Driving steering driven rear axle device matched with balanced hydro-pneumatic suspension

Abstract

The invention provides an active steering driven rear axle device matched with a balanced hydro-pneumatic suspension. The active steering driven rear axle device comprises an active steering hydraulic control subunit and a hydro-pneumatic suspension hydraulic control subunit. The driving steering hydraulic control subunit comprises a steering gear, a driving oil cylinder and a centering oil cylinder, and by controlling the oil flow direction between the driving oil cylinder and the centering oil cylinder, the steering gear is used for achieving deflection and straight movement of driven rear axle wheels; the hydro-pneumatic suspension hydraulic control subunit comprises two hydro-pneumatic springs; the upper end of the hydro-pneumatic spring is connected to the frame, and the lower end is connected to the supporting shaft through a support; the upper cavity of the first hydro-pneumatic spring is communicated with the lower cavity of the second hydro-pneumatic spring and is communicated with the second energy accumulator; the lower cavity of the first hydro-pneumatic spring is communicated with the upper cavity of the second hydro-pneumatic spring and is communicated with a third energy accumulator; the balance device is used for balancing the load difference of the left side and the right side of the driven rear axle on the premise of bearing the vertical load. Through a hydraulic system and electric control, the functions of driving steering of the vehicle following the front axle, driven axle rear wheel locking and the like are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of automobile technology, and in particular relates to a matched balanced oil-gas suspension active steering driven rear axle device. Background Art

[0002] Multi-axle vehicles, such as 10×4 vehicles, have a relatively large turning radius due to their large number of axles, resulting in relatively poor maneuverability. Currently, a common solution is one-, two-, and five-axle steering, with three- and four-axle drive. The first, second, and fifth axles are all driven axles, and the first and second axles utilize a "mechanical linkage + hydraulic power steering" approach for precise steering control. The fifth axle offers two steering modes: follow-up steering and active steering. Suitable suspension types primarily include leaf springs and air suspension. With follow-up steering for the fifth axle, the tires rely on ground friction for steering, which results in rapid tire wear. Furthermore, when reversing, the wheels require a reverse lock to lock the fifth axle's steering tie rods to maintain a straight-ahead position. This prevents the follow-up steering tires from slipping when not in a straight-ahead position. Currently, the most common control schemes for the fifth axle are "hydraulic + electronic control" or "pure hydraulic system." Typical examples include "valve-controlled cylinder active steering (dual centering cylinders + single steering cylinder) + angle encoder for angle positioning control." Compared with the follow-up steering solution, the active steering solution can better meet the steering characteristics of the vehicle in terms of the tire angle relationship of the fifth axle wheels. The tire wear is less, and the steering of the rear wheels can be better controlled when reversing, without the need for steering lock when reversing.

[0003] Furthermore, with the first, second, and fifth axles steering and the third and fourth axles driving, when a vehicle passes through low-lying areas such as bridge tunnels, and then climbs uphill to a flatter area, the first and fifth axles (or the first, second, and fifth axles) may be forced to suspend the drive axle. At this point, the drive axle will be unable to provide driving force, rendering the vehicle unable to move. When the vehicle passes through soft terrain, the rear drive wheels may become stuck in muddy areas, making it difficult for the vehicle to escape. Summary of the Invention

[0004] To solve the above technical problems, the present invention proposes a matched balanced oil-pneumatic suspension active steering driven rear axle device. This device can better match the active steering driven rear axle with multi-axle vehicles, improve the vehicle's adaptability to working conditions, and enhance the convenience of use and maintenance.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A matched balanced oil-gas suspension active steering driven rear axle device, comprising an active steering hydraulic control subunit and an oil-gas suspension hydraulic control subunit sharing a common oil source;

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

[0008] The oil-gas suspension hydraulic control subunit includes a first oil-gas spring 10 and a second oil-gas spring 11; the upper ends of the first oil-gas spring 10 and the second oil-gas spring 11 are connected to the vehicle frame, and the lower ends are connected to the support shaft through supports; the upper chamber of the first oil-gas spring 10 is connected to the lower chamber of the second oil-gas spring 11, and is connected to the second accumulator 15; the lower chamber of the first oil-gas spring 10 is connected to the upper chamber of the second oil-gas spring 11, and is connected to the third accumulator 16; it is used to achieve balancing the load difference on the left and right sides of the driven rear axle under the premise of bearing the vertical load.

