A front wheel steering mechanism for an unmanned vehicle

Abstract

This invention belongs to the field of unmanned electric vehicle technology, and specifically relates to a front wheel steering mechanism for an unmanned vehicle. It includes a steering wheel plate with a through hole on its upper surface. A bearing sleeve is fixedly connected to the wall of the through hole, and a front fork weldment is fixedly installed on the inner wall of the bearing sleeve. Connecting bearings are fixedly fitted onto the bottom protrusions on both sides of the front fork weldment. Crank weldments are fixedly fitted onto the outer wall of the outer ring of the connecting bearings, and mounting holes are formed on the outer walls of both crank weldments. This invention uses an automotive-grade EPS power steering assembly as the power source, and achieves high-precision steer-by-wire through low-backlash conical gear transmission and closed-loop control with a steering encoder. The steering control is sensitive and efficient, meeting the core requirements of precise steering and flexible obstacle avoidance in unmanned operations. Furthermore, the front wheel steering mechanism also features efficient shock absorption and air cooling, significantly improving steering reliability, driving stability, and adaptability to various operating conditions, making it suitable for the needs of unmanned cleaning equipment operations.

Description

Technical Field

[0001] This invention belongs to the field of unmanned electric vehicle technology, and in particular relates to a front wheel steering mechanism for an unmanned vehicle. Background Technology

[0002] With the rapid development of new energy vehicles and autonomous driving technology, traditional manned small sweepers are gradually being replaced by small, unmanned electric sweepers. These small, unmanned electric sweepers require no human operation and can autonomously complete cleaning tasks through navigation and path planning systems. This not only significantly reduces labor costs but also enables 24-hour continuous operation, resulting in a substantial improvement in cleaning efficiency. Furthermore, their electric drive mode consumes less energy and produces zero emissions, meeting the green and low-carbon development needs of various cleaning scenarios. They also offer higher operational precision, effectively avoiding the errors inherent in manual operation.

[0003] Most existing small unmanned electric sweepers use the same front-wheel steering mechanism as traditional cleaning equipment, primarily employing a chain drive structure. Some products also use a servo motor-driven gear drive mechanism. The steering wheels of the front-wheel steering mechanism are often equipped with spring damping structures. However, these mechanisms have the following drawbacks in actual unmanned operation:

[0004] First, chain drives have inherent backlash and deformation problems under stress, and there is no dedicated backlash elimination mechanism, which directly leads to lag in steering response and insufficient control precision. Meanwhile, servo motor drive solutions mostly use industrial-grade components, which cannot meet the high reliability requirements of automotive-grade applications in vehicle scenarios and are prone to failure under long-term cleaning operations.

[0005] Moreover, both of these transmission schemes lack a real-time feedback mechanism for steering shaft angle, making it impossible to build a high-precision closed-loop control system. This not only results in insufficient steering positioning accuracy and excessive deviation, but also makes it difficult to efficiently coordinate with the navigation, path planning, and vehicle electronic control systems of unmanned vehicles, thus failing to meet the core requirements of precise steering and flexible obstacle avoidance in unmanned operations.

[0006] Secondly, the existing spring damping structure for steering wheels has insufficient damping response when encountering minor road bumps, and cannot effectively filter vibrations, which can easily cause problems such as missed cleaning and uneven cleaning coverage. When encountering major road bumps, the stiff rebound of the springs can easily cause secondary bumps, aggravate vehicle body shaking, reduce driving stability, cause steering control deviation, and continuously impact the steering transmission mechanism, accelerating component wear.

[0007] To address this issue, we propose a front-wheel steering mechanism for autonomous vehicles. Summary of the Invention

[0008] The purpose of this invention is to address the above-mentioned problems by providing a front-wheel steering mechanism for an unmanned vehicle.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: a front wheel steering mechanism for an unmanned vehicle, comprising a steering square plate, a through hole on the upper surface of the steering square plate, a bearing sleeve fixedly connected to the wall of the through hole, a front fork weldment fixedly installed on the inner wall of the bearing sleeve, connecting bearings fixedly sleeved on the bottom protrusions on both sides of the front fork weldment, a crank weldment fixedly sleeved on the outer wall of the outer ring of the connecting bearing, mounting holes on the outer walls of the two crank weldments, and a steering wheel installed on the wall of the mounting holes via a rolling bearing; shock absorption mechanisms are respectively installed on the outer ends of the two crank weldments and the outer wall of the front fork weldment.

