All-wheel steering system of double-head vehicle, steering control method of double-head vehicle and double-head vehicle

Abstract

The invention relates to the technical field of vehicles, and provides a double-end vehicle all-wheel steering system, a double-end vehicle steering control method and a double-end vehicle. The all-wheel steering system of the double-headed vehicle comprises a front axle steering system, a rear axle steering system and a rear axle steering system, the front axle steering system comprises a front steering column, a front steering axle, a front hydraulic steering gear and a front electric driving part, and the front hydraulic steering gear is in transmission connection with the front steering axle; the front electric driving part is in transmission connection with the front hydraulic steering gear and used for connecting a first hydraulic oil way corresponding to the front hydraulic steering gear. The rear axle steering system comprises a rear steering column, a rear steering axle, a rear hydraulic steering gear and a rear electric driving part, and the rear hydraulic steering gear is in transmission connection with the rear steering axle; the rear electric driving part is in transmission connection with the rear hydraulic steering gear and used for connecting a second hydraulic oil way corresponding to the rear hydraulic steering gear. And the front electric driving piece and the rear electric driving piece are in communication connection with the steering controller. The system is simple in structure, low in cost and capable of guaranteeing the safety of forward and backward driving.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and in particular to an all-wheel steering system for a double-headed vehicle, a steering control method for a double-headed vehicle, and a double-headed vehicle. Background Art

[0002] With the continuous advancement of engineering technology and the diversification of engineering needs, commercial vehicles used for cargo, dumping, traction, rescue, etc. often encounter narrow and complex operating environments such as traffic tunnels or urban lanes, such as fire trucks quickly entering and exiting the rescue site. Traditional commercial vehicles often need a large space and time to turn around in a narrow space, which not only reduces work efficiency, but also may increase safety hazards.

[0003] In order to solve the problem of commercial vehicles having difficulty turning around in this operating environment, double-headed vehicles came into being. Double-headed vehicles have two cabs in the front and rear, which realize the function of two-way driving and greatly improve work efficiency and safety. In order to achieve all-wheel steering of double-headed vehicles, in the related technology, independent power steering gears and electronically controlled hydraulic power cylinders are configured on the front and rear steering axles, and the system structure is complex and costly. Alternatively, a power steering gear is only set for the front steering axle, and the same power steering gear is used to control the steering when driving forward and backward. When driving backward, the steering axle is the rear axle, and the operating mechanism is complex and there are safety risks. Summary of the invention

[0004] The present invention provides a double-headed vehicle all-wheel steering system, a double-headed vehicle steering control method and a double-headed vehicle, which are used to solve the problems of the double-headed vehicle all-wheel steering system in the prior art, such as complex structure, high cost and safety risk.

[0005] The present invention provides an all-wheel steering system for a double-headed vehicle, comprising: A front axle steering system, comprising a front steering column, a front steering axle, a front hydraulic steering gear and a front electric drive, wherein the front hydraulic steering gear is drivingly connected to the front steering axle; the front electric drive is drivingly connected to the front hydraulic steering gear and is used to connect a first hydraulic oil circuit corresponding to the front hydraulic steering gear; A rear axle steering system, comprising a rear steering column, a rear steering axle, a rear hydraulic steering gear and a rear electric drive member, wherein the rear hydraulic steering gear is drivingly connected to the rear steering axle; the rear electric drive member is drivingly connected to the rear hydraulic steering gear and is used to connect a second hydraulic oil circuit corresponding to the rear hydraulic steering gear; A steering controller, the front electric drive component and the rear electric drive component are respectively connected to the steering controller for communication.

[0006] According to the all-wheel steering system for a dual-head vehicle provided by the present invention, the front axle steering system further includes a first sensor, and the rear axle steering system further includes a second sensor; The first sensor and the second sensor are respectively connected to the steering controller for communication; the first sensor is used to detect the rotation angle and torque of the front steering column, and the second sensor is used to detect the rotation angle and torque of the rear steering column.

[0007] According to the all-wheel steering system for a dual-head vehicle provided by the present invention, the front axle steering system further includes a third sensor, and the rear axle steering system further includes a fourth sensor; The third sensor and the fourth sensor are respectively connected to the steering controller for communication; the third sensor is used to detect the rotation angle and torque of the front electric drive component, and the fourth sensor is used to detect the rotation angle and torque of the front electric drive component.

[0008] According to a double-headed vehicle all-wheel steering system provided by the present invention, the front steering column is connected to the input shaft of the front hydraulic steering gear for connecting the first hydraulic oil circuit; the rear steering column is connected to the input shaft of the rear hydraulic steering gear for connecting the second hydraulic oil circuit.

