A matched balanced oil gas suspension active steering driven rear axle device

Abstract

The application provides a matched balanced oil-gas suspension active steering driven rear axle device, which comprises an active steering hydraulic control subunit and an oil-gas suspension hydraulic control subunit; the active steering hydraulic control subunit comprises a steering gear, an active oil cylinder and a centering oil cylinder, the oil flow direction between the active oil cylinder and the centering oil cylinder is controlled, and the steering gear is used to realize the deflection and straight running of the driven rear axle wheel; the oil-gas suspension hydraulic control subunit comprises two oil-gas springs; the upper end of the oil-gas spring is connected to a vehicle frame, the lower end is connected to a supporting shaft through a support; the upper cavity of the first oil-gas spring is communicated with the lower cavity of the second oil-gas spring and is communicated with a second accumulator; the lower cavity of the first oil-gas spring is communicated with the upper cavity of the second oil-gas spring and is communicated with a third accumulator; and the device is used to balance the load difference between the left and right sides of the driven rear axle under the premise of bearing the vertical load. The device realizes the functions of the active steering of the vehicle following the front axle, the locking of the driven rear axle and the like through a hydraulic system and electronic control.

Description

Technical Field

[0001] This invention belongs to the field of automotive technology, and specifically relates to a matching and balancing hydropneumatic suspension active steering driven rear axle device. Background Technology

[0002] Multi-axle vehicles, such as 10×4, have relatively large turning radii and relatively poor overall passability due to their numerous axles. Currently, a common solution is to use a 1-2-5 axle steering and a 3-4 axle drive system. Axles 1, 2, and 5 are all driven axles. The first and second axles use a "mechanical linkage + hydraulic power steering" method for precise steering control, while the fifth axle offers two steering modes: passive steering and active steering. The matching suspension types mainly include leaf spring suspension and air suspension. In the passive steering scheme, the tires rely on ground friction for steering, resulting in faster tire wear. Furthermore, when reversing, the wheels need to be locked using a reverse lock to maintain a straight-line position, preventing tire slippage when not in a straight-line driving state. In the active steering scheme, the most common control modes are "hydraulic system + electronic control" or "pure hydraulic system," typically using "valve-controlled cylinder active steering (dual centering cylinders + single steering cylinder) + angle encoder for angle positioning control." Compared to the follow-up steering system, the active steering system allows the tire angle relationship of the fifth axle wheels to better meet the overall vehicle steering characteristics. It also results in less tire wear and better control of the rear wheel steering when reversing, eliminating the need for steering lock during reversing.

[0003] Furthermore, when the vehicle is equipped with steering on axles 1-2-5 and drive on axles 3-4, during the transition from flat road to low-lying areas and then back up to flat road, the first and fifth axles (or the first-2-5 axles) may become suspended in mid-air due to stress. In this situation, the drive axles will be unable to provide driving force, and the vehicle will be unable to move. When the vehicle passes through soft terrain, the rear drive wheels may become stuck in the mud, and the vehicle will not be able to easily get out of trouble. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a matching and balancing hydropneumatic suspension active steering driven rear axle device. This enables better matching and application of the active steering driven rear axle in multi-axle vehicles, improving vehicle adaptability to operating conditions and enhancing ease of use and maintenance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A matching and balancing hydropneumatic suspension active steering driven rear axle device includes an active steering hydraulic control subunit and a hydropneumatic suspension hydraulic control subunit that share a common oil source.

[0007] The active steering hydraulic control subunit includes a steering gear 3, an active cylinder 2 mounted and fixed to the frame and connected to the steering rocker arm, and a centering cylinder 4 mounted on the driven rear axle support shaft and hinged to the steering knuckle arm. By controlling the oil flow direction between the active cylinder 2 and the centering cylinder 4, the steering gear 3 is used to achieve the deflection of the driven rear axle wheels and straight-line movement.

[0008] The hydraulic control subunit of the hydropneumatic suspension includes a first hydropneumatic spring 10 and a second hydropneumatic spring 11; the upper ends of the first hydropneumatic spring 10 and the second hydropneumatic spring 11 are both connected to the vehicle frame, and the lower ends are both connected to the support shaft through a bracket; the upper cavity of the first hydropneumatic spring 10 is connected to the lower cavity of the second hydropneumatic spring 11, and is also connected to the second accumulator 15; the lower cavity of the first hydropneumatic spring 10 is connected to the upper cavity of the second hydropneumatic spring 11, and is also connected to the third accumulator 16; this is used to balance the load difference between the left and right sides of the driven rear axle while bearing the vertical load.

[0009] Furthermore, the first gas spring 10 and the second gas spring 11 are connected to the driven rear axle by corresponding gas spring supports that are fixed to the driven rear axle support shaft.

[0010] Furthermore, the balanced hydropneumatic suspension also includes: a V-shaped thrust rod 1A and a longitudinal thrust rod 6A;

[0011] The V-shaped thrust rod 1A is connected to the driven rear axle through a V-shaped thrust rod support 3A that is installed and fixed on the upper wing surface of the driven rear axle support shaft;

[0012] The longitudinal thrust rod 6A includes a left longitudinal thrust rod and a right longitudinal thrust rod, both of which are installed on the lower flange of the support shaft.