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

[0010] Furthermore, the balanced oil-gas suspension further comprises: 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 via a V-shaped thrust rod support 3A fixed to the upper wing surface of the driven rear axle support shaft;

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

[0013] Furthermore, the active steering hydraulic control subunit controls the oil flow between the active oil cylinder 2 and the centering oil cylinder 4 to achieve the deflection of the driven rear axle wheel using the steering gear 3, including the following process:

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

[0015] Furthermore, the active steering hydraulic control subunit controls the oil flow between the active oil cylinder 2 and the centering oil cylinder 4 to achieve the deflection of the driven rear axle wheel using the steering gear 3, and the process also includes:

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

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

[0018] When the vehicle is moving straight, the active cylinder 2 is in the middle position, and the 2A chamber of the active cylinder 2 is connected to the 2B chamber of the active cylinder 2, and the pressure in the 4A chamber of the centering cylinder 4 is the same as the pressure in the 4B chamber of the centering cylinder 4. At this time, the pressure in the 4C chamber of the centering cylinder 4 and the 4D chamber of the centering cylinder 4 are the pressure of the first accumulator 5. The floating pistons 41 and 42 in the 4C chamber of the centering cylinder 4 and the 4D chamber of the centering cylinder 4 are pressed on the internal limit of the centering cylinder 4 under the accumulator pressure. Because the force on the floating piston 42 is greater than the force on the floating piston 41, the piston rod of the centering cylinder 4 is pressed in the middle position by the floating pistons 41 and 42, and the driven rear axle wheels are in the straight moving state.

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

[0020] The front wheels are moving straight ahead, and the rear wheels of the driven axle are moving straight ahead;

[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 in the right-deflection state, and the rear wheel of the driven axle is in the left-deflection state.

[0023] Furthermore, the process of the oil-gas suspension hydraulic control subunit balancing the load difference between the left and right sides of the driven rear axle includes:

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

[0025] When the suspension is in load-bearing function, all solenoid valves in the control valve group 8 are de-energized. The oil in the lower chamber of the first oil-gas spring 10 communicates with the oil in the upper chamber of the second oil-gas spring 11 through the damping valve 93 and the 85th valve 85, and is then connected to the third accumulator 16. The oil in the upper chamber of the first oil-gas spring 10 communicates with the lower chamber of the second oil-gas spring 11 through the 91st valve 91 and the damping valve 94, and is then connected to the second accumulator 15. When the driven rear axle simultaneously bears vertical loads and jumps upward, the oil in the upper chamber of the first oil-gas spring 10 is compressed into the second accumulator 15. The oil in the upper chamber of the second oil-gas spring 11 is compressed into the third accumulator 16, and the air pressure in the stored energy cushions the upward shock.

[0026] When the driven rear axle jumps down, the volume of the upper chamber 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 chamber of the first oil-gas spring 11 increases under the action of the air pressure in the third accumulator 16 .

[0027] Furthermore, the oil-gas suspension hydraulic control subunit is also used to realize the lifting, lowering, arbitrary length locking and synchronous movement of the first oil-gas spring 10 and the second oil-gas spring 11 within their travel range.

[0028] Furthermore, the device is also used to achieve oil replenishment of the second accumulator 15 and the third accumulator 16 .

[0029] The effects provided in the summary of the invention are only the effects of the embodiments, not all the effects of the invention. One of the above technical solutions has the following advantages or beneficial effects:

[0030] The present invention proposes a matched balanced oil-gas suspension active steering driven rear axle device, comprising an active steering hydraulic control subunit and an oil-gas suspension hydraulic control subunit with a common oil source; the active steering hydraulic control subunit comprises a steering gear, an active oil cylinder fixed to a vehicle frame and connected to a steering rocker arm, and a centering oil cylinder installed on a driven rear axle support shaft and hinged to a steering knuckle arm, and the steering gear is used to realize the deflection and straightening of the driven rear axle wheels by controlling the oil flow direction between the active oil cylinder and the centering oil cylinder; the oil-gas suspension hydraulic control subunit comprises a first oil-gas spring and a second oil-gas spring; the upper ends of the first oil-gas spring and the second oil-gas spring are both connected to the vehicle frame, and the lower ends are both connected to the support shaft through supports; the upper chamber of the first oil-gas spring is connected to the lower chamber of the second oil-gas spring, and is connected to the second accumulator; the lower chamber of the first oil-gas spring is connected to the upper chamber of the second oil-gas spring, and is connected to the third accumulator; it is used to realize balancing the load difference between the left and right sides of the driven rear axle under the premise of bearing the vertical load. The present invention can realize main functions such as active steering of the vehicle following the front axle and locking of the rear wheels of the driven axle through "hydraulic system + electronic control". At the same time, it can also realize other functions such as wheel position correction of the driven axle wheels and accumulator oil replenishment, thereby simplifying use and maintenance.

