical locking function of the lock hook.

[0094] c. Rigid support function

[0095] When the vehicle crosses the trench, in order to ensure the vehicle's passability, the tracked walking unit (5) needs to be lowered to the ground and the hydraulic spring (2) needs to be rigidly locked, so that the tracked walking unit is rigidly supported. The specific operation is as follows: The controller receives the tracked walking unit's external release command through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group of the main oil chamber filling oil circuit of the hydraulic spring (2), and fills the main oil chamber of the hydraulic spring (2) with oil. After the tracked walking unit is lowered to the ground, the controller receives the hydraulic spring (2)'s rigid locking command through the CAN bus and locks it. The solenoid valve of the hydraulic valve group in the oil circuit opens, filling the oil port (202) of the oil-air spring (2) with oil, pushing the self-pressurizing device inside the oil-air spring (2) to isolate the hydraulic oil and high-pressure nitrogen inside the oil-air spring (2). In this state, the oil-air spring (2) is rigid, so the entire track walking unit is also in a rigid state. After the preparation work is completed, the driver drives the vehicle forward until the first axle tire of the vehicle is suspended in the air. Due to the rigid support of the track walking unit lifting system, the vehicle body posture can be kept consistent with the first axle tire when it is on the ground, so that the vehicle can pass through the trench smoothly.

[0096] d. Vibration reduction function

[0097] When the tracked walking unit (5) travels with the vehicle on a soft road surface, it will be impacted by the ground. Through the balance elbow assembly (6) and the pull arm (9), the impact force transmitted from the ground to the tracked walking unit can be transmitted to the oil-gas spring (2). The piston rod of the oil-gas spring (2) is compressed inward, and the hydraulic oil in the main oil chamber flows to the cylinder to push the floating piston to compress the high-pressure nitrogen gas, generating elastic force, buffering and suppressing the impact caused by uneven road surface, and improving the overall comfort of the vehicle.

[0098] Moreover, the damping valve installed inside the cylinder of the gas spring (2) can generate damping force, which can accelerate the attenuation of vibration.

[0099] e. Drive function

[0100] The tracked walking unit is equipped with a pump motor. With the addition of a hydraulic control system, the controller receives the command to drive the tracked walking unit via the CAN bus. The hydraulic system drives the pump motor to realize the forward and backward functions of the tracked walking unit.

[0101] Since the wheels and track travel unit (5) cannot achieve synchronous movement, especially when the wheel speed is greater than the track travel unit speed, the track travel unit will be dragged, that is, the hydraulic system oil supply cannot meet the pump motor demand. In this state, the pump motor will suck in air and dry run, causing damage to the internal structure. In order to avoid this problem, the return oil pipeline from the pump motor return port to the hydraulic oil tank is increased, which can ensure that the pump motor will not suck in air and dry run in this state, and extend the service life of the pump motor.

[0102] Example 1

[0103] This embodiment is a lifting system and usage method for a tracked walking unit of an amphibious vehicle, including an upper support for a gas spring (1), a gas spring (2), a limit lock (3), a pull rod (4), a tracked walking unit (5), a balance elbow assembly (6), a balance elbow sub-seat (7), a limit rod (8), a rocker arm (9), a vehicle body (10), a sliding valve lifting wheel valve group (28), a locking control valve group (29), and a double overflow valve group (30), etc.

[0104] The hydropneumatic spring (2) mainly includes a connecting body (204), a hydraulic cylinder (207), a pneumatic cylinder (205), and a main piston rod (206), and is equipped with a main oil chamber port (201), an annular chamber port (203), and a locking port (202). The ports on the hydropneumatic spring (2) are connected to the corresponding functional valve group ports through pipelines. Under the control of the hydraulic control system, the functions of extending and retracting the track walking unit and rigidly locking the hydropneumatic spring (2) are realized.

