Linear displacement active suspension and vehicle applying same

Abstract

The invention relates to a linear displacement active suspension and a vehicle applying the same, belongs to the technical field of vehicle chassis, and particularly relates to a roll driving control technology of an active roll vehicle. A suspension formed by a linear motion mechanism drives a single wheel to do large displacement and linear motion, the two sets of linear displacement suspensions independently control the wheels on the two sides to do reverse linear motion relative to a vehicle body, vehicle rolling is achieved, and a new rolling drive control method is provided for a narrow-body active rolling vehicle. The suspension drives the wheels to independently move relative to the vehicle body to achieve active profiling of the vehicle to the ground, a ground profiling vehicle is formed, the surface of a platform on the vehicle body can be kept horizontal all the time in the vehicle running process, running at a fixed roll angle or a fixed pitch angle can also be achieved, and targeting operation of parts such as a mechanical arm is facilitated.

Description

Technical Field

[0001] The present invention relates to a linear displacement active suspension and a vehicle applying the suspension, belonging to the technical field of vehicle chassis, and particularly to the technical field of roll drive control of active roll vehicles. Background Art

[0002] The active roll control system improves the driving stability, ride comfort, passing speed and safety of the vehicle by controlling the degree of tilting of the vehicle towards the inner side of the curve when turning. For small wheelbase and narrow-body vehicles, the active roll technology can make the vehicle automatically tilt at a certain angle when cornering or driving over an inclined road surface, generating a balancing moment to resist the centrifugal force or rollover force acting on the vehicle's center of mass to maintain the stable driving of the vehicle.

[0003] During the cornering of an active roll vehicle, if the driving speed is further increased, the generated centrifugal force increases, and a larger roll angle is required for the vehicle to drive stably. The active roll vehicle uses the suspension roll system to make the two wheels move relative to the vehicle body quickly and with a large displacement to achieve the positive timing and large-angle roll of the vehicle, which requires a rapid response of the roll movement and a rapid roll to the position. The commonly used trailing arm suspension can obtain a large displacement movement of the two wheels relative to the vehicle body by the rotation of the wheel axis relative to the vehicle body to achieve vehicle roll. When the vehicle rolls, the wheel axis is simultaneously affected by the centrifugal force and the tangential force. The tangential force realizes the rapid response of the roll movement and the rapid roll to the position, while the centrifugal force of the roll movement acting on the wheel axis will cause fluctuations in the vehicle driving speed. Explore a suspension formed by a linear motion mechanism, with two sets of independently controlled linear motion suspensions arranged on both sides of the vehicle body, controlling the reverse linear motion of the two wheels relative to the vehicle body to achieve vehicle roll, and providing a new roll drive control method for active roll vehicles. Summary of the Invention

[0004] The object of the present invention is to provide a linear displacement active suspension and a vehicle applying the suspension. The suspension formed by the linear motion mechanism drives a single wheel to move linearly with a large displacement, and two sets of linear displacement suspensions independently control the reverse linear motion of the two wheels relative to the vehicle body to achieve vehicle roll.

[0005] The technical solutions adopted to achieve the object of the present invention include: Linear displacement active suspension, comprising: one end of two equal-length rocker arms (11) is respectively rotatably connected to the vehicle body (10), at two connection points A and B; the other end of the two rocker arms (11) is respectively rotatably connected to the balance bar (12), at two connection points D and C; the rotation axes at the four connection points are parallel to each other and perpendicular to the central vertical plane of the vehicle body, forming a parallelogram ABCD closed kinematic chain with the same relative motion plane, and this relative motion plane is parallel to the central vertical plane of the vehicle body; one end of three equal-length connecting rods (14) is rotatably connected around the same axis, at connection point F, the other end of the first connecting rod is rotatably connected to the balance bar (12), the connection point is at point E on the extension line of DC and EC = BC, the other end of the second connecting rod is rotatably connected to the vehicle body (10) at point B, the other end of the third connecting rod is rotatably connected to one end of the trailing arm (13), at connection point G, the other end of the trailing arm (13) is rotatably connected to the balance bar (12) at point D, and the wheel (16) is rotatably connected to the trailing arm (13) at point G to drive the vehicle to travel, and the rotation axes at each rotatable connection point are perpendicular to the central vertical plane of the vehicle body; within the same relative motion plane parallel to the central vertical plane of the vehicle body, the geometric conditions are satisfied: AD = BC, FE = FB = FG = 2BC, AB = DC = 3BC, DG = DE = 4BC; the motor (17) is fixedly installed on the vehicle body (10) after being connected in series with the reducer (18), and the output shaft of the reducer (18) drives the rocker arm AD to rotate relative to the vehicle body by an angle α, and α controls the movement of the wheel center along a straight line passing through point B and perpendicular to AB. When α > 0 and the balance bar (12) is located above the AB line segment of the vehicle body, a shock absorber (15) with the same length as the connecting rod is used to replace the first connecting rod FE, and the connection method is the same, forming a linear displacement active suspension.

