A multi-axle vehicle dual-side independent steering system

Abstract

The present application relates to the technical field of vehicle steering system, particularly relates to a kind of double-side independent steering system of multi-axle vehicle, including symmetrically arranged single-side independent steering mechanism, single-side independent steering mechanism includes drive assembly, drive assembly is connected with the front steering assembly for controlling the steering of vehicle front end, for controlling the steering of vehicle middle part intermediate steering assembly and for controlling the steering of vehicle rear end rear steering assembly, and intermediate steering assembly is arranged between front steering assembly and rear steering assembly;Drive assembly includes steering machine, and the transmission gear of steering machine is engaged with the front axle steering rack for driving front steering assembly action and the rear axle steering rack for driving rear steering assembly action.The present application is arranged by symmetric single-side independent steering mechanism, not only effectively reduce the occupation of chassis space by steering system;Every side of vehicle can also be independently steered, effectively improve the flexibility of steering and off-road performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle steering systems, in particular to a double-sided independent steering system for multi-axle vehicles. BACKGROUND

[0002] With the rapid development of transportation demand, multi-axle vehicles are widely used in military, engineering and other special vehicle fields due to their excellent load capacity and off-road performance. Special vehicles have higher demands in heavy load transportation, power performance and off-road passability. Therefore, the design of the steering system puts forward high requirements on performance, reliability and space utilization.

[0003] In traditional multi-axle vehicles, the Ackerman steering system has been the mainstream design for a long time due to its mechanical structure based on trapezoidal linkage. However, this design has significant shortcomings in multi-axle vehicle steering systems. The transverse trapezoidal linkage structure requires a large installation space, while the multi-axle vehicle chassis is complex and carries various equipment and power units, leaving limited space for the arrangement of the steering system. In addition, as the number of axles increases, the traditional design requires additional mechanical components for each steering axle, resulting in significant increases in system complexity, manufacturing cost and overall vehicle weight.

[0004] With the development of drive-by-wire technology, independent drive-by-wire steering systems have become a research hotspot. This system eliminates mechanical linkages and improves steering flexibility by independently controlling each steering wheel, reducing space occupation, and optimizing the dynamics and handling performance of multi-axle vehicles. However, the application of independent drive-by-wire steering in multi-axle vehicles still faces challenges. First, independent steering requires the configuration of actuators and steering motors for each steering wheel, which significantly increases system complexity and cost for multi-axle vehicles. Second, multi-axle steering requires precise coordinated control under different vehicle speeds and road conditions, and the real-time and accuracy requirements of the steering algorithm for the drive-by-wire system are extremely high. If the coordination is insufficient, it may cause tire slip, inconsistent steering or excessive power loss, seriously affecting the handling performance and stability of the vehicle.

[0005] Therefore, there is an urgent need for a double-sided independent steering system for multi-axle vehicles that can reduce space occupation and improve overall steering performance. SUMMARY

[0006] The purpose of the present application is to provide a double-sided independent steering system for multi-axle vehicles to solve the problems existing in the prior art.

[0007] In order to achieve the above object, the application provides a kind of multi-axle vehicle double-side independent steering system, including symmetrically arranged single-side independent steering mechanism, the single-side independent steering mechanism includes drive assembly, the drive assembly is transmission connected with the front steering assembly for controlling the steering of vehicle front end, the intermediate steering assembly for controlling the steering of vehicle middle part and the rear steering assembly for controlling the steering of vehicle tail end, the intermediate steering assembly is arranged between the front steering assembly and the rear steering assembly;The drive assembly includes steering machine, the transmission gear of the steering machine is engaged with the front axle steering rack for driving the front steering assembly to act and the rear axle steering rack for driving the rear steering assembly to act.

[0008] Preferably, the front axle steering rack and the rear axle steering rack are symmetrically arranged.

[0009] Preferably, the front steering assembly includes front wheel, the front wheel is connected with front axle steering rocker arm, and the front axle steering rocker arm is transmission connected with the front axle steering rack through front axle steering pull rod.

