JPS59186715A - Suspension for automobile - Google Patents

Abstract

PURPOSE:To control the variative rate and quantity of a roll angle in time of turning a car around, by intensifying the spring force of a variable rate spring when a roll angle variation goes beyond the setting value, in ease of a suspension carrying a damping force variable damper and the variable rate spring. CONSTITUTION:Each of suspension systems 1 and 2 for both front and rear wheels is constituted of shock absorbers 3b, 4b inclusive of damping force variable dampers 3b, 4b, and spring force variable rate air springs 5, 6. Spring force in these air springs 5 and 6 is adjustable with solenoid valves 13 and 14 and controlled by a controller 15. That is to say, each of first and second weighted mean values thetam and thetan to be found from a steering angle signal Stheta out of a steering detector 16 is compared with the exciting steering angle theta, and when a difference between theta and thetam or a difference between theta and thetan is larger than the setting value, solenoid valves 13 and 14 or solenoids 7 and 8 are driven whereby spring force in these air springs 5 and 6 or damping force in dampers 3b and 4b is controlled so as to be intensified.

Description

DETAILED DESCRIPTION OF THE INVENTION An automobile suspension system supports the weight of a vehicle;
It has the role of buffering road surface irregularities, and it not only improves ride comfort, but also improves riding comfort.
-1 has a significant effect on pitching and rolling while driving, as well as stability and responsiveness when turning. Therefore,
It is desirable to be able to variously change the dynamic characteristics of an automobile by appropriately changing the characteristics of the suspension of the front and rear wheels. For example, Utsukai Showa 56-/'7
7/θ7 uses a steering sensor that detects changes in steering angle and a vehicle speed sensor to calculate roll speed (roll angle change rate).
A device has been proposed that detects this and prevents the roll speed during turning from exceeding a predetermined value by controlling to increase the damping force of the shock absorbers of all wheels, that is, to make the damping force harder. According to this device, the roll speed is reduced when turning, making it possible to improve both maneuverability and riding comfort, but controlling the shock absorber alone cannot reduce the roll angle itself, that is, the amount of change in the roll angle. This was not possible, and improvements in this respect were desired.

SUMMARY OF THE INVENTION An object of the present invention is to provide a suspension control device that can suppress not only the rate of change in roll angle but also the amount of change in roll angle when an automobile turns.

The present invention relates to an automobile suspension that includes a variable damping force damper and a variable spring for suspending automobile wheels on a vehicle body, the damping force adjusting means for adjusting the damping force of the variable damper, and the variable spring. A spring force adjusting means for adjusting the spring force of the steering wheel, a steering angle detecting means for detecting the steering angle of the steering wheel, and a steering angle signal outputted by the steering angle detecting means are input, and the roll angle is changed based on the steering angle signal of the steering angle detecting means. a steering angle signal processing means for calculating and outputting a roll angle change rate signal indicating the roll angle change rate and a roll angle change amount signal indicating the roll angle change amount; and inputting the roll angle change rate signal 2 and the roll angle change amount signal. , when the roll angle change rate indicated by the roll angle change rate signal is larger than the fixed value fa, outputs a variable damper control signal that increases the damping force of the variable damper to the damping force adjustment means, and outputs the roll angle change amount signal to the damping force adjusting means. The present invention is characterized by comprising a control means for outputting a variable spring control signal for increasing the spring force of the variable spring to the spring force adjusting means when the amount of change in roll angle shown by is larger than a set value.

In the automobile suspension of the present invention having the above-described structure, the Dan/? In addition, the spring force of the spring can be made variable, and when the amount of change in roll angle exceeds a set value, the spring force of the spring can be increased by means of a spring force adjustment means, so that the roll angle when the car turns is adjusted. Both the rate of change (roll speed) and the amount of change in roll angle can be suppressed, further improving riding comfort.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An automobile suspension according to a preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view showing an automobile suspension according to an embodiment of the present invention, and FIG. 2 is a system diagram of its main parts.