[0031] The present invention can realize the active steering function of the driven rear axle following the front wheels. Under this function, the minimum turning circle diameter of the vehicle can be effectively reduced, and the vehicle's passability can be improved. This function is mainly used in low-speed and off-road operating conditions; it can realize the steering locking function of the rear wheels of the driven rear axle, that is, the driven rear axle does not turn with the steering of the front wheels. This function is mainly used in high-speed road driving conditions; the present invention can also realize the wheel position correction function and the accumulator oil replenishment function. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0033] Figure 2 A top view of the driven rear axle proposed in Example 1 of the present invention;

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

[0035] Legend:

[0036] 1A-V-type thrust rod, 3A-V-type thrust rod support, 4A-oil and gas spring support, 5A-first thrust rod mounting support, 6A-longitudinal thrust rod, 7A-second thrust rod mounting support, 8A-support shaft, 9A-transverse 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 oil-gas spring, 11-Second oil-gas 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 DESCRIPTION

[0038] In order to clearly illustrate the technical features of this solution, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings. The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. In addition, the present invention may repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplicity and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed. It should be noted that the components illustrated in the accompanying drawings are not necessarily drawn to scale. The present invention omits descriptions of well-known components and processing technologies and processes to avoid unnecessary limitations on the present invention.

[0039] Example 1

[0040] The present invention proposes an active steering driven rear axle device matched with a balanced oil-gas suspension, which is used to achieve better matching and application of active steering driven rear axles for multi-axle vehicles such as 10×4, improve the vehicle's adaptability to working conditions, and increase the convenience of use and maintenance.

[0041] The present invention proposes a matched balanced oil-gas suspension active steering driven rear axle device, comprising an active steering hydraulic control subunit and an oil-gas suspension hydraulic control subunit sharing an oil source;

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

[0043] The oil-gas suspension hydraulic control subunit includes a first oil-gas spring and a second oil-gas spring; the upper ends of the first oil-gas spring and the second oil-gas spring are connected to the vehicle frame, and the lower ends are connected to the support shaft through supports; the upper chamber of the first oil-gas spring is connected to the lower chamber of the second oil-gas spring, and is connected to the second accumulator; the lower chamber of the first oil-gas spring is connected to the upper chamber of the second oil-gas spring, and is connected to the third accumulator; it is used to achieve balancing the load difference on the left and right sides of the driven rear axle under the premise of bearing the vertical load.

[0044] The driven rear axle has a steering kingpin with an inclination angle and a steering tie rod 9A. It has the self-centering ability of a steering axle and is a driven load-bearing axle with steering centering ability.

[0045] The active steering hydraulic control subunit and the oil-gas suspension hydraulic control subunit share a common oil source and a common electric-hydraulic control module.

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

[0047] The driven rear axle oil-gas suspension structure is an oil-gas suspension using an oil-gas separation oil-gas spring structure, 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 oil-gas spring 10, a second oil-gas spring 11 and an oil-gas spring support 4A.

[0048] The V-shaped thrust rod 1A has a ball joint at its tip, and two symmetrical ball joints at its other end, located along the longitudinal plane of symmetry 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, mounted on the upper wing surface of the driven rear axle support shaft. Its other end is connected to the vehicle frame via two symmetrical ball joints along the longitudinal plane of symmetry of the vehicle frame. Two longitudinal thrust rods 6A, one on each side, are mounted on the lower wing surface 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 a gas spring support 4A, mounted on the driven rear axle support shaft. Their other ends are connected to the vehicle frame via the gas spring upper support. The V-shaped thrust rod 1A and the longitudinal thrust rods 6A of the suspension system are used to address both longitudinal and lateral forces during vehicle use. The gas springs buffer vertical forces and balance force deviations between the left and right sides of the driven rear axle.

[0049] Figure 3 This is the original diagram of the hydraulic control proposed in Example 1 of the present invention; the active steering hydraulic control subunit of the present application is composed of a double hydraulic pump 1 installed and fixed on the engine steering hydraulic pump connection interface, an active oil cylinder 2 hingedly installed and fixed on the frame and connected to the steering rocker arm, a steering gear 3, a centering oil cylinder 4 hingedly installed on 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, a safety valve group 7, etc.

