WO2020042366A1

WO2020042366A1 - Mechanical active suspension system

Info

Publication number: WO2020042366A1
Application number: PCT/CN2018/114779
Authority: WO
Inventors: 石海军
Original assignee: 石海军
Priority date: 2018-08-28
Filing date: 2018-11-09
Publication date: 2020-03-05
Also published as: CN109050194A

Abstract

A mechanical active suspension system for a vehicle. A fixed end of a spring in a suspension is connected to a vehicle body by means of a screw-nut mechanism (9, 10) or a worm gear-worm mechanism (28, 29). An ECU (39) controls a servo motor (20) to drive the nut (10) or the worm (29) to rotate, so that the screw (9) and the worm gear (28) drive a swing arm connected thereto to generate lifting and lowering motions with respect to the vehicle body, thereby adjusting the height of a vehicle chassis. A multi-stage spring is used in the suspension to achieve the soft and hard adjustment of the suspension. The ECU controls the operation of each motor in real time according to data fed back by each sensor. The lifting and lowering of each independent suspension are adjusted so as to counteract the actions of the vehicle body of turning and tilting, brake nodding and starting and raising the head. In an unequal-length double wishbone suspension, one wishbone (3) is connected to the vehicle body by means of an eccentric shaft (22), and the ECU (39) controls a servo motor (21) to drive a worm (24) or a worm gear (23) to drive the eccentric shaft (22) to rotate, thereby adjusting the inclination angle between the wheel and the ground. The present mechanical active suspension system for a vehicle solves the problems of the high price and subsequent excessive maintenance costs of current active suspensions, and further improves the performance thereof.

Description

Mechanical active suspension system Ranch

Technical field

The invention relates to a vehicle suspension system, in particular to a mechanical active suspension system.

Background technique

The ideal vehicle suspension system should be: when the vehicle is driving on bumpy roads, off-road roads, the chassis is required to be higher, the suspension is softer to improve the vehicle's passability and comfort; when the vehicle is on paved roads When driving on high-speed roads at high speeds, the chassis is required to be lower and the suspension is harder to improve the stability and handling of the vehicle. Under traditional chassis technology, handling and comfort are a natural contradiction. Generally, they can only focus on one side of the training. Designers try to find the balance between the two as much as possible. Therefore, an active suspension capable of high energy, low energy, and soft energy can be more popular. At present, there are three widely used active suspension systems: air suspension, hydraulic suspension, and electromagnetic suspension.

The air suspension is composed of air spring, adjustable shock absorber, air pump, etc. It has the ability to adjust the height of the chassis and change the stiffness of the suspension. It can be adjusted to the best state according to needs. It has good applicability and is currently the most widely used. Active suspension form. The chassis height adjustment is mainly determined by the length of the air spring, so the adjustment range is not large. At the same time, because the structure of the air suspension is more complicated, it is expensive and has a higher failure rate. It will cause the air pump to overheat during frequent use and affect it. Life, air springs generally need to be replaced within 60,000 to 80,000 kilometers, and subsequent maintenance costs are high.

Each wheel of the hydraulic suspension has a hydraulic sub-pump, which adjusts the height and hardness of the suspension by adjusting the amount of oil filled in the cylinder and the size of the damping valve. Compared with air suspension, hydraulic suspension has strong load capacity, small size and convenient layout. The disadvantages are the slow response speed, narrow adjustment range, and the problem that it needs to be replaced after using it for a certain number of kilometers.

The electromagnetic suspension controls the viscosity of the electromagnetic fluid in the shock absorber by adjusting the current to adjust its damping, thereby adjusting the stiffness of the shock absorber. It is characterized by fast response speed and high safety. However, the height of the chassis cannot be adjusted. The suspension can only be adjusted through the shock absorber, which is considered a semi-active suspension.

technical problem

The current active suspension system is only used on some luxury cars because of its high cost and low cost performance. Therefore, there is an urgent need for a suspension system that is cheap and durable, has low maintenance costs, and can meet the functional requirements of active suspensions to meet the consumer demand of the masses.

Technical solutions

The purpose of the present invention is to solve the problems of the current high prices of active suspension systems, the need to replace components for a certain period of time, high maintenance costs and insufficient comprehensive performance.