[0013] Furthermore, the active steering hydraulic control subunit controls the oil flow between the active cylinder 2 and the centering cylinder 4, and uses the steering gear 3 to achieve the deflection of the driven rear axle wheels. The process includes:

[0014] When the front wheel turns right, oil enters through port 2C of the active cylinder 2 and returns through port 2D. The piston rod of the active cylinder 2 moves to the right, squeezing the oil in the 2A chamber through the sixty-seventh valve 67 to port 4A of the centering cylinder 4. The oil in the corresponding chamber of port 4B goes through the sixty-fourth valve 64 to port 2B of the active cylinder 2. The oil corresponding to port 4D is compressed, with part of it replenishing the 4C chamber and part of it going to the first accumulator 5, causing the driven rear axle wheel to turn to the left.

[0015] Furthermore, the active steering hydraulic control subunit, by controlling the oil flow direction between the active cylinder 2 and the centering cylinder 4, utilizes the steering gear 3 to achieve the deflection of the driven rear axle wheels, also includes:

[0016] When the front wheel turns left, oil enters through port 2D of the active cylinder 2 and returns through port 2C. The piston rod of the active cylinder 2 moves to the left, squeezing the oil in the 2B cavity through the sixty-fourth valve 64 to port 4B of the centering cylinder 4. The oil in the corresponding cavity of port 4A goes through the sixty-seventh valve 67 to port 2A of the active cylinder 2. The oil in the 4C cavity is compressed and replenished to the 4D cavity. At the same time, a portion of the oil in the first accumulator 5 also replenishes the 4D cavity, causing the driven rear axle wheel to turn to the right.

[0017] Furthermore, the active steering hydraulic control subunit controls the oil flow between the active cylinder 2 and the centering cylinder 4, and uses the steering gear 3 to achieve straight-line movement of the driven rear axle wheels, including:

[0018] When the vehicle is traveling straight, the active cylinder 2 is in the neutral position, and chambers 2A and 2B of the active cylinder 2 are connected. The pressure in chamber 4A of the centering cylinder 4 is the same as the pressure in chamber 4B of the centering cylinder 4. At this time, the pressure in chambers 4C and 4D of the centering cylinder 4 is the pressure of the first accumulator 5. Under the pressure of the accumulator, the first floating piston 41 and the second floating piston 42 in chambers 4C and 4D of the centering cylinder 4 are pressed against the internal limit of the centering cylinder 4. Because the force on the second floating piston 42 is greater than the force on the first floating piston 41, the piston rod of the centering cylinder 4 is pressed into the neutral position by the first floating piston 41 and the second floating piston 42, and the driven rear axle wheel is in the straight-going state.

[0019] Furthermore, the active steering hydraulic control subunit is also used to implement the steering lock function of the driven rear axle rear wheels. When the steering is locked, it specifically includes:

[0020] The front wheels are in a straight-line driving state, and the rear wheels of the driven axle are in a straight-line driving state.

[0021] The front wheel is deflected to the left, and the rear wheel of the driven axle is deflected to the right.

[0022] The front wheel is deflected to the right, and the driven axle's rear wheel is deflected to the left.

[0023] Furthermore, the process by which the hydraulic control subunit of the hydropneumatic suspension balances the load differences between the left and right sides of the driven rear axle includes:

[0024] While bearing the vertical load, balance the load difference between the left and right sides of the driven rear axle;

[0025] When the suspension is under load, all solenoid valves and electromagnets in the control valve group 8 are de-energized. The oil in the lower chamber of the first gas spring 10 is connected to the oil in the upper chamber of the second gas spring 11 through the first damping valve 93, the eighty-fifth valve 85, and the third accumulator 16. The oil in the upper chamber of the first gas spring 10 is connected to the lower chamber of the second gas spring 11 through the ninety-first valve 91 and the second damping valve 94, and is connected to the second accumulator 15. When the driven rear axle is simultaneously subjected to vertical load and jumps, the oil in the upper chamber of the first gas spring 10 is compressed to the second accumulator 15. The oil in the upper chamber of the second gas spring 11 is compressed to the third accumulator 16, relying on the air pressure in the accumulator to buffer the upward impact.

[0026] When the driven rear axle jumps down, the air pressure in the second accumulator 15 increases the volume of the upper cavity of the first gas spring 10; the air pressure in the third accumulator 16 increases the volume of the upper cavity of the second gas spring 11.

[0027] Furthermore, the hydraulic control subunit of the hydropneumatic suspension is also used to realize the lifting, lowering, arbitrary length locking, and synchronized operation of the first hydropneumatic spring 10 and the second hydropneumatic spring 11 within their stroke range.

[0028] Furthermore, the device is also used to replenish the oil in the second accumulator 15 and the third accumulator 16.

[0029] The effects described in the invention are merely those of the embodiments, and not all the effects of the invention. One of the above technical solutions has the following advantages or beneficial effects:

[0030] This invention proposes a matching and balancing hydropneumatic suspension active steering driven rear axle device, including an active steering hydraulic control subunit and a hydropneumatic suspension hydraulic control subunit sharing a common oil source. The active steering hydraulic control subunit includes a steering gear, an active cylinder mounted and fixed to the vehicle frame and connected to the steering rocker arm, and a centering cylinder mounted on the driven rear axle support shaft and hinged to the steering knuckle arm. By controlling the oil flow direction between the active cylinder and the centering cylinder, the steering gear is used to achieve wheel deflection and straight-line movement of the driven rear axle. The hydropneumatic suspension hydraulic control subunit includes a first hydropneumatic spring and a second hydropneumatic spring. The upper ends of both the first and second hydropneumatic springs are connected to the vehicle frame, and the lower ends are connected to the support shaft through supports. The upper cavity of the first hydropneumatic spring is connected to the lower cavity of the second hydropneumatic spring and is connected to a second accumulator. The lower cavity of the first hydropneumatic spring is connected to the upper cavity of the second hydropneumatic spring and is connected to a third accumulator. This device is used to balance the load difference between the left and right sides of the driven rear axle while bearing vertical loads. This invention, through a "hydraulic system + electronic control", can realize the main functions of active steering of the vehicle following the front axle and locking of the rear wheels of the driven axle. At the same time, it can also realize other functions such as wheel position correction of the driven axle and oil replenishment of the accumulator, simplifying the use and maintenance.