[0009] According to the present invention, a dual-head vehicle all-wheel steering system further comprises: A hydraulic pump, the front hydraulic steering gear and the rear hydraulic steering gear are respectively connected to the hydraulic pump through hydraulic pipelines, and the power input end of the hydraulic pump is suitable for transmission connection with the engine.

[0010] The present invention also provides a dual-head vehicle steering control method, which is used for any of the above dual-head vehicle all-wheel steering systems, comprising: In the case of forward driving, the steering controller obtains a first rotation parameter of the front steering column or the front electric drive member, determines a first control parameter according to the first rotation parameter, and controls the action of the rear electric drive member based on the first control parameter to connect or disconnect the second hydraulic oil circuit; When driving backward, the steering controller obtains a second rotation parameter of the rear steering column or the rear electric drive component, determines a second control parameter based on the second rotation parameter, and controls the action of the front electric drive component based on the second control parameter to connect or disconnect the first hydraulic oil circuit.

[0011] A dual-head vehicle steering control method provided by the present invention also includes: Get the steering mode and current vehicle speed; In the case of forward driving, the steering controller determines the first control parameter according to the steering mode, the first rotation parameter and the current vehicle speed; In the case of backward driving, the steering controller determines the second control parameter according to the steering mode, the second rotation parameter and the current vehicle speed.

[0012] According to a steering control method for a double-headed vehicle provided by the present invention, the steering modes include at least two of a single-bridge steering mode, a high-speed all-wheel steering mode, a low-speed all-wheel steering mode, a crab steering mode and a pure wire-controlled steering mode.

[0013] According to a steering control method for a double-headed vehicle provided by the present invention, in the high-speed all-wheel steering mode, the front steering axle and the rear steering axle move in the same direction; in the low-speed all-wheel steering mode, the front steering axle and the rear steering axle move in opposite directions; in the crab steering mode, the front steering axle and the rear steering axle move in the same direction, and the turning angle of the front wheels is the same as the turning angle of the rear wheels.

[0014] The present invention also provides a double-headed vehicle, comprising: a front cab, a rear cab and any one of the above-mentioned double-headed vehicle all-wheel steering systems; the front axle steering system is arranged below the front cab, and the rear axle steering system is arranged below the rear cab.

[0015] The double-headed vehicle all-wheel steering system, double-headed vehicle steering control method and double-headed vehicle provided by the present invention are provided with a front hydraulic steering gear, a rear hydraulic steering gear, a front electric drive and a rear electric drive, wherein the front electric drive is connected to the front hydraulic steering gear by transmission, and the rear electric drive is connected to the rear hydraulic steering gear by transmission. When driving forward, the first hydraulic oil circuit can be connected by manually operating the front steering column or by wire-controlled rear electric drive, and the second hydraulic oil circuit can be connected or disconnected by wire-controlled rear drive. When driving backward, the second hydraulic oil circuit can be connected by manually operating the rear steering column or by wire-controlled front electric drive, and the first hydraulic oil circuit can be connected or disconnected by wire-controlled front drive.

[0016] The all-wheel steering system of the dual-head vehicle can realize single-bridge steering mode and different all-wheel steering modes, and can meet the steering requirements in normal driving, high-speed driving, low-speed driving and fast lane change scenarios, and can also realize unmanned driving. The overall structure of the system is simple and the cost is low; the driving mode of forward driving and backward driving is exactly the same, ensuring driving safety; both can be conveniently and flexibly switched between single-bridge steering and all-wheel steering, and the steering mode switching is convenient; it can realize multi-axis independent steering, with high control accuracy, and is more in line with the Ackerman angle, which can reduce tire wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 The present invention provides a structural block diagram of the all-wheel steering system for a double-headed vehicle.

[0019] Figure 2 The present invention is a schematic diagram of the structure of a hydraulic system in the all-wheel steering system of a double-headed vehicle.

[0020] Figure 3 It is a schematic diagram of the chassis structure of the double-headed vehicle provided by the present invention.

[0021] Figure 4 The figure is a side view of the chassis structure of the double-headed vehicle provided by the present invention.

[0022] Figure 5 The figure is a top view of the chassis structure of the double-headed vehicle provided by the present invention.

[0023] Reference numerals: 100. Front axle steering system; 11. Front steering column; 12. Front steering axle; 13. Front hydraulic steering gear; 131. First rotary valve; 132. First power cylinder; 14. Front electric drive; 15. First sensor; 16. Third sensor; 200. Rear axle steering system; 21. Rear steering column; 22. Rear steering axle; 23. Rear hydraulic steering gear; 231. Second rotary valve; 232. Second power cylinder; 24. Rear electric drive; 25. Second sensor; 26. Fourth sensor; 300. Steering controller; 41. Rocker arm; 42. Tie rod; 5. Hydraulic pump. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "first"... "fourth" are for the purpose of clearly describing the numbering of product components and do not represent any substantial difference. The terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a connection between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances. "And / or" in the specification and claims means at least one of the connected objects, and the character " / " generally indicates that the previously associated objects are in an "or" relationship.