In order to solve the above problems, the present invention provides a mechanical active suspension system, in which an upper end of a helical spring in the suspension is connected to a frame or a body through a worm gear mechanism or a fixed end of a torsion bar spring The electric control device (ECU) controls the servo motor to drive the nut and the worm to rotate, and then drives the spring and the swing arm connected to the spring to generate a lifting movement relative to the vehicle body through the screw nut mechanism or the worm gear mechanism, thereby realizing the lifting of the vehicle chassis and each independent suspension Height adjustment.

In the mechanical active suspension system, two or more springs are juxtaposed in a suspension, a spiral spring is connected to a screw rod in a main spring, a torsion bar spring is connected to a worm wheel, and a secondary spring is directly connected to the vehicle body. When the chassis is raised, the auxiliary spring is suspended, and only the main spring is used for support At this time, the suspension is soft; when the chassis is lowered to a certain height, the main spring and the auxiliary spring are jointly supported in the suspension, and the suspension is harder at this time. In this way, the soft and hard adjustment of the suspension is achieved. If multiple auxiliary springs of different heights are connected in parallel in the suspension, the multi-level hardness adjustment of the suspension can be realized.

In the mechanical active suspension system, each independent suspension is driven by an independent servo motor, and the ECU is based on a steering wheel angle sensor, a vehicle speed sensor, an acceleration sensor, a body displacement sensor, a vehicle height sensor, a brake pressure sensor, etc. The feedback data controls the movement of each servo motor, and the body attitude is adjusted by adjusting the height of each independent suspension.

In the mechanical active suspension system, in an unequal-length double-wishbone or double-wishbone suspension, an eccentric shaft structure is adopted as a connecting pin between the swing arm and the vehicle body, and one end of the eccentric shaft is connected with a worm gear mechanism. It is driven by a servo motor controlled by the ECU. Through the rotation of the eccentric shaft, the position of a swing arm and the connecting shaft of the vehicle body relative to the vehicle body is changed, so that any height of the wheel in the chassis lifting range can be kept constant with the inclination of the road change.

Beneficial effect

(1) The invention adopts the traditional coil spring and torsion bar spring based on the mechanical structure of the screw nut and the worm gear to achieve the height adjustment of the suspension, and the use of multi-level springs to achieve the soft and hard suspension Adjustment. Because its structure is a purely mechanical structure, it is more stable and durable than an air suspension, has a longer life and can be used for life. The manufacturing costs of traditional mechanical components such as coil springs, torsion bar springs and screw nuts are also lower.

(2) The lifting height of the chassis in the present invention depends on the height of the screw rod connected to the coil spring and the rotation angle of the worm wheel connected to the fixed end of the torsion bar spring, and has nothing to do with the height of the spring. Therefore, compared with the air suspension, the suspension chassis of the present invention has a larger lifting range, and can freely switch between the height of the off-road vehicle chassis and the height of the sports car chassis.

(3) The present invention uses a servo motor as the drive unit. Compared with air pumps and hydraulic pumps in air suspensions and hydraulic suspensions, the technology has a mature technology, simple structure, faster response, and more accurate control.

(4) The screw nut mechanism and the worm gear mechanism used in the present invention have good self-locking characteristics. The servo motor only performs work when the suspension needs to be adjusted, and it does not need to perform work after adjusting in place, so the suspension system consumes It also has less energy.

(5) The present invention uses an eccentric shaft to adjust the coupling position of one of the cross arms in the double wishbone suspension relative to the vehicle body, and solves the problem that the wheel inclination angle changes greatly when the double wishbone suspension is adjusted in a wide range.

(6) The servo motor driving mechanism used in the present invention can accurately adjust the height position of each independent suspension. When the vehicle turns and brakes, most of the air suspension, hydraulic suspension and electromagnetic suspension improve the stiffness of the spring or shock absorber to reduce the roll of the vehicle when turning and the nodding action when braking. The invention can raise the outer suspension and lower the inner suspension according to the data of various sensors when the vehicle is turning; when the vehicle is braking, the two front wheel suspensions are raised to completely offset the camber and braking when the vehicle is turning The nodding action makes the body more stable and comfortable.

Compared with the existing active suspension system, the mechanical active suspension system of the present invention has a more stable and durable structure, lower cost, more accurate control, and more comprehensive functions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a vehicle suspension system including a coil spring and a torsion bar spring according to the present invention.