[0031] This invention enables the driven rear axle to actively steer following the front wheels, effectively reducing the vehicle's minimum steering circle diameter and improving its passability. This function is primarily used in low-speed and off-road operating conditions. It also enables the driven rear axle to lock the rear wheels, preventing the driven rear axle from steer with the front wheels. This function is primarily used in high-speed road driving conditions. Furthermore, this invention enables wheel position correction and accumulator refueling. Attached Figure Description

[0032] Figure 1 This is a front view of the driven rear axle proposed in Embodiment 1 of the present invention;

[0033] Figure 2 This is a top view of the driven rear axle proposed in Embodiment 1 of the present invention;

[0034] Figure 3 This is a schematic diagram of the original hydraulic control system proposed in Embodiment 1 of the present invention;

[0035] Legend:

[0036] 1A-V-type thrust rod, 3A-V-type thrust rod support, 4A-oil spring support, 5A-first thrust rod mounting support, 6A-longitudinal thrust rod, 7A-second thrust rod mounting support, 8A-support shaft, 9A-tie rod;

[0037] 1-Double hydraulic pump, 2-Active cylinder, 3-Steering gear, 4-Centering cylinder, 5-First accumulator, 6-Driven rear axle control valve group, 7-Safety valve group, 8-Control valve group, 10-First pneumatic spring, 11-Second pneumatic spring, 15-Second accumulator, 16-Third accumulator, 60-Sixtieth valve, 61-Sixty-first valve, 62-Sixty-second valve, 63-Sixty-third valve, 64-Sixty-fourth valve, 67-Sixty-seventh valve, 68-Sixty-eighth valve, 81-Eighty-first valve, 82-Eighty-second valve, 84-Eighty-fourth valve, 85-Eighty-fifth valve, 86-Eighty-sixth valve, 87-Eighty-seventh valve, 91-Ninety-first valve, 93-Ninety-third valve, 94-Ninety-fourth valve. Detailed Implementation

[0038] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure of the invention, components and arrangements of specific examples are described below. Furthermore, reference numerals and / or letters may be repeated in different examples. This repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components, processing techniques, and processes are omitted in this invention to avoid unnecessarily limiting the invention.

[0039] Example 1

[0040] This invention proposes a matching and balancing hydropneumatic suspension active steering driven rear axle device, which is used to better match the application of active steering driven rear axle in multi-axle vehicles such as 10×4, improve the vehicle's adaptability to operating conditions, and improve the convenience of use and maintenance.

[0041] This invention proposes a matching and balancing hydropneumatic suspension active steering driven rear axle device, including an active steering hydraulic control subunit with a shared oil source and a hydropneumatic suspension hydraulic control subunit;

[0042] The active steering hydraulic control subunit includes a steering gear, an active cylinder mounted and fixed to the frame and connected to the steering rocker arm, and a centering cylinder mounted on the driven rear axle support shaft and hinged to the steering knuckle arm. By controlling the oil flow direction between the active cylinder and the centering cylinder, the steering gear is used to achieve the deflection of the driven rear axle wheels and straight-line movement.

[0043] The hydraulic control subunit of the hydropneumatic suspension includes a first hydropneumatic spring and a second hydropneumatic spring; the upper ends of both the first and second hydropneumatic springs are connected to the vehicle frame, and the lower ends are connected to the support shaft through supports; the upper cavity of the first hydropneumatic spring is connected to the lower cavity of the second hydropneumatic spring, and is also connected to a second accumulator; the lower cavity of the first hydropneumatic spring is connected to the upper cavity of the second hydropneumatic spring, and is also connected to a third accumulator; this is used to balance the load difference between the left and right sides of the driven rear axle while bearing vertical load.

[0044] The driven rear axle has a steering kingpin with an inclination angle and a steering tie rod 9A. It has its own steering axle self-centering capability, making it a driven load-bearing axle with steering self-centering capability.

[0045] The active steering hydraulic control subunit and the hydropneumatic suspension hydraulic control subunit share the same oil source and the same electro-hydraulic control module.

[0046] Figure 1 This is a front view of the driven rear axle proposed in Embodiment 1 of the present invention; Figure 2 This is a top view of the driven rear axle proposed in Embodiment 1 of the present invention;

[0047] The driven rear axle hydropneumatic suspension structure is a hydropneumatic suspension using a hydropneumatic spring structure with separate hydropneumatic springs, such as... Figure 1 As shown, the suspension consists of a V-shaped thrust rod 1A, a V-shaped thrust rod support 3A, a longitudinal thrust rod 6A, a first thrust rod mounting support 5A, a second thrust rod mounting support 7A, a first gas spring 10, a second gas spring 11, and a gas spring support 4A.