[0105] The splined shaft of the balance elbow assembly (6) passes through the outside of the vehicle body (10) into the splined hole of the balance elbow sub-seat (7) and the rocker arm (9), and aligns the pin (604) installed on the balance elbow splined shaft (601) with the missing tooth of the spline in the rocker arm (9), thus fixing the angle between the balance elbow body and the rocker arm (9). Finally, the position of the balance elbow assembly (6) is adjusted, and the balance elbow assembly (6) is fixed on the balance elbow sub-seat (7) with bolts. The balance elbow optical shaft (603) is hinged to the metal bushing of the through hole of the track walking unit, which can realize the rotation and support of the track walking unit. The mounting holes at both ends of the tie rod (4) are fitted with metal bushings, which are hinged to the shafts welded on the vehicle body and the track walking unit, respectively, forming a parallelogram structure with the balance elbow body (602) and the tie rod (4) as parallel sides, ensuring that the track walking unit can maintain a horizontal state during the rising and falling process.

[0106] The following explains the specific usage of the tracked walking unit lifting system:

[0107] a. Extension control function

[0108] When the vehicle is traveling on a soft road surface, the tracked walking unit needs to be extended out of the wheel well until it contacts the ground. The specific process is as follows: The controller receives the tracked walking unit extension command through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group, and the hydraulic oil is filled through the oil port (301) on the limit lock (3), which retracts the lock hook (302) of the limit lock into the limit lock, and the limit lock is in the open state; then the main oil chamber is filled with oil through the oil port (201) of the main oil chamber of the air spring (2), which drives the pull arm (9) and the balance elbow assembly (6) to rotate around the center line of the balance elbow spline shaft (601), and lowers the tracked walking unit (5) to contact the ground, completing the tracked walking unit extension process.

[0109] A double overflow valve assembly is installed in the main oil chamber of the gas spring (2). By setting two different overflow pressures, it can be ensured that the extension length of the tracked walking unit can meet the requirements of the vehicle bottom height under both unloaded and fully loaded load conditions, thereby ensuring the normal posture of the vehicle body. A slide valve lifting wheel valve assembly is installed in the annular cavity oil circuit of the gas spring (2). When the hydraulic system fills the main oil chamber of the gas spring (2) and lowers the tracked walking unit, the hydraulic oil in the annular cavity of the gas spring (2) is squeezed out. The squeezed hydraulic oil passes through the slide valve lifting wheel valve, which can slow down the descent speed of the tracked walking unit and avoid the tracked walking unit from falling too fast and causing an impact with the ground.

[0110] b. Contraction function control

[0111] When the vehicle switches to water mode, in order to reduce water resistance, the tracked walking unit (5) needs to be retracted into the track wheel bay. The specific process is as follows: The controller receives the tracked walking unit retraction command through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group, and the hydraulic oil is filled through the oil port (301) on the limit lock (3), which retracts the lock hook (302) into the limit lock, and the limit lock is opened; then, the annular cavity is filled with oil through the annular cavity oil port (203) of the oil spring (2), which drives the pull arm (9) and the balance elbow assembly (6) to rotate around the center line of the balance elbow spline shaft (601), and retracts the tracked walking unit (5) into the track wheel bay, completing the tracked walking unit retraction process. At this time, the limit rod (8) on the balance elbow assembly (6) stays at the center position of the lock hook. After the control system is powered off, the limit lock (3) can pop out the lock hook through the internal spring mechanism to realize the mechanical locking function of the lock hook.

[0112] c. Rigid support function

[0113] When the vehicle crosses the trench, in order to ensure the vehicle's passability, the tracked walking unit (5) needs to be lowered to the ground and the gas spring (2) needs to be rigidly locked, so that the tracked walking unit is rigidly supported. The specific operation is as follows: The controller receives the external command of the tracked walking unit through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group of the main oil chamber of the gas spring (2) to fill the main oil chamber of the gas spring (2). When the tracked walking unit is lowered to the ground, the controller receives the rigid locking command of the gas spring (2) through the CAN bus, the solenoid valve of the locking oil circuit hydraulic valve group opens, fills the locking oil port (202) of the gas spring (2) with oil, and pushes the internal self-pressurization device of the gas spring (2) to isolate the hydraulic oil and high-pressure nitrogen inside the gas spring (2). In this state, the gas spring (2) is rigid, so the entire tracked walking unit is also in a rigid state. After the preparations are completed, the driver drives the vehicle forward until the first axle tire is suspended in the air. Due to the rigid support of the track walking unit lifting system, the vehicle body posture can be kept consistent with the first axle tire when it is on the ground, so that the vehicle can pass through the trench smoothly.