[0006] Wherein: the rocker arm AD rotates relative to the vehicle body (10), the wheel rotation axis moves along a straight line passing through point B and perpendicular to AB, and this straight line is parallel to the central vertical plane of the vehicle body. When the line segment AB is in the horizontal plane of the vehicle body, the wheel rotation axis moves along a straight line passing through point B and perpendicular to the horizontal plane of the vehicle body.

[0007] In the above linear displacement active suspension, when α < 0 and the balance bar (12) is located below the AB line segment of the vehicle body, the first connecting rod FE is retained, and a shock absorber (15) with the same length as the connecting rod is used to replace the second connecting rod FB or the third connecting rod FG, and the connection method is the same. α controls the movement of the wheel center along a straight line passing through point B and perpendicular to AB, forming another linear displacement active suspension. The distance H between the wheel rotation axis and the AB line segment of the vehicle body has a larger variation range, so as to improve the passing performance of the vehicle on complex ground and is suitable for vehicle off-road.

[0008] In the above linear displacement active suspension, the output shaft of the reducer (18) drives another rocker arm BC to rotate relative to the vehicle body by an angle α, and α controls the movement of the wheel center along a straight line passing through point B and perpendicular to AB, having the same linear displacement active suspension function.

[0009] In the above-mentioned linear displacement active suspension, the motor (17) is a brake motor, and the reducer (18) is a planetary gear reducer or an RV reducer; when powered on, the brake is released and the motor is energized. The brake motor is connected in series with the planetary gear reducer or the RV reducer to drive the rocker arm to rotate. The center of the wheel moves along a straight line passing through point B and perpendicular to AB, and the height of the vehicle body from the ground changes. When the height of the vehicle body increases, the passing performance of the vehicle improves; after power-off, the motor stops energizing and the brake brakes the motor shaft, and the height of the vehicle body relative to the ground is locked.

[0010] In the above-mentioned linear displacement active suspension, the motor (17) is a permanent magnet synchronous motor, and the reducer (18) is a worm reducer with reverse self-locking function; when the motor is energized, the worm pair reduces the speed and transmits power. The motor is connected in series with the worm reducer to drive the rocker arm to rotate. The center of the wheel moves along a straight line passing through point B and perpendicular to AB, and the height of the vehicle body from the ground changes. When the height of the vehicle body decreases, the high-speed driving stability of the vehicle improves; when the motor stops energizing, the worm pair drives in reverse and self-locks, and the height of the vehicle body relative to the ground is locked.

[0011] An active roll vehicle includes: two sets of linear displacement active suspensions with the same structure and performance parameters are symmetrically arranged left and right with respect to the central vertical plane of the vehicle body according to the given wheelbase and share the same vehicle body. On the same vehicle body, single wheels are arranged in front according to the given wheelbase and share the same central vertical plane of the vehicle body. The front wheels are steered, and the double rear wheels are driven. The front and rear wheel tires are all arc-curved section tires; the left and right motors drive the rocker arms in the two sets of linear displacement active suspensions to rotate in opposite directions relative to the vehicle body through reducers. The double rear wheels move in opposite straight lines relative to the vehicle body, and the vehicle rolls. The single front wheel rolls adaptively with the vehicle body, forming an active roll tricycle with the characteristics of double rear-wheel drive and front-wheel steering to improve the maneuverability and driving stability of narrow-body vehicles.