[0048] The "tip" of the V-shaped thrust rod 1A is a ball joint structure, and the other end consists of two ball joint structures symmetrically arranged along the longitudinal plane of the vehicle frame. The V-shaped thrust rod 1A is connected to the driven rear axle via a V-shaped thrust rod support 3A fixed to the upper flange of the driven rear axle support shaft, and the other end is connected to the vehicle frame via two ball joints symmetrically arranged along the longitudinal plane of the vehicle frame. There are two longitudinal thrust rods 6A, one on each side, mounted on the lower flange of the support shaft via a first thrust rod mounting support 5A, and connected to the vehicle frame via a second thrust rod mounting support 7A. The first and second gas springs 10 and 11 are both connected to the driven rear axle via gas spring supports 4A fixed to the driven rear axle support shaft, and the other end is connected to the vehicle frame via a gas spring upper support. The V-shaped thrust rod 1A and longitudinal thrust rod 6A of the suspension system are used to handle forces in both the longitudinal and lateral directions during vehicle use, while the gas springs buffer vertical forces and balance the force deviation on the left and right sides of the driven rear axle.

[0049] Figure 3 The diagram below is a schematic representation of the hydraulic control system proposed in Embodiment 1 of this invention. The active steering hydraulic control subunit of this application consists of a dual hydraulic pump 1 installed and fixed to the engine steering hydraulic pump connection interface, an active cylinder 2 hinged to the vehicle frame and connected to the steering rocker arm, a steering gear 3, a centering cylinder 4 hinged to the driven rear axle support shaft and hinged to the steering knuckle arm, a first accumulator 5, a driven rear axle control valve group 6, and a safety valve group 7.

[0050] The active steering hydraulic control subunit also includes an electro-hydraulic control module. The electro-hydraulic control module can receive the stroke sensor signal built into the centering cylinder, determine the position of the centering cylinder, that is, determine the position of the driven rear axle wheel, and then realize the expected tire reset, accumulator oil replenishment and other functions by turning on and off the solenoid valves, etc.

[0051] The active steering hydraulic control subunit in this application can realize the active steering function of the driven rear axle following the front wheels. This function is mainly suitable for low-speed (e.g., ≤60km / h) and off-road operating conditions, which can effectively reduce the minimum steering circle diameter of the vehicle and improve the vehicle's passability. Under this function, all electromagnets DT1, DT2, DT3, DT4, DT5, DT6, DT7, DT8, and DT9 in the driven rear axle control valve group 6 are not energized.

[0052] When the front wheel turns right, oil enters through port 2C of the active cylinder 2 and returns through port 2D. The piston rod of the active cylinder 2 moves to the right, squeezing the oil in the 2A chamber through the sixty-seventh valve 67 to port 4A of the centering cylinder 4. The oil in the corresponding chamber of port 4B goes through the sixty-fourth valve 64 to port 2B of the active cylinder 2. The oil corresponding to port 4D is compressed, with part of it replenishing the 4C chamber and part of it going to the first accumulator 5, causing the driven rear axle wheel to turn to the left.

[0053] When the front wheel turns left, oil enters through port 2D of the active cylinder 2 and returns through port 2C. The piston rod of the active cylinder 2 moves to the left, squeezing the oil in the 2B cavity through the sixty-fourth valve 64 to port 4B of the centering cylinder 4. The oil in the corresponding cavity of port 4A goes through the sixty-seventh valve 67 to port 2A of the active cylinder 2. The oil in the 4C cavity is compressed and replenished to the 4D cavity. At the same time, a portion of the oil in the first accumulator 5 also replenishes the 4D cavity, causing the driven rear axle wheel to turn to the right.

[0054] When the vehicle is traveling straight, the active cylinder 2 is in the neutral position, and chambers 2A and 2B of the active cylinder 2 are connected. The pressure in chamber 4A of the centering cylinder 4 is the same as the pressure in chamber 4B of the centering cylinder 4. At this time, the pressure in chambers 4C and 4D of the centering cylinder 4 is the pressure of the first accumulator 5. Under the pressure of the accumulator, the first floating piston 41 and the second floating piston 42 in chambers 4C and 4D of the centering cylinder 4 are pressed against the internal limit of the centering cylinder 4. Because the force on the second floating piston 42 is greater than the force on the first floating piston 41, the piston rod of the centering cylinder 4 is pressed into the neutral position by the first floating piston 41 and the second floating piston 42, and the driven rear axle wheel is in the straight-going state.

[0055] The active steering hydraulic control subunit in this application can also realize the rear wheel steering lock function of the driven rear axle. This function means that the driven rear axle actively steers without following the steering of the front wheels, mainly used in high-speed driving conditions, which can effectively improve the vehicle's handling and stability. Rear wheel steering lock must be operated when the vehicle is stationary. There are three operating conditions when steering is locked:

[0056] First operating condition: Front wheels traveling straight, rear wheels of the driven axle traveling straight.

[0057] When this function switch is turned on, the electro-hydraulic control module detects the position of the piston rod of the centering cylinder 4 through the sensor built into the centering cylinder 2. If the piston rod of the centering cylinder 4 is in the neutral position, DT7 in the driven rear axle control valve group 6 is energized, and chamber 2A of the driving cylinder 2 is connected to chamber 2B of the driving cylinder 2. At this time, regardless of which chamber 2C or 2D of the driving cylinder 2 is filled with oil, the oil in chambers 2A and 2B flows and replenishes each other during the left and right movement of the driving cylinder 2. The centering cylinder 4 is always in the neutral position under the pressure of the first accumulator 5, and the driven rear axle wheels are in a straight-line state.

[0058] The second operating condition: the front wheels are turning left, and the rear wheels of the driven axle are turning right.