[0026] Combine the following Figure 1-Figure 5 The invention describes a double-headed vehicle all-wheel steering system, a double-headed vehicle steering control method and a double-headed vehicle.

[0027] like Figure 1 As shown, the all-wheel steering system for a double-headed vehicle provided by an embodiment of the present invention includes a front axle steering system 100, a rear axle steering system 200 and a steering controller 300. Among them, the front axle steering system 100 includes a front steering column 11, a front steering axle 12, a front hydraulic steering gear 13 and a front electric drive 14. The front hydraulic steering gear 13 is transmission-connected to the front steering axle 12. The front electric drive 14 is transmission-connected to the front hydraulic steering gear 13, and is used to connect the first hydraulic oil circuit corresponding to the front hydraulic steering gear 13. The rear axle steering system 200 includes a rear steering column 21, a rear steering axle 22, a rear hydraulic steering gear 23 and a rear electric drive 24, and the rear hydraulic steering gear 23 is transmission-connected to the rear steering axle 22. The rear electric drive 24 is transmission-connected to the rear hydraulic steering gear 23, and is used to connect the second hydraulic oil circuit corresponding to the rear hydraulic steering gear 23. The front electric drive 14 and the rear electric drive 24 are respectively connected to the steering controller 300 for communication.

[0028] When driving forward, the steering controller 300 is used to control the movement of the rear electric drive 24 according to the rotation of the front steering column 11 or the front electric drive 14 to connect the second hydraulic oil circuit corresponding to the rear hydraulic steering gear 23 .

[0029] When driving backward, the steering controller 300 is used to control the front electric drive 14 to operate according to the rotation of the rear steering column 21 or the rear electric drive 24 , so as to connect the first hydraulic oil circuit corresponding to the front hydraulic steering gear 13 .

[0030] like Figure 2 As shown, the front hydraulic steering gear 13 is provided with a first rotary valve 131 and a first booster cylinder 132. The first booster cylinder 132 is connected to a hydraulic pump via the first rotary valve 131. The first hydraulic oil circuit refers to the hydraulic oil circuit between the first booster cylinder 132 and the hydraulic pump. The front electric drive 14 is transmission-connected to the input shaft of the front hydraulic steering gear 13, and can drive the input shaft of the front hydraulic steering gear 13 to rotate so that the first rotary valve 131 is connected to the first hydraulic oil circuit. The front electric drive 14 can be a rotary motor or other electrically controllable rotary drive. When the front steering column 11 is transmission-connected to the front hydraulic steering gear 13, the rotation of the front steering column 11 can also connect the first rotary valve 131 to the first hydraulic oil circuit.

[0031] Similarly, the rear hydraulic steering gear 23 is provided with a second rotary valve 231 and a second booster cylinder 232, and the second booster cylinder 232 is connected to a hydraulic pump via the second rotary valve 231, and the second hydraulic oil circuit refers to the hydraulic oil circuit between the second booster cylinder 232 and the hydraulic pump. The rotation of the rear steering column 21 can connect the second rotary valve 231 to the second hydraulic oil circuit. The rear electric drive 24 is transmission-connected to the input shaft of the rear hydraulic steering gear 23, and can drive the input shaft of the rear hydraulic steering gear 23 to rotate, so that the second rotary valve 231 is connected to the second hydraulic oil circuit. The rear electric drive 24 can be a rotary motor or other electrically controllable rotary drive. When the rear steering column 21 is transmission-connected to the rear hydraulic steering gear 23, the rotation of the rear steering column 21 can also connect the second rotary valve 231 to the second hydraulic oil circuit.

[0032] When driving forward, the driver controls the front steering column 11 to rotate through the front steering wheel in the front cab, so that the first rotary valve 131 is connected to the first hydraulic oil circuit. The hydraulic pressure of the front hydraulic steering gear 13 is transmitted to the front steering axle 12 through the transmission mechanism, thereby driving the front steering axle 12 to perform the steering action. At the same time, the steering controller 300 controls the action of the rear electric drive 24 according to the rotation of the front steering column 11, and the rear electric drive 24 drives the input shaft of the rear hydraulic steering gear 23 to rotate, so that the second rotary valve 231 is connected to the second hydraulic oil circuit. The hydraulic pressure of the rear hydraulic steering gear 23 is transmitted to the rear steering axle 22 through the transmission mechanism, thereby driving the rear steering axle 22 to perform the steering action, and realizing the all-wheel steering mode of driving forward.