A front wheel suspension 1 and a rear wheel suspension 2 are provided associated with the front wheels and the rear wheels, respectively. These suspensions 1 and 2 each have a spring 3a
, 4a and oleo damper 3b.

A shock absorber 3.4 consisting of a shock absorber 3bs4b is provided, and an air spring 5.6 constituted by a diamond slam made of a suitable elastic material is provided around the periphery of the damper 3bs4b. The dampers /f3b and 4b are variable dampers whose damping force can be adjusted, and therefore the diameter of the orifice provided in the piston (not shown) is variable.

A piston rod 3c is used to change the diameter of this orifice.

A grunger (not shown) is provided in 4c, which is driven by a solenoid 7.8.
It is rotated by the excited solenoids 7 and 8 to reduce the diameter of the oriice, increase the damping force of the dampers/f3b and 4b, and harden the suspension characteristics of the suspension 1.2. In addition, the air spring 5.6 is
They are each connected to a control air chamber 11.12 by an air line 9.10, and the air spring 5 is activated by actuation of a solenoid valve 13.14 provided at the inlet of this chamber 11.12.
．． 6 and the air chambers 11 and 120 are controlled.

In this example, communication is interrupted when the solenoids of solenoid pulps 13, 14 are energized. When the communication between the air spring 5.6 and the air chamber 11.12 is cut off in this way, the effective volume of the air chamber of the air spring 5.6 is reduced, so that the air spring 5.60 is strongly suffocated. However, the suspension characteristics of Suspension 1.2 become harder.

Excitation of the solenoid 7.8 for adjusting the damping force of the variable dampers 3b, 4b and the solenoid pulp 13.14 for adjusting the spring force of the air spring 5.6 is performed by the controller 15. This controller 15 has a steering angle θ of the steering handle H.
A steering angle detector 16 is connected to detect the steering angle and output a steering angle signal S indicating the steering angle. The above controller 15
is a steering angle signal S, which is an analog signal output from the steering angle detector 16, as shown in FIG. 3, for example. It has an A/D converter 11 which receives the signal and converts it into digital data. The output end of the A/D converter 17 receives the steering angle signal S digitized by the A/D converter 17, and receives the steering angle signal S, which is given by the following formula (c, c2). Average value θm1
An arithmetic circuit 18 that calculates on (hereinafter referred to as a first weighted average value θm and a second weighted average value θn, respectively) is connected. Note that the weighted average value θm is for splash control, and on is for damper control.

The weighted average value used in the previous control, k,
7 is a value indicating the number of times of weighting, and θ1 is a steering angle signal S.

represents the current steering angle indicated by .

Note that the weighted average value θm− used in the previous control
/, θn-/, are stored in the storage circuit 19.

After calculating the above formula, the calculation circuit 18 calculates the absolute values 101-0m1 and 1θ of the difference between the weighted average values θm and on obtained by this calculation and the current steering angle θ1.
Calculate 1-on1. Next, this calculated absolute value 1θ
Determine whether I-0m1 is larger than θX, which is the set value at which the spring force of spring 5.6 should be switched, and whether the absolute value 1θ1-on1 is the set value at which the damping force of Dan/f3b, 4b should be switched. It is determined whether or not θy is greater than a certain value. The arithmetic circuit 18 calculates the above 1θ1−θml)θX
When the judgment is YES, solenoid pulp 13.14
the solenoid pulp 13.14 via the output device 20.
by outputting a pulp actuation signal S, which should actuate the spring 5.
Increase the spring force in step 6. Further, the arithmetic circuit 18
If the above determination of 1θI−θnl)θy is YES,
A solenoid actuation signal S to actuate the solenoids 7-, 8 via the output device 20. is output to increase the damping force of Dan/f3b and 4b.

The electric circuit 18 that performs each of the above functions of the arithmetic circuit 18 will be explained with reference to FIG.