[0050] The active steering hydraulic control subunit also includes an electro-hydraulic control module, which 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 resetting, accumulator oil replenishment and other functions by turning on and off the power of the solenoid valve, etc.

[0051] The active steering hydraulic control subunit in this application enables active steering, with the driven rear axle following the front wheels. This function is primarily suitable for low-speed (e.g., ≤60 km / h) and off-road operating conditions, effectively reducing the vehicle's minimum turning circle diameter and improving its maneuverability. In this function, all electromagnets DT1, DT2, DT3, DT4, DT5, DT6, DT7, DT8, and DT9 in the driven rear axle control valve group 6 are de-energized.

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

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

[0054] When the vehicle is moving straight, the active cylinder 2 is in the middle position, and the 2A chamber of the active cylinder 2 is connected to the 2B chamber of the active cylinder 2, and the pressure in the 4A chamber of the centering cylinder 4 is the same as the pressure in the 4B chamber of the centering cylinder 4. At this time, the pressure in the 4C chamber of the centering cylinder 4 and the 4D chamber of the centering cylinder 4 are the pressure of the first accumulator 5. The floating pistons 41 and 42 in the 4C chamber of the centering cylinder 4 and the 4D chamber of the centering cylinder 4 are pressed on the internal limit of the centering cylinder 4 under the accumulator pressure. Because the force on the floating piston 42 is greater than the force on the floating piston 41, the piston rod of the centering cylinder 4 is pressed in the middle position by the floating pistons 41 and 42, and the driven rear axle wheels are in the straight moving 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 will actively steer without following the steering of the front wheels. It is mainly used in high-speed road conditions and can effectively improve the vehicle's handling stability. The rear wheel steering lock must be operated when the vehicle is stationary. When the steering is locked, there are three operating conditions:

[0056] The first working condition: the front wheels are moving straight, and the rear wheels of the driven axle are moving straight

[0057] When this function switch is turned on, the electro-hydraulic control module detects the piston rod position 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 middle position, the DT7 in the driven rear axle control valve group 6 is energized, and the 2A chamber of the active cylinder 2 is connected to the 2B chamber of the active cylinder 2. At this time, no matter which chamber 2C or 2D of the active cylinder 2 is filled with oil, the oil in the 2A and 2B chambers flows and complements each other during the left and right movement of the active cylinder 2. The centering cylinder 4 is always in the middle position under the pressure of the first accumulator 5, and the driven rear axle wheels are in a straight-ahead state.

[0058] The second working condition: the front wheel deflects to the left, and the rear wheel of the driven axle deflects to the right

[0059] When this function switch is turned on, the electro-hydraulic control module detects the position of the piston rod of centering cylinder 4 via the sensor built into centering cylinder 2. If the piston rod of centering cylinder 4 is in the right-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 right-side small-displacement pump of the tandem pump passes through the 60th valve 60 and the 62nd valve 62 to port 4A of the centering cylinder. The oil from port 4B of centering cylinder 4 returns to the tank through the 61st valve 61 and the 60th valve 60. When the electro-hydraulic control module detects that the piston rod of 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 which point the rear wheels of the driven axle are in the straight-ahead state.

[0060] The third working condition: the front wheel deflects to the right, and the rear wheel of the driven axle deflects to the 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 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, and the oil of the small-displacement pump on the right side of the double pump is pumped to the 4B port of the centering cylinder 4 through the 60th valve 60 and the 61st valve 61, and the oil at the 4A port of the centering cylinder 4 is returned to the 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 middle position, the electromagnets DT2, DT3, DT4, DT5, DT6, DT7, and DT8 are de-energized and DT7 is energized. At this time, the rear wheel of the driven axle is in the straight-ahead state.

[0062] The active steering hydraulic control subunit in this invention can implement wheel position correction. During long-term use of the hydraulic system, minor oil leaks from the first accumulator 5 are inevitable, leading to a decrease in pressure. This can cause the centering cylinder 4, which should be in a neutral position, to shift slightly out of the neutral position, causing the driven rear axle wheels to slightly deviate from their straight-ahead position. Therefore, correction is necessary. Wheel position correction must be performed while the vehicle is stationary, under the following two operating conditions:

[0063] The first working condition: the rear driven axle wheel deflects slightly to the left

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

[0065] The second working condition: the rear driven axle wheel deflects slightly to the right

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

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

[0068] The first accumulator 5 is replenished after the rear driven axle's wheel position is corrected. After the electro-hydraulic control module completes wheel position correction, it automatically de-energizes all corresponding wheel position correction solenoids. DT2, DT3, DT6, and DT9 are then energized. Oil from the right-hand small-displacement pump of the duplex pump flows through valves 60, 61, and 63 to the first accumulator. Once the required pressure is reached, excess oil returns to the tank through valve 68. DT2, DT3, DT6, and DT9 are de-energized, completing the replenishment of the first accumulator.