[0033] When driving backward, the driver controls the rear steering column 21 to rotate through the rear steering wheel in the rear cab, so that the second rotary valve 231 is connected to the second hydraulic oil circuit. The hydraulic pressure of the rear hydraulic steering gear 23 is transmitted to the rear steering axle 22 through the transmission mechanism, thereby driving the rear steering axle 22 to perform the steering action. At the same time, the steering controller 300 controls the front electric drive 14 to operate according to the rotation of the rear steering column 21, and the front electric drive 14 drives the input shaft of the front hydraulic steering gear 13 to rotate, so that the first rotary valve 131 is connected to the first hydraulic oil circuit. The hydraulic pressure of the front hydraulic steering gear 13 is transmitted to the front steering axle 12 through the transmission mechanism, thereby driving the front steering axle 12 to perform the steering action, and realizing the all-wheel steering mode for driving backward.

[0034] Since the front electric drive 14 and the rear electric drive 24 are provided, the steering controller 300 can directly control the front electric drive 14 and the rear electric drive 24 to respectively drive the input shafts of the front hydraulic steering gear 13 and the rear hydraulic steering gear 23 to rotate, so that the first rotary valve 131 connects to the first hydraulic oil circuit and the second rotary valve 231 connects to the second hydraulic oil circuit, thereby realizing a pure wire control steering mode. At this time, the driver does not need to perform steering operations on the front steering column 11 and the rear steering column 21, and unmanned driving can be realized.

[0035] When the driver manually controls the steering wheel to drive forward and backward, or when the driver manually controls the steering wheel to drive forward and backward, the steering controller 300 can control the rear electric drive 24 to adjust the rotation angle and direction of the input shaft of the rear hydraulic steering gear 23 to obtain different driving modes to adapt to different scenarios. When the driver manually controls the steering wheel to drive backward, the steering controller 300 can control the front electric drive 14 to adjust the rotation angle and direction of the input shaft of the front hydraulic steering gear 13 to obtain different driving modes to adapt to different driving scenarios.

[0036] When driving forward, the steering controller 300 controls the rear electric drive 24 to operate, so that the second rotary valve 231 cuts off the second hydraulic oil circuit, and the rear electric drive 24 locks the input shaft of the rear hydraulic steering gear 23, so that the front wheel steering is realized. Similarly, when driving backward, the steering controller 300 controls the front electric drive 14 to operate, so that the first rotary valve 131 cuts off the first hydraulic oil circuit, and the front electric drive 14 locks the input shaft of the front hydraulic steering gear 13, so that the rear wheel steering is realized. In this way, the single-bridge steering mode is realized.

[0037] When driving forward, the steering controller 300 controls the rear electric drive member 24 to rotate forward, so that the steering of the rear wheels is the same as that of the front wheels; similarly, when driving backward, the steering controller 300 controls the front electric drive member 14 to rotate forward, so that the steering of the front wheels is the same as that of the rear wheels. In this way, a high-speed all-wheel steering mode is realized. This all-wheel steering mode is suitable for vehicles driving at high speeds, so that the deflection angle between the vehicle body and the driving direction is reduced when the vehicle is turning, thereby improving the handling stability and ensuring the vehicle's stable steering on wet roads.

[0038] When driving forward, the steering controller 300 controls the rear electric drive member 24 to rotate forward, so that the steering of the rear wheels is the same as that of the front wheels, and the rotation angle is the same; similarly, when driving backward, the steering controller 300 controls the front electric drive member 14 to rotate forward, so that the steering of the front wheels is the same as that of the rear wheels, and the rotation angle is the same. In this way, the crab steering mode is realized. This all-wheel steering mode is suitable for vehicles to realize rapid lane changes in rescue conditions such as urban roads.

[0039] When driving forward, the steering controller 300 controls the rear electric drive member 24 to rotate in the opposite direction, so that the rear wheels turn in the opposite direction to the front wheels. Similarly, when driving backward, the steering controller 300 controls the front electric drive member 14 to rotate in the opposite direction, so that the front wheels turn in the opposite direction to the rear wheels. In this way, a low-speed all-wheel steering mode is achieved. This all-wheel steering mode is suitable for vehicles driving at low speeds. According to the Ackerman angle, the turning radius of the vehicle can be significantly reduced, making the vehicle more flexible.