[0059] When this function switch is turned on, the electro-hydraulic control module detects the position of the piston rod of the centering cylinder 4 through the sensor built into the centering cylinder 2. If the piston rod of the centering cylinder 4 is in the right-hand deflection state of the rear wheel, the electromagnets DT1, DT3, DT4, DT5, DT6, DT7, and DT8 of the driven rear axle control valve group 6 are energized, and the oil from the small displacement pump on the right side of the double pump is pumped. The oil flows through the 60th valve 60 and the 62nd valve to port 4A of the centering cylinder, and the oil from port 4B of the centering cylinder 4 returns to the oil tank through the 61st valve 61 and the 60th valve 60. When the electro-hydraulic control module detects that the piston rod of the centering cylinder 4 is in the neutral position, the electromagnets DT1, DT3, DT4, DT5, DT6, DT7, and DT8 are de-energized, and DT7 is energized. At this time, the driven rear wheel is in a straight-line state.

[0060] The third operating condition: the front wheels are turning right, and the rear wheels of the driven axle are turning left.

[0061] When this function switch is turned on, the electro-hydraulic control module detects the position of the piston rod of the centering cylinder 4 through the sensor built into the centering cylinder 2. If the piston rod of the centering cylinder 4 is in the left-hand deflection state of the rear wheel, the electromagnets DT2, DT3, DT4, DT5, DT6, DT7, and DT8 of the driven rear axle control valve group 6 are energized. The oil from the small displacement pump on the right side of the double pump flows through the 60th valve 60 and the 61st valve 61 to port 4B of the centering cylinder 4. The oil from port 4A of the centering cylinder 4 returns to the oil tank through the 62nd valve 62 and the 60th valve 60. When the electro-hydraulic control module detects that the piston rod of the centering cylinder 4 is in the neutral position, the electromagnets DT2, DT3, DT4, DT5, DT6, DT7, and DT8 are de-energized, and DT7 is energized. At this time, the driven rear wheel is in a straight-line state.

[0062] In this invention, the active steering hydraulic control subunit can achieve wheel alignment correction. During long-term use of the hydraulic system, a small amount of oil leakage is inevitable in the first accumulator 5, causing a pressure drop. This results in the alignment cylinder 4, which should be in the neutral position, not being in the neutral position, and the driven rear axle wheels slightly deviating from the straight-line state. Therefore, it is necessary to correct its state. Wheel alignment correction must be performed when the vehicle is stationary, under the following two conditions:

[0063] In the first operating condition, the rear driven axle wheels deflect slightly to the left.

[0064] When this function switch is turned on, the electro-hydraulic control module detects the position of the piston rod of the centering cylinder 4 through the sensor built into the centering cylinder 2, and automatically corrects the tire deflection.

[0065] In the second operating condition, the rear driven axle wheels deflect slightly to the right.

[0066] When this function switch is turned on, the electro-hydraulic control module detects the position of the piston rod of the centering cylinder 4 through the sensor built into the centering cylinder 2, and automatically corrects the tire deflection.

[0067] The active steering hydraulic control subunit in this application can realize the oil replenishment function of the first accumulator.

[0068] Oil replenishment to the first accumulator 5 is performed after the rear driven axle wheel position correction. After the electro-hydraulic control module completes the wheel position correction, it automatically de-energizes all corresponding wheel position correction electromagnets. Then, DT2, DT3, DT6, and DT9 are energized. Oil from the small displacement pump on the right side of the dual pump flows through valves 60, 61, and 63 to the first accumulator. Once the pressure in the first accumulator reaches the required level, excess oil returns to the oil tank through valve 68. DT2, DT3, DT6, and DT9 are then de-energized, and oil replenishment to the first accumulator is complete.

[0069] In this application, whether the driven rear axle is actively steering in accordance with the front wheels or the driven rear axle is in a locked steering state, the reversing function can be achieved without any additional operation.

[0070] exist Figure 3 In this system, the hydropneumatic suspension hydraulic control subunit and the active steering hydraulic control subunit share a single controller, namely the electro-hydraulic control module.

[0071] The active steering hydraulic control subunit can realize the suspension load-bearing function. An important function of the suspension system is to mitigate the impact of the road surface. The first air spring 10 and the second air spring 11, as elastic elements in the system, bear the vertical load. As a specially designed balanced air suspension, it can balance the load difference between the left and right sides of the driven rear axle while bearing the vertical load.

[0072] The process by which the hydraulic control subunit of the hydropneumatic suspension balances the load difference between the left and right sides of the driven rear axle includes:

[0073] When the suspension is under load, all solenoid valves and electromagnets in the control valve group 8 are de-energized. The oil in the lower chamber of the first gas spring 10 is connected to the oil in the upper chamber of the second gas spring 11 through the first damping valve 93, the eighty-fifth valve 85, and the third accumulator 16. The oil in the upper chamber of the first gas spring 10 is connected to the lower chamber of the second gas spring 11 through the ninety-first valve 91 and the second damping valve 94, and the second accumulator 15. When the driven rear axle is subjected to vertical load and jumps, the oil in the upper chamber of the first gas spring 10 is compressed to the second accumulator 15. The oil in the upper chamber of the second gas spring 11 is compressed to the third accumulator 16, where the air pressure in the accumulator buffers the upward impact. When the driven rear axle jumps downward, the air pressure in the second accumulator 15 increases the volume of the upper chamber of the first gas spring 10. The air pressure in the third accumulator 16 increases the volume of the upper chamber of the second gas spring 11.

[0074] When one of the left or right wheels of the driven rear axle encounters an obstacle and lifts up, the load on the lifted side increases, the upper chamber of the corresponding air spring is compressed, and the pressure rises. The increased oil pressure will inevitably lead to an increase in the oil pressure in the lower chamber of the air spring on the non-lifted side, pushing the air spring on the non-lifted side to compress the oil in the upper chamber. This increases the load on the air spring on the non-lifted side to reduce the force on the air spring on the lifted side. In other words, it is equivalent to transferring the force of the air spring on the lifted side, which is under greater force, to the non-lifted side to balance the force on the left and right sides of the driven rear axle.