[0010] An EPS bearing housing is fixedly connected to the outer wall of the directional square plate, and a steering assist mechanism is fixedly connected to the inner wall of the EPS bearing housing.

[0011] The outer wall of the fork weldment is fixedly sleeved with a large directional gear that cooperates with the transmission end of the power steering mechanism.

[0012] In the aforementioned front wheel steering mechanism of an unmanned vehicle, the shock absorption mechanism includes a connecting protrusion rotatably mounted to the outer end of a crank weldment. A connecting block is fixedly connected to one end of the connecting protrusion near the steering wheel. A buffer air cylinder is fixedly connected to the top of the connecting block. A cylinder cover is fixedly connected to the top of the buffer air cylinder by bolts. A thick-walled hollow rod is movably connected to the inner wall of the cylinder cover. A support ring is fixedly sleeved at the bottom end of the thick-walled hollow rod. A rubber piston is fixedly sleeved on the outer wall of the support ring. The outer wall of the rubber piston is slidably and sealingly connected to the inner wall of the buffer air cylinder. An auxiliary mechanism and a damping buffer rubber sleeve are fixedly sleeved on the outer wall of the top end of the thick-walled hollow rod. A vent hole is opened on the outer wall of the thick-walled hollow rod at the damping buffer rubber sleeve. An annular connecting ring is fixedly and sealingly connected to the top end of the thick-walled hollow rod. A fixed bearing is fixedly sleeved on the inner wall of the annular connecting ring. A fixing component is fixedly installed on the inner wall of the inner ring of the fixed bearing. The side end of the fixing component is fixedly connected to the outer wall of the front fork weldment.

[0013] In the aforementioned front wheel steering mechanism of an unmanned vehicle, a fixed through hole is provided on the bottom side wall of the buffer air cylinder, and an air inlet is fixedly connected to the hole wall of the fixed through hole.

[0014] In the aforementioned front wheel steering mechanism of an unmanned vehicle, the steering assist mechanism includes a mounting bearing fixedly connected to the inner wall of an EPS bearing housing. A tapered shaft is fixedly connected to the inner wall of the mounting bearing. A tapered pinion that meshes with a steering gear is fixedly sleeved at the bottom end of the tapered shaft. An EPS steering assist assembly is fixedly mounted at the top end of the EPS bearing housing. A coupling is fixedly mounted together with the top end of the EPS steering assist assembly and the top end of the tapered shaft. A steering encoder is fixedly connected to the top end of the front fork welded part through the coupling.

[0015] In the aforementioned front wheel steering mechanism of an unmanned vehicle, the auxiliary mechanism includes a top plate fixedly sleeved to the outer wall of the top end of a thick-walled hollow rod. A through hole is formed on the upper surface of the top plate, and an air inlet pipe is fixedly connected to the wall of the through hole. A flexible hose is fixedly connected to the outlet end of the air inlet pipe, and a one-way air valve is fixedly connected to the outlet end of the flexible hose. The outlet end of the one-way air valve is fixedly connected to the outer wall of the control box of the EPS power steering assembly. An exhaust one-way valve is fixedly connected to the outer wall of the control box of the EPS power steering assembly. A rubber corrugated sleeve is fixedly connected to the lower surface of the top plate, and the bottom end of the rubber corrugated sleeve is fixedly connected to the upper surface of a cylinder cover. Multiple vent holes are formed on the upper surface of the cylinder cover. A connecting circular hole is formed on the outer wall of the top end of the buffer air cylinder, and a one-way air inlet valve is fixedly connected to the wall of the connecting circular hole.

[0016] In the aforementioned front wheel steering mechanism of an unmanned vehicle, a filter screen is provided on the outside of the one-way air intake valve. The side wall of the filter screen is fixedly connected to the outer wall of the buffer air cylinder. The filter screen is a stainless steel mesh screen with a pore size of 0.3mm to 0.4mm.

[0017] In the aforementioned front wheel steering mechanism of an unmanned vehicle, the wall of the hose is fixedly fitted with multiple clamps, and the outer walls of the multiple clamps are respectively fixedly connected to the outer walls of the EPS bearing housing and the EPS power steering assembly.