[0114] d. Vibration reduction function

[0115] When the tracked walking unit (5) travels with the vehicle on a soft road surface, it will be impacted by the ground. Through the balance elbow assembly (6) and the pull arm (9), the impact force transmitted from the ground to the tracked walking unit can be transmitted to the oil-gas spring (2). The piston rod of the oil-gas spring (2) is compressed inward, and the hydraulic oil in the main oil chamber flows to the cylinder to push the floating piston to compress the high-pressure nitrogen gas, generating elastic force, buffering and suppressing the impact caused by uneven road surface, and improving the overall comfort of the vehicle.

[0116] Moreover, the damping valve installed inside the cylinder of the gas spring (2) can generate damping force, which can accelerate the attenuation of vibration.

[0117] e. Drive function

[0118] The tracked walking unit is equipped with a pump motor. With the addition of a hydraulic control system, the controller receives the command to drive the tracked walking unit via the CAN bus. The hydraulic system drives the pump motor to realize the forward and backward functions of the tracked walking unit.

[0119] Since the wheels and track travel unit (5) cannot achieve synchronous movement, especially when the wheel speed is greater than the track travel unit speed, the track travel unit will be dragged, that is, the hydraulic system oil supply cannot meet the pump motor demand. In this state, the pump motor will suck in air and dry run, causing damage to the internal structure. In order to avoid this problem, the return oil pipeline from the pump motor return port to the hydraulic oil tank is increased, which can ensure that the pump motor will not suck in air and dry run in this state, and extend the service life of the pump motor.

[0120] The beneficial effects of this invention are as follows: When the vehicle travels on soft ground, extending the tracked running unit to the ground increases the vehicle's ground contact area, reduces ground pressure, and improves the vehicle's passability. The tracked running unit has a separate hydraulic drive unit, which increases the vehicle's driving force on soft ground. When the vehicle travels on water, the tracked running unit retracts into the compartment, reducing water resistance and increasing the vehicle's speed on water. The tracked running unit provides rigid support, acting as a rigid support when the vehicle crosses trenches, thus improving the vehicle's stability when crossing trenches.

[0121] Furthermore, the beneficial effects of the present invention are: by adopting the structure of the gas spring (2), the balance elbow assembly (6), and the rocker arm (9), under the same lifting height of the tracked walking unit (5), compared with the vertical lifting method described in patent CN203372314U, the height of the wheel well of the tracked walking unit is greatly reduced, the lateral space in the vehicle compartment is increased, and the overall layout of the vehicle is more conducive to the overall arrangement of the vehicle.

[0122] Furthermore, the beneficial effects of the present invention are as follows: a slide valve lifting wheel valve group is added to the oil circuit of the annular cavity of the oil spring (2). When the main oil chamber of the oil spring (2) is filled with oil and the track walking unit (5) is lowered, the hydraulic oil in the annular cavity is squeezed out and flows through the slide valve lifting wheel valve group, which can ensure that the track walking unit descends smoothly and will not cause the track walking unit to fall rapidly and hit the ground, thus protecting the track walking unit and its associated pump motor and other components.

[0123] Furthermore, the beneficial effects of the present invention are: a double overflow valve group is provided on the oil circuit of the main oil chamber of the gas spring (2). By setting two different overflow pressures, the lowering height of the track walking unit can be satisfied under both no-load and full-load conditions of the vehicle, and the height and posture of the vehicle body are not affected.

[0124] Furthermore, the beneficial effects of the present invention are as follows: a pump motor is provided on the tracked walking unit (5), which, driven by the hydraulic system, can independently realize the bidirectional rotation of the tracked walking unit. When the vehicle is traveling on a soft road surface, the tracked walking unit, after being lowered, not only increases the ground contact area of ​​the entire vehicle and reduces the ground contact specific pressure, but also provides additional driving force for the vehicle, improving the vehicle's passability.

[0125] Furthermore, the beneficial effects of the present invention are: by assembling the spline shaft of the balance elbow assembly (6) with the rocker arm (9), the assembly accuracy and product stability can be guaranteed, preventing axial and radial loosening after long-term use, and providing stable and effective support for the tracked walking unit when it is working.