[0075] In this application, the hydraulic control subunit of the hydropneumatic suspension realizes the lifting, lowering, arbitrary length locking, and synchronous operation of the hydropneumatic spring within its stroke range.

[0076] This function primarily addresses the issue where, when vehicles pass through low-lying areas such as underpasses, the first and fifth axles (or the first, second, and fifth axles) may become suspended in the air due to stress, preventing them from providing driving force. It also resolves the problem of the rear drive wheels getting stuck in mud when traversing soft terrain. When the drive axle fails to provide driving force due to low-lying areas, the driven rear axle can be raised until it makes good contact with the ground, at which point it will provide driving force. When stuck in mud, the driven rear axle can be lowered to lift the vehicle and assist in getting it out of trouble.

[0077] The gas spring locking function operates when the vehicle is stationary. Selecting the gas suspension control function from the driver's cab disables the active steering function.

[0078] When the hydropneumatic spring lifting function is selected, the electromagnet DT1 of the active steering control valve group 6 is energized, and the hydropneumatic suspension control valve groups DT22, DT28, DT36, DT27, DT25, DT35, DT33, DT32, and DT24 are energized. The hydraulic fluid flows through the 60th valve 60 of the active steering control valve group 6, the 81st valve 81, the 86th valve 86, and the 93rd valve 93 of the hydropneumatic suspension control valve group 8 to the lower chamber of the first hydropneumatic spring 10, and through the 60th valve 60 of the active steering control valve group 6, the 81st valve 81, the 82nd valve 82, and the 94th valve 94 of the hydropneumatic suspension control valve group 8 to the lower chamber of the second hydropneumatic spring 11. The upper chambers of the first hydropneumatic spring 10 and the second hydropneumatic spring 11 are compressed. The hydraulic fluid in the upper chamber of the first hydropneumatic spring 10 flows back to the oil tank through the 82nd valve 82 and the 81st valve 81, and the hydraulic fluid in the upper chamber of the second hydropneumatic spring 11 flows back to the oil tank through the 87th valve 87 and the 81st valve 81. When the lifting function is activated, select the stop switch corresponding to the lifting function, de-energize the electromagnet DT1 of the active steering control valve group 6, de-energize all valves of the hydropneumatic suspension control valve group 8 except for DT27, DT25, DT35, and DT33, and lock the first hydropneumatic spring 10 and the second hydropneumatic spring 11.

[0079] When the hydropneumatic spring descent function is selected, the electromagnet DT1 of the active steering control valve group 6 is energized, and DT21, DT24, DT25, DT27, DT28, DT32, DT35, DT36, DT33, DT91, and DT82 of the hydropneumatic suspension control valve group 8 are energized. The hydraulic fluid flows through the 60th valve 60 of the active steering control valve group 6, the 81st valve 81, and the 82nd valve 82 of the hydropneumatic suspension control valve group 8 to the upper chamber of the first hydropneumatic spring 10, and then through the active steering... The oil level in the upper chambers of the first and second air springs 10 and 11 increases as the oil in the upper chambers of the first air spring 10 and 11 flows to the upper chambers of the control valve group 6 (sixtieth valve 60), the air suspension control valve group 8 (eighty-first valve 81 and eighty-seventh valve 87). The oil in the lower chamber of the first air spring 10 flows back to the oil tank via the ninety-third valve 93, the eighty-sixth valve 86, and the eighty-first valve 81. The oil in the lower chamber of the second air spring 11 flows back to the oil tank via the ninety-fourth valve 94, the eighty-second valve 82, and the eighty-first valve 81. When the descent function is activated, selecting the stop switch corresponding to the descent function de-energizes the electromagnet DT1 of the active steering control valve group 6 and de-energizes all valves in the air suspension control valve group 8 except DT27, DT25, DT35, and DT33. Both the first and second air springs 10 and 11 are locked.

[0080] During the aforementioned lifting and lowering process, because the weight on the left and right sides of the driven rear axle cannot be completely uniform when lifting, and the resistance during lowering cannot be completely uniform, a problem of asynchronous lifting and lowering of the driven rear axle will occur. To solve this problem, the system monitors the stroke of the pneumatic springs during this process and adjusts the oil supply to the pneumatic springs in real time to synchronize the lifting and lowering of the left and right pneumatic springs. The specific implementation is as follows:

[0081] First, asynchronous correction control during the lifting process

[0082] If, during the lifting process, the second pneumatic spring 11 cannot follow the first pneumatic spring 10, the electro-hydraulic control module automatically controls the corresponding solenoid valves to switch on and off. It de-energizes DT28 and DT24 of the DT1, DT22, DT28, DT36, DT27, DT25, DT35, DT33, DT32, and DT24 valves that were originally energized during the lifting process. At this point, oil flows to the second pneumatic spring 11 until its stroke exceeds the stroke of the first pneumatic spring 10 by a certain value (e.g., 5mm). Then, the electro-hydraulic control module determines that the stroke of the first pneumatic spring 10 cannot keep up with the stroke of the second pneumatic spring 11. At this point, DT28 and DT24, which were previously de-energized, are energized, while DT32 and DT36 are de-energized. Oil flows to the first pneumatic spring 10 until its stroke again exceeds the stroke of the second pneumatic spring 11 by a certain value. This process is dynamically repeated until synchronized lifting is achieved.