[0069] In this application, whether the driven rear axle is in an active steering state following the front wheels, or the driven rear axle rear wheel steering is locked, the reversing function can be achieved without any extra operation.

[0070] exist Figure 3 In the system, the oil-gas suspension hydraulic control subunit and the active steering hydraulic control subunit share a controller, namely the electric-hydraulic control module.

[0071] The active steering hydraulic control subunit can realize the suspension load-bearing function. The important function of the suspension system is to alleviate the impact of the road. The first oil-gas spring 10 and the first oil-gas spring 11 are elastic elements in the system that bear the vertical load. As a specially designed balanced oil-gas suspension, it can balance the load difference on the left and right sides of the driven rear axle while bearing the vertical load.

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

[0073] When the suspension is in load-bearing function, all the solenoid valve electromagnets of the control valve group 8 are de-energized, and the oil in the lower chamber of the first oil-gas spring 10 is connected to the oil in the upper chamber of the second oil-gas spring 11 through the damping valve 93, the eighty-fifth valve 85, and the third accumulator 16; the oil in the upper chamber of the first oil-gas spring 10 is connected to the lower chamber of the second oil-gas spring 11 through the ninety-first valve 91 and the damping valve 94, and is connected to the second accumulator 15; when the driven rear axle simultaneously bears the vertical load and jumps up, the oil in the upper chamber of the first oil-gas spring 10 is compressed to the second accumulator 15; the oil in the upper chamber of the second oil-gas spring 11 is compressed to the third accumulator 16 and relies on the air pressure in the energy storage to buffer the impact of the jump; when the driven rear axle jumps down, the volume of the upper chamber 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 chamber of the first oil-gas spring 11 increases under the action of the air pressure in the third accumulator 16.

[0074] When the wheels on the left or right side of the driven rear axle are lifted on one side due to an obstacle, the load on the lifted side increases, the upper chamber of the oil and gas spring on the corresponding side is compressed, and the pressure increases. The increased oil pressure will inevitably lead to an increase in the oil pressure in the lower chamber of the oil and gas spring on the non-lifted side, pushing the oil and gas spring on the non-lifted side to compress the oil in the upper chamber, thereby increasing the load on the oil and gas spring on the non-lifted side to reduce the force on the oil and gas spring on the lifted side. This is equivalent to transferring the force of the oil and gas spring on the lifted side with greater force to the non-lifted side to balance the force on the left and right sides of the driven rear axle.

[0075] In the present application, the hydraulic control subunit of the oil-gas suspension realizes the lifting, lowering, arbitrary length locking and action synchronization of the oil-gas spring within its travel range.

[0076] This function is mainly used to solve the problem that the first and fifth bridges (or the first, second and fifth bridges) are subjected to force and the drive axle is suspended in the air when the vehicle passes through low-lying areas such as bridge tunnels. It also solves the problem that the rear drive wheels of the vehicle are stuck in mud and cannot be easily freed when the vehicle passes through soft terrain. When the drive axle cannot provide driving force when passing through low-lying areas, the driven rear axle can be raised until the drive axle has a good contact with the ground, at which point the drive force can be provided for the vehicle to move forward. When stuck in muddy areas, the driven rear axle can be lowered to jack up the vehicle to assist in getting out of trouble.

[0077] The hydro-pneumatic spring locking function is activated when the vehicle is stationary. When the hydro-pneumatic suspension control function in the cab is selected, the active steering function is deactivated.

[0078] Select the oil-gas spring lifting function. At this time, the electromagnet DT1 of the active steering control valve group 6 is energized, and DT22, DT28, DT36, DT27, DT25, DT35, DT33, DT32, and DT24 of the oil-gas suspension control valve group 8 are energized. The oil 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 oil-gas suspension control valve group 8 to the lower chamber of the first oil-gas spring 10, and flows 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 oil-gas suspension control valve group 8 to the lower chamber of the second oil-gas spring 11. The upper chambers of the first oil-gas spring 10 and the second oil-gas spring 11 are compressed, and the oil in the upper chamber of the first oil-gas spring 10 flows back to the oil tank through the 82nd valve 82 and the 81st valve 81, and the oil in the upper chamber of the second oil-gas spring 11 flows back to the oil tank through the 87th valve 87 and the 81st valve 81. When the rising function is activated, the stop switch corresponding to the rising function is selected, the electromagnet DT1 of the active steering control valve group 6 is powered off, and all the oil-gas suspension control valve group 8 except DT27, DT25, DT35, and DT33 are powered off, and the first oil-gas spring 10 and the second oil-gas spring 11 are both locked.

