Steering wheel linear driving stabilizing mechanism and application mode thereof

Abstract

The invention relates to a steering wheel linear driving stabilizing mechanism and an application mode thereof, belongs to the technical field of vehicle chassis, is applied to the vehicle linear driving stability control technology, and is characterized in that based on the relative spiral motion principle of a transmission shaft and an axial cam, when the transmission shaft rotates relative to the cam, aligning torque opposite to the rotation direction is output; the device is used for restraining steering wheels, resisting interference of road surfaces on linear motion of the steering wheels and improving the linear driving stability of a vehicle. The aligning torque is irrelevant to the steering wheel load and the moving speed, the steering aligning function irrelevant to the vehicle load distribution and the driving speed is achieved, and the theoretical reference significance and the practical application value are achieved for vehicle automatic driving.

Description

Technical Field

[0001] This invention relates to a steering wheel straight-line driving stability mechanism and its application, belonging to the field of vehicle chassis technology, and particularly to the field of vehicle straight-line driving stability technology. Background Technology

[0002] Active roll control improves vehicle stability, speed, and safety when cornering by controlling the degree to which the vehicle tilts towards the inside of the curve. The vehicle's roll control system can automatically tilt the vehicle at a certain angle when cornering, generating a balancing torque to counteract the centrifugal force on the vehicle, thus maintaining a stable driving posture for micro-vehicles with small wheelbases or high centers of gravity.

[0003] When a vehicle enters a curve, the centrifugal force exerts a momentary impact on the human body, causing discomfort and other negative effects. To improve driving smoothness and ride comfort while ensuring vehicle safety, the invention patent "Active Tilt Vehicle Single-Wheel Steering Delay Transmission Device" (CN112896146) connects the steering gear, delay device, and steering wheel in series. Through steering delay, it achieves synchronous control of vehicle steering and body tilt. A damper connects the steering wheel to the vehicle body, applying damping constraints to the steering wheel to maintain vehicle directional stability. This is suitable for stable driving on ordinary roads. However, when the steering wheel crosses protrusions such as manhole covers or large potholes, it becomes difficult to maintain directional stability, requiring manual correction and stabilization. The vehicle's straight-line stability depends on the straight-line motion stability of the steering wheel, reflected in the steering wheel's road surface resistance and the vehicle's steering return function. Further exploration of the steering wheel's straight-line motion resistance and improvement of vehicle straight-line stability has theoretical significance and practical value for autonomous driving. Summary of the Invention

[0004] The purpose of this invention is to provide a steering wheel straight-line driving stabilization mechanism and its application. Based on the principle of relative helical motion between the drive shaft and the axial cam, when the drive shaft rotates relative to the cam, it outputs a return torque opposite to the direction of rotation to resist the interference of the road surface on the straight-line motion of the steering wheel and improve the straight-line driving stability of the vehicle.

[0005] The technical solutions adopted to achieve the purpose of this invention include: The steering wheel straight-line driving stabilization mechanism includes: a cam (11) is an axial cam, a cam profile (11a) is provided on the cam (11), the cam (11) is rotatably connected to the drive shaft (12) on the same axis and is controlled by the cam profile (11a) to move relative to the drive shaft along the axis, the drive shaft (12) is provided with a pin (12a) and a roller (12b), the roller (12b) rotates freely relative to the pin (12a), the rotation axis is perpendicular to the axis of the drive shaft (12), the preload nut (14) compresses the spring (13), the spring force keeps the roller (12b) in contact with the cam profile (11a), the cam (11) is rotatably connected to the vehicle body (10) along the cam axis, the drive shaft (12) is rotatably connected to the vehicle body (10) around its axis, and the vehicle body (10) restricts the drive shaft (12) from moving along its axis, thus forming the steering wheel straight-line driving stabilization mechanism; Wherein: when the drive shaft (12) rotates relative to the cam (11), the rotation angle is φ, the cam (11) is controlled by the cam profile (11a) to move along the axis, the displacement is h=f(φ), the relative motion between the drive shaft and the cam is a spiral motion, when the rotation angle of the drive shaft φ≠0, the contact pressure N between the roller (12b) and the cam profile (11a), the horizontal component of N is T=Ncosα, the output return torque of the drive shaft is M=T×R0, the return torque M is opposite to the rotation angle φ of the drive shaft, where: the theoretical radius of the cam profile is R0, the pressure angle of the cam profile is α=g(φ).

[0006] In the above-mentioned steering wheel straight-line driving stabilization mechanism: by adjusting the position of the preload nut (14) along the axis of the transmission shaft (12) and changing the spring preload, the value of the contact pressure N between the roller (12b) and the cam profile (11a) can be changed, thereby changing the magnitude of the return torque M. Increasing M can reduce the interference of the road surface on the straight-line motion of the steering wheel and improve the straight-line driving stability of the vehicle.

[0007] In the above-mentioned steering wheel straight-line driving stabilization mechanism: the cam profile (11a) curve h=f(φ) set on the axial cam (11) is symmetrical about φ=0, so the corresponding return torque M is equal when φ=φ0 and φ=-φ0, and the left and right steering are symmetrical; the cam profile curve h=f(φ) is set according to the usage requirements. When the shape of the cam profile curve h=f(φ) is changed, the cam profile pressure angle α=g(φ) changes, and the return torque M changes, so as to adapt to the requirements of different performance vehicles.