[0040] The all-wheel steering system for a double-headed vehicle provided in an embodiment of the present invention is provided with a front hydraulic steering gear 13, a rear hydraulic steering gear 23, a front electric drive 14 and a rear electric drive 24, wherein the front electric drive 14 is transmission-connected to the front hydraulic steering gear 13, and the rear electric drive 24 is transmission-connected to the rear hydraulic steering gear 23. When driving forward, the first hydraulic oil circuit can be connected by manpower operating the front steering column 11 or by wire-controlling the rear electric drive 24, and the second hydraulic oil circuit can be connected or disconnected by wire-controlling the rear electric drive 24. When driving backward, the second hydraulic oil circuit can be connected by manpower operating the rear steering column 21 or by wire-controlling the front electric drive 14, and the first hydraulic oil circuit can be connected or disconnected by wire-controlling the front electric drive 14.

[0041] The all-wheel steering system of the dual-head vehicle can realize single-bridge steering mode and different all-wheel steering modes, and can meet the steering requirements in normal driving, high-speed driving, low-speed driving and fast lane change scenarios, and can also realize unmanned driving. The overall structure of the system is simple and the cost is low; the driving mode of forward driving and backward driving is exactly the same, ensuring driving safety; both can be conveniently and flexibly switched between single-bridge steering and all-wheel steering, and the steering mode switching is convenient; it can realize multi-axis independent steering, with high control accuracy, and is more in line with the Ackerman angle, which can reduce tire wear.

[0042] like Figure 3 As shown, in the embodiment of the present invention, the front steering column 11 is drivingly connected to the input shaft of the front hydraulic steering gear 13 for connecting the first hydraulic oil circuit. The rear steering column 21 is drivingly connected to the input shaft of the rear hydraulic steering gear 23 for connecting the second hydraulic oil circuit.

[0043] One end of the front steering column 11 is connected to the front steering wheel, and the other end is in driving connection with the input shaft of the front hydraulic steering gear 13, so that the first hydraulic oil circuit can be connected by manually operating the front steering wheel. One end of the rear steering column 21 is connected to the rear steering wheel, and the other end is in driving connection with the input shaft of the rear hydraulic steering gear 23, so that the second hydraulic oil circuit can be connected by manually operating the rear steering wheel.

[0044] In this embodiment, both the front steering column 11 and the front electric drive 14 can drive the input shaft of the front hydraulic steering gear 13 to rotate, so as to connect and disconnect the first hydraulic oil circuit, and there is no transmission interference between the front steering column 11 and the front electric drive 14. Both the rear steering column 21 and the rear electric drive 24 can drive the input shaft of the rear hydraulic steering gear 23 to transmit, so as to connect and disconnect the second hydraulic oil circuit, and there is no transmission interference between the front steering column 11 and the front electric drive 14.

[0045] It should be noted that the front steering column 11 may not be drivingly connected to the input shaft of the front hydraulic steering gear 13, and the rear steering column 21 may not be drivingly connected to the input shaft of the rear hydraulic steering gear 23. This can decouple the control system from the hydraulic system and realize pure wire-controlled steering.

[0046] like Figure 1 As shown, in the embodiment of the present invention, the front axle steering system 100 further includes a first sensor 15, and the rear axle steering system 200 further includes a second sensor 25. The first sensor 15 and the second sensor 25 are respectively connected to the steering controller 300 for communication. The first sensor 15 is used to detect the rotation angle and torque of the front steering column 11. The second sensor 25 is used to detect the rotation angle and torque of the rear steering column 21.

[0047] And / or, the front axle steering system 100 further includes a third sensor 16, and the rear axle steering system 200 further includes a fourth sensor 26. The third sensor 16 and the fourth sensor 26 are respectively connected to the steering controller 300 for communication. The third sensor 16 is used to detect the rotation angle and torque of the front electric drive 14. The fourth sensor 26 is used to detect the rotation angle and torque of the rear electric drive 24.

[0048] Specifically, the first sensor 15 is disposed on the front steering column 11 , and the second sensor 25 is disposed on the rear steering column 21 , the third sensor 16 is disposed on the front electric drive 14 , and the fourth sensor 26 is disposed on the rear electric drive 24 .

[0049] Wherein, when the first sensor 15 and the second sensor 25 are provided, the first hydraulic oil circuit can be connected by the driver manipulating the front steering wheel, the angle and torque of the front steering column 11 can be obtained through the first sensor 15, and the steering controller 300 controls the movement of the rear electric drive 24 according to the angle and torque. The second hydraulic oil circuit can be connected by the driver manipulating the rear steering wheel, the angle and torque of the rear steering column 21 can be obtained through the second sensor 25, and the steering controller 300 controls the movement of the front electric drive 14 according to the angle and torque.