[0012] A ground contour-following vehicle includes: four sets of linear displacement active suspensions with the same structure and performance parameters are symmetrically arranged left and right with respect to the central vertical plane of the vehicle body according to the given wheelbase and wheel track and share the same vehicle body. The four wheels are independently driven, and the inner and outer wheels have differential steering. The four sets of linear displacement active suspensions are independently controlled, and the four wheels independently follow the ground contour, forming an all-terrain off-road vehicle with all-wheel drive and all-wheel active contour following; because the four wheels move independently relative to the vehicle body to achieve active contour following of the vehicle on the ground, the platform surface on the vehicle body can always be kept horizontal during vehicle driving, or it can also achieve driving at a fixed roll angle or a fixed pitch angle, which is beneficial to the target operation of components such as manipulators.

[0013] The beneficial effects of the present invention are as follows. A linear displacement active suspension and a vehicle applying the suspension provide a new roll drive control method for narrow-body active roll vehicles. At the same time, the suspension can be applied to the fast and large-displacement profiling motion on non-road ground to improve the adaptability of the vehicle to complex ground. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is the mechanism motion schematic diagram of the linear displacement active suspension; Figure 2 is the schematic diagram of the linear displacement active suspension in its relative motion plane; Figure 3 is the schematic diagram of the composition of the linear displacement active suspension; Figure 4 is the schematic diagram of the second linear displacement active suspension in its relative motion plane; Figure 5 is the schematic diagram of the third linear displacement active suspension in its relative motion plane; Figure 6 is another configuration schematic diagram of the linear displacement active suspension; Figure 7 is the schematic diagram of the composition of the active roll tricycle; Figure 8 is the suspension motion schematic diagram of the active roll tricycle; Figure 9 is the roll schematic diagram of the active roll tricycle; Figure 10 is the schematic diagram of the composition of a ground profiling vehicle; Figure 11 is the non-road ground profiling schematic diagram of a ground profiling vehicle; In the figure: 10 - vehicle body, 11 - rocker arm, 12 - balance bar, 13 - trailing arm, 14 - connecting rod, 15 - shock absorber, 16 - wheel, 17 - motor, 18 - reducer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The embodiments of the present invention will be described below with reference to the accompanying drawings: Figure 3The schematic diagram of the composition principle of the linear displacement active suspension is shown. The linear displacement active suspension includes: one end of two equal-length rocker arms (11) is respectively rotatably connected to the vehicle body (10) at two connection points A and B, and the other end of the two rocker arms (11) is respectively rotatably connected to the balance bar (12) at two connection points D and C. The rotation axes at the four connection points are parallel to each other and perpendicular to the vertical plane of the vehicle body, forming a parallelogram ABCD closed kinematic chain with the same relative motion plane, and this relative motion plane is parallel to the vertical plane of the vehicle body; one end of three equal-length connecting rods (14) is rotatably connected around the same axis at connection point F. The other end of the first connecting rod is rotatably connected to the balance bar (12). The connection point is at point E on the extension line of DC, and EC = BC. The other end of the second connecting rod is rotatably connected to the vehicle body (10) at point B. The second connecting rod and the rocker arm BC are coaxially rotatable relative to the vehicle body (10) at point B. The other end of the third connecting rod is rotatably connected to one end of the trailing arm (13) at connection point G. The other end of the trailing arm (13) is rotatably connected to the balance bar (12) at point D. The trailing arm (13), the balance bar (12) and the rocker arm AD are coaxially rotatable relative to each other at point D. The wheel (16) is rotatably connected to the trailing arm (13) at point G to drive the vehicle to travel. The wheel (16) is coaxially rotatable relative to the trailing arm (13) and the third connecting rod at point G. The rotation axes at each rotatable connection point are perpendicular to the vertical plane of the vehicle body, as Figure 1 shown; in the same relative motion plane parallel to the vertical plane of the vehicle body, the geometric conditions are satisfied: AD = BC, FE = FB = FG = 2BC, AB = DC = 3BC, DG = DE = 4BC; the motor (17) is fixedly installed on the vehicle body (10) after being connected in series with the reducer (18). The output shaft of the reducer (18) drives the rocker arm AD to rotate relative to the vehicle body by an angle α. α controls the movement of the wheel center along the straight line passing through point B and perpendicular to AB. When α > 0, the balance bar (12) is located above the AB line segment of the vehicle body, as Figure 2 shown. A shock absorber (15) with the same length as the connecting rod is used to replace the first connecting rod FE, and the connection method is the same, forming a linear displacement active suspension.