[0079] Select the oil-gas spring descending function. At this time, 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 oil-gas suspension control valve group 8 are energized. The oil 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 oil-gas suspension control valve group 8 to the upper chamber of the first oil-gas spring 10, and then flows through the active steering control valve group 6. The oil in the upper chambers of the first and second oil-gas springs 10 and 11 increases, flowing through the 60th valve 60 of the control valve group 6, the 81st valve 81, and the 87th valve 87 of the oil-gas suspension control valve group 8, and into the upper chamber of the second oil-gas spring 11. The oil in the lower chamber of the first oil-gas spring 10 flows back to the tank via the 93rd valve 93, the 86th valve 86, and the 81st valve 81. The oil in the lower chamber of the second oil-gas spring 11 flows back to the tank via the 94th valve 94, the 82nd valve 82, and the 81st valve 81. When the lowering function is activated, the corresponding stop switch is selected, de-energizing the solenoid DT1 of the active steering control valve group 6 and all other valves in the oil-gas suspension control valve group 8 except DT27, DT25, DT35, and DT33. The first and second oil-gas springs 10 and 11 are locked.

[0080] During the aforementioned lifting and lowering process, the weight on the left and right sides of the driven rear axle cannot be completely consistent when lifting, and the resistance cannot be completely consistent when lowering. This will cause the driven rear axle to lift and lower asynchronously. To solve this problem, the system monitors the stroke of the oil-gas springs during this process and adjusts the oil supply to the oil-gas springs in real time, so that the left and right oil-gas springs lift and lower synchronously. The specific implementation is as follows:

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

[0082] If during the lifting process, the second oil and gas spring 11 cannot follow the lifting of the first oil and gas spring 10, the electro-hydraulic control module automatically controls the corresponding solenoid valve to perform on-off control, and cuts off the power to DT28 and DT24 among DT1, DT22, DT28, DT36, DT27, DT25, DT35, DT33, DT32, and DT24 that were originally energized during the lifting process. At this time, the oil flows to the second oil and gas spring 11 until the stroke of the second oil and gas spring 11 is greater than the stroke of the first oil and gas spring 10 by a certain value (such as 5mm). At this time, the electro-hydraulic control module determines that the stroke of the first oil and gas spring 10 cannot keep up with the stroke of the second oil and gas spring 11. At this time, the de-energized DT28 and DT24 are energized, and DT32 and DT36 are de-energized. The oil flows to the first oil and gas spring 10 until the stroke of the first oil and gas spring 10 exceeds the stroke of the second oil and gas spring 11 by a certain value. The dynamic process is repeated to finally achieve synchronous lifting.

[0083] Second, asynchronous correction control during descent

[0084] If during the descent process, the second oil and gas spring 11 cannot follow the first oil and gas spring 10 to descend, the electro-hydraulic control module automatically controls the corresponding solenoid valve to perform on-off control, and DT28 among DT1, DT21, DT24, DT25, DT27, DT28, DT32, DT35, DT36, DT33, DT91, and DT82 that were originally energized during the descent process is de-energized, and DT23 is energized. At this time, the oil flows to the second oil and gas spring 11 until the stroke of the second oil and gas spring 11 is greater than the stroke of the first oil and gas spring 10 by a certain value (such as 5mm). At this time, the electro-hydraulic control module determines that the stroke of the first oil and gas spring 10 cannot keep up with the stroke of the second oil and gas spring 11. At this time, the de-energized DT28 is energized, DT36 is de-energized, and DT24 is energized. The oil flows to the first oil and gas spring 10 until the stroke of the first oil and gas spring 10 exceeds the stroke of the second oil and gas spring 11 by a certain value. The dynamic process is repeated to finally achieve descent and lifting.

[0085] Third, suspension empty and full load state adjustment

[0086] When the vehicle is stationary, select the function switch corresponding to the no-load or fully loaded mid-position function. The electro-hydraulic control module automatically adjusts the position of the gas spring according to the set mid-position value of the gas spring. The specific control method is similar to the lifting and lowering function operations.