[0018] In the aforementioned front wheel steering mechanism of an unmanned vehicle, a buffer spring is movably sleeved on the wall of the thick-walled hollow rod, and the two ends of the buffer spring are fixedly connected to the upper surface of the support ring and the lower surface of the cylinder cover, respectively.

[0019] In the aforementioned front wheel steering mechanism of an unmanned vehicle, a first directional limiting block is fixedly connected to the lower surface of the directional large square plate, and two second directional limiting blocks that cooperate with the first directional limiting block are fixedly connected to the upper surface of the directional large gear.

[0020] Compared with existing technologies, the advantages of this invention are:

[0021] 1. Through the configured power steering mechanism and steering wheel plate, when the front wheel steering mechanism is working, the power steering mechanism controls the conical pinion to rotate by a corresponding angle according to the received control command. The rotation of the conical pinion, through the low-backlash conical gear pair formed with the steering wheel, drives the steering wheel to rotate synchronously. Then, the steering wheel drives the front fork welded parts to rotate synchronously. The front fork welded parts, through the crank welded parts, drive the steering wheel to rotate by a corresponding angle, completing the steering action. This solves the core problems of traditional unmanned cleaning vehicle steering mechanisms, such as low steering accuracy, slow response, insufficient reliability, and inability to adapt to the precise control requirements of unmanned systems. This front wheel steering mechanism is automotive-grade. The advanced EPS power steering assembly serves as the power source, replacing traditional industrial-grade servo drives and meeting the high reliability requirements of automotive scenarios. Through a low-backlash bevel gear pair consisting of a small bevel gear and a large steering gear, the transmission backlash is minimized. The steering encoder is coaxially mounted on the top of the front fork weld, providing real-time feedback on the actual steering wheel angle. It forms a closed-loop control with the EPS controller in the EPS power steering assembly control box, effectively compensating for the nonlinear effects caused by residual backlash. Ultimately, it achieves millisecond-level response and high-precision positioning for steering actions. It can efficiently collaborate with unmanned vehicle navigation and path planning systems to meet the core needs of precise steering and flexible obstacle avoidance in unmanned cleaning operations.

[0022] 2. Through the designed shock absorption mechanism, combined with a composite buffer structure consisting of a buffer air cylinder, rubber piston, damping buffer rubber sleeve, and buffer spring, the industry pain points of traditional steering wheel spring shock absorption structures are solved, namely insufficient shock absorption response for small bumps and easy secondary bumps caused by rebound from large bumps. The pre-filled compressed air in the buffer air cylinder is the main buffer damping, which, together with the elastic buffer of the buffer spring, forms a dual shock absorption system. The inflation pressure inside the buffer air cylinder can be pre-adjusted through the air inlet to adapt to the buffer stiffness requirements of different operating scenarios. Ultimately, this effectively ensures the driving stability of the small unmanned electric sweeper, reduces the continuous impact of road vibration on the steering transmission mechanism, delays component wear, and significantly extends the service life of the mechanism.

[0023] 3. Through the auxiliary mechanism, air is input into the control box of the EPS power steering assembly, constructing a convection cooling structure for the EPS power steering assembly control box. This solves the problems of overheating and shutdown of the electronic control components of the steering mechanism in traditional unmanned cleaning vehicles during 24-hour continuous operation, and the problem of air pollution caused by dusty and humid cleaning environments. In addition, no additional energy consumption is required. The reciprocating motion of the shock-absorbing mechanism buffers and absorbs vibrations, driving the rubber corrugated sleeve to extend and retract synchronously. When extended, filtered clean air is drawn in through the one-way air intake valve and stainless steel filter screen. When contracted, the internal compressed air is continuously input into the control box of the EPS power steering assembly through the air inlet pipe, hose and one-way air guide valve. With the help of the exhaust one-way valve on the outer wall of the control box, a continuous forced air convection circulation is formed inside to achieve air cooling. Ultimately, this effectively reduces the operating temperature of the core electronic control components such as the EPS controller and drive circuit in the EPS power steering assembly control box, avoids overheating and shutdown failures during long-term continuous operation, significantly improves the automotive-grade reliability and adaptability to complex working conditions of the mechanism, and extends the service life of the electronic control components. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the front wheel steering mechanism of an unmanned vehicle provided by the present invention;