[0008] In the above-mentioned steering wheel straight-line driving stabilization mechanism: two sets of pins (12a) and rollers (12b) are symmetrically arranged on the drive shaft (12). The rollers (12b) rotate freely relative to each pin (12a). The two rollers (12b) are coaxial, and the axis intersects perpendicularly with the axis of the drive shaft (12). The corresponding cam profile (11a) curve h=f(φ) is symmetrical about φ=0 and φ=90° so that the drive shaft (12) is balanced by force and the left and right steering is symmetrical.

[0009] In the above-mentioned steering wheel straight-line driving stabilization mechanism: the roller (12b) is selected from the national standard general sliding bearing or needle roller bearing, and the spring (13) is a compression spring.

[0010] In the above-mentioned steering wheel straight-line driving stabilization mechanism: the transmission shaft and cam helical motion remain unchanged, the cam is fixedly connected to the vehicle body, and the transmission shaft outputs a return torque M when it rotates, forming a steering wheel straight-line driving stabilization mechanism, including: the cam (11) is an axial cam, the cam (11) is provided with a cam profile (11a), the transmission shaft (12) is rotatably connected to the cam (11) along the same axis and is controlled by the cam profile (11a) to move relative to the cam along the axis, the transmission shaft (12) is provided with a shaft pin (12a) and a roller (12b), the roller (12b) rotates freely relative to the shaft pin (12a), the rotation axis is perpendicular to the axis of the transmission shaft (12), the preload nut (14) compresses the spring (13), the spring force keeps the roller (12b) in contact with the cam profile (11a), the cam (11) is fixedly connected to the vehicle body (10), forming a steering wheel straight-line driving stabilization mechanism; Wherein: when the drive shaft (12) rotates relative to the cam (11), the rotation angle is φ, the drive shaft (12) is controlled by the cam profile (11a) to move along the axis, the displacement is h=f(φ), the relative motion between the drive shaft and the cam is a spiral motion, when the rotation angle of the drive shaft φ≠0, the contact pressure N between the roller (12b) and the cam profile (11a), the horizontal component of N is T=Ncosα, the output return torque of the drive shaft is M=T×R0, the return torque M is opposite to the rotation angle φ of the drive shaft, where: the theoretical radius of the cam profile is R0, the pressure angle of the cam profile is α=g(φ).

[0011] Application of steering wheel straight-line stability mechanisms in vehicles: A single-wheel steering vehicle straight-line stability device includes: a steering spindle (23) which is a combination of an upper cylinder and a lower double wishbone; the cylinder of the steering spindle (23) is rotatably connected to the vehicle body (10); the rotation axis K is located in the vertical plane of the vehicle body; within the vertical plane of the vehicle body, K forms a backward tilt angle with the horizontal vertical plane of the vehicle body; and a steering fork (24) which is a U-shaped arm; the open end of the U-shaped arm of the steering fork (24) is rotatably connected to the wheel (25); and the bottom of the U-shaped arm of the steering fork (24) rotates with the end of the double wishbone of the steering spindle (23). The U-shaped arm of the steering fork (24) is rotatably connected to two shock absorbers (22), and the other end of each shock absorber (22) is rotatably connected to the double fork arm of the steering spindle (23). The rotation axes at each rotation connection point are parallel to each other and perpendicular to K. The rotation axis of the wheel (25) is perpendicular to K. The wheel center plane perpendicular to the rotation axis of the wheel (25) passes through K. The two shock absorbers (22) are under pressure and work to form a single-wheel steering wheel positioning mechanism symmetrical about the wheel center plane. In the above-mentioned steering wheel straight-line driving stabilization mechanism, the axis of the drive shaft (12) is parallel to K, one end of the connecting rod (21) is rotatably connected to a point on the drive shaft (12), and the other end is rotatably connected to a point on the steering main shaft (23) in the single-wheel steering wheel positioning mechanism. The rotation axes at the two connection points on the connecting rod (21) are both parallel to K. The steering wheel straight-line driving stabilization mechanism (20) and the single-wheel steering wheel positioning mechanism share the same vehicle body (10), forming a single-wheel steering vehicle straight-line driving stabilization device. During the straight-line driving process, the steering angle θ=0 and the drive shaft rotation angle φ=0. When the external force on the road interferes with the direction of the wheel (25), the steering main shaft (23) generates an angle variable △θ, which is transmitted to the drive shaft (12) through the connecting rod (21). The drive shaft outputs a return torque △M, which is transmitted back to the wheel (25) through the connecting rod (21) to stabilize the wheel direction, reduce road interference, and maintain the vehicle's straight-line stable driving. When the vehicle turns, the steering wheel inputs torque P and rotation angle ρ. After the steering gear with a reduction ratio of i reduces the torque, the steering main shaft (23) obtains a steering torque Q=P×i to overcome the rotation. The torque (QE) is transmitted to the drive shaft (12) through the connecting rod (21) after the resistance torque E and the steering angle θ = ρ / i overcome the return torque M and the drive shaft rotation angle φ. The steering angle θ ≠ 0 and the vehicle turns and moves. After the vehicle turns, P = 0, the steering torque Q = 0, the drive shaft outputs the return torque M, which is transmitted back to the steering main shaft (23) through the connecting rod (21) to overcome the return resistance torque. The wheel (25) returns to center and the vehicle continues to travel in a straight line. The return torque M is independent of the steering wheel load and the moving speed. It has a steering return function that is independent of the vehicle load distribution and driving speed, which is beneficial to the automatic driving of the vehicle.