[0083] Second, asynchronous correction control during descent.

[0084] If, during the descent, the second pneumatic spring 11 cannot follow the first pneumatic spring 10, the electro-hydraulic control module automatically controls the corresponding solenoid valves to switch on and off. It de-energizes DT28 (one of the valves DT1, DT21, DT24, DT25, DT27, DT28, DT32, DT35, DT36, DT33, DT91, and DT82 that were energized during the descent, and energizes DT23. At this point, oil flows to the second pneumatic spring 11 until its stroke exceeds the stroke of the first pneumatic spring 10 by a certain value (e.g., 5mm). Then, the electro-hydraulic control module determines that the stroke of the first pneumatic spring 10 cannot keep up with the stroke of the second pneumatic spring 11. At this point, DT28 (which was de-energized) is energized, DT36 is de-energized, and DT24 is energized. Oil flows to the first pneumatic spring 10 until its stroke again exceeds the stroke of the second pneumatic spring 11 by a certain value. This process repeats dynamically, ultimately achieving the descent and lifting.

[0085] Third, suspension adjustment under no-load and full-load conditions.

[0086] When the vehicle is stationary, select the corresponding function switch for the no-load or full-load neutral position. The electro-hydraulic control module will automatically adjust the position of the hydraulic spring according to the set neutral position value. The specific control method is similar to the operation of the lifting and lowering functions.

[0087] Fourth, replenishing oil in the hydro-pneumatic spring accumulator.

[0088] When the vehicle is stationary, selecting the hydraulic spring accumulator replenishment function will cause the electro-hydraulic control module to automatically detect the hydraulic spring accumulator pressure. If the pressure meets the set pressure, no replenishment will be made; if the pressure is lower than the set pressure, replenishment will be made. When the second accumulator 15 is replenished, DT1, DT21, DT24, DT31, and DT27 are energized. Once the pressure of the second accumulator 15 reaches the set pressure, it will automatically de-energize. When the third accumulator 16 is replenished, DT1, DT21, DT23, DT32, and DT35 are energized. Once the pressure of the third accumulator 16 reaches the set pressure, it will automatically de-energize.

[0089] Embodiment 1 of this invention proposes a matching balance hydropneumatic suspension active steering driven rear axle device, which uses two hydropneumatic springs. Through "hydraulic system + electronic control", it can realize the main functions such as active steering of the vehicle following the front axle and locking of the driven axle rear wheels. At the same time, it can also realize other functions such as driven axle wheel position correction and accumulator oil replenishment, simplifying use and maintenance.

[0090] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the elements inherent in a process, method, article, or apparatus that includes a list of elements are included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, portions of the technical solutions provided in the embodiments of this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.

[0091] While specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art can make other modifications or variations based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A matching and balancing hydropneumatic suspension active steering driven rear axle device, characterized in that, This includes an active steering hydraulic control subunit that shares a common oil source and an oil-pneumatic suspension hydraulic control subunit; The active steering hydraulic control subunit includes a steering gear (3), an active cylinder (2) mounted and fixed to the frame and connected to the steering rocker arm, and a centering cylinder (4) mounted on the driven rear axle support shaft and hinged to the steering knuckle arm. By controlling the oil flow direction between the active cylinder (2) and the centering cylinder (4), the steering gear (3) is used to achieve the deflection of the driven rear axle wheels and straight-line movement. The hydraulic control subunit of the hydropneumatic suspension includes a first hydropneumatic spring (10) and a second hydropneumatic spring (11) located on the left and right sides of the driven rear axle, respectively; the upper ends of the first hydropneumatic spring (10) and the second hydropneumatic spring (11) are both connected to the vehicle frame, and the lower ends are both connected to the support shaft through the support; the upper cavity of the first hydropneumatic spring (10) is connected to the lower cavity of the second hydropneumatic spring (11) and is connected to the second accumulator (15); the lower cavity of the first hydropneumatic spring (10) is connected to the upper cavity of the second hydropneumatic spring (11) and is connected to the third accumulator (16); it is used to balance the load difference between the left and right sides of the driven rear axle under the premise of bearing the vertical load; The hydraulic control subunit of the hydropneumatic suspension is also used to realize the lifting, lowering, arbitrary length locking, and synchronous operation of the first hydropneumatic spring (10) and the second hydropneumatic spring (11) within their stroke range; When the drive axle cannot provide driving force due to a low-lying area, the driven rear axle will be lifted until the drive axle makes good contact with the ground. When stuck in mud, the vehicle can be lifted by lowering the driven rear axle to help it get out of trouble; The motion synchronization control includes: if the second hydraulic spring (11) cannot follow the first hydraulic spring (10) in lifting or lowering during the lifting or lowering process, the electro-hydraulic control module automatically controls the corresponding solenoid valve to turn on and off, so that the oil flows to the second hydraulic spring (11) until the stroke of the second hydraulic spring (11) is greater than the stroke of the first hydraulic spring (10) by a certain value. Then, the electro-hydraulic control module determines that the stroke of the first hydraulic spring (10) cannot keep up with the stroke of the second hydraulic spring (11). Then, the electro-hydraulic control module automatically controls the corresponding solenoid valve to turn on and off again, so that the oil flows to the first hydraulic spring (10) until the stroke of the first hydraulic spring (10) exceeds the stroke of the second hydraulic spring (11) by a certain value. This process is repeated dynamically, and finally, synchronous lifting or lowering is achieved.

2. The matching and balancing hydropneumatic suspension active steering driven rear axle device according to claim 1, characterized in that, The first gas spring (10) and the second gas spring (11) are connected to the driven rear axle by corresponding gas spring supports that are fixed to the driven rear axle support shaft.