[0025] Figure 2 This is the present invention. Figure 1 A side view of the structure of the steering wheel section;

[0026] Figure 3 This is a cross-sectional structural schematic diagram of the shock absorption mechanism and auxiliary mechanism in the front wheel steering mechanism of an unmanned vehicle provided by the present invention;

[0027] Figure 4 This is a partially enlarged structural schematic diagram of the EPS steering assist assembly in the front wheel steering mechanism of an unmanned vehicle provided by the present invention;

[0028] Figure 5 This is a schematic diagram illustrating the working principle of a front wheel steering mechanism for an unmanned vehicle provided by the present invention.

[0029] In the diagram: 1. Directional square plate; 2. Bearing sleeve; 3. Front fork weldment; 4. Connecting bearing; 5. Crank weldment; 6. Steering wheel; 7. Shock absorption mechanism; 71. Connecting cam; 72. Connecting block; 73. Buffer air cylinder; 74. Cylinder cover; 75. Thick-walled hollow rod; 76. Support ring; 77. Rubber piston; 78. Damping buffer rubber sleeve; 79. Vent hole; 710. Annular connecting ring; 711. Fixed bearing; 712. Fixing component; 8. Auxiliary mechanism; 81. Top plate; 82. Air inlet pipe; 83. Hose; 8 4 One-way air guide valve, 85 One-way exhaust valve, 86 Rubber bellows sleeve, 87 Vent hole, 88 One-way intake valve, 9 Power steering mechanism, 91 Mounting bearing, 92 Tapered shaft, 93 Tapered pinion, 94 EPS power steering assembly, 95 Coupling, 96 Steering encoder, 10 EPS bearing housing, 11 Directional gear, 12 Air inlet, 13 Filter screen, 14 Pipe clamp, 15 Buffer spring, 16 First direction limit block, 17 Second direction limit block. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] like Figures 1-5As shown, a front wheel steering mechanism for an unmanned vehicle includes a steering plate 1. A through hole is formed on the upper surface of the steering plate 1, and a bearing sleeve 2 is fixedly connected to the wall of the through hole. A front fork weldment 3 is fixedly installed on the inner wall of the bearing sleeve 2. Connecting bearings 4 are fixedly fitted onto the bottom protrusions on both sides of the front fork weldment 3. Crank weldments 5 are fixedly fitted onto the outer wall of the outer ring of the connecting bearings 4. Two crank weldments 5 have mounting holes on their outer walls, and steering wheels 6 are mounted on the walls of these holes via rolling bearings. Shock-absorbing mechanisms 7 are respectively installed on the outer ends of the two crank weldments 5 and the outer walls of the front fork weldment 3. Each shock-absorbing mechanism 7 includes a connecting protrusion 71 rotatably mounted to the outer end of the crank weldment 5. A connecting block 72 is fixedly connected to the end of the connecting protrusion 71 near the steering wheel 6. A buffer air cylinder 73 is fixedly connected to the top of the connecting block 72, and a cylinder cap 74 is fixedly connected to the top of the buffer air cylinder 73 by bolts. A thick-walled hollow rod 75 is movably connected to the inner wall of the cylinder cover 74. A support ring 76 is fixedly sleeved at the bottom end of the thick-walled hollow rod 75. A rubber piston 77 is fixedly sleeved on the outer wall of the support ring 76. The outer wall of the rubber piston 77 is slidably and sealed to the inner wall of the buffer cylinder 73. An auxiliary mechanism 8 and a damping buffer rubber sleeve 78 are fixedly sleeved on the outer wall of the top end of the thick-walled hollow rod 75. A vent hole 79 is opened on the outer wall of the thick-walled hollow rod 75 at the damping buffer rubber sleeve 78. An annular connecting ring 710 is fixedly and sealed to the top end of the thick-walled hollow rod 75. A fixed bearing 711 is fixedly sleeved on the inner wall of the annular connecting ring 710. A fixing member 712 is fixedly installed on the inner wall of the inner ring of the fixed bearing 711. The side end of the fixing member 712 is fixedly connected to the outer wall of the front fork weldment 3. A fixed through hole is opened on the side wall of the bottom end of the buffer cylinder 73, and an air inlet 12 is fixedly and sealed to the hole wall of the fixed through hole.