FIG. 2 is a three-dimensional schematic view showing the structure of an embodiment of a double wishbone suspension according to the present invention.

FIG. 3 is a schematic diagram of a state in which the main spring and the auxiliary spring are jointly supported when the suspension is lowered in the embodiment shown in FIG. 2.

FIG. 4 is a schematic view of a suspension height adjustment state in the embodiment shown in FIG. 2.

FIG. 5 is a three-dimensional schematic view of an embodiment in which a torsion bar spring is used for a rear suspension according to the present invention.

Fig. 6 is an isometric view of an eccentric shaft part according to the present invention.

FIG. 7 is a schematic diagram illustrating the state of adjusting the upper transverse arm of the eccentric shaft in three different positions a, b, and c in the embodiment shown in FIG. 2.

Part numbers described in the drawings: 1, frame; 2, lower cross arm; 3, upper cross arm; 4, front shock absorber; 5, main spring; 6, spring support plate; 7, auxiliary spring; 8, Bogie; 9, screw rod; 10, nut; 11, thrust bearing; 12, nut support sleeve; 13, spherical pad; 14, upper support seat; 15, support sleeve nut; 16, nut lock pieces; 17, 18 Bevel gear; 19, screw rod anti-rotation rod; 20, front main motor; 21, front auxiliary motor; 22, eccentric shaft; 23, worm gear; 24, worm; 25, torsion bar spring; 26, torsion bar spring bracket; 27 The rear main motor; 28, the worm gear; 29, the worm; 30, the worm gear; 31, the rear shock absorber; 32, the upper bracket of the shock absorber; 33, the auxiliary spring support; 34, the auxiliary spring; 35, the vice Unsprung support base; 36, longitudinal swing arm; 37, swing arm support rod; 38, torsion bar spring torsion arm; 39, ECU; 40, steering wheel angle sensor; 41, brake and accelerator pedal sensor; 42, brake Pressure sensors; 43, acceleration sensors; 44, body displacement sensors; 45, body height sensors; 46, vehicle speed sensors. The above-mentioned motors are all servo motors.

Best practice

Exemplary embodiments of the present invention will be described below with reference to the drawings. Throughout the description, the same reference numerals refer to the same parts, and the same parts in the left-right symmetric mechanism will omit repeated reference numerals and descriptions. The drawings are only for better describing the concept of the present invention, and the understanding of the concept of the present invention is not limited to the drawings.

1. Height adjustment of suspension.

As shown in FIGS. 1 and 2, FIG. 2 is an embodiment of an unequal-length double-wishbone front suspension. The lower cross arm 2, the upper cross arm 3, and the bogie 8 constitute a double-wishbone suspension mechanism. The upper ends of the main spring 5 and the shock absorber 4 are connected in series with the screw rod 9, and the lower end of the shock absorber 4 uses a pin shaft and The lower cross arm 2 is connected, and the lower ends of the main spring 5 and the auxiliary spring 7 are supported by a spring support plate 6. The screw rod 9 is connected to the frame 1 through a nut 10, a thrust bearing 11, a nut support sleeve 12, and a spherical pad 13 support seat 14. The upper end of the nut support sleeve 12 is provided with a support sleeve nut 15, and the middle of the nut 10 is provided with a nut fastener 16. The upper end of the nut 10 is passed through a key and a bevel gear. 17 phase connection. The screw rod anti-rotation rod 19 restricts the rotation of the screw rod 9.

ECU 39 controls the forward and reverse rotation of the main motor 20. The front main motor 20 drives the nut 10 to rotate through the bevel gears 18 and 17, and the screw rod 9 matched with the nut 10 realizes vertical movement. The screw rod 9 drives the main spring 5, the shock absorber 4 and the lower cross arm 2 to move together to realize the height adjustment of the suspension.

Figure 3 shows the state when the suspension is lowered.

Figure 4 shows the state when the suspension is raised.