[0087] Fourth, oil filling of gas spring accumulator

[0088] When the vehicle is stationary, select the oil-gas spring accumulator recharge function. The electro-hydraulic control module automatically detects the oil-gas spring accumulator pressure. If the pressure meets the set pressure, no recharge is performed. If the pressure is lower than the set pressure, recharge is performed. When recharging the second accumulator 15, DT1, DT21, DT24, DT31, and DT27 are energized. When the pressure in the second accumulator 15 reaches the set pressure, the power is automatically cut off. When recharging the third accumulator 16, DT1, DT21, DT23, DT32, and DT35 are energized. When the pressure in the third accumulator 16 reaches the set pressure, the power is automatically cut off.

[0089] Embodiment 1 of the present invention proposes a matched balanced oil-gas suspension active steering driven rear axle device, which adopts two oil-gas springs and can realize the main functions such as active steering of the vehicle following the front axle and locking of the rear wheels of the driven axle through "hydraulic system + electronic control". At the same time, it can also realize other functions such as wheel position correction of the driven axle and accumulator oil replenishment, thereby simplifying the use and maintenance work.

[0090] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device comprising a series of elements are inherent to the elements. In the absence of further restrictions, the elements limited by the statement "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device comprising the elements. In addition, the above-mentioned technical solutions provided in the embodiments of the present application are not described in detail in accordance with the corresponding technical solutions in the prior art to achieve the same principle, so as to avoid excessive elaboration.

[0091] Although the above description is of specific embodiments of the present invention in conjunction with the accompanying drawings, it does not limit the scope of protection of the present invention. For those skilled in the art, other different forms of modifications or variations can be made based on the above description. It is not necessary and impossible to list all embodiments here. Based on the technical solution of the present invention, various modifications or variations that can be made by those skilled in the art without expending creative effort are still within the scope of protection of the present invention.

Claims

1. A matched balanced oil-gas suspension active steering driven rear axle device, characterized in that: Including an active steering hydraulic control subunit and an oil-gas suspension hydraulic control subunit sharing a common oil source; The active steering hydraulic control subunit comprises a steering gear (3), an active oil cylinder (2) fixed to a vehicle frame and connected to a steering rocker arm, and a centering oil cylinder (4) installed on a driven rear axle support shaft and hinged to a steering knuckle arm. The steering gear (3) is used to realize the deflection and straight driving of the wheels of the driven rear axle by controlling the oil flow direction between the active oil cylinder (2) and the centering oil cylinder (4). The oil-gas suspension hydraulic control subunit comprises a first oil-gas spring (10) and a second oil-gas spring (11); the upper ends of the first oil-gas spring (10) and the second oil-gas spring (11) are connected to the vehicle frame, and the lower ends are connected to the support shaft through a support; the upper chamber of the first oil-gas spring (10) is connected to the lower chamber of the second oil-gas spring (11), and is connected to the second accumulator (15); the lower chamber of the first oil-gas spring (10) is connected to the upper chamber of the second oil-gas spring (11), and is connected to the third accumulator (16); and is used to achieve balancing the load difference between the left and right sides of the driven rear axle under the premise of bearing the vertical load.

2. The matched balanced oil-gas suspension active steering driven rear axle device according to claim 1, characterized in that: The first oil-gas spring (10) and the second oil-gas spring (11) are connected to the driven rear axle via corresponding oil-gas spring supports which are installed and fixed on the driven rear axle support shaft.

3. The matched balanced oil-gas suspension active steering driven rear axle device according to claim 1, characterized in that: The balanced oil-gas 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) which is fixedly mounted on the upper wing surface of the driven rear axle support shaft; The longitudinal thrust rod (6A) comprises a left longitudinal thrust rod and a right longitudinal thrust rod, both of which are installed on the lower wing surface of the support shaft.

4. The matched balanced oil-gas suspension active steering driven rear axle device according to claim 1, characterized in that: The process in which the active steering hydraulic control subunit controls the oil flow direction between the active oil cylinder (2) and the centering oil cylinder (4) and uses the steering gear (3) to realize the deflection of the driven rear axle wheel includes: When the front wheel turns right, oil enters port 2C of the active oil cylinder (2) and returns oil to port 2D. The piston rod of the active oil cylinder (2) moves rightward, squeezing the oil in the 2A cavity through the sixty-seventh valve (67) to port 4A of the centering oil cylinder (4). The oil in the corresponding cavity of port 4B passes through the sixty-fourth valve (64) to port 2B of the active oil cylinder (2). The oil corresponding to port 4D is compressed, part of which is replenished to cavity 4C and part of which is replenished to the first accumulator (5), so that the driven rear axle wheel deflects to the left.