[0032] An EPS bearing housing 10 is fixedly connected to the outer wall of the steering gear 1. A steering assist mechanism 9 is fixedly connected to the inner wall of the EPS bearing housing 10. The steering assist mechanism 9 includes a mounting bearing 91 fixedly connected to the inner wall of the EPS bearing housing 10. A tapered shaft 92 is fixedly connected to the inner wall of the mounting bearing 91. A tapered pinion 93 that meshes with the steering gear 11 is fixedly sleeved at the bottom end of the tapered shaft 92. An EPS steering assist assembly 94 is fixedly installed at the top end of the EPS bearing housing 10. A coupling 95 is fixedly installed together with the top end of the EPS steering assist assembly 94 and the top end of the tapered shaft 92. A steering encoder 96 is fixedly connected to the top end of the front fork weldment 3 through the coupling.

[0033] The auxiliary mechanism 8 includes a top plate 81 fixedly sleeved to the outer wall of the top end of the thick-walled hollow rod 75. A through hole is formed on the upper surface of the top plate 81, and an air inlet pipe 82 is fixedly connected to the wall of the through hole. A flexible hose 83 is fixedly connected to the outlet end of the air inlet pipe 82, and a one-way air guide valve 84 is fixedly connected to the outlet end of the flexible hose 83. The outlet end of the one-way air guide valve 84 is fixedly connected to the outer wall of the control box of the EPS power steering assembly 94. An exhaust check valve 85 is fixedly connected to the outer wall of the control box of the EPS power steering assembly 94. A rubber corrugated sleeve 86 is fixedly connected to the lower surface of the top plate 81, and the bottom end of the rubber corrugated sleeve 86 is connected to the cylinder cover 7. The upper surface of the cylinder cover 74 is fixedly connected to the upper surface of the cylinder cover 74. Multiple vent holes 87 are opened on the upper surface of the cylinder cover 74. A connecting round hole is opened on the outer wall of the top of the buffer cylinder 73. A one-way air intake valve 88 is fixedly connected to the wall of the connecting round hole. A filter screen 13 is provided on the outside of the one-way air intake valve 88. The side wall of the filter screen 13 is fixedly connected to the outer wall of the buffer cylinder 73. The filter screen 13 is a stainless steel mesh cover with a hole diameter of 0.35mm. Multiple pipe clamps 14 are fixedly sleeved on the wall of the hose 83. The outer walls of the multiple pipe clamps 14 are fixedly connected to the outer walls of the EPS bearing seat 10 and the EPS power steering assembly 94, respectively.

[0034] The outer wall of the fork weldment 3 is fixedly sleeved with a large steering gear 11 that cooperates with the transmission end of the power steering mechanism 9. After the conical pinion 93 meshes with the large steering gear 11, a reliable low-backlash conical gear pair transmission structure is formed. The thick-walled hollow rod 75 is movably sleeved with a buffer spring 15. The two ends of the buffer spring 15 are fixedly connected to the upper surface of the support ring 76 and the lower surface of the cylinder cover 74, respectively.

[0035] A first directional limiting block 16 is fixedly connected to the lower surface of the directional large square plate 1, and two second directional limiting blocks 17 that cooperate with the first directional limiting block 16 are fixedly connected to the upper surface of the directional large gear 11.