As shown in FIGS. 1 and 5, FIG. 5 is an embodiment of a rear suspension using a torsion bar spring. The torsion bar spring 25 rotates in the torsion bar spring bracket 26, and the fixed end of the torsion bar spring 25 is fixedly connected to the turbine 28. (Because the rotation adjustment range of the worm gear 28 is not large, only a part of it is taken). The worm gear 28 is coupled to the vehicle frame 1 through a worm 29 and a worm gear frame 30. The other end of the torsion bar spring 25 is coupled to the longitudinal swing arm 36 through a torsion bar spring torsion arm 38 and a swing arm support rod 37.

By ECU 39 The forward and reverse rotation of the rear main motor 27 is controlled. The rear main motor 27 drives the worm 29 to rotate. The worm 29 drives the worm wheel 28 and the torsion bar spring 25, the torsion bar spring torsion arm 38 rotates, and the torsion bar spring torsion arm 38 drives the swing arm support rod. 37. The swing arm 36 moves up and down to realize the height adjustment of the suspension.

Implementation

2. Soft and hard adjustment of suspension.

As shown in FIG. 2, in the suspension, the main spring 5 is juxtaposed with the auxiliary spring 7 and the shock absorber 4. The lower end of the main spring 5 is connected to the lower cross arm 2 through a spring support disc 6, and the upper end of the main spring 5 is connected with a wire. The rod 9, the nut 10, the thrust bearing 11, the nut support sleeve 12, the spherical pad 13, and the upper support seat 14 are connected to the frame 1. The upper end of the auxiliary spring 7 is coupled to the lower end of the nut support sleeve 12, and then coupled to the vehicle frame 1 through the spherical pad 13 and the upper support frame 14.

As shown in Figures 2 and 4, when the suspension is raised, the lower end of the auxiliary spring 7 does not contact the spring support plate 6, the auxiliary spring 7 is in a suspended state, and only the main spring 5 is used for support. At this time, the suspension is relatively soft. For comfort.

As shown in FIG. 3, when the suspension is lowered, the lower ends of the main spring 5 and the auxiliary spring 7 are in contact with the spring support plate 6, and the main and auxiliary springs are supported together. At this time, the suspension is relatively rigid and in a moving state.

As shown in FIG. 5, in the torsion bar spring-type rear suspension, when the suspension is raised, the auxiliary spring 34 is in a suspended state, and only the torsion bar spring 25 is supported at this time, and the suspension is in a relatively soft and comfortable state. When the suspension is lowered, the secondary spring support base 35 and the secondary spring 34 At this time, the torsion bar spring 25 and the auxiliary spring 34 are supported together, and the suspension is relatively rigid and in a moving state.

3. Adjustment of wheel inclination.

In currently commonly used unequal-length double-wishbone or double-wishbone suspensions, when the height of the suspension is adjusted too large, the inclination of the wheel and the road surface is changed, thereby causing uneven tire wear and changing the tire's grip. To change this situation, the present invention uses an eccentric shaft mechanism to adjust the upper cross arm.

As shown in FIGS. 1, 2 and 6, both ends of the eccentric shaft 22 are coupled to the frame 1, the middle eccentric portion is coupled to the upper cross arm 3, and the longer end is connected to the turbine 23 by a key. ECU 39 Calculate the corresponding data according to the signal data of the vehicle height sensor 45, and then control the auxiliary motor 21 to drive the worm 24 to drive the worm wheel 23 and the eccentric shaft 22 through a certain angle, and adjust the position of the joint of the upper cross arm 3 relative to the frame 1. The cross arm 3 pushes the bogie 8 to adjust the included angle with the ground, so that any height of the wheel in the chassis adjustment range can ensure that the inclination angle with the road surface remains unchanged.

As shown in Figure 7, Figures a and b Figure c shows the position of the eccentric shaft 22 when adjusting the coupling position of the upper cross arm 3 with respect to the frame 1 when the eccentric shaft 22 is moved outward, middle, and inward, respectively.

4. Control of the suspension.

As shown in Figure 1, each independent suspension is driven by an independent servo motor, two main motors 20 drive two front suspensions, two rear main motors 27 drive two rear suspensions, and two auxiliary The motors 21 drive the eccentric shafts, respectively. ECU 39 According to the signal data fed back from the steering wheel angle sensor 40, the brake and accelerator pedal sensor 41, the brake pressure sensor 42, the acceleration sensor 43, the body displacement sensor 44, the vehicle height sensor 45, and the vehicle speed sensor 46, the main motor 20 and The movement of the rear main motor 27 and the auxiliary motor 21 adjusts the height of each suspension.