[0050] In the case where the third sensor 16 and the fourth sensor 26 are provided, the first hydraulic oil circuit can be connected by means of wire-controlled front electric drive 14, the angle and torque of the front electric drive 14 can be obtained by the third sensor 16, and the steering controller 300 controls the movement of the rear electric drive 24 according to the angle and torque to achieve pure forward wire-controlled steering. The second hydraulic oil circuit can be connected by means of wire-controlled rear electric drive 24, the angle and torque of the rear electric drive 24 can be obtained by the fourth sensor 26, and the steering controller 300 controls the movement of the front electric drive 14 according to the angle and torque to achieve pure backward wire-controlled steering.

[0051] When the first sensor 15, the second sensor 25, the third sensor 16 and the fourth sensor 26 are provided at the same time, both of the above two driving modes are possible, that is, when driving forward or backward, steering can be performed by manpower operating the steering column, and steering can also be performed by the wire-controlled electric drive.

[0052] In pure steer-by-wire driving, the chassis controller sends the vehicle's driving curvature, angle, and angular velocity to the steering controller 300. When driving forward, the steering controller 300 determines the angle and torque of the rear electric drive 24 based on the angle and torque detected by the first sensor or the third sensor, as well as the current vehicle speed, curvature, angle, and angular velocity, and then controls the action of the rear electric drive 24 based on the angle and torque. When driving backward, the steering controller 300 determines the angle and torque of the front electric drive 14 based on the angle and torque sent by the second sensor or the fourth sensor, as well as the current vehicle speed, curvature, angle, and angular velocity, and then controls the action of the front electric drive 14 based on the angle and torque.

[0053] like Figure 3 , Figure 4 and Figure 5 As shown, the all-wheel steering system for a double-headed vehicle provided by the embodiment of the present invention further includes a rocker arm 41 and a tie rod 42. The front hydraulic steering gear 13 and the rear hydraulic steering gear 23 are both provided with mutually meshing worms and gear fans, the gear fan is coaxially connected to one end of the rocker arm 41, the other end of the rocker arm 41 is rotationally connected to one end of the tie rod 42, and the other end of the tie rod 42 is connected to the steering axle through a knuckle arm. The manpower and hydraulic thrust input by the steering wheel are amplified through the worm gear fan transmission, the gear fan drives the rocker arm 41 to swing, the swing of the rocker arm 41 drives the tie rod 42, and the tie rod 42 pushes the steering axle through the knuckle arm to rotate the wheel.

[0054] like Figure 2 As shown, the double-headed vehicle all-wheel steering system provided by the embodiment of the present invention also includes a hydraulic pump 5, the front hydraulic steering gear 13 and the rear hydraulic steering gear 23 are respectively connected to the hydraulic pump 5 through hydraulic pipelines, and the power input end of the hydraulic pump 5 is suitable for transmission connection with the engine.

[0055] It can be understood that the first rotary valve 131 of the front hydraulic steering gear 13 and the second rotary valve 231 of the rear hydraulic steering gear 23 are connected to the same hydraulic pump 5, which takes power from the engine and provides hydraulic power to the first booster cylinder 132 of the front hydraulic steering gear 13 and the second booster cylinder 232 of the rear hydraulic steering gear 23. This hydraulic transmission system has a simple structure and low cost.

[0056] The embodiment of the present invention further provides a dual-head vehicle steering control method, which is used in the dual-head vehicle all-wheel steering system described in the above embodiment, comprising: When driving forward, the steering controller 300 obtains the first rotation parameter of the front steering column 11 or the front electric drive 14, determines the first control parameter according to the first rotation parameter, and controls the rear electric drive 24 based on the first control parameter to connect or disconnect the second hydraulic oil circuit.

[0057] When driving backward, the steering controller 300 obtains the second rotation parameter of the rear steering column 21 or the rear electric drive component 24, determines the second control parameter according to the second rotation parameter, and controls the front electric drive component 14 based on the second control parameter to connect or disconnect the first hydraulic oil circuit.

[0058] The first rotation parameter of the front steering column 11 is detected by the first sensor. The first rotation parameter of the front electric drive 14 is detected by the third sensor. The second rotation parameter of the rear steering column 21 is detected by the second sensor. The second rotation parameter of the rear electric drive 24 is detected by the fourth sensor.

[0059] When driving forward, when the driver manually operates the steering wheel to drive the front steering column 11 to rotate to connect the first hydraulic oil circuit, the first rotation parameter is the rotation angle and torque of the front steering column 11. When the steering controller 300 controls the front electric drive 14 to rotate to connect the first hydraulic oil circuit, the first rotation parameter is the rotation angle and torque of the front electric drive 14.

[0060] The first control parameter is the rotation angle and torque of the rear electric drive 24. The steering controller 300 controls the rear electric drive 24 based on the first control parameter, so that the rear electric drive 24 drives the input shaft of the rear hydraulic steering gear 23 to rotate, and when the first rotary valve 131 is rotated to connect the second hydraulic oil circuit, all-wheel steering is achieved, and when the first rotary valve 131 is rotated to disconnect the second hydraulic oil circuit, single-bridge steering is achieved.