[0016] Among them: The mechanism movement principle of the linear displacement active suspension is based on the Kempe straight-line motion mechanism principle. As Figure 1 shown, the rocker arm AD rotates relative to the vehicle body (10), and the wheel center G moves along the straight line passing through point B and perpendicular to AB, and this straight line is parallel to the vertical plane of the vehicle body. When the line segment AB is in the horizontal plane of the vehicle body, the wheel center G moves along the straight line passing through point B and perpendicular to the horizontal plane of the vehicle body.

[0017] Figure 4 、 5In the shown linear displacement active suspension, when the balance bar (12) is below the AB line segment of the vehicle body and α < 0, the first link FE and the third link FG are retained, and a shock absorber (15) with the same length as the link is used to replace the second link FB, with the same connection method. α controls the movement of the wheel center along the line passing through point B and perpendicular to AB, forming the second type of linear displacement active suspension, as Figure 4 shown; when the balance bar (12) is below the AB line segment of the vehicle body and α < 0, the first link FE and the second link FB are retained, and a shock absorber (15) with the same length as the link is used to replace the third link FG, with the same connection method. α controls the movement of the wheel center along the line passing through point B and perpendicular to AB, forming the third type of linear displacement active suspension, as Figure 5 shown; the distance H between the wheel rotation axis and the AB line segment of the vehicle body has a larger variation range, so as to improve the passing performance of the vehicle on complex ground and is suitable for vehicle off-road.

[0018] Figure 2 、 4 In the linear displacement active suspension shown in Fig. 5, the output shaft of the reducer (18) drives another rocker BC to rotate relative to the vehicle body by an angle α. α controls the movement of the wheel center along the line passing through point B and perpendicular to AB, having the same linear displacement active suspension function, which is convenient for the installation of the motor (17) and the reducer (18) on the vehicle body (10) and the longitudinal configuration of the vehicle center of gravity.

[0019] Figure 3 In the schematic diagram of the composition of the shown linear displacement active suspension, the motor (17) is selected as a brake motor, and the reducer (18) is selected as a planetary gear reducer or an RV reducer; when powered on, the brake is released and the motor is energized. The brake motor is connected in series with the planetary gear reducer or the RV reducer to drive the rocker to rotate. The wheel center moves along the line passing through point B and perpendicular to AB, and the height of the vehicle body from the ground changes. When the vehicle body height increases, the passing performance of the vehicle improves; after powering off, the motor stops energizing and the brake brakes the motor shaft, and the height of the vehicle body relative to the ground is locked.

[0020] Figure 6 In another schematic diagram of the configuration of the shown linear displacement active suspension, the motor (17) is selected as a permanent magnet synchronous motor, and the reducer (18) is selected as a worm reducer with a reverse self-locking function; when the motor is energized, the worm pair reduces the speed and drives the rocker to rotate. The wheel center moves along the line passing through point B and perpendicular to AB, and the height of the vehicle body from the ground changes. When the vehicle body height decreases, the high-speed driving stability of the vehicle improves; when the lead angle of the worm is less than the equivalent friction angle between the meshing teeth of the worm wheel, the worm pair has reverse drive self-locking, and the formed worm reducer has self-locking performance; when the motor stops energizing, the worm pair has reverse drive self-locking, and the height of the vehicle body relative to the ground is locked.