[0012] The dual-wheel steering vehicle straight-line stability device includes: a vehicle body (10), a lower swing arm (31), a steering knuckle kingpin (32), and an upper swing arm (33) connected in sequence. The rotation axis at each connection point is perpendicular to the vehicle body's horizontal plane, forming a quadrilateral closed kinematic chain with the same relative motion plane. The steering knuckle (34) is rotatably connected to the steering knuckle kingpin (32) around its axis. The steering knuckle (34) connects to the steering wheel (35) and controls its direction. The steering wheel (35) rotates around the steering knuckle (34) and revolves around the steering knuckle kingpin axis together with the steering knuckle (34), forming a set of steering wheel control mechanisms. Two identical sets of steering wheel control mechanisms are arranged symmetrically on the left and right sides of the vehicle body's vertical plane according to the given wheel track and share the same vehicle body. The balance bar (36) is rotatably connected to the vehicle body (10) at its midpoint in the vehicle body's horizontal plane, and the rotation axis is located in the vehicle body's vertical plane. (36) Each end is rotatably connected to a shock absorber (22). The other ends of the two shock absorbers (22) are rotatably connected to the lower swing arm (31) in the left and right steering wheel control mechanisms, respectively. The two rotatable connection points are symmetrical about the vertical plane of the vehicle body. The rotation axis at each rotatable connection point is perpendicular to the horizontal plane of the vehicle body. The two shock absorbers (22) are working under pressure. The connection points of the steering arm (38) are arranged in an isosceles triangle. The vertex of the isosceles triangle on the steering arm (38) is rotatably connected to the vehicle body (10) on the horizontal plane of the vehicle body. The rotation axis is located in the vertical plane of the vehicle body. The two ends of the base of the isosceles triangle on the steering arm (38) are each connected to a steering tie rod (37) by ball hinges. The other ends of the two equal-length steering tie rods (37) are respectively connected to the steering knuckle (34) in the left and right steering wheel control mechanisms by ball hinges. The two connection points are symmetrical about the vertical plane of the vehicle body, forming a double-wheel steering wheel positioning mechanism. In the above-mentioned steering wheel straight-line driving stabilization mechanism, the axis of the drive shaft (12) is parallel to the rotation axis of the steering arm (38) relative to the vehicle body (10). One end of the connecting rod (21) is rotatably connected to a point on the drive shaft (12), and the other end is rotatably connected to a point on the steering arm (38) in the dual-wheel steering wheel positioning mechanism. The rotation axes at the two connection points on the connecting rod (21) are both parallel to the axis of the drive shaft (12). The steering wheel straight-line driving stabilization mechanism (20) and the dual-wheel steering wheel positioning mechanism share the same vehicle body (10), forming a dual-wheel steering vehicle straight-line driving stabilization device. During the straight-line driving process, when the steering angle θ=0 and the drive shaft rotation angle φ=0, and the road surface external force interferes with the direction of the steering wheel (35), the steering arm (38) generates an angle variable △θ, which is transmitted to the drive shaft (12) through the connecting rod (21). The drive shaft outputs a return torque △M, which is transmitted back to the steering wheel through the connecting rod (21) and the steering arm (38) in the opposite direction, stabilizing the direction of the two steering wheels, reducing road surface interference, and maintaining the vehicle's straight-line stable driving. When the vehicle turns, the steering wheel inputs torque P and rotation angle ρ. After the steering gear with a reduction ratio of i reduces the torque, the steering arm (38) obtains a steering torque Q=P×i, which overcomes the steering resistance torque E and the steering angle ρ. Angle θ=ρ / i, torque (QE) is transmitted to drive shaft (12) through link (21), overcomes return torque M, drive shaft rotation angle φ, steering angle θ≠0, outer steering wheel deflection angle θe and inner steering wheel deflection angle θi satisfy Ackermann steering conditions, and the vehicle turns and drives; after the vehicle turns, P=0, steering torque Q=0, drive shaft output return torque M is transmitted back to steering arm (38) through link (21) to overcome return resistance torque, steering wheel returns to center, vehicle continues to drive straight, return torque M is independent of steering wheel load and moving speed, has steering return function independent of vehicle load distribution and driving speed, which is beneficial to vehicle automatic driving.

[0013] In the above-mentioned dual-wheel steering vehicle straight-line driving stabilization device, the balance bar (36) has an angle β with the vertical plane of the vehicle body. Changing β causes the vehicle to tilt, and locking β=90º causes the vehicle to drive upright. The steering wheel straight-line driving stabilization mechanism can be applied to the steering return of active tilt vehicles and traditional vehicles.