[0036] The operating principle of this invention is described as follows: When the front wheel steering mechanism is mounted on the chassis of a small unmanned electric sweeper via the steering square plate 1, and the steering encoder 96 is coaxially mounted on the top of the front fork weldment 3 via a coupling, with its stator end fixedly connected to the corresponding position of the sweeper chassis via bolts, when the unmanned vehicle control system of the small unmanned electric sweeper needs to control the front wheel steering mechanism to perform a steering action, it first sends a steer-by-wire command to the control box of the EPS steering assist assembly 94, which conforms to automotive-grade standards (such as AEC-Q standards). After receiving the command, the EPS controller in the control box of the EPS steering assist assembly 94 immediately controls the output end of the steering motor of the EPS steering assist assembly 94 to rotate by a corresponding angle, and the EPS steering... The output end of the steering motor of the power steering assembly 94 drives the tapered shaft 92 to rotate through the coupling 95. The tapered shaft 92 is supported by the mounting bearing 91 and the EPS bearing housing 10 to ensure coaxiality and stability during rotation. Moreover, the tapered pinion 93 and the steering gear 11 can form a reliable low-backlash tapered gear pair transmission. Then, the tapered shaft 92 drives the tapered pinion 93 to rotate synchronously. The tapered pinion 93 meshes with the steering gear 11 through a high-precision tapered gear pair that is pre-tightened and backlash-free, driving the front fork weldment 3 to rotate a corresponding angle inside the bearing sleeve 2. The front fork weldment 3, through the connecting bearing 4 at its bottom end and the crank weldment 5, synchronously drives the steering wheel 6 to rotate a corresponding steering angle, completing the steering action.

[0037] Throughout the entire steering process, the real-time steering angle change of the steering wheel 6 is synchronously transmitted to the steering encoder 96 at its top through the fork weld 3. The steering encoder 96 converts the real-time rotation angle of the steering wheel 6 into an electrical signal and feeds it back to the EPS controller in the EPS power steering assembly 94 control box in real time, forming a closed-loop control of command output, action execution, angle feedback and deviation correction. This closed-loop control system can effectively compensate for the nonlinear effects caused by the extremely small residual backlash of the gear transmission, and achieve millisecond-level response and high-precision positioning of the steering action.

[0038] When the real-time rotation angle of the steering wheel 6 fed back by the steering encoder 96 is consistent with the target angle specified in the command sent by the unmanned vehicle control system, the EPS controller immediately controls the steering motor output of the EPS steering power assembly 94 to stop rotating and lock, completing precise steering control. During this process, the conical pinion 93 and the steering gear 11 are pre-tightened and backlash-free installed using a high-precision conical gear pair, which can minimize transmission backlash. Combined with the closed-loop control of the steering encoder 96, it solves the core problems of large backlash, slow response, and insufficient steering accuracy of traditional chain drives, as well as the poor backlash elimination capability of traditional servo gear drives, which cannot adapt to the precise control requirements of unmanned vehicles. It can efficiently coordinate with the navigation, path planning and vehicle electronic control system of unmanned vehicles to meet the core requirements of precise steering and flexible obstacle avoidance in unmanned cleaning operations.

[0039] While controlling the steering angle, the two second-direction limiting blocks 17, which rotate synchronously with the steering gear 11, will form a rigid abutment with the first-direction limiting block 16 fixed on the lower surface of the steering plate 1 when the steering angle reaches the preset safety limit value. This directly restricts the continued rotation of the steering gear 11, thereby forming a mechanical hard limit on the maximum steering angle of the front fork welded part 3 and the steering wheel 6 in both the left and right directions. This structure can avoid overload and tooth breakage of the transmission gear and damage to the steering mechanism components caused by exceeding the steering angle limit. On the other hand, it can form a double limit protection with the electronic limit of the EPS steering power assembly 94, effectively avoiding the risk of steering over-limit, loss of driving control and equipment collision caused by abnormality of the electronic control system in unmanned control scenarios, and greatly improving the safety and reliability of the mechanism operation.

[0040] Throughout the entire process of driving and cleaning operations of the small unmanned electric sweeper, the shock absorption mechanism 7 and the auxiliary mechanism 8 work synchronously to ensure the stability and reliability of the mechanism's operation.

[0041] When the steering wheel 6 encounters a bumpy road surface, the vibration impact force is transmitted to the connecting protrusion 71 and connecting block 72 of the shock absorption mechanism 7 through the crank weld 5, which in turn drives the buffer air cylinder 73 to reciprocate along the axial direction of the thick-walled hollow rod 75. The inflation pressure inside the buffer air cylinder 73 can be pre-adjusted through the air inlet 12 to adapt to the buffer stiffness requirements of different operating scenarios. The pre-filled compressed air inside the buffer air cylinder 73 forms the main buffer damping, which, together with the elastic buffering of the buffer spring 15 on the outer wall of the thick-walled hollow rod 75, can quickly absorb the vibration energy generated by the bumpy road surface. For small-amplitude high-frequency bumps on the road surface, the front wheel steering mechanism can effectively filter the vibration through the viscous damping effect of compressed air, avoiding the problems of missed cleaning and uneven cleaning coverage caused by the continuous shaking of the chassis of the small unmanned electric sweeper.