[0061] When driving backward, when the driver manually operates the steering wheel to drive the rear steering column 21 to rotate to connect the second hydraulic oil circuit, the second rotation parameter is the rotation angle and torque of the rear steering column 21. When the steering controller 300 controls the rear electric drive member 24 to rotate to connect the second hydraulic oil circuit, the second rotation parameter is the rotation angle and torque of the rear electric drive member 24.

[0062] The second control parameter is the rotation angle and torque of the front electric drive 14. The steering controller 300 controls the front electric drive 14 based on the second control parameter, so that the front electric drive 14 drives the input shaft of the front hydraulic steering gear 13 to rotate, and when the second rotary valve 231 is rotated to connect the first hydraulic oil circuit, all-wheel steering is achieved, and when the second rotary valve 231 is rotated to disconnect the first hydraulic oil circuit, single-bridge steering is achieved.

[0063] The dual-head vehicle steering control method provided by the embodiment of the present invention further includes acquiring a steering mode and a current vehicle speed.

[0064] In the case of forward driving, the steering controller 300 determines the first control parameter according to the steering mode, the first rotation parameter and the current vehicle speed.

[0065] In the case of backward driving, the steering controller 300 determines the second control parameter according to the steering mode, the second rotation parameter and the current vehicle speed.

[0066] In different steering modes, the relative relationship between the turning angle and direction of the front wheels and the turning angle and direction of the rear wheels will be different. In the case of different vehicle speeds, considering the safety and functionality of steering, it is also necessary to control the turning angle and direction of the front wheels and the turning angle and direction of the rear wheels. The steering controller 300 of this embodiment determines the first control parameter and the second control parameter according to the steering mode, the rotation parameter and the current vehicle speed, and can realize the switching of different steering modes to meet different steering function requirements while ensuring the safety of steering driving.

[0067] Among them, the steering mode can be selected by the driver from the control panel or control button, the steering controller 300 receives the steering mode switching control instruction information, and then calculates the first control parameter according to the first rotation parameter, or calculates the second control parameter according to the second rotation parameter.

[0068] In the embodiment of the present invention, the steering modes include at least two of a single-bridge steering mode, a high-speed all-wheel steering mode, a low-speed all-wheel steering mode, a crab steering mode, and a pure wire-controlled steering mode. The steering principles of these steering modes have been described in detail in the above embodiments and will not be repeated here.

[0069] In the wire control steering mode, the vehicle running curvature, angle and angular velocity are also obtained. In the case of forward driving and backward driving, the steering controller 300 determines the first control parameter or the second control parameter according to the vehicle running curvature, angle and angular velocity, so as to control the actions of the front electric drive member 14 and the rear electric drive member 24.

[0070] In the high-speed all-wheel steering mode, the front steering axle 12 and the rear steering axle 22 move in the same direction. In the low-speed all-wheel steering mode, the front steering axle 12 and the rear steering axle 22 move in opposite directions. In the crab steering mode, the front steering axle 12 and the rear steering axle 22 move in the same direction, and the steering angle of the front wheels is the same as the steering angle of the rear wheels.

[0071] Specifically, in the high-speed all-wheel steering mode, when driving forward, the steering controller 300 controls the rear electric drive 24 according to the first control parameter, drives the rear steering axle 22 to move in the same direction as the front steering axle 12, so that the rear wheels rotate in the same direction as the front wheels. When driving backward, the steering controller 300 controls the front electric drive 14 according to the second control parameter, drives the front steering axle 12 to move in the same direction as the rear steering axle 22, so that the front wheels rotate in the same direction as the rear wheels.

[0072] In the low-speed all-wheel steering mode, when driving forward, the steering controller 300 controls the rear electric drive 24 according to the first control parameter, drives the rear steering axle 22 to move in the opposite direction of the front steering axle 12, so that the rear wheels follow the front wheels to rotate in the opposite direction. When driving backward, the steering controller 300 controls the front electric drive 14 according to the second control parameter, drives the front steering axle 12 to move in the opposite direction of the rear steering axle 22, so that the front wheels follow the rear wheels to rotate in the opposite direction.

[0073] In the crab steering mode, when driving forward, the steering controller 300 controls the rear electric drive 24 according to the first control parameter, drives the rear steering axle 22 to move in the same direction as the front steering axle 12, and the movement amplitude is the same, so that the rear wheels follow the front wheels to deflect by the same angle. When driving forward, the steering controller 300 controls the front electric drive 14 according to the second control parameter, drives the front steering axle 12 to move in the same direction as the rear steering axle 22, and the movement amplitude is the same, so that the front wheels follow the rear wheels to deflect by the same angle.