[0126] Furthermore, the beneficial effects of the present invention are as follows: In the structure connecting the balance elbow assembly (6) to the vehicle body, a sealing structure and a needle roller bearing support structure are provided from the outer side to the inner side of the vehicle body. The sealing structure can effectively prevent the influence of external mud and sand impurities when driving on land, and can also prevent seawater from entering the vehicle body and causing corrosion of the components inside the vehicle compartment after entering water. The needle roller bearings on both sides can support the spline shaft, and can also reduce the friction force during rotation when the balance elbow assembly (6) rotates.

[0127] In summary, this invention proposes a tracked running unit lifting system and its usage method for amphibious vehicles. When the vehicle is traveling on soft ground, the hydraulic control system fills the main oil chamber of the gas spring with oil, pushing the rocker arm and causing the balance elbow to swing until the tracked running unit contacts the ground. Under these conditions, the tracked running unit can bear part of the vehicle's load, increasing the contact area between the vehicle and the ground, reducing the ground pressure of the entire vehicle, and improving the vehicle's passability on soft ground. When the vehicle is traveling on water, the hydraulic control system fills the annular cavity of the gas spring with oil, causing the piston rod to contract and drive the rocker arm and balance elbow to swing, ultimately lifting the tracked running unit into the wheel well, thereby reducing the resistance brought by the tracked running unit and increasing the vehicle's speed on water. When the vehicle crosses a trench, the tracked running unit provides rigid support by rigidly locking the gas spring, improving the stability of the vehicle when crossing the trench. Meanwhile, a pump motor is installed on the tracked traveling unit, which can be driven by a hydraulic system to rotate the tracked traveling unit, adding extra power to the vehicle and improving its passability on soft terrain. A twin-tube gas spring is used as the actuator to meet the vehicle's vibration damping requirements.

[0128] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A tracked walking unit lifting system for an amphibious vehicle, characterized in that, The system includes: upper support of the gas spring (1), double-cylinder gas spring (2), limit lock (3), pull rod (4), track walking unit (5), balance elbow assembly (6), balance elbow sub-seat (7), limit rod (8), rocker arm (9), and vehicle body (10). The double-cylinder hydropneumatic spring (2) includes: a connecting body (204), a hydraulic cylinder (207), a pneumatic cylinder (205), and a main piston rod (206); and is provided with a main oil chamber port (201), an annular chamber port (203), and a locking port (202); the ports on the hydropneumatic spring (2) are connected to the corresponding functional valve group ports through pipelines, and under the control of the hydraulic control system, the extension and retraction of the track walking unit and the rigid locking function of the hydropneumatic spring (2) are realized. The splined shaft of the balance elbow assembly (6) passes through the outside of the vehicle body (10) into the balance elbow sub-seat (7) and the inner splined hole of the rocker arm (9), and aligns the pin (604) installed on the balance elbow splined shaft (601) with the missing tooth of the inner spline of the rocker arm (9), thereby fixing the angle between the balance elbow body and the rocker arm (9); finally, adjust the position of the balance elbow assembly (6) and fix the balance elbow assembly (6) on the balance elbow sub-seat (7) with bolts; the balance elbow optical shaft (603) and the track walking unit mounting through hole are connected by a metal... The bushing is hinged to realize the rotation and support of the tracked walking unit; the mounting holes at both ends of the tie rod (4) are fitted with metal bushings and are respectively hinged to the shafts welded on the vehicle body and the tracked walking unit, so that the four hinge points of the balance elbow assembly (6) and the tie rod (4) with the vehicle body (10) and the tracked walking unit assembly (5) form a parallelogram structure, wherein the balance elbow body (602) and the tie rod (4) are parallel sides, ensuring that the tracked walking unit maintains a horizontal state during the rising and falling process; Among them, the spline shaft of the balance elbow assembly (6) is machined with a pin hole, the center line of the pin hole is located at the center line of the bottom of the outer involute spline tooth groove and the center line is located on the center surface of the balance elbow body, and a positioning pin is installed at the pin hole. Among them, the nut (16) passes through the through hole on the vehicle body and connects to the threaded hole (105) of the upper support of the gas spring, and the reamed hole bolt (11) connects to the reamed hole (104) of the upper support of the gas spring to ensure the installation position and installation angle of the upper support of the gas spring on the vehicle body; the pin (12) passes through the through hole (102) of the gas spring and the bearing hole (208) of the gas spring connector and then passes into the blind hole (103) of the pin of the upper support of the gas spring, and then the right angle pin (17) passes through the locking hole (101) of the upper support of the gas spring. After the round hole at the front end of the right angle pin (17) passes through the locking hole at the far end of the upper support of the gas spring, the cotter pin (18) passes through the round hole on the right angle pin (17) to prevent the right angle pin from falling off. The balance elbow sub-seat (7) is fixedly connected to the bottom plate of the vehicle body (10) by welding; The pin (12) passes through the round hole on the rocker arm (9) and the bearing hole (209) of the lower hinge of the double-cylinder oil spring in sequence until the pin (12) is completely pressed on the rocker arm (9). Then the right-angle pin (17) passes through the two locking holes (901) of the rocker arm. After the round hole at the front end of the right-angle pin (17) passes through the locking hole at the far end of the rocker arm, the cotter pin (18) passes through the round hole on the right-angle pin (17) to prevent the right-angle pin from falling off.