[0014] The beneficial effects of this invention are that the proposed steering wheel straight-line driving stabilization mechanism and its application are based on the principle of relative helical motion between the drive shaft and the axial cam. When the drive shaft rotates relative to the cam, it outputs a return torque opposite to the direction of rotation, which resists the interference of the road surface on the straight-line motion of the steering wheel, improves the straight-line driving stability of the vehicle, and has a steering return function that is independent of the vehicle load distribution and driving speed, which is beneficial to the autonomous driving of the vehicle. Attached Figure Description

[0015] Figure 1 A simplified diagram of the steering wheel straight-line stability mechanism; Figure 2 A simplified structural diagram of the steering wheel straight-line stability mechanism, (a) front view, (b) perspective view; Figure 3 The diagrams show the mechanical characteristics of the cam: (a) axial cam profile curve h=f(φ), (b) force diagram for φ<0, (c) state diagram for φ=0, and (d) force diagram for φ>0. Figure 4The diagram shows the relative motion between the drive shaft and the cam, where (a) φ=0, h=0, and (b) φ≠0, h>0. Figure 5 A simplified diagram of a steering wheel straight-line stability mechanism; Figure 6 A simplified structural diagram of a steering wheel straight-line driving stabilization mechanism, (a) front view, (b) perspective view; Figure 7 A simplified diagram of a single-wheel steering wheel positioning mechanism; Figure 8 Schematic diagram of a straight-line stability device for a single-wheel steering vehicle; Figure 9 A simplified diagram of a two-wheel steering wheel positioning mechanism; Figure 10 Schematic diagram of a straight-line stability device for a two-wheel steering vehicle; In the diagram: 10--body, 11--cam, 12--drive shaft, 13--spring, 14--preload nut, 15--sliding bearing, 16--thrust bearing, 17--guide screw, 18--rolling bearing, 19--locating screw; 20--Steering wheel straight-line stability mechanism, 21--Linkage, 22--Shock absorber, 23--Steering spindle, 24--Steering fork, 25--Wheel, 31--Lower control arm, 32--Steering knuckle kingpin, 33--Upper control arm, 34--Steering knuckle, 35--Steering wheel, 36--Stabilizer bar, 37--Steering tie rod, 38--Steering arm; Wherein: 11a--cam profile, 11b--cam guide groove, 11c--cam positioning hole, 12a--shaft pin, 12b--roller. Implementation

[0016] The embodiments of the present invention will now be described with reference to the accompanying drawings: Figure 1The diagram shown is a simplified representation of the steering wheel straight-line stability mechanism. The steering wheel straight-line stability mechanism includes: a cam (11) which is an axial cam, and a cam profile (11a) is provided on the cam (11). The cam (11) is rotatably connected to the drive shaft (12) coaxially through a sliding bearing (15) and is controlled by the cam profile (11a) to move relative to the drive shaft along the axis. The inner cylindrical surface of the cam (11) is interference-fitted with the outer cylindrical surface of the sliding bearing (15). The inner cylindrical surface of the sliding bearing (15) is rotatably connected to the journal of the drive shaft (12) coaxially along the axis L. The cam (11) is controlled by the cam profile (11a) to move relative to the drive shaft (12) along the axis L. The drive shaft (12) is provided with a pin (12a) and a roller (12b). The roller (12b) rotates freely relative to the pin (12a), and its rotation axis intersects perpendicularly with the axis of the drive shaft (12). The preload nut (14) compresses the spring (13) through the thrust bearing (16), and the spring force keeps the roller (12b) in tangential contact with the cam profile (11a). The cam (11) is provided with a cam guide groove (11b) along the axial direction. The cam (11) is connected to the vehicle body (10) along the cam axis direction by the guide screw (17) through the cam guide groove (11b). The drive shaft (12) is rotatably connected to the vehicle body (10) around its axis L by the rolling bearing (18), and the vehicle body (10) restricts the movement of the drive shaft (12) along its axis L through the rolling bearing (18), forming a straight-line driving stabilization mechanism for the steering wheels (e.g., Figure 2 (as shown) Wherein: when the drive shaft (12) rotates relative to the cam (11), the rotation angle is φ, the cam (11) is controlled by the cam profile (11a) to move along the axis, the displacement is h=f(φ), the relative motion between the drive shaft and the cam is helical motion, when the rotation angle of the drive shaft φ≠0, the contact pressure N between the roller (12b) and the cam profile (11a), the horizontal component of N is T=Ncosα, such as Figure 3 As shown in (b) and (d), the return torque output by the drive shaft is M = T × R0. The return torque M is opposite to the drive shaft rotation angle φ, as follows: Figure 4 As shown, where: the theoretical radius of the cam profile R0, and the pressure angle of the cam profile α = g(φ).

[0017] Figure 2 The diagram shows a simplified structure of the steering wheel straight-line driving stabilization mechanism. In the steering wheel straight-line driving stabilization mechanism: by adjusting the position of the preload nut (14) along the axis of the transmission shaft (12) and changing the spring preload, the value of the contact pressure N between the roller (12b) and the cam profile (11a) can be changed, thereby changing the magnitude of the return torque M. Increasing M can reduce the interference of the road surface on the straight-line motion of the steering wheel and improve the straight-line driving stability of the vehicle.