[0042] In response to significant road impacts and bumps, as the rubber piston 77 compresses air upwards with the buffer cylinder 73, the throttling damping formed by the vent hole 79 on the thick-walled hollow rod 75 and the damping buffer rubber sleeve 78 can significantly reduce the impact force of the buffer rebound, avoiding secondary bumps caused by the hard rebound of the traditional spring damping structure, ensuring the vehicle's driving stability, and at the same time reducing the continuous impact of road vibration on the steering transmission mechanism, delaying component wear, and extending the service life of the mechanism. This solves the problems of insufficient buffering response, easy occurrence of secondary bumps, and aggravated vehicle body sway and mechanism wear of the traditional front wheel steering mechanism's matching spring damping structure.

[0043] During the reciprocating motion of the shock absorption mechanism 7, the auxiliary mechanism 8 works synchronously. The rubber corrugated sleeve 86 extends and retracts synchronously with the relative movement of the top plate 81 and the cylinder cover 74. When the rubber corrugated sleeve 86 extends, it draws in filtered clean air through the one-way air inlet valve 88 and the filter screen 13. The filter screen 13 can filter dust in the air.

[0044] When the rubber corrugated sleeve 86 contracts, the compressed air inside it is continuously input into the control box of the EPS power steering assembly 94 through the air inlet pipe 82, hose 83 and one-way air valve 84. The air in the control box can be discharged in one direction through the exhaust one-way valve 85, thereby forming a continuous forced air convection circulation inside the control box, achieving air cooling without additional energy consumption. This structure can provide air cooling for the core electronic control components such as the EPS controller and drive circuit in the control box of the EPS power steering assembly 94, preventing the electronic control components from overheating and shutting down when the unmanned vehicle is operating continuously for 24 hours. This ensures the stability of long-term operation and solves the problem of the electronic control components of the steering mechanism of traditional unmanned cleaning vehicles being prone to overheating and damage and having poor adaptability under continuous working conditions. It further improves the automotive-grade reliability and service life of the front wheel steering mechanism.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A front wheel steering mechanism for an unmanned vehicle, comprising a steering square plate (1), characterized in that, The upper surface of the directional square plate (1) is provided with a through hole, and a bearing sleeve (2) is fixedly connected to the hole wall. A front fork weldment (3) is fixedly installed on the inner wall of the bearing sleeve (2). A connecting bearing (4) is fixedly sleeved on the bottom protrusions on both sides of the front fork weldment (3). A crank weldment (5) is fixedly sleeved on the outer wall of the outer ring of the connecting bearing (4). A mounting round hole is provided on the outer wall of both crank weldments (5), and a steering wheel (6) is installed on the hole wall of the mounting round hole through a rolling bearing. A shock absorption mechanism (7) is installed on the outer side of the two crank weldments (5) and the outer wall of the front fork weldment (3). An EPS bearing seat (10) is fixedly connected to the outer wall of the directional large square plate (1), and a steering assist mechanism (9) is fixedly connected to the inner wall of the EPS bearing seat (10). The outer wall of the fork weldment (3) is fixedly sleeved with a large directional gear (11) that cooperates with the transmission end of the steering assist mechanism (9).

2. The front wheel steering mechanism of an unmanned vehicle according to claim 1, characterized in that, The shock absorption mechanism (7) includes a connecting protrusion (71) rotatably mounted to the outer end of the crank weldment (5). A connecting block (72) is fixedly connected to one end of the connecting protrusion (71) near the steering wheel (6). A buffer air cylinder (73) is fixedly connected to the top of the connecting block (72). A cylinder cover (74) is fixedly connected to the top of the buffer air cylinder (73) by bolts. A thick-walled hollow rod (75) is movably connected to the inner wall of the cylinder cover (74). A support ring (76) is fixedly sleeved at the bottom end of the thick-walled hollow rod (75). A rubber piston (77) is fixedly sleeved on the outer wall of the support ring (76). The outer wall of the rubber piston (77) is connected to... The inner wall of the buffer cylinder (73) is sealed and slidably connected. The outer wall of the top end of the thick-walled hollow rod (75) is fixedly sleeved with an auxiliary mechanism (8) and a damping buffer rubber sleeve (78). The outer wall of the thick-walled hollow rod (75) located at the damping buffer rubber sleeve (78) has a vent hole (79). The top end of the thick-walled hollow rod (75) is sealed and fixedly connected with an annular connecting ring (710). The inner wall of the annular connecting ring (710) is fixedly sleeved with a fixed bearing (711). The inner wall of the inner ring of the fixed bearing (711) is fixedly installed with a fixing member (712). The side end of the fixing member (712) is fixedly connected to the outer wall of the fork weld (3).

