JPH11291735A - Air suspension system of automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce adverse influence of centrifugal force generated when an automobile turns by detecting the direction, the angle and a traveling speed of steered wheels by a steering angle sensor, controlling air suspensions by calculating the direction and the magnitude of centrifugal force generated in a car body, and inclining the car body in the direction for resisting the centrifugal force. SOLUTION: A steering angle sensor 10 is arranged on a tie rod 9 of a steering mechanism, and a car body inclination sensor 11 is installed in a car body proper place to detect the direction and an angle of front wheels 1 being steered wheels and a longitudinal inclination of a car body. At turning time, the direction and the magnitude of centrifugal force generated in the car body are calculated from the direction of the front wheels 1 detected by the steering angle sensor 10 and a traveling speed detected by a traveling speed sensor to control a car height by opening/closing electric control valves 7, 8 arranged in respective suspensions 3 so that the car body is forcedly inclined in the turning direction to thereby reduce a quantity by which a vector of upper body weight applied to the upper body gravity center of an occupant falls wide of the center line of a seat so as to increase stability of the occupant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air suspension for arbitrarily changing the height of an automobile and a control method thereof.

[0002]

2. Description of the Related Art Conventionally, when a four-wheeled vehicle turns, simply changing the direction of the steered wheels by steering operation is performed.
Although a stabilizer or a differential wheel was used for the wheel, there was no such thing as tilting the vehicle body in the turning direction like a motorcycle.

[0003] However, the centrifugal force generated by the turning causes various problems in running, and in an extreme case, there is a danger that the vehicle body may be rolled over or the vehicle may not be able to turn a curve to cause an accident.

[0004] Further, the centrifugal force also affects the occupant, and acts to tilt the upper body sideways to make the body unstable, which may hinder driving.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the adverse effect of a centrifugal force generated when a vehicle turns, and to maintain the safety of traveling and the stability of occupants.

In order to solve the above-mentioned problems, according to the present invention, when a vehicle turns, a steering angle sensor detects the direction of a steered wheel, its angle (turning radius), and traveling speed, and detects the direction of centrifugal force generated in the vehicle body. The microcomputer of the control device calculates the size and the size, controls the air suspension, and tilts the vehicle body in a direction against the centrifugal force to reduce the adverse effect of the centrifugal force.

[0007] The air suspension is constructed by piping compressed air stored in an air tank by an air conditioner to an air spring, and opening and closing an air supply valve provided in the middle and an exhaust valve connected to the air spring. The height is changed to control the vehicle height.
Using a device that is electrically controlled by a solenoid, a motor, or the like, control is performed by a current from a control device.

[0008] The air spring of the air suspension may be one in which a piston is inserted into a cylinder or one in which a bellows or a diaphragm is used. The air spring is directly integrated with a shock absorber.

Further, if a stroke sensor for easily and accurately detecting the stroke of the air spring is provided on the end plate, the troke can be read easily and accurately, and the control can be reliably performed.

On a slope, the inclination of the vehicle body is detected by a vehicle body inclination sensor. On an uphill, the stroke of the air suspension of the rear wheel is increased to lift the rear vehicle body.
On a downhill, control is performed so that the stroke of the air suspension of the front wheels is increased to lift the front vehicle body.

The control of the air suspension is preferably performed automatically or manually.

[0012]

The air suspension system configured as described above tilts the vehicle body in the turning direction by controlling the air suspension by the control device when the vehicle turns, and on a slope, moves the body closer to the horizontal according to the slope. Work on.

Further, since the stroke of the four-wheel air suspension can be controlled independently, even when the load on the vehicle body is uneven, the air pressure in that portion is increased to keep the vehicle body horizontal.

Further, since the vehicle height can be arbitrarily changed, the vehicle height can be increased on off-road without rubbing the bottom, and conversely, a high-off-road vehicle can travel on a highway or the like. When doing so, the effect of the crosswind can be reduced by lowering the vehicle height.

Further, since the air suspension is made by integrating the shock absorber with the air spring, the number of parts can be reduced and the mounting space is not required, so that the air suspension can be mounted in the same manner as a conventional automobile suspension.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
Reference numeral 2 denotes a pipe for compressed air to the air suspensions 3 of the front wheels 1 and the rear wheels 2. Compressed air produced by the air compressor 4 is stored in an air tank 5, and from there, the air suspensions 3 are connected via pipe joints 6. A valve 7 for air supply, which is opened and closed by electric control, is provided in the middle, and a valve 8 for exhaust air similar to the above is attached to each air suspension 3.

The tie rod 9 of the steering mechanism
The steering angle sensor 10 and the body tilt sensor 1
1 to detect the direction and angle of the front wheel 1, which is a steering wheel, and the forward and backward inclination of the vehicle body.