[0018] Figure 3The cam mechanical characteristic diagram shown shows that in the straight-line driving stabilization mechanism of the steering wheel: the cam profile (11a) curve h=f(φ) set on the axial cam (11) is symmetrical about φ=0. Therefore, when φ=φ0 and φ=-φ0, the corresponding return torque M is equal, and the left and right steering are symmetrical. The cam profile curve h=f(φ) is set according to the usage requirements. When the shape of the cam profile curve h=f(φ) is changed, the cam profile pressure angle α=g(φ) changes, and the return torque M changes, so as to adapt to the requirements of different performance vehicles.

[0019] In the aforementioned steering wheel straight-line stability mechanism: two sets of pins (12a) and rollers (12b) are symmetrically arranged on the drive shaft (12). The rollers (12b) rotate freely relative to each pin (12a). The two rollers (12b) are coaxial, and this axis intersects perpendicularly with the axis L of the drive shaft (12). The corresponding cam profile (11a) curve h=f(φ) is symmetrical about φ=0 and φ=90°, as shown in the figure. Figure 3 As shown in (a), so that the drive shaft (12) is in force balance and the left and right turns are symmetrical.

[0020] Figure 2 The diagram shows a simplified structure of the steering wheel straight-line driving stabilization mechanism. In the steering wheel straight-line driving stabilization mechanism: the roller (12b) is selected from the national standard general sliding bearing GB / T 18327.2-2001 or needle roller bearing GB / T 6445-2007; the sliding bearing (15) is selected from the powder metallurgy sliding bearing GB / T 2688-2012 or copper alloy bushing GB / T 18324-2001; the thrust bearing (16) is selected from the thrust ball bearing GB / T 301-2015 or thrust cylindrical roller bearing GB / T 4663-2017; the rolling bearing (18) is selected from the deep groove ball bearing GB / T 276-2013 or self-aligning ball bearing GB / T 281-2013; and the spring (13) is a compression spring.

[0021] Figure 5 The diagram shown is a simplified representation of a steering wheel straight-line stability mechanism. Figure 1In the steering wheel straight-line driving stabilization mechanism shown: the drive shaft and cam helical motion remain unchanged, the cam is fixed to the vehicle body, and the drive shaft outputs a return torque M when it rotates, forming a steering wheel straight-line driving stabilization mechanism, including: the cam (11) is an axial cam, the cam (11) is provided with a cam profile (11a), the drive shaft (12) is rotatably connected to the cam (11) along the same axis through a sliding bearing (15), and is controlled by the cam profile (11a) to move relative to the cam along the axis, the inner cylindrical surface of the cam (11) is interference-fitted with the outer cylindrical surface of the sliding bearing (15), the inner cylindrical surface of the sliding bearing (15) is rotatably connected to the journal of the drive shaft (12) along the same axis L, and the drive shaft (11) is rotatably connected to the journal of the drive shaft (12) along the same axis L, and the drive shaft (11) is rotatably connected to the journal of the drive shaft (12) along the same axis L. 2) Controlled by the movement of the cam profile (11a) relative to the cam (11) along the axis L, the transmission shaft (12) is provided with a pin (12a) and a roller (12b). The roller (12b) rotates freely relative to the pin (12a), and the axis of rotation is perpendicular to the axis of the transmission shaft (12). The preload nut (14) compresses the spring (13) through the thrust bearing (16). The spring force keeps the roller (12b) in tangential contact with the cam profile (11a). The cam (11) is provided with a cam positioning hole (11c) in the radial direction. The cam (11) is fixedly connected to the vehicle body (10) through the cam positioning hole (11c) by the positioning screw (19), forming a steering wheel straight-line driving stabilization mechanism (such as... Figure 6 (as shown) Wherein: when the drive shaft (12) rotates relative to the cam (11), the rotation angle is φ, the drive shaft (12) is controlled by the cam profile (11a) to move along the axis, the displacement is h=f(φ), the relative motion between the drive shaft and the cam is a spiral motion, when the rotation angle of the drive shaft φ≠0, the contact pressure N between the roller (12b) and the cam profile (11a), the horizontal component of N is T=Ncosα, the output return torque of the drive shaft is M=T×R0, the return torque M is opposite to the rotation angle φ of the drive shaft, where: the theoretical radius of the cam profile is R0, the pressure angle of the cam profile is α=g(φ).