For example, controlling body roll: when the vehicle turns, the ECU 39 According to the feedback signals from the steering wheel angle sensor 40, the vehicle speed sensor 46, the vehicle height sensor 45, and the vehicle displacement sensor 44, the outer suspension is raised in real time, and the inner suspension is lowered to offset the camber movement of the vehicle body. ECU 39 According to the feedback signals from the brake and accelerator pedal sensor 41, acceleration sensor 43, brake pressure sensor 42, vehicle speed sensor 46, and vehicle height sensor 45, the front suspension is raised and the rear suspension is lowered in real time to offset the nod of the body brake. Action; Controlling the acceleration of the car body: ECU 39 According to the signal data of the feedback from the brake and accelerator pedal sensor 41, the acceleration sensor 43, and the vehicle height sensor 45, the front suspension is lowered and the rear suspension is lowered to cancel the acceleration of the vehicle body.

Another example: suspension control can be divided into intelligent mode and manual mode. Manual mode can be divided into off-road, urban, sports and other modes. When the vehicle system is shut down, the chassis is minimized, and the secondary spring is used as the main support, which can reduce the load of the main spring; when the system is started, the chassis recovers the height based on the memory; when the vehicle load increases, the ECU adjusts the suspension according to the vehicle height sensor signal To keep the body at a certain height; in off-road mode, the suspension chassis is raised, the suspension is comfortable, and the presence of the auxiliary spring can prevent the suspension of the suspension; in the urban mode, the suspension is reduced to the normal Car chassis height; in sport mode, the chassis is lowered to the double spring support height, the suspension becomes harder, the center of gravity is lower, and the handling is improved.

In the intelligent mode, the ECU automatically adjusts the height of the suspension according to the vehicle speed and body posture. For example: when the vehicle speed exceeds a certain set value, the chassis drops to a motion state; when the vehicle speed decreases to a certain value, the chassis rises to an urban state; when the vehicle speed decreases and the body attitude changes greatly, then The chassis is raised to off-road conditions and so on.

The above description is only an embodiment of the present invention, so the implementation scope of the present invention cannot be limited by this.

Claims

A mechanical active suspension system, characterized in that the coupling end of the coil spring and the frame in the suspension is connected with the frame by a screw nut mechanism or the fixed end of the torsion bar spring and the frame by a worm gear mechanism The electric control device (ECU) controls the servo motor to drive the nut or worm to rotate, and then the spring and the swing arm connected to the spring are driven by the screw nut mechanism or the worm gear mechanism to generate a lifting movement relative to the vehicle body to achieve the height adjustment of each independent suspension. And lifting of the chassis.
The mechanical active suspension system according to claim 1, characterized in that: two or more springs are juxtaposed in the suspension, and in the main support spring, a helical spring is connected to the frame through a screw nut, The torsion bar spring is connected to the frame through a worm gear, and the auxiliary spring is directly connected to the frame. When the chassis is raised, the auxiliary spring is suspended, and only the main spring supports it. At this time, the suspension is soft; when the chassis is lowered to a certain height At this time, the main spring and the auxiliary spring are supported together, and the suspension becomes hard at this time. Multiple secondary springs can be connected in parallel in the suspension to achieve multi-level hardness adjustment of the suspension.
The mechanical active suspension system according to claim 1, characterized in that each independent suspension is driven by an independent servo motor, and the ECU is based on a steering wheel angle sensor, a brake and accelerator pedal sensor, a vehicle speed sensor, and acceleration. Data from sensors, body displacement sensors, body height sensors, brake pressure sensors, etc. are used to control the movement of each servo motor in real time, and the body attitude is adjusted by adjusting the height of each independent suspension.
The mechanical active suspension system according to claim 1, wherein in the unequal-length double-wishbone suspension, an eccentric shaft structure is adopted as a coupling pin between the swing arm and the vehicle body, and one end of the eccentric shaft and the worm gear The worm mechanism is connected and driven by a servo motor controlled by the ECU. The position of a swing arm and the body coupling pin relative to the frame is changed by the rotation of the eccentric shaft, so that the wheel can be at any height within the lifting range of the chassis. Keep the inclination to the road.