[0010] Preferably, the front wheel is hinged with front wheel kingpin through front axle steering knuckle, so that the front wheel rotates around the front wheel kingpin.

[0011] Preferably, the rear steering assembly includes rear wheel, the rear wheel is connected with rear axle steering rocker arm, and the rear axle steering rocker arm is transmission connected with the rear axle steering rack through rear axle steering pull rod.

[0012] Preferably, the rear wheel is hinged with rear wheel kingpin through rear axle steering knuckle, so that the rear wheel rotates around the rear wheel kingpin.

[0013] Preferably, the intermediate steering assembly includes second axle wheel and third axle wheel, the second axle wheel is arranged close to the front wheel, and the third axle wheel is arranged close to the rear wheel.

[0014] Preferably, the second axle wheel is connected with second axle steering rocker arm, and the second axle steering rocker arm is connected with the front axle steering pull rod.

[0015] Preferably, the third axle wheel is connected with third axle steering rocker arm, and the third axle steering rocker arm is connected with the rear axle steering pull rod.

[0016] Preferably, the second axle wheel is hinged with second axle kingpin through second axle steering knuckle, so that the second axle wheel rotates around the second axle kingpin; and the third axle wheel is hinged with third axle kingpin through third axle steering knuckle, so that the third axle wheel rotates around the third axle kingpin.

[0017] The application discloses the following technical effects:

[0018] The application effectively reduces the occupation of the chassis space by the steering system through the symmetrically arranged single-side independent steering mechanism, provides greater freedom for the suspension and power unit arrangement, and enables each side of the vehicle to independently steer, thereby effectively improving the steering flexibility and off-road performance of the multi-axle vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description only constitute some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0020] Figure 1 It is a schematic diagram of the two-axle vehicle bilateral independent steering structure of the present application.

[0021] Figure 2 It is a schematic diagram of the three-axle vehicle bilateral independent steering structure of the present application.

[0022] Figure 3 It is a schematic diagram of the four-axle vehicle bilateral independent steering structure of the present application.

[0023] Figure 4 It is a schematic diagram of the relationship between the steering rack displacement and the wheel rotation angle of the present application.

[0024] Figure 5 It is a curve diagram of the relationship between the steering rack displacement and the wheel rotation angle of the present application.

[0025] Figure 6 It is a schematic diagram of the left-turn process of the two-axle vehicle bilateral independent steering of the present application.

[0026] Figure 7 It is a schematic diagram of the instantaneous steering center of the two-axle vehicle bilateral independent steering of the present application.

[0027] Figure 8 It is a schematic diagram of the left-turn process of the three-axle vehicle bilateral independent steering of the present application.

[0028] Figure 9 It is a schematic diagram of the instantaneous steering center of the three-axle vehicle bilateral independent steering of the present application.

[0029] Figure 10 It is a schematic diagram of the left-turn process of the four-axle vehicle bilateral independent steering of the present application.

[0030] Figure 11 It is a schematic diagram of the instantaneous steering center of the four-axle vehicle bilateral independent steering of the present application.

[0031] Wherein, 1, front wheel kingpin; 2, front axle knuckle; 3, front wheel; 4, front axle steering arm; 5, front axle steering drag link; 6, front axle steering rack; 7, steering machine; 8, rear axle steering rack; 9, rear axle steering drag link; 10, rear axle steering arm; 11, rear axle knuckle; 12, rear wheel; 13, rear wheel kingpin; 14, second axle kingpin; 15, second axle wheel; 16, second axle knuckle; 17, second axle steering arm; 18, third axle wheel; 19, third axle steering arm; 20, third axle knuckle; 21, third axle kingpin. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0033] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0034] With reference to Figures 1-11 The present application provides a kind of multi-axle vehicle double-side independent steering system, including symmetrically arranged single-side independent steering mechanism, single-side independent steering mechanism includes drive assembly, drive assembly is connected with for controlling the front end of vehicle steering front steering assembly, for controlling the steering of vehicle middle part intermediate steering assembly and for controlling the steering of vehicle tail end rear steering assembly, intermediate steering assembly is arranged between front steering assembly and rear steering assembly;Drive assembly includes steering machine 7, the transmission gear of steering machine 7 is engaged with for driving front steering assembly to act front axle steering rack 6 and for driving rear steering assembly to act rear axle steering rack 8.Front axle steering rack 6 and rear axle steering rack 8 are limited along the front-back direction of vehicle and translate.