[0022] Application of steering wheel straight-line stability mechanisms in vehicles: Figure 8The schematic diagram of the single-wheel steering vehicle straight-line stability device shown is as follows: The single-wheel steering vehicle straight-line stability device includes: a steering main shaft (23) which is a combination of an upper cylinder and a lower double wishbone. The cylinder of the steering main shaft (23) is rotatably connected to the vehicle body (10), and the rotation axis K is located in the vertical plane of the vehicle body. In the vertical plane of the vehicle body, K forms a back tilt angle δ=5~10° with the horizontal vertical plane of the vehicle body. The steering fork (24) is a U-shaped arm. The open end of the U-shaped arm of the steering fork (24) is rotatably connected to the wheel (25). The bottom of the U-shaped arm of the steering fork (24) is rotated with the end of the double wishbone of the steering main shaft (23). The steering fork (24) is rotatably connected to two shock absorbers (22) at its U-shaped arm. The other end of each shock absorber (22) is rotatably connected to the double fork arm of the steering spindle (23). The rotation axes at each connection point are parallel to each other and perpendicular to K. The rotation axis of the wheel (25) is perpendicular to K. The distance between the two perpendicularly intersecting axes is the wheel offset distance e = 10-50 mm. The wheel center plane perpendicular to the rotation axis of the wheel (25) passes through K. The two shock absorbers (22) are under pressure and work to form a single-wheel steering wheel positioning mechanism symmetrical about the wheel center plane (e.g., Figure 7 (as shown) Depend on Figure 1 In the straight-line driving stabilization mechanism of the steering wheel shown, the axis L of the drive shaft (12) is parallel to K. One end of the connecting rod (21) is rotatably connected to a point on the drive shaft (12), and the other end is rotatably connected to a point on the steering main shaft (23) in the single-wheel steering wheel positioning mechanism. The rotation axes at the two connection points on the connecting rod (21) are both parallel to K. The straight-line driving stabilization mechanism (20) of the steering wheel and the single-wheel steering wheel positioning mechanism share the same vehicle body (10) to form a single-wheel steering vehicle straight-line driving stabilization device.

[0023] During the straight-line driving process, the steering angle θ=0 and the drive shaft rotation angle φ=0. When the external force on the road interferes with the direction of the wheel (25), the steering main shaft (23) generates an angle variable △θ, which is transmitted to the drive shaft (12) through the connecting rod (21). The drive shaft outputs a return torque △M, which is transmitted back to the wheel (25) through the connecting rod (21) to stabilize the wheel direction, reduce road interference, and maintain the vehicle's straight-line stable driving. When the vehicle turns, the steering wheel inputs torque P and rotation angle ρ. After the steering gear with a reduction ratio of i=5~12 reduces the torque, the steering main shaft (23) obtains a steering torque Q=P×i, which overcomes the steering resistance torque E. The steering angle θ = ρ / i, the torque (QE) is transmitted to the drive shaft (12) through the connecting rod (21), and overcomes the return torque M, the drive shaft rotation angle φ, the steering angle θ ≠ 0, and the vehicle turns and moves; after the vehicle turns, P = 0, the steering torque Q = 0, the drive shaft outputs the return torque M, which is transmitted back to the steering main shaft (23) through the connecting rod (21) to overcome the return resistance torque F, the wheel (25) returns to center, and the vehicle continues to travel in a straight line. The return torque M is independent of the steering wheel load and the moving speed, and has a steering return function independent of the vehicle load distribution and the driving speed V. It has theoretical reference significance and practical application value for vehicle autonomous driving.

[0024] Figure 10The schematic diagram of the straight-line stability device for a dual-wheel steering vehicle is shown. The dual-wheel steering vehicle straight-line stability device includes: a vehicle body (10), a lower swing arm (31), a steering knuckle kingpin (32), and an upper swing arm (33) connected in sequence. The rotation axis at each rotation connection point is perpendicular to the horizontal plane of the vehicle body, forming a parallelogram closed kinematic chain with the same relative motion plane. The steering knuckle (34) is rotatably connected to the steering knuckle kingpin (32) around its axis. The steering knuckle (34) is connected to the steering wheel (35) and controls its direction. The steering wheel (35) rotates around the steering knuckle (34) and revolves together with the steering knuckle (34) around the steering knuckle kingpin axis, forming a set of steering wheel control mechanisms. The two sets of identical steering wheel control mechanisms are arranged symmetrically on the left and right sides of the vehicle body's vertical plane according to the given wheel track and share the same vehicle body. The balance bar (36) is rotatably connected to the vehicle body (10) at the midpoint of the horizontal plane of the vehicle body, and the rotation axis is located at the center of the horizontal plane of the vehicle body. Within the vertical plane of the vehicle body, each end of the stabilizer bar (36) is rotatably connected to a shock absorber (22). The other ends of the two shock absorbers (22) are rotatably connected to the lower swing arm (31) in the left and right steering wheel control mechanisms, respectively. The two rotatable connection points are symmetrical about the vertical plane of the vehicle body, and the rotation axis at each rotatable connection point is perpendicular to the horizontal plane of the vehicle body. The two shock absorbers (22) are working under pressure. The connection points of the steering arm (38) are arranged in an isosceles triangle. The vertex of the isosceles triangle on the steering arm (38) is rotatably connected to the vehicle body (10) on the horizontal plane of the vehicle body. The rotation axis is located within the vertical plane of the vehicle body. The two ends of the base of the isosceles triangle on the steering arm (38) are each connected to a steering tie rod (37) by a ball hinge. The other ends of the two equal-length steering tie rods (37) are respectively connected to the steering knuckle (34) in the left and right steering wheel control mechanisms by a ball hinge. The two connection points are symmetrical about the vertical plane of the vehicle body, forming a dual-wheel steering wheel positioning mechanism (e.g. Figure 9 (as shown) Depend on Figure 1 In the steering wheel straight-line driving stabilization mechanism shown, the axis L of the drive shaft (12) is parallel to the rotation axis of the steering arm (38) relative to the vehicle body (10). One end of the connecting rod (21) is rotatably connected to a point on the drive shaft (12), and the other end is rotatably connected to a point on the steering arm (38) in the dual-wheel steering wheel positioning mechanism. The rotation axes at the two connection points on the connecting rod (21) are both parallel to the axis L of the drive shaft (12). The steering wheel straight-line driving stabilization mechanism (20) and the dual-wheel steering wheel positioning mechanism share the same vehicle body (10), forming a dual-wheel steering vehicle straight-line driving stabilization device.