The steering angle sensor 10 can be mounted at an appropriate position between the steering mechanism and the steered wheels, and the tie rod 9 is not particularly required.

FIG. 3 shows the action of a centrifugal force generated when a conventional automobile turns right. The centrifugal force acts in a direction opposite to the turning direction, and the vehicle body 12 is tilted outward. The vehicle center of gravity 13 also moves outward, and acts so that the vehicle body load is applied to the outer wheels and the inner wheels float.

At the same time, a similar force acts on the middle occupant 14, and the upper body weight W is applied to the upper center of gravity 15 of the occupant 14 on the seat 16 in the direction synthesized by the centrifugal force C and the vector of gravity G. As a result, the vector of the upper body weight W deviates from the center line 17 of the seat 16, and the larger the deviation, the more easily the occupant 14 falls and becomes unstable.

FIG. 4 shows the effect of the centrifugal force generated when a vehicle using the present invention turns right.
When turning, the body 12 is forcibly tilted in the turning direction, so that the vehicle center of gravity 13 also moves in the turning direction, so that even if the centrifugal force acts in the opposite direction to the turning direction, the wheels are evenly loaded. Similarly, the upper body weight W is applied to the upper center of gravity 15 of the occupant 14 on the seat 16 in the direction synthesized by the vector of the centrifugal force C and the gravity G as described above. 17 is smaller than in the case of a conventional car,
The stability of the occupant 14 is increased.

The vehicle body 12 can be tilted by lifting or lowering one side, but it is also possible to perform both.

FIG. 5 shows a state in which the vehicle using the present invention travels on an uphill 18 and the vehicle body inclination sensor 11 works to lift the vehicle body 12 at the rear wheel 2 and travel. It is possible to prevent the front wheel 1 from floating, reduce the load imposed on the rear wheel 2 by the vehicle load, and reduce the inclination of the seat backward.

FIG. 6 shows a state in which the vehicle is traveling on a downhill 19, in which the vehicle body inclination sensor 11 works to lift the vehicle body 12 of the front wheel 1 and travels. And the seat is prevented from leaning forward.

FIG. 7 relates to an air suspension 3 using an air spring 22 having a piston 21 provided in a cylinder 20. The upper end of the cylinder 20 is sealed by an upper end plate 23, and the lower end plate 24 is closed by a lower end. Attach. Piston 21 in cylinder 20
The outer shell 26 of the shock absorber 25
Through the lower end plate 24 and the shell end 27
And the piston rod 28 is passed over the piston 21 so that the rod end 29 is connected to the upper end plate 23.
Fixed to.

In the cylinder 20, a coil spring 30 for cushioning the piston 21 is provided on upper and lower end plates 23 and 24.
30a, and pipes 31 and 32 communicating with the inside of the cylinder 20 are fixed to the upper end plate 23.
The valves 1 and 32 are respectively provided with an air supply valve 7 and an exhaust valve 8 which are electrically controlled.

An air hole 33 is provided in the lower end plate 24, and a stroke sensor 36 is attached to the lower end plate 24. The stroke detection rod 35 is pressed against the bottom of the piston 21 by a coil spring 34 to synchronize with the movement of the piston 21.
When the stroke detection rod 35 moves up and down, the stroke sensor 36 reads a signal that changes electrically, magnetically, and optically, and detects a stroke that is the total length of the air suspension 3 that changes.

To detect a stroke from the position of the piston 21, a rack 37 or a magnetic tape may be provided on the outer shell 26 of the shock absorber 25, and the stroke may be detected by rotation of a pinion assembled to the rack 37 or a magnetic head.

FIG. 8 shows a bellows type air spring 22.
a, the lower end plate 24a of the air spring 22a.
The shell end 27a of the outer shell 26a of the shock absorber 25a is fixed to the piston rod 28a.
Through the air spring 22a to fix the rod end 29a to the upper end plate 23a.

The upper end plate 23a has pipes 31a. 32a is fixed,
A valve 7a for air supply and a valve 8a for exhaust, which are respectively electrically controlled, are provided there.

Further, the upper end of a stroke detecting rod 35a provided with two electric resistance wires 38 in parallel to the side surface of the upper end plate 23a, and the lower part thereof is a detecting rod guide 42 provided on the side surface of the lower end plate 24a. And the two-branch brush 39 provided there is brought into contact with the two electric resistance wires 38 to cause a short circuit.
The change in the distance of the lead wire 4a is regarded as the change in the electric resistance value.
It reads from 0 and detects a stroke.