[0035] The present application is arranged by symmetrically arranged single-side independent steering mechanism, not only effectively reduces the occupation of chassis space by steering system, provides greater freedom for suspension and power unit arrangement;Also can make each side of vehicle can carry out independent steering;Effectively improve the steering flexibility and off-road performance of multi-axle vehicle.

[0036] Steering machine 7 is the key component in the steering system of automobile, mainly for controlling the direction of vehicle steering, helps driver to accurately control vehicle. Its function is to change the steering torque and steering angle from steering wheel appropriately, and then output to steering drag link mechanism, so as to realize automobile steering. Steering machine 7 is a speed reduction transmission device, which can increase the force transmitted from steering wheel to steering transmission mechanism, and change the transmission of force.

[0037] The transmission gear of the steering machine 7 synchronously drives the front axle steering rack 6 and the rear axle steering rack 8 to act, so that the front axle steering rack 6 can effectively drive the front steering assembly to act, and the rear axle steering rack 8 can effectively drive the rear steering assembly to act, so that each side of the vehicle can be independently steered.

[0038] The rack and pinion steering gear: simple structure, compact, large stiffness, low cost, sensitive steering, high forward and reverse attack rate, easy to arrange, suitable for cars and micro and light trucks.

[0039] The recirculating ball steering gear: flexible steering, large steering torque, suitable for high-speed steering occasions such as highways.

[0040] The worm crank pin steering gear: complex structure, but large steering torque, suitable for large vehicles.

[0041] Further optimization scheme, the front axle steering rack 6 and the rear axle steering rack 8 are symmetrically arranged. The front axle steering rack 6 and the rear axle steering rack 8 can act synchronously.

[0042] Further optimization scheme, the front steering assembly includes a front wheel 3, the front wheel 3 is connected with a front axle steering rocker arm 4, and the front axle steering rocker arm 4 is in transmission connection with the front axle steering rack 6 through a front axle steering drag link 5.

[0043] Further optimization scheme, the front wheel 3 is hinged with a front wheel kingpin 1 through a front axle steering knuckle 2, so that the front wheel 3 can rotate around the front wheel kingpin 1.

[0044] The front axle steering drag link 5 is driven by the front axle steering rack 6 to act, the front axle steering rocker arm 4 is driven by the front axle steering drag link 5 to act, and the front axle steering rocker arm 4 can drive the front wheel 3 to act, so that the front wheel 3 can stably rotate around the front wheel kingpin 1 through the front axle steering knuckle 2, and the steering action of the front wheel 3 is completed.

[0045] Further optimization scheme, the rear steering assembly includes a rear wheel 12, the rear wheel 12 is connected with a rear axle steering rocker arm 10, and the rear axle steering rocker arm 10 is in transmission connection with the rear axle steering rack 8 through a rear axle steering drag link 9.

[0046] Further optimization scheme, the rear wheel 12 is hinged with a rear wheel kingpin 13 through a rear axle steering knuckle 11, so that the rear wheel 12 can rotate around the rear wheel kingpin 13.

[0047] The rear axle steering drag link 9 is driven by the rear axle steering rack 8 to act, the rear axle steering rocker arm 10 is driven by the rear axle steering drag link 9 to act, and the rear axle steering rocker arm 10 can drive the rear wheel 12 to act, so that the rear wheel 12 can stably rotate around the rear wheel kingpin 13 through the rear axle steering knuckle 11, and the steering action of the rear wheel 12 is completed.