[0025] During the straight-line driving process, when the steering angle θ=0 and the drive shaft rotation angle φ=0, and the external force on the road interferes with the direction of the steering wheel (35), the steering arm (38) generates an angle variable △θ, which is transmitted to the drive shaft (12) through the connecting rod (21). The drive shaft outputs a return torque △M, which is transmitted back to the steering wheel through the connecting rod (21) and the steering arm (38) in the opposite direction, stabilizing the direction of the two steering wheels, reducing road interference, and maintaining the vehicle's straight-line stable driving. When the vehicle turns, the steering wheel inputs torque P and rotation angle ρ. After the steering gear with a reduction ratio of i=5~12 reduces the torque, the steering arm (38) obtains a steering torque Q=P×i, which overcomes the steering resistance torque E and the steering angle θ=ρ / i. After the torque (QE) is transmitted to the drive shaft (12) through the connecting rod (21), it overcomes the return torque M, the drive shaft rotation angle φ, the steering angle θ≠0, the outer steering wheel deflection angle θe and the inner steering wheel deflection angle θi to satisfy the Ackermann steering condition, and the vehicle turns and moves. After the vehicle turns, P=0, the steering torque Q=0, the drive shaft outputs the return torque M and transmits it back to the steering arm (38) through the connecting rod (21) to overcome the return resistance torque F, the steering wheel returns to center, and the vehicle continues to drive straight. The return torque M is independent of the steering wheel load and the moving speed, and has a steering return function that is independent of the vehicle load distribution and the driving speed V. It has theoretical reference significance and practical application value for vehicle autonomous driving.

[0026] In the above-mentioned dual-wheel steering vehicle straight-line driving stabilization device, the balance bar (36) makes an angle β with the vertical plane of the vehicle body. The balance bar is driven to rotate relative to the vehicle body by the actuator, and β is changed, causing the vehicle to tilt. The balance bar (36) is fixedly connected to the vehicle body and locked at β=90º, so the vehicle can drive upright. The steering wheel straight-line driving stabilization mechanism can be applied to the steering return of active tilt vehicles and traditional vehicles.

Claims

1. A steering wheel straight-line stability mechanism, characterized in that, include: The cam is an axial cam with a cam profile. The cam is rotatably connected to the drive shaft along the same axis and is controlled by the movement of the cam profile relative to the drive shaft along the axis. The drive shaft is equipped with a pin and a roller. The roller rotates freely relative to the pin, and the axis of rotation is perpendicular to the axis of the drive shaft. The preload nut compresses the spring, and the spring force keeps the roller in contact with the cam profile. The cam is rotatably connected to the vehicle body along the cam axis. The drive shaft is rotatably connected to the vehicle body around its axis, and the vehicle body restricts the movement of the drive shaft along its axis. Wherein: when the drive shaft rotates relative to the cam, the rotation angle is φ; the cam is controlled by the cam profile to move along the axis, the displacement is h=f(φ); the relative motion between the drive shaft and the cam is helical motion; when the rotation angle of the drive shaft φ≠0, the contact pressure N between the roller and the cam profile, the horizontal component of N is T=Ncosα; the output return torque of the drive shaft is M=T×R0, the return torque M is opposite to the rotation angle φ of the drive shaft; where: the theoretical radius of the cam profile is R0, and the pressure angle of the cam profile is α=g(φ).

2. The steering wheel straight-line driving stabilization mechanism according to claim 1, characterized in that, Adjusting the position of the preload nut along the axis of the drive shaft changes the value of the contact pressure N between the roller and the cam profile, thereby changing the magnitude of the return torque M.

3. The steering wheel straight-line stabilization mechanism according to claim 1, characterized in that, The cam profile curve h=f(φ) set on the axial cam is symmetrical about φ=0, and the left and right rotations are symmetrical. The cam profile curve h=f(φ) is set according to the usage requirements. When the shape of the cam profile curve h=f(φ) is changed, the cam profile pressure angle α=g(φ) changes, and the return torque M changes.

4. The steering wheel straight-line stabilization mechanism according to claim 1, characterized in that, Two sets of pins and rollers are symmetrically arranged on the drive shaft. The rollers rotate freely relative to each pin. The two rollers are coaxial, and the axis intersects the axis of the drive shaft perpendicularly. The corresponding cam profile curve h=f(φ) is symmetrical about φ=0 and φ=90°, and the drive shaft is in force balance.