3. The front wheel steering mechanism of an unmanned vehicle according to claim 2, characterized in that, The bottom side wall of the buffer air cylinder (73) is provided with a fixed through hole, and the hole wall of the fixed through hole is sealed and fixedly connected to an air inlet (12).

4. The front wheel steering mechanism of an unmanned vehicle according to claim 2, characterized in that, The power steering mechanism (9) includes a mounting bearing (91) fixedly connected to the inner wall of the EPS bearing housing (10). A tapered shaft (92) is fixedly connected to the inner wall of the mounting bearing (91). A tapered pinion (93) that meshes with the steering gear (11) is fixedly sleeved at the bottom end of the tapered shaft (92). An EPS power steering assembly (94) is fixedly installed at the top end of the EPS bearing housing (10). A coupling (95) is fixedly installed at the output end of the EPS power steering assembly (94) and the top end of the tapered shaft (92). A steering encoder (96) is fixedly connected to the top end of the fork weldment (3) through the coupling.

5. The front wheel steering mechanism of an unmanned vehicle according to claim 4, characterized in that, The auxiliary mechanism (8) includes a top plate (81) fixedly sleeved to the outer wall of the top end of the thick-walled hollow rod (75). The upper surface of the top plate (81) has a through hole, and an air inlet pipe (82) is fixedly connected to the wall of the through hole. The air outlet of the air inlet pipe (82) is fixedly connected to a flexible hose (83). The air outlet of the flexible hose (83) is fixedly connected to a one-way air guide valve (84). The air outlet of the one-way air guide valve (84) is fixedly connected to the outer wall of the control box of the EPS power steering assembly (94). The outer wall of the control box of the EPS power steering assembly (94) is fixedly connected to an exhaust one-way valve (85). The lower surface of the top plate (81) is fixedly connected to a rubber corrugated sleeve (86). The bottom end of the rubber corrugated sleeve (86) is fixedly connected to the upper surface of the cylinder cover (74). The upper surface of the cylinder cover (74) is provided with multiple vent holes (87). The outer wall of the top of the buffer cylinder (73) is provided with a connecting round hole, and the hole wall of the connecting round hole is fixedly connected to a one-way air intake valve (88).

6. The front wheel steering mechanism of an unmanned vehicle according to claim 5, characterized in that, The one-way air intake valve (88) is provided with a filter screen (13) on its outer side. The side wall of the filter screen (13) is fixedly connected to the outer wall of the buffer air cylinder (73). The filter screen (13) is a stainless steel mesh screen with a hole diameter of 0.3mm to 0.4mm.

7. The front wheel steering mechanism of an unmanned vehicle according to claim 5, characterized in that, The hose (83) is fixedly sleeved with multiple clamps (14), and the outer walls of the multiple clamps (14) are respectively fixedly connected to the outer walls of the EPS bearing seat (10) and the EPS power steering assembly (94).

8. The front wheel steering mechanism of an unmanned vehicle according to claim 2, characterized in that, The thick-walled hollow rod (75) has a buffer spring (15) movably sleeved on its wall. The two ends of the buffer spring (15) are fixedly connected to the upper surface of the support ring (76) and the lower surface of the cylinder cover (74), respectively.

9. The front wheel steering mechanism of an unmanned vehicle according to claim 1, characterized in that, The lower surface of the large directional plate (1) is fixedly connected to a first directional limiting block (16), and the upper surface of the large directional gear (11) is fixedly connected to two second directional limiting blocks (17) that cooperate with the first directional limiting block (16).

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