3. The matching and balancing hydropneumatic suspension active steering driven rear axle device according to claim 1, characterized in that, The balanced hydropneumatic suspension also includes: a V-shaped thrust rod (1A) and a longitudinal thrust rod (6A). The V-shaped thrust rod (1A) is connected to the driven rear axle via a V-shaped thrust rod support (3A) that is installed and fixed on the upper wing surface of the driven rear axle support shaft; The longitudinal thrust rod (6A) includes a left longitudinal thrust rod and a right longitudinal thrust rod, both of which are installed on the lower flange of the support shaft.

4. The matching and balancing hydropneumatic suspension active steering driven rear axle device according to claim 1, characterized in that, The active steering hydraulic control subunit controls the oil flow between the active cylinder (2) and the centering cylinder (4) to achieve the deflection of the driven rear axle wheels using the steering gear (3). The process includes: When the front wheel turns right, oil enters through port 2C and returns through port 2D of the active cylinder (2). The piston rod of the active cylinder (2) moves to the right, squeezing the oil in the 2A cavity through the sixty-seventh valve (67) to port 4A of the centering cylinder (4). The oil in the corresponding cavity of port 4B goes through the sixty-fourth valve (64) to port 2B of the active cylinder (2). The oil corresponding to port 4D is compressed, with part of it replenishing the 4C cavity and part of it going to the first accumulator (5). The driven rear axle wheel turns to the left.

5. A matching and balancing hydropneumatic suspension active steering driven rear axle device according to claim 4, characterized in that, The active steering hydraulic control subunit controls the oil flow between the active cylinder (2) and the centering cylinder (4) to achieve the deflection of the driven rear axle wheels using the steering gear (3). The process also includes: When the front wheel turns left, oil enters through port 2D and returns through port 2C of the active cylinder (2). The piston rod of the active cylinder (2) moves to the left, squeezing the oil in the 2B cavity through the sixty-fourth valve (64) to port 4B of the centering cylinder (4). The oil in the cavity corresponding to port 4A goes through the sixty-seventh valve (67) to port 2A of the active cylinder (2). The oil corresponding to the 4C cavity is compressed and replenished to the 4D cavity. At the same time, a portion of the oil in the first accumulator (5) also replenishes the 4D cavity, causing the driven rear axle wheel to turn right.

6. The matching and balancing hydropneumatic suspension active steering driven rear axle device according to claim 1, characterized in that, The active steering hydraulic control subunit controls the oil flow between the active cylinder (2) and the centering cylinder (4) to achieve straight-line movement of the driven rear axle wheels using the steering gear (3). The process includes: When the vehicle is traveling straight, the active cylinder (2) is in the neutral position, and the 2A chamber of the active cylinder (2) is connected to the 2B chamber of the active cylinder (2). The pressure of the 4A chamber of the centering cylinder (4) is the same as the pressure of the 4B chamber of the centering cylinder (4). At this time, the pressure of the 4C chamber and the 4D chamber of the centering cylinder (4) is the pressure of the first accumulator (5). The first floating piston (41) and the second floating piston (42) of the 4C chamber and the 4D chamber of the centering cylinder (4) are pressed on the internal limit of the centering cylinder (4) under the pressure of the accumulator. Because the force on the second floating piston (42) is greater than the force on the first floating piston (41), the piston rod of the centering cylinder (4) is pressed into the neutral position by the first floating piston (41) and the second floating piston (42), and the driven rear axle wheel is in the straight-going state.

7. A matching and balancing hydropneumatic suspension active steering driven rear axle device according to claim 1, characterized in that, The active steering hydraulic control subunit is also used to implement the steering lock function of the driven rear axle rear wheels. When the steering is locked, it specifically includes: The front wheels are in a straight-line driving state, and the rear wheels of the driven axle are in a straight-line driving state. The front wheel is deflected to the left, and the rear wheel of the driven axle is deflected to the right. The front wheel is deflected to the right, and the driven axle's rear wheel is deflected to the left.

8. A matching and balancing hydropneumatic suspension active steering driven rear axle device according to claim 1, characterized in that, The process by which the hydraulic control subunit of the hydropneumatic suspension balances the load difference between the left and right sides of the driven rear axle includes: While bearing the vertical load, balance the load difference between the left and right sides of the driven rear axle; When the suspension is under load, all solenoid valves and electromagnets in the control valve group (8) are de-energized. The oil in the lower chamber of the first gas spring (10) is connected to the oil in the upper chamber of the second gas spring (11) through the first damping valve (93), the eighty-fifth valve (85), and the third accumulator (16). The oil in the upper chamber of the first gas spring (10) is connected to the lower chamber of the second gas spring (11) through the ninety-first valve (91) and the second damping valve (94) and the second accumulator (15). When the driven rear axle is simultaneously subjected to vertical load and jumps, the oil in the upper chamber of the first gas spring (10) is compressed to the second accumulator (15). The oil in the upper chamber of the second gas spring (11) is compressed to the third accumulator (16) to buffer the jump impact by relying on the air pressure in the accumulator. When the driven rear axle jumps down, the volume of the upper cavity of the first oil-gas spring (10) increases under the action of the air pressure in the second accumulator (15); the volume of the upper cavity of the second oil-gas spring (11) increases under the action of the air pressure in the third accumulator (16).

9. A matching and balancing hydropneumatic suspension active steering driven rear axle device according to claim 1, characterized in that, The device is also used to replenish the oil in the second accumulator (15) and the third accumulator (16).

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