[0021] Figure 7The schematic diagram of the composition of the active roll tricycle shown, an active roll vehicle, includes: two sets of linear displacement active suspensions with the same structure and performance parameters are symmetrically arranged on the left and right of the vehicle body's central vertical plane according to the given wheelbase S and share the same vehicle body. A single front wheel is placed in front according to the given wheelbase on the same vehicle body and shares the same central vertical plane of the vehicle body. The front wheel steers, and the hub motors of the two rear wheels drive. The front and rear wheel tires are all motorcycle tires GB 518 - 2007 with an arc - shaped cross - section. The left and right motors drive the rocker arms in the two sets of linear displacement active suspensions to rotate in opposite directions relative to the vehicle body through reducers. The two rear wheels move linearly in opposite directions relative to the vehicle body, causing the vehicle to roll. The single front wheel rolls adaptively with the vehicle body, forming an active roll tricycle with the characteristics of dual - rear - wheel drive and front - wheel steering to improve the maneuverability and driving stability of narrow - body vehicles, which is defined as a light - duty vehicle for urban life.

[0022] Among them: The right - hand motor drives the rocker arm in the right - hand linear displacement active suspension to rotate relative to the vehicle body through a reducer, with an angle of rotation α1. The distance between the axis of rotation of the right wheel and the AB line segment of the vehicle body is H1. The left - hand motor drives the rocker arm in the left - hand linear displacement active suspension to rotate relative to the vehicle body through a reducer, with an angle of rotation α2. The distance between the axis of rotation of the left wheel and the AB line segment of the vehicle body is H2. The distance between the axes of rotation of the two rear wheels is ΔH = H1 - H2, as Figure 8 shown; The roll angle of the vehicle is β, and tanβ = ΔH / S, as Figure 9 shown; Given the wheelbase L of the vehicle, assuming the vehicle's driving speed is v, the gravitational acceleration is g, and the vehicle's mass is m. When the vehicle is driving on a curve, the steering angle θ is given by single - wheel steering, and the turning radius R = L / tanθ. To satisfy the force - balance condition during turning: mg×tanβ = mv 2 / R, that is, the stability condition for the active roll vehicle when driving on a curve is: tanβ = v 2 / (g×R).

[0023] Figure 10 The schematic diagram of the composition of a ground - profiling vehicle shown, a ground - profiling vehicle, includes: four sets of linear displacement active suspensions with the same structure and performance parameters are symmetrically arranged on the left and right of the vehicle body's central vertical plane according to the given wheelbase and track width and share the same vehicle body. The hub motors of the four wheels drive independently, and the inner and outer wheels have differential steering. The four sets of linear displacement active suspensions are controlled independently, and the four wheels independently profile the ground, forming an all - terrain off - road vehicle with all - wheel drive and all - wheel active profiling.

[0024] Among them: In the four sets of linear displacement active suspensions, the four motors drive the rocker arms they are connected to rotate relative to the vehicle body through reducers independently. The axis of rotation of each wheel moves along a straight - line trajectory to achieve active profiling of the vehicle on the ground, as Figure 11As shown; the movement trajectories of the centers of the four wheels remain unchanged relative to the vehicle body, and the wheelbase and track of the vehicle remain unchanged during the profiling driving process; due to the independent control of the active suspension for each linear displacement, the independent linear movement of the centers of the four wheels enables the vehicle to actively profile the ground, and the platform surface on the vehicle body can always be kept horizontal during the vehicle driving process, or it can also achieve driving with a fixed roll angle or a fixed pitch angle, which is beneficial to the target alignment operation of components such as manipulators.

