JPH02237809A - Control device for suspension - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a suspension control device that varies suspension characteristics in accordance with lateral acceleration acting on a vehicle body.

2. Description of the Related Art As a conventional suspension control device of this type, one described, for example, in Japanese Utility Model Publication No. 6:2-38402 has been provided.

In this world, the suspension control device has a set value of vehicle speed (30kph).
"m" or more and the steering angular velocity is the set value (20"a"8)
- or the lateral acceleration (lateral G) is set M (0
．． 2G) is configured to output a control signal that increases the spring constant and damping force of the suspension. Therefore, when the door steering wheel is steered rapidly, the spring constant and damping force are controlled to be hard regardless of the steering angle, while when the steering wheel is slowly operated and the steering angle becomes large, The lateral G sensor detects acceleration above the set value in the lateral direction and switches the spring constant and damping force to hard regardless of the steering angle at that time, thereby reducing the roll that occurs in the vehicle body [7] It is something that

Problems to be Solved by the InventionHowever, in the conventional control device described above, a plurality of set values are provided depending on the relative relationship between the vehicle speed, steering angular velocity, and the output value of the lateral G sensor, and the The spring constant and damping force of the suspension are changed to hard settings. In other words, when the vehicle speed is 30"'8 or more and less than 80'""8, the steering angular velocity is 20"'8 or more, L, and the lateral G is 0.2 or more, - When the steering angular velocity is 8 or more and the steering angular velocity is 10''K or more, the suspension is switched to hard when the lateral G is 0.1 or more. Conditions are set separately from time. For this reason, it is not possible to control the spring constant or damping force characteristics of the suspension promptly when lateral acceleration occurs. As a result, not only the running stability and handling of the vehicle are not sufficiently achieved, but also the riding comfort is affected.

Means for Solving the Problems The present invention was devised in view of the problems of the conventional device described above, and as shown in FIG. A variable means B that increases or decreases, a lateral G sensor C that detects lateral acceleration acting on the vehicle body, and at least one of the damping force or the spring constant of the suspension A is increased or decreased according to the output of the lateral G sensor C. and a control means D that outputs a control signal, wherein the control means D outputs a control signal from the lateral G sensor C.
and an acceleration change rate value obtained from the acceleration signal value, and outputs a control signal to the variable means based on the positive and negative waveform phases of both values. It is a feature.

Operation According to the above configuration, when the structural G sensor C detects the lateral acceleration acting on the vehicle body, the calculation means E calculates the acceleration change rate, that is, the differential value, based on the value of the acceleration signal, and calculates the acceleration change rate. Compare the value of −G with the value of the acceleration signal τ
If the waveform phases of both values are in phase, the suspension Δ
A control signal for increasing at least one of the damping force and the spring constant of the variable means is output to the variable means. On the other hand, when the waveform phase is in the opposite phase, a control signal is output to the variable means B to reduce at least one of the damping force or the spring constant of the suspension.

(7) Therefore, when lateral acceleration occurs in the vehicle body, it is possible to quickly control the vehicle speed and steering speed, regardless of whether it is a steady roll or an excessive roll.

Example Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

That is, as shown in FIG. 2, the control device for this gas bench includes a lateral G sensor 1 that detects lateral acceleration acting on the vehicle body, and a control means that inputs an output signal from the lateral G sensor 1. Taru Micro Fun Viewer Unit 2,
The variable means 5 is attached to the hydraulic shock absorber 3 provided on the vehicle body and each wheel, and is driven by a control signal from the microcomputer unit 2.

The above microcomputer unit 2 has the above mG
Input circuit G having an A/D converter to which sensor 1 is connected
and an arithmetic circuit 7 which performs arithmetic processing on the output signal from the input circuit 6 at input 1- based on a flowchart described later.
and a control condition setting circuit 8 which stores in advance as data a comparison value for the processed signal of the arithmetic circuit 7'' and a control condition of the variable means 5 for the result, and a control condition setting circuit 8 which controls the variable means 5 according to the signal from the arithmetic circuit 7. It has a drive circuit 9 that outputs a voltage signal for driving.The arithmetic circuit 7, the control condition setting circuit 8, and the drive circuit 9 constitute a calculation means. The circuit 6 includes a vehicle speed sensor 1
The output signal from 0 is also input.

1. The hydraulic shock absorber 3 is connected to the cylinder 1 as shown in FIG.
A piston rod 1 is inserted from one end of 1 so as to be freely removable and removable.
A piston 15 is fixed to the tip of the cylinder 11 and slides while separating the inside of the cylinder 11 into an upper liquid chamber 13 and a lower liquid chamber 14. A damping force generating mechanism 16 including a valve 16b is provided.

Also,. The variable means 5 is provided on the piston rod l2, and this variable means 5 is arranged on the piston rod 12.
An actuator 17 provided at the upper end and driven based on a control signal from the drive circuit 9, and a rotary rotatably connected to the actuator 17 via a drive rod 18 and rotatably housed in the piston rod 12. It is composed of a valve l9. Then, rotate this rotary valve 19 to a desired position to connect its large and small diameter orifices to the side holes 12a and 12b of the screw 1 and rod 12.
by selecting and matching them appropriately, and applying the generated damping force to the hard H
It is designed to be controlled in three stages: , medium M, and soft S. In addition, 20 in the figure is a bracket for mounting on the vehicle body, 2
1 is an underspring seat.