5. The steering wheel straight-line stabilization mechanism according to claims 1 to 4, characterized in that, The cam is an axial cam with a cam profile. The drive shaft is rotatably connected to the cam along the same axis and is controlled by the movement of the cam profile relative to the cam along the axis. The drive shaft is equipped with a pin and a roller. The roller rotates freely relative to the pin, and the axis of rotation is perpendicular to the axis of the drive shaft. The preload nut compresses the spring, and the spring force keeps the roller in contact with the cam profile. The cam is fixedly connected to the vehicle body, forming a steering wheel straight-line driving stabilization mechanism. Wherein: when the drive shaft rotates relative to the cam, the rotation angle is φ; the drive shaft is controlled by the cam profile moving along the axis, the displacement is h=f(φ); the relative motion between the drive shaft and the cam is helical motion; when the rotation angle of the drive shaft φ≠0, the contact pressure N between the roller and the cam profile, the horizontal component of N is T=Ncosα, the output return torque of the drive shaft is M=T×R0, the return torque M is opposite to the rotation angle φ of the drive shaft, where: the theoretical radius of the cam profile is R0, and the pressure angle of the cam profile is α=g(φ).

6. A single-wheel steering vehicle straight-line stability device, characterized in that, include: The steering spindle is a combination of an upper cylinder and a lower double wishbone. The cylinder of the steering spindle is rotatably connected to the vehicle body, and the rotation axis K is located in the vertical plane of the vehicle body. In the vertical plane of the vehicle body, K forms a backward tilt angle with the horizontal vertical plane of the vehicle body. The steering fork is a U-shaped arm. The open end of the U-shaped arm of the steering fork is rotatably connected to the wheel. The bottom of the U-shaped arm of the steering fork is rotatably connected to the end of the double wishbone of the steering spindle. The middle part of the U-shaped arm of the steering fork is rotatably connected to two shock absorbers. The other end of each shock absorber is rotatably connected to the double wishbone of the steering spindle. The rotation axes at each rotation connection point are parallel to each other and perpendicular to K. The wheel rotation axis is perpendicular to K. The wheel center plane perpendicular to the wheel rotation axis passes through K. The two shock absorbers are working under pressure, forming a single-wheel steering wheel positioning mechanism symmetrical about the wheel center plane. In the steering wheel straight-line driving stabilization mechanism according to claim 1, the axis of the transmission shaft is parallel to K, one end of the connecting rod is rotatably connected to a point on the transmission shaft, and the other end is rotatably connected to a point on the steering main shaft in the single-wheel steering wheel positioning mechanism. The rotation axes at both connection points on the connecting rod are parallel to K. The steering wheel straight-line driving stabilization mechanism and the single-wheel steering wheel positioning mechanism share the same vehicle body, forming a single-wheel steering vehicle straight-line driving stabilization device.

7. A two-wheel steering vehicle straight-line stability device, characterized in that, include: The body, lower control arm, steering knuckle kingpin, and upper control arm are sequentially connected by rotation. The rotation axes at each connection point are perpendicular to the body's transverse vertical plane, forming a quadrilateral closed kinematic chain with the same relative motion plane. The steering knuckle and steering knuckle kingpin are connected by rotation around their axis. The steering knuckle connects to the steering wheel and controls its direction. The steering wheel rotates around the steering knuckle and revolves with the steering knuckle around the steering knuckle kingpin axis, forming a set of steering wheel control mechanisms. Two identical sets of steering wheel control mechanisms are arranged symmetrically on the left and right sides of the body's mid-vertical plane according to a given wheelbase, sharing the same body. The stabilizer bar is rotatably connected to the body at its midpoint within the body's transverse vertical plane, with its rotation axis located within the body's mid-vertical plane. Each end of the stabilizer bar is rotatably connected to a reducer. The shock absorbers are connected at the other ends to the lower control rods in the left and right steering wheel control mechanisms, respectively. The two connection points are symmetrical about the vertical plane of the vehicle body, and the rotation axis at each connection point is perpendicular to the horizontal plane of the vehicle body. The two shock absorbers are under pressure. The steering arm connection points are arranged in an isosceles triangle. The vertex of the isosceles triangle on the steering arm is rotatably connected to the vehicle body on the horizontal plane of the vehicle body, and the rotation axis is located in the vertical plane of the vehicle body. The two ends of the base of the isosceles triangle on the steering arm are each connected to a steering tie rod by a ball joint. The other ends of the two equal-length steering tie rods are connected to the steering knuckle ball joints in the left and right steering wheel control mechanisms, respectively. The two connection points are symmetrical about the vertical plane of the vehicle body, forming a dual-wheel steering wheel positioning mechanism. In the steering wheel straight-line driving stabilization mechanism according to claim 1, the axis of the drive shaft is parallel to the axis of rotation of the steering arm relative to the vehicle body. One end of the connecting rod is rotatably connected to a point on the drive shaft, and the other end is rotatably connected to a point on the steering arm in the dual-wheel steering wheel positioning mechanism. The axis of rotation at both connection points on the connecting rod is parallel to the axis of the drive shaft. The steering wheel straight-line driving stabilization mechanism and the dual-wheel steering wheel positioning mechanism share the same vehicle body, forming a dual-wheel steering vehicle straight-line driving stabilization device.

8. The two-wheel steering vehicle straight-line stability device according to claim 7, characterized in that, The angle β between the stabilizer bar and the vertical plane of the vehicle body changes, causing the vehicle to tilt. Locking β = 90º allows the vehicle to travel upright.

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