[0048] Further optimization scheme, the intermediate steering assembly includes the second axle wheel 15 and the third axle wheel 18, the second axle wheel 15 is arranged close to the front wheel 3, and the third axle wheel 18 is arranged close to the rear wheel 12.

[0049] Further optimization scheme, the second axle wheel 15 is connected with the second axle steering rocker arm 17, and the second axle steering rocker arm 17 is connected with the front axle steering drag link 5.

[0050] Further optimization scheme, the third axle wheel 18 is connected with the third axle steering rocker arm 19, and the third axle steering rocker arm 19 is connected with the rear axle steering drag link 9.

[0051] Further optimization scheme, the second axle wheel 15 is hinged with the second axle kingpin 14 through the second axle steering knuckle 16, so that the second axle wheel 15 rotates around the second axle kingpin 14; the third axle wheel 18 is hinged with the third axle kingpin 21 through the third axle steering knuckle 20, so that the third axle wheel 18 rotates around the third axle kingpin 21.

[0052] The front axle steering drag link 5 is driven to move by the front axle steering rack 6, the second axle steering rocker arm 17 is driven to move by the front axle steering drag link 5, the second axle steering rocker arm 17 can drive the second axle wheel 15 to move, so that the second axle wheel 15 can stably rotate around the second axle kingpin 14 through the second axle steering knuckle 16, and the steering action of the second axle wheel 15 is completed.

[0053] The rear axle steering drag link 9 is driven to move by the rear axle steering rack 8, the third axle steering rocker arm 19 is driven to move by the rear axle steering drag link 9, the third axle steering rocker arm 19 can drive the third axle wheel 18 to move, so that the third axle wheel 18 can stably rotate around the third axle kingpin 21 through the third axle steering knuckle 20, and the steering action of the third axle wheel 18 is completed.

[0054] The present application cancels the traditional trapezoidal transverse connecting rod structure, optimizes the space utilization rate of the vehicle, and can realize the adjustment of the wheel rotation angles of the left and right sides of the vehicle through the single-side independent steering mechanism on the two sides of the vehicle, while supporting the multi-wheel coordinated control and reverse steering functions, and effectively improving the steering flexibility of the vehicle.

[0055] The intermediate steering assembly can be flexibly adjusted according to different vehicles.

[0056] Working process:

[0057] The steering wheel rotation angle input signal is transmitted to the steering mechanisms 7 on the two sides through the vehicle control unit (VCU), the transmission gears of the steering mechanisms 7 synchronously drive the front axle steering rack 6 and the rear axle steering rack 8 to move, linear displacement is generated, the front axle steering rocker arm 4 and the rear axle steering rocker arm 10 are respectively rotated through the front axle steering drag link 5 and the rear axle steering drag link 9, so that the front wheel 3 and the rear wheel 12 generate a steering angle.

[0058] With reference to Figures 4-5 , the relationship between rack displacement Δx and wheel angle δ can be obtained by using the planar mechanism motion analysis vector equation graphic method as follows

[0059]

[0060] In the formula, x0 is the initial position of the steering rack relative to the steering kingpin; Δx is the steering rack displacement; l AB is the distance from the steering kingpin to the intersection of the steering rocker and the steering tie rod; θ is the initial angle of the steering rocker; δ is the wheel angle; l BC is the straight-line distance of the steering tie rod BC point; e is the offset distance of the rack and the steering kingpin.

[0061] Based on the relationship between the steering rack displacement and the wheel angle of the double-sided independent steering system, the numerical solution is obtained by using the numerical iteration method given the design parameters, and the relationship curve between the steering rack displacement Δx and the wheel angle δ is obtained, which is used as a calibration curve for optimizing the steering ratio or steering control.