The operation of this embodiment will be explained below with reference to the flowchart of FIG. In other words, when the vehicle is running, the lateral G
When the sensor 1 detects the lateral acceleration acting on the vehicle body, the lateral G is converted into digital by the A/D converter of the input circuit 6, and this digitally converted data is sequentially read into the calculation circuit 7 ( Section 1). Next, in sexing 2, from the above current lateral G value, its rate of change G
Calculate the value by calculating by differentiation. Subsequently, in section 3, as shown in FIG. 5, it is determined whether the waveform phases of the above-mentioned drawn G value and the change rate G value are in phase. Here, Y
If it is determined that they are in phase, that is, if a force is acting on the vehicle in the roll direction,
A hard H control signal is output to the drive circuit 9.

If it is determined in section 3 that the phase is negative, that is, if the vehicle body posture has been recovered, then in section 5, a control signal for the drive circuits 9C and 1-S is output.

Therefore, if no roll occurs in the vehicle body, a soft S signal is output from the drive circuit 9 to the actuator 17, and if a roll occurs (2), a hard H signal is output. Actuator 17 according to
rotates the rotary valve 19 to a predetermined position, and
- In the case of S, the large-diameter orifice and the side holes 12a, 12b are matched, and in the case of hard H, the small-diameter orifice or a position where there is no orifice and the side hole 12a. Match i2b. Therefore, when a lateral G is generated in the vehicle body, the damping force is quickly controlled to the hard 1{ side, regardless of the vehicle speed or the steering if of the steering wheel, that is, regardless of the magnitude of the full G.

In the J7 model, the restoring force is increased using the damping force characteristic of the Soft i-S on the rolling back [, side of the vehicle body, so that stability is ensured and a good ride comfort is obtained.

FIG. 6 shows another embodiment of the invention, which is applicable to an air suspension.

That is, in the figure, 22... is the cylinder 1 of the hydraulic shock absorber 3.
Rolling diaphragm provided in each of the 11 parts, 23
24 is an air combiner generator that generates compressed air, and 24 is an air valve unit 1, 2G that distributes the air compressed from the air compressor/server 23 into each rolling diaphragm 22 via a dryer 25. The exhaust valves that adjust the pressure of the compressed air generated by the air conditioner breather 23, the second exhaust hub 26, the air first breather 23, and the air valve unit 24, are operated and controlled by the control unit 2.In other words, When the lateral acceleration of the vehicle body is detected by the lateral G sensor 1, the air compressor 23 is turned on by the output signal from the control unit 2 based on the control method of the arithmetic circuit 7.
The compressed air is delivered to each rolling diaphragm 22...
This increases the spring constant of the suspension, while the air compressor 23 is turned off when the vehicle body posture has recovered or is in the normal posture.
The supply of compressed air is stopped to reduce the sustained stiffness constant.

Furthermore, the air valve units 1 and 24 operate the rolling diaphragms 22 and 24 in response to signals from the control unit 2 according to the acceleration characteristics of the vehicle body in the lateral direction and longitudinal direction.
・It is designed to control the compressed air supply supplied to the inside.

In addition, the exhaust valve 26 may be used, for example, after adjusting the vehicle height.
It also has a function of discharging the compressed air inside the rolling diaphragm 22 to the outside based on a signal from the rolling unit 2.

Therefore, in this embodiment, as described above,
It becomes possible to quickly control the spring constant of the Air Svensiffen in response to the occurrence of a curve, thereby ensuring maneuverability and driving stability.

In addition, further different examples and 1. , then, by combining the first embodiment and the second embodiment, the damping force of the hydraulic shock absorber 3... and o
-The spring constant due to the ring diaphragm 22...-
It is also possible to control the vehicle body at the same time, thereby making it possible to more reliably counter the roll of the vehicle body.

It should be noted that the control signal output from the calculation means E to the variable means B does not necessarily have to be the same for all four wheels, but is output only for the variable f stage ■3 on either the left or right side. cormorant(
You can also strain it.

Effects of the Invention As is clear from the second explanation, according to the present invention, the horizontal G
The acceleration signal from the sensor and the value of the acceleration change rate determined from the value of the acceleration signal are compared and calculated, and at least one of the damping force or the spring constant of the suspension is variably controlled based on the positive and negative phases of both values. Therefore, regardless of the vehicle speed or steering speed, the control of the above symbol can be performed immediately when lateral acceleration occurs in the vehicle body.

As a result, it is possible to improve steering stability and ride comfort.

[Brief explanation of drawings]

Fig. 1 is a diagram corresponding to the claims of the present invention, Fig. 2 is a block diagram showing an embodiment of the present invention, Fig. 3 is a partial sectional view showing a liquid shock absorber used in this embodiment, Fig. 4 The figure is a control flowchart of this embodiment, and Figure 5 shows lateral G and lateral G during vehicle body roll.
FIG. 6 is a diagram showing the waveform phase of the rate of change and control switching characteristics, and is a block diagram showing a second embodiment of the present invention. A... Suspension, B... Variable means, C...
Lateral G sensor, ■)...control means, E...calculation means. 3 people Figure 1 Figure 4

Claims (1)

[Claims] (1) Variable means for increasing or decreasing at least one of the damping force or spring constant of the suspension, a lateral G sensor that detects lateral acceleration acting on the vehicle body, and a damping force of the suspension according to the output of the lateral G sensor or a control device that outputs a control signal for increasing or decreasing at least one of the spring constants, the control device comprising an acceleration signal from the lateral G sensor and a value of the acceleration signal. 1. A suspension control device comprising: arithmetic means for comparing a value of an acceleration change rate and outputting a control signal to the variable means based on positive and negative phases of both values.