FIG. 9 is an enlarged view of a main part of the stroke sensor 36a. A mounting portion 41 of the stroke sensor 36a is fixed to a side surface of the upper end plate 23a with a screw or the like, and a stroke detection rod 35a extended downward. Is made of an insulator such as plastic, and two electric resistance wires 38 are embedded and protruded from the surface of the inner surface thereof, and the fork brush 3 in the detection rod guide 42 provided on the lower end plate 24a is formed.
9 is contacted, and a change in the electric resistance value is read by a lead wire 40 attached to the upper end of the electric resistance wire 38.

FIG. 10 is an example of a block diagram showing a main circuit relating to an air suspension of an automobile to which the present invention is applied.

A control device 43 having a microcomputer includes a steering angle sensor 10, a vehicle body inclination sensor 11, and a traveling speed sensor 4.
4. Air tank pressure sensor 45, stroke sensor 36
More digital and analog signals are transmitted, and the control device 43
Reads the signals and opens and closes the electric control valves 7 and 8 provided on each air suspension pen 3 to control the vehicle height.

[0035]

Since the present invention is configured as described above, it has the following effects.

According to the first aspect of the present invention, the adverse effect of the centrifugal force generated on the vehicle body and the occupant during turning of the automobile can be reduced, which can contribute to driving safety.

The second aspect of the present invention contributes to the stability of the vehicle body and the occupant when going up and down a slope, and promotes safe driving.

According to the third aspect of the present invention, since the outer shell of the shock absorber is used for the piston rod of the air spring, the number of parts is reduced, and no mounting space is required.

According to the fourth aspect of the present invention, the piston rod of the shock absorber is passed through the air spring so that it becomes a guide and is hardly bent, and can be mounted in the same manner as a conventional passenger car.

According to the fifth and sixth aspects of the present invention, it is possible to obtain a sensor for easily and surely detecting the stroke, which is the total length of the air suspension.

[Brief description of the drawings]

FIG. 1 is a plan view showing a pipe according to an embodiment of the present invention.

FIG. 2 is a left side view showing a pipe according to an embodiment of the present invention.

FIG. 3 is a view of the automobile as viewed from the rear.

FIG. 4 is a view of the automobile as viewed from the rear.

FIG. 5 is a diagram showing a side view of the automobile.

FIG. 6 is a view showing a side surface of the automobile.

FIG. 7 is a longitudinal sectional view of an embodiment according to the present invention.

FIG. 8 is a longitudinal sectional view of an embodiment according to the present invention.

FIG. 9 is an enlarged view of a main part in FIG.

FIG. 10 is a block diagram showing a main circuit according to the present invention.

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 Front wheel 2 Rear wheel 3 Air suspension 4 Air compressor 5 Air tank 6 Pipe joint 7, 8 valve 10 Steering angle sensor 11 Body inclination sensor 20 Cylinder 21 Piston 22, 22a Air spring 23, 23a Upper end plate 24, 24a Lower end plate 25, 25a Shock absorber 26, 26a Outer shell 28, 28a Piston rod 30, 30a, 34 Coil spring 35, 35a Stroke detecting rod 36, 36a Stroke sensor

Claims (6)

[Claims] In a vehicle equipped with an air suspension whose electric height can be changed by electric control on all wheels, a control device determines a centrifugal force generated in the vehicle body from a direction and an angle of a steered wheel and a traveling speed, and an air spring of the air suspension. An air suspension system for an automobile, characterized in that the air pressure of the vehicle is adjusted so that the vehicle body is tilted in a direction against centrifugal force. 2. In an automobile equipped with an air suspension whose electric height can be changed by electric control on all wheels, the inclination of the vehicle is detected by a sensor on a slope, and the control device accordingly raises the rear part of the vehicle body on an uphill. An air suspension system for a vehicle, wherein the vehicle is controlled so that the front of the vehicle body is lifted on a downhill. 3. A shell end of an outer shell of a shock absorber is fixed to a piston of a cylinder serving as an air spring, a rod end is fixed to an upper end plate through a piston rod of the shock absorber above the piston, and an electric end is fixed to the upper end plate. 3. An air suspension according to claim 1, further comprising an air supply and exhaust valve communicating with the cylinder to be controlled. 4. A shell end of an outer shell of a shock absorber is fixed to a lower end plate of an air spring using a bellows or a diaphragm, and a piston rod is passed through the air spring to fix a rod end to an upper end plate. 3. An air suspension according to claim 1, further comprising an air supply and exhaust valve communicating with an electrically controlled air spring on the upper end plate. 5. The air suspension according to claim 3, wherein a stroke sensor for detecting the position of the piston based on the movement of the piston or the outer shell of the shock absorber is provided on the lower end plate of the cylinder. 6. A stroke detection rod is fixed at one end to an upper end plate and a lower end plate of an air spring and provided at another end, and a change in the distance between the upper and lower end plates is changed by a change in the length of the stroke detection rod. 5. The air suspension according to claim 4, wherein a stroke sensor is used instead of the air suspension.