[0062] With reference to Figure 1 and Figure 6 When a two-axle vehicle is used, no intermediate steering component is installed, only front and rear steering components are installed, and the left turning process of the two-axle vehicle is as follows: the steering wheel angle input signal is transmitted to the two sides of the steering machine 7 through the vehicle control unit (VCU). The steering machine 7 rotates clockwise to drive the front axle steering rack 6 to displace forward, and then drives the front axle steering rocker 4 to rotate counterclockwise by pushing the front axle steering tie rod 5, so that the left front wheel 3 rotates around the front wheel kingpin 1 to generate a left turning angle; at the same time, the rear axle steering rack 8 is driven to displace backward, and then the rear axle steering rocker 10 is driven to rotate clockwise by pushing the rear axle steering tie rod 9, so that the left rear wheel 12 rotates around the rear wheel kingpin 13 to generate a right turning angle; similarly, the right steering machine 7 drives the front axle steering rack 6 and the rear axle steering rack 8 to move linearly, and drives the front axle steering rocker 4 and the rear axle steering rocker 10 to rotate through the front axle steering tie rod 5 and the rear axle steering tie rod 9 respectively, so that the front wheel 3 and the rear wheel 12 generate left and right turning angles respectively; the right turning process of the two-axle vehicle is the same as the left turning process, that is, when turning right, the steering machine 7 rotates counterclockwise.

[0063] With reference to Figure 7 , the vehicle control unit (VCU) calculates the control signals of the left and right steering motors according to the steering wheel input signal and the real-time state of the vehicle, so as to accurately determine the turning angle relationship of the left and right wheels; the relationship is calculated based on the instantaneous center of rotation (ICR) principle, which ensures that the wheels meet the pure rolling condition during turning, thereby effectively avoiding tire slip phenomenon, prolonging the service life of the tire, and improving the steering performance and control stability of the vehicle.

[0064] With reference toFigure 2 and Figures 8-9 When a three-axle vehicle is used, the middle steering assembly is installed at the second axle wheel 15, and since the second axle wheel 15 of the three-axle vehicle is located at the longitudinal center of the vehicle, and the tire track is always consistent with the vertical direction of the instantaneous steering center, therefore, the middle steering assembly of the three-axle vehicle does not need to be steered; the second axle wheel 15 remains fixed in the direction to meet the geometric constraints of the vehicle steering, thereby simplifying the structure of the steering system, reducing the complexity and manufacturing cost of the system.

[0065] With reference to Figure 3 and Figures 10-11 When a four-axle vehicle is used, the front steering assembly for controlling the steering of the front end of the vehicle, the middle steering assembly for controlling the steering of the middle part of the vehicle, and the rear steering assembly for controlling the steering of the tail end of the vehicle are all installed; when turning left, the steering machine 7 rotates clockwise to drive the front axle steering rack 6 to displace forward, and then drives the second axle steering rocker arm 17 to rotate counterclockwise by pushing the front axle steering pull rod 5, so that the left second axle wheel 15 rotates counterclockwise around the second axle kingpin 14 to generate a left turning angle. At the same time, the rear axle steering rack 8 is displaced backward, and the third axle steering rocker arm 19 is rotated clockwise by pushing the rear axle steering pull rod 9, so that the left third axle wheel 18 rotates clockwise around the third axle kingpin 21 to generate a right turning angle; at the same time, the right steering machine 7 pulls the right front axle steering pull rod 5 and the rear axle steering pull rod 9 to make the right front wheel 3 and the rear wheel 12 generate left and right turning angles, respectively; the right turning process of the four-axle vehicle is the same as the left turning process, that is, when turning right, the steering machine 7 rotates counterclockwise.

[0066] The turning angle of the second axle wheel 15 is smaller than that of the front wheel 3, and the turning angle of the third axle wheel 18 is smaller than that of the rear wheel 12, which can meet the pure rolling condition of each wheel in the steering process, thereby effectively avoiding tire slip phenomenon.