[0074] The embodiment of the present invention further provides a double-headed vehicle, comprising a front cab, a rear cab and the double-headed vehicle all-wheel steering system described in any of the above embodiments. The front axle steering system 100 is arranged below the front cab. The rear axle steering system 200 is arranged below the rear cab.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual-head vehicle all-wheel steering system, characterized in that: include: A front axle steering system, comprising a front steering column, a front steering axle, a front hydraulic steering gear and a front electric drive, wherein the front hydraulic steering gear is drivingly connected to the front steering axle; the front electric drive is drivingly connected to the front hydraulic steering gear and is used to connect a first hydraulic oil circuit corresponding to the front hydraulic steering gear; A rear axle steering system, comprising a rear steering column, a rear steering axle, a rear hydraulic steering gear and a rear electric drive member, wherein the rear hydraulic steering gear is drivingly connected to the rear steering axle; the rear electric drive member is drivingly connected to the rear hydraulic steering gear and is used to connect a second hydraulic oil circuit corresponding to the rear hydraulic steering gear; A steering controller, the front electric drive component and the rear electric drive component are respectively connected to the steering controller for communication.

2. The all-wheel steering system for a double-headed vehicle according to claim 1, characterized in that: The front axle steering system further includes a first sensor, and the rear axle steering system further includes a second sensor; The first sensor and the second sensor are respectively connected to the steering controller for communication; the first sensor is used to detect the rotation angle and torque of the front steering column, and the second sensor is used to detect the rotation angle and torque of the rear steering column.

3. The all-wheel steering system for a double-headed vehicle according to claim 1, characterized in that: The front axle steering system further includes a third sensor, and the rear axle steering system further includes a fourth sensor; The third sensor and the fourth sensor are respectively connected to the steering controller for communication; the third sensor is used to detect the rotation angle and torque of the front electric drive component, and the fourth sensor is used to detect the rotation angle and torque of the rear electric drive component.

4. The all-wheel steering system for a double-headed vehicle according to claim 1, characterized in that: The front steering column is drivingly connected to the input shaft of the front hydraulic steering gear for connecting the first hydraulic oil circuit; the rear steering column is drivingly connected to the input shaft of the rear hydraulic steering gear for connecting the second hydraulic oil circuit.

5. The all-wheel steering system for a double-headed vehicle according to claim 1, characterized in that: Also includes: A hydraulic pump, the front hydraulic steering gear and the rear hydraulic steering gear are respectively connected to the hydraulic pump through hydraulic pipelines, and the power input end of the hydraulic pump is suitable for transmission connection with the engine.

6. A steering control method for a double-headed vehicle, used in the double-headed vehicle all-wheel steering system according to any one of claims 1 to 5, characterized in that: include: In the case of forward driving, the steering controller obtains a first rotation parameter of the front steering column or the front electric drive member, determines a first control parameter according to the first rotation parameter, and controls the action of the rear electric drive member based on the first control parameter to connect or disconnect the second hydraulic oil circuit; When driving backward, the steering controller obtains a second rotation parameter of the rear steering column or the rear electric drive component, determines a second control parameter based on the second rotation parameter, and controls the action of the front electric drive component based on the second control parameter to connect or disconnect the first hydraulic oil circuit.

7. The dual-head vehicle steering control method according to claim 6, characterized in that: Also includes: Get the steering mode and current vehicle speed; In the case of forward driving, the steering controller determines the first control parameter according to the steering mode, the first rotation parameter and the current vehicle speed; In the case of backward driving, the steering controller determines the second control parameter according to the steering mode, the second rotation parameter and the current vehicle speed.

8. The dual-head vehicle steering control method according to claim 7, characterized in that: The steering modes include at least two of a single-bridge steering mode, a high-speed all-wheel steering mode, a low-speed all-wheel steering mode, a crab steering mode and a pure wire-control steering mode.

9. The dual-head vehicle steering control method according to claim 8, characterized in that: In the high-speed all-wheel steering mode, the front steering axle and the rear steering axle move in the same direction; in the low-speed all-wheel steering mode, the front steering axle and the rear steering axle move in opposite directions; in the crab steering mode, the front steering axle and the rear steering axle move in the same direction, and the turning angle of the front wheels is the same as the turning angle of the rear wheels.

10. A double-headed vehicle, characterized in that: include: A front cab, a rear cab and an all-wheel steering system for a double-headed vehicle as claimed in claims 1 to 5; The front axle steering system is arranged below the front cab, and the rear axle steering system is arranged below the rear cab.

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