Claims

1. Linear displacement active suspension, characterized in that: include: One end of the two equal-length rocker arms is rotationally connected to the vehicle body, two connection points A and B, the other ends of the two rocker arms are rotationally connected to the balance bar, two connection points D and C, the rotation axes at the four connection points are parallel to each other and perpendicular to the median vertical plane of the vehicle body, forming a parallelogram ABCD closed kinematic chain with the same relative motion plane, and the relative motion plane is parallel to the median vertical plane of the vehicle body; one end of the three equal-length connecting rods is rotationally connected around the same axis, connection point F, the other end of the first connecting rod is rotationally connected to the balance bar, the connection point is located at point E on the extension line of DC, and EC=BC, the other end of the second connecting rod is rotationally connected to the vehicle body at point B, the other end of the third connecting rod is rotationally connected to one end of the trailing arm, connection point G, the trailing arm The other end is rotationally connected to the balance bar at point D, and the wheel is rotationally connected to the trailing arm at point G to drive the vehicle. The rotation axes at each rotation connection point are perpendicular to the median vertical plane of the vehicle body. In the same relative motion plane parallel to the median vertical plane of the vehicle body, the geometric conditions are satisfied: AD=BC, FE=FB=FG=2BC, AB=DC=3BC, DG=DE=4BC. The motor is connected in series with the reducer and is fixedly installed on the vehicle body. The output shaft of the reducer drives the rocker arm AD to rotate relative to the vehicle body, with an angle of α. α controls the straight line motion of the wheel center passing through point B and perpendicular to AB. When the balance bar is located above the AB line segment of the vehicle body and α>0, a shock absorber with the same length as the connecting rod is used to replace the first connecting rod FE, and the connection method is the same.

2. The linear displacement active suspension according to claim 1, characterized in that: When the balance bar is located below the AB line segment of the vehicle body and α is less than 0, the first connecting rod FE is retained, and a shock absorber with the same length as the connecting rod is used to replace the second connecting rod FB or the third connecting rod FG, and the connection method is the same. α controls the straight line movement of the wheel center through point B perpendicular to AB.

3. The linear displacement active suspension according to claim 1 or 2, characterized in that: The output shaft of the reducer drives another rocker arm BC to rotate relative to the vehicle body at an angle α, and α controls the straight line movement of the wheel center passing through point B and perpendicular to AB.

4. The linear displacement active suspension according to claim 1, 2 or 3, characterized in that: The motor is a brake motor, and the reducer is a planetary gear reducer or an RV reducer; when power is on, the brake is released and the motor is energized, and the brake motor is connected in series with the planetary gear reducer or the RV reducer to drive the rocker arm to rotate, the center of the wheel moves along a straight line perpendicular to AB through point B, and the height of the vehicle body from the ground changes; after power is off, the motor stops energizing, the brake brakes the motor shaft, and the height of the vehicle body relative to the ground is locked.

5. The linear displacement active suspension according to claim 1, 2 or 3, characterized in that: The motor is a permanent magnet synchronous motor, and the reducer is a worm reducer with a reverse self-locking function; when the motor is energized, the worm pair is driven to reduce speed, and the motor is connected in series with the worm reducer to drive the rocker arm to rotate, the center of the wheel moves along a straight line perpendicular to AB through point B, and the height of the vehicle body from the ground changes; when the motor stops energizing, the worm pair reverses and self-locks, and the height of the vehicle body relative to the ground is locked.

6. An active roll vehicle, characterized in that: include: According to claim 1, 2 or 3, the two groups of linear displacement active suspensions with the same structure and performance parameters are arranged symmetrically on the left and right sides of the vehicle body according to a given wheelbase. On the same vehicle body, a single wheel is placed in front according to a given wheelbase and shares the same vehicle body middle vertical plane. The front wheel is steered and the rear wheels are driven. The front and rear wheel tires are both arc-shaped tires. The left and right motors drive the rocker arms in the two groups of linear displacement active suspensions to rotate in opposite directions relative to the vehicle body through the reducer. The double rear wheels move linearly in opposite directions relative to the vehicle body and the vehicle rolls. The single front wheel rolls adaptively with the vehicle body.

7. A ground contouring vehicle, characterized in that: include: According to claim 1, 2 or 3, the four groups of linear displacement active suspensions with the same structure and performance parameters are arranged symmetrically on the mid-vertical plane of the vehicle body according to a given track width and wheelbase, share the same vehicle body, the four wheels are independently driven, the inner and outer wheels are differentially steered, the four groups of linear displacement active suspensions are independently controlled, and the four wheels independently follow the ground.

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