5. The matched balanced oil-gas suspension active steering driven rear axle device according to claim 4, characterized in that: The process in which the active steering hydraulic control subunit controls the oil flow direction between the active oil cylinder (2) and the centering oil cylinder (4) and uses the steering gear (3) to realize the deflection of the driven rear axle wheel also includes: When the front wheel turns left, oil enters the 2D port of the active oil cylinder (2) and returns to the 2C port. The piston rod of the active oil cylinder (2) moves leftward, squeezing the oil in the 2B port to the 4B port of the centering oil cylinder (4) through the sixty-fourth valve (64). The oil in the corresponding cavity of the 4A port is sent to the 2A port of the active oil cylinder (2) through the sixty-seventh valve (67). The oil corresponding to the 4C port is compressed and replenished to the 4D cavity. At the same time, part of the oil in the first accumulator (5) also replenishes the 4D cavity, and the driven rear axle wheel deflects to the right.

6. The matched balanced oil-gas suspension active steering driven rear axle device according to claim 1, characterized in that: The process in which the active steering hydraulic control subunit controls the oil flow direction between the active oil cylinder (2) and the centering oil cylinder (4) and uses the steering gear (3) to achieve the straight-moving of the driven rear axle wheels includes: When the vehicle is in a straight-moving state, the active cylinder (2) is in a 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 of the centering cylinder (4) and the 4D chamber of the centering cylinder (4) are the pressure of the first accumulator (5). Under the accumulator pressure, the floating pistons (41) and (42) of the 4C chamber of the centering cylinder (4) and the 4D chamber of the centering cylinder (4) are pressed on the internal limit of the centering cylinder (4). Because the force on the floating piston (42) is greater than the force on the floating piston (41), the piston rod of the centering cylinder (4) is pressed in a neutral position by the floating pistons (41) and (42), and the driven rear axle wheels are in a straight-moving state.

7. The matched balanced oil-gas suspension active steering driven rear axle device according to claim 1, characterized in that: The active steering hydraulic control subunit is also used to realize the rear wheel steering lock function of the driven rear axle. When the steering is locked, it specifically includes: The front wheels are moving straight, and the rear wheels of the driven axle are moving straight; The front wheel is in the left-deflection state, and the rear wheel of the driven axle is in the right-deflection state; The front wheel is in the right-deflection state, and the rear wheel of the driven axle is in the left-deflection state.

8. The matched balanced oil-gas suspension active steering driven rear axle device according to claim 1, characterized in that: The process by which the hydro-pneumatic suspension hydraulic control subunit balances the load differences on the left and right sides of the driven rear axle includes: Under the premise of bearing the vertical load, balance the load difference between the left and right sides of the driven rear axle; When the suspension is in load-bearing function, all electromagnetic valves of the control valve group (8) are powered off, and the oil in the lower chamber of the first oil-gas spring (10) is connected to the oil in the upper chamber of the second oil-gas spring (11) through the damping valve (93) and the eighty-fifth valve (85), and is connected to the third accumulator (16); the oil in the upper chamber of the first oil-gas spring (10) is connected to the lower chamber of the second oil-gas spring (11) through the ninety-first valve (91) and the damping valve (94), and is connected to the second accumulator (15); when the driven rear axle is simultaneously subjected to the vertical load and jumps upward, the oil in the upper chamber of the first oil-gas spring (10) is compressed to the second accumulator (15); the oil in the upper chamber of the second oil-gas spring (11) is compressed to the third accumulator (16), and the air pressure in the accumulator buffers the upward shock; When the driven rear axle jumps down, the volume of the upper chamber of the first oil-gas spring (10) increases under the action of the air pressure in the second accumulator (15); and the volume of the upper chamber of the first oil-gas spring (11) increases under the action of the air pressure in the third accumulator (16).

9. The matched balanced oil-gas suspension active steering driven rear axle device according to claim 1, characterized in that: The oil-gas suspension hydraulic control subunit is also used to realize the lifting, lowering, arbitrary length locking and synchronous action of the first oil-gas spring (10) and the second oil-gas spring (11) within their travel range.

10. The matched balanced oil-gas suspension active steering driven rear axle device according to claim 1, characterized in that: The device is also used to realize oil replenishment of the second accumulator (15) and oil replenishment of the third accumulator (16).

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