2. The tracked walking unit lifting system for an amphibious vehicle as described in claim 1, characterized in that, The limit lock (3) has an oil port (14). Oil is injected into the oil port through the hydraulic control system, and the lock hook (15) is retracted into the limit lock. When the oil injection into the oil port (14) is stopped, the spring-back device inside the limit lock pops the lock hook (15) out and restores it to the locked state.

3. The tracked walking unit lifting system for an amphibious vehicle as described in claim 2, characterized in that, The tracked walking unit (5) is placed on the ground under the action of the hydraulic control system. The pump motor on the tracked walking unit (5) is driven by the hydraulic system to realize the forward and backward walking function of the tracked walking unit (5).

4. The tracked walking unit lifting system for an amphibious vehicle as described in claim 3, characterized in that, The limiting rod (8) is riveted to the balance elbow. After the track walking unit is retracted into the wheel well, the limiting rod is locked in the locking hook to form a mechanical protection device to prevent the track walking unit from falling due to internal leakage of the hydraulic system.

5. The tracked walking unit lifting system for an amphibious vehicle as described in claim 4, characterized in that, The rocker arm (9) needs to have its splines milled off at specific locations for positioning and installation when assembled with the balance elbow assembly.

6. The tracked walking unit lifting system for an amphibious vehicle as described in claim 5, characterized in that, Under soft road conditions, hydraulic oil is filled into the main oil chamber of the gas spring (2) through the hydraulic control system. The piston rod of the gas spring (2) extends and drives the pull arm and balance elbow to rotate, so that the track walking unit is extended outside the wheel well until it contacts the ground. Under this condition, the track walking unit bears part of the load of the whole vehicle, increases the contact area between the whole vehicle and the ground, reduces the ground pressure of the whole vehicle, and improves the passability of the vehicle on soft roads. Under water conditions, the gas spring (2) is controlled to retract through the hydraulic control system, so that the track walking unit is completely retracted into the vehicle body, reducing the water resistance during the whole vehicle's driving process and increasing the vehicle speed under water conditions. The limiting rod (8) is riveted to the balance elbow body. By operating the lifting wheel key on the control panel, the hydraulic system fills the annular cavity of the gas spring (2) with oil, driving the rocker arm (9) and the balance elbow assembly (6) to rotate around the central axis of the balance elbow spline, thus retracting the track walking unit (5) into the wheel well. At the same time, the hydraulic system fills the oil port (301) on the limiting lock (3) with oil, retracting the locking hook (302) of the limiting lock into the limiting lock. At this time, the limiting lock is in the unlocked state. When the gas spring (2) is retracted to its shortest position... After positioning, the limit rod (8) is located at the center of the limit lock hook. After releasing the lifting wheel key, the hydraulic system stops filling the annular cavity of the gas spring (2) and the limit lock with oil. The annular cavity of the gas spring (2) forms a high-pressure cavity, which prevents the piston rod of the gas spring (2) from extending, ensuring that the tracked walking unit remains in the retracted wheel chamber state. At the same time, the rebound device set inside the limit lock will pop out the lock hook and lock the limit rod inside the lock hook, forming a mechanical protection device to prevent the tracked walking unit from falling due to internal leakage of the hydraulic system. The cylinder of the gas spring (2) is filled with high-pressure nitrogen. When the vehicle is driving normally, the tracked walking unit transmits the ground excitation to the gas spring (2) through the balance elbow assembly (6) and rocker arm (9). The piston rod compresses the high-pressure nitrogen to alleviate the ground impact. At this time, the tracked walking unit lifting system is regarded as an elastic lifting system. Driven by the hydraulic system, the oil spring (2) realizes the retraction and extension of the track walking unit through the rocker arm (9) and the balance elbow assembly (6); its oil filling circuit is equipped with a double overflow valve group, with two different overflow pressures, to ensure that the extension length of the track walking unit can meet the ground clearance requirements of the vehicle under both unloaded and fully loaded conditions, thereby ensuring the normal posture of the vehicle body. The gas spring (2) has a self-pressurizing locking device. Its locking oil circuit valve group consists of two normally closed solenoid valves and one check valve. Before the vehicle crosses the trench, after the track wheel travel unit is placed on the ground, press and hold the locking button on the control panel of the gas spring (2) for more than 10 seconds. The hydraulic oil enters the locking port of the gas spring (2) through the locking oil circuit, pushing the internal piston to move and realizing the separation of the hydraulic oil and high-pressure nitrogen inside the gas spring (2). In this state, the gas spring (2) is in a rigid state. When the vehicle travels to the point where the front axle tires are above the trench, the front axle tires are off the ground. At this time, the track travel unit provides rigid support to ensure that the vehicle passes through the trench smoothly in a stable posture. The slide valve lifting wheel valve group, which is formed by two one-way valves interconnected and then connected in series with a three-position four-way valve, is set in the oil filling circuit of the annular cavity of the gas spring (2). When the hydraulic system is controlled by the operation panel to fill the main oil cavity of the gas spring (2) and release the track walking unit, all the solenoid valves of the return oil circuit valve group of the annular cavity of the gas spring (2) are opened. The hydraulic oil in the annular cavity flows through the slide valve lifting wheel valve group, which slows down the descent speed of the track walking unit and avoids the track walking unit from falling too fast and causing an impact with the ground. The balance elbow assembly (6) passes through the wheel well into the vehicle body. The splined shaft of the balance elbow assembly (6) is provided with a sealing groove. The sealing groove is equipped with a sealing element, which forms a rotary sealing fit with the bearing seat and the inner surface of the through hole of the balance elbow support. Needle roller bearings are installed on both sides of the splined shaft to provide rotational support between the splined shaft and the balance elbow support. The outer end of the balance elbow assembly (6) is an optical shaft, and the through hole of the track walking unit (5) is fitted with a metal bushing. The optical shaft (603) of the balance elbow is fitted with the metal bushing of the through hole of the track walking unit with clearance, so as to realize the hinged assembly of the output end of the balance elbow assembly (6) and the track walking unit. The through holes at both ends of the tie rod (4) are fitted with metal bushings. The through holes and the metal bushings are interference fit. The metal bushings are fitted with the shafts welded on the vehicle body and the track walking unit with clearance to form a hinged pair.

7. The tracked walking unit lifting system for an amphibious vehicle as described in claim 6, characterized in that, Under the action of the hydraulic control system, oil is supplied and discharged to different oil ports of the oil spring through the hydraulic system functional valve group, so as to realize the functions of slow lowering, retraction and rigid locking of the tracked traveling unit, and meet the usage requirements of the tracked traveling unit of the vehicle under different operating conditions.