[0067] Through the steering machines 7 on both sides of the vehicle, reverse steering of multiple wheels of various multi-axle vehicles can be realized, the turning radius is reduced, and the flexibility of the vehicle is improved.

[0068] The present application effectively reduces the occupation of the steering system to the chassis space by canceling the traditional trapezoidal linkage design, provides greater freedom for suspension and power unit arrangement, and solves the problems of complex chassis and limited layout space of multi-axle vehicles; the present application can realize accurate regulation and control of the turning angles of the left and right wheels of the vehicle through the single-sided independent steering mechanism on both sides of the vehicle, supports multi-wheel coordinated control and reverse steering function, reduces the turning radius, and effectively improves the flexibility and handling performance of the vehicle; at the same time, the present application can also meet the steering requirements of two-axle, three-axle, four-axle and even more multi-axle vehicles for vehicles with different numbers of axles, and is suitable for the application of various special vehicles in heavy load transportation and off-road scenes.

[0069] In the description of the present application, it is to be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are intended to indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0070] The above-described embodiments are only to describe the preferred modes of the present application, and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A dual-side independent steering system for a multi-axle vehicle, characterized in that: The system includes a symmetrically arranged single-sided independent steering mechanism. The single-sided independent steering mechanism includes a drive assembly. The drive assembly is drively connected to a front steering assembly for controlling the steering of the front end of the vehicle, an intermediate steering assembly for controlling the steering of the middle part of the vehicle, and a rear steering assembly for controlling the steering of the rear end of the vehicle. The intermediate steering assembly is disposed between the front steering assembly and the rear steering assembly. The drive assembly includes a steering gear (7), the transmission gear of which meshes with a front axle steering rack (6) for driving the front steering assembly and a rear axle steering rack (8) for driving the rear steering assembly. The front steering assembly includes a front wheel (3), the front wheel (3) is connected to a front axle steering rocker arm (4), and the front axle steering rocker arm (4) is connected to the front axle steering rack (6) via a front axle steering tie rod (5). The rear steering assembly includes a rear wheel (12), the rear wheel (12) is connected to a rear axle steering rocker arm (10), and the rear axle steering rocker arm (10) is connected to the rear axle steering rack (8) via a rear axle steering tie rod (9). The intermediate steering assembly includes a second axle wheel (15) and a third axle wheel (18), with the second axle wheel (15) positioned close to the front wheel (3) and the third axle wheel (18) positioned close to the rear wheel (12). The second axle wheel (15) is connected to the second axle steering rocker arm (17), which is connected to the front axle steering tie rod (5).

2. The multi-axle vehicle dual-side independent steering system according to claim 1, characterized in that: The front axle steering rack (6) is symmetrically arranged with respect to the rear axle steering rack (8).

3. The multi-axle vehicle dual-side independent steering system according to claim 1, characterized in that: The front wheel (3) is hinged to the front wheel kingpin (1) via the front axle steering knuckle (2), so that the front wheel (3) rotates around the front wheel kingpin (1).

4. The multi-axle vehicle dual-side independent steering system according to claim 1, characterized in that: The rear wheel (12) is hinged to the rear wheel kingpin (13) via the rear axle steering knuckle (11), so that the rear wheel (12) rotates around the rear wheel kingpin (13).

5. The multi-axle vehicle dual-side independent steering system according to claim 1, characterized in that: The third axle wheel (18) is connected to a third axle steering rocker arm (19), which is connected to the rear axle steering tie rod (9).

6. The multi-axle vehicle dual-side independent steering system according to claim 5, characterized in that: The second axle wheel (15) is hinged to the second axle kingpin (14) via the second axle steering knuckle (16), so that the second axle wheel (15) rotates around the second axle kingpin (14); the third axle wheel (18) is hinged to the third axle kingpin (21) via the third axle steering knuckle (20), so that the third axle wheel (18) rotates around the third axle kingpin (21).

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