8. A method of using the tracked walking unit lifting system for an amphibious vehicle as described in any one of claims 1-7, characterized in that, The method includes: a. Extension control function When the vehicle is traveling on a soft road surface, the tracked walking unit needs to be extended out of the wheel well until it contacts the ground. The specific process is as follows: The controller receives the tracked walking unit extension command through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group, and the hydraulic oil is filled through the oil port (301) on the limit lock (3), which retracts the lock hook (302) of the limit lock into the limit lock, and the limit lock is in the open state. Then, the main oil chamber is filled with oil through the oil port (201) of the main oil chamber of the oil spring (2), which drives the rocker arm (9) and the balance elbow assembly (6) to rotate around the center line of the balance elbow spline shaft (601), and lowers the tracked walking unit (5) to contact the ground, thus completing the tracked walking unit extension process. A double overflow valve group is provided in the main oil chamber of the gas spring (2). By setting two different overflow pressures, the extension length of the tracked walking unit can meet the requirements of the vehicle bottom height under both no-load and full-load conditions, thereby ensuring the normal posture of the vehicle body. A sliding valve lifting wheel valve group is provided in the annular cavity oil circuit of the gas spring (2). When the hydraulic system fills the main oil chamber of the gas spring (2) and lowers the tracked walking unit, the hydraulic oil in the annular cavity of the gas spring (2) is squeezed out. The squeezed hydraulic oil passes through the sliding valve lifting wheel valve to slow down the descent speed of the tracked walking unit and avoid the tracked walking unit from falling too fast and causing an impact with the ground. b. Contraction function control When the vehicle switches to water mode, in order to reduce water resistance, the tracked walking unit (5) needs to be retracted into the track wheel bay. The specific process is as follows: The controller receives the tracked walking unit retraction command through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group, and the hydraulic oil is filled through the oil port (301) on the limit lock (3), which retracts the lock hook (302) of the limit lock into the limit lock, and the limit lock is opened. Then, the annular cavity is filled with oil through the annular cavity oil port (203) of the oil spring (2), which drives the rocker arm (9) and the balance elbow assembly (6) to rotate around the center line of the balance elbow spline shaft (601), and retracts the tracked walking unit (5) into the track wheel bay, completing the tracked walking unit retraction process. At this time, the limit rod (8) on the balance elbow assembly (6) stays at the center position of the lock hook. After the control system is powered off, the limit lock (3) ejects the lock hook through the internal spring device to realize the mechanical locking function of the lock hook. c. Rigid support function When the vehicle crosses the trench, in order to ensure the vehicle's passability, the tracked walking unit (5) needs to be lowered to the ground and the hydraulic spring (2) needs to be rigidly locked, so that the tracked walking unit is rigidly supported; the specific operation is as follows: the controller receives the tracked walking unit's external release command through the CAN bus, controls the opening and closing of the solenoid valve of the hydraulic valve group of the main oil chamber filling oil circuit of the hydraulic spring (2), and fills the main oil chamber of the hydraulic spring (2) with oil. After the tracked walking unit is lowered to the ground, the controller receives the hydraulic spring (2)'s rigid locking command through the CAN bus. The solenoid valve of the hydraulic valve group of the closed oil circuit is opened, and oil is filled into the closed oil port (202) of the oil-air spring (2), which pushes the self-pressurization device inside the oil-air spring (2) to isolate the hydraulic oil and high-pressure nitrogen inside the oil-air spring (2). In this state, the oil-air spring (2) is rigid, so the entire track walking unit is also in a rigid state. After the preparation work is completed, the driver drives the vehicle forward until the first axle tire of the vehicle is suspended. Due to the rigid support of the track walking unit lifting system, the vehicle body posture is consistent with the first axle tire when it touches the ground, so that the vehicle passes through the trench smoothly.

9. The method of using the tracked walking unit lifting system for an amphibious vehicle as described in claim 8, characterized in that, d. Vibration reduction function When the tracked walking unit (5) travels with the vehicle on a soft road surface, it will be impacted by the ground. Through the balance elbow assembly (6) and rocker arm (9), the impact force transmitted from the ground to the tracked walking unit is transmitted to the oil-gas spring (2). The piston rod of the oil-gas spring (2) is compressed inward, and the hydraulic oil in the main oil chamber flows to the cylinder to push the floating piston to compress the high-pressure nitrogen gas, generating elastic force, buffering and suppressing the impact caused by uneven road surface, and improving the overall comfort of the vehicle. Moreover, the damping valve installed inside the cylinder by the gas spring (2) generates damping force, which accelerates the attenuation of vibration.

10. The method of using the tracked walking unit lifting system for an amphibious vehicle as described in claim 9, characterized in that, e. Drive function The tracked walking unit is equipped with a pump motor. With the addition of a hydraulic control system, the controller receives the command to drive the tracked walking unit via the CAN bus. The hydraulic system drives the pump motor to realize the forward and backward functions of the tracked walking unit.

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