The electric circuit 18 includes a spring control system including a first integrating circuit 18a, a first differential amplifier 18b, and a first comparator 18c;
The second integrating circuit 18d, the second differential amplifier 18e and the first
The damper control system includes a comparator 18c. The first and second integration circuits 18as18d have a time number corresponding to the weighted number of times, and a steering angle signal S indicating the current steering angle θ1 from the steering angle detector 16. is input, the calculation of the above formula (c) (2) is substantially performed, and a weighted average value signal S indicating the weighted average value θm1 on of the steering angle is obtained.
and output S. The first and θ0/
θ02 and the differential amplifiers 18b and 18e are the absolute value circuit 18.
b', 18e', and the weighted average value signal S%S and the rudder θθ/
The steering angle signal S is input from the θ02 angle detector 16, and the above-mentioned 1θ1-0m1 and 101-on1 are calculated from these signals. The comparators 18c and 18f are connected to the Iθi−θ
It is determined whether m1 and 1θi-on1 are larger than θset, which is the set value θx1θy, and if it is larger, the pulp operation signal SS and solenoid operation No. 43 S are activated. Output.

Next, the controller 15 having the above configuration,
The spring force of the above spring 5.6 and the above Dan/'e3
Steering angle θ, spring 5 when controlling the damping force of b, 4b
．． 7th weighted average value θm1 used to control the spring force of 6, 7th weighted average value 6 used to control the damping force of dampers 3b, 4b, pulp actuation signal S
The relationship between the roll angle change a1 and the roll angle change ib will be explained with reference to FIG.

First, the steering angle θ of the steering handle H is shown in Fig. 3 (A
) If K changes as shown by the solid line, the first weighted average value θm changes as shown by the broken line in Figure S (4). It is preferable that the first weighted average value θm is set such that the number of times k of weighting is reduced so that the weight of the current steering angle θ is reduced so that the first weighted average value θm changes gradually.

In the above case, a period in which the difference between θ and θm is greater than the set value θset is a period in which slashes are applied.

During the above period, the controller 5 outputs the pulp actuation signal Ss as shown in FIG. As a result, the amount of change in roll angle is controlled so as not to exceed a predetermined value, as shown in the left diagram (O).

On the other hand, the co-weighted average value θn changes as shown by the broken line in FIG. The weighted average value θn is obtained by setting the weighting number l small so that it changes relatively rapidly in this way,
It is desirable to give a large weight to the current steering angle θ. In the above case, the period in which the difference between θ and θm is greater than the set value θset is the period indicated by a slash in (0) in FIG.

During this period, the controller 5 outputs a solenoid activation signal S as shown in FIG.
, reduce the diameter of the orifice of 4b, reduce the diameter of the orifice of damper 3b, 4b.
Increase the damping force of As a result, the roll angle change rate, that is, the roll speed, becomes high only at the beginning of turning the steering wheel H, as shown in FIG. 5(F), and its magnitude can be suppressed. Therefore, while the automobile is turning, the dampers 3b and 4b are softened, so that the riding comfort is improved.

As described above, in this embodiment, the spring force of the spring and the damping force of the damper are comprehensively controlled when the automobile turns, thereby making the riding comfort even better. Furthermore, in this embodiment, since the weighted average value of the steering angle is used as the reference value for controlling the spring force of the spring and the damping force of the damper, the initial settings of the steering angle detector etc. can be made with less precision. There is no need to carry out the adjustment, and the adjustment has the advantage that a complicated differential circuit for detecting or calculating the rate of change in the steering angle is not required.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing a suspension suspension of an automobile according to an embodiment of the present invention. FIG. 2 is a system diagram of the main parts of the suspension shown in FIG. 1. FIG. Figure D is an electric circuit diagram showing an electric circuit that performs the same function as the arithmetic circuit shown in Figure 3. Figure S is an electric circuit diagram showing the electronic control system of the suspension shown in Figure 3.
This is a time chart for explaining the functions of the arithmetic circuit. 1.2... Suspension, 3b, 4b... Oleo damper, 5.6... Air spring, 7.8... Solenoid, 13.14... Solenoid pulp, 15... Controller, 16. ... Rudder angle detector. Patent applicant: Toyo Kogyo Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] (1) An automobile suspension comprising a variable damping force damper for suspending automobile wheels on a vehicle body and a variable spring force spring, the damping force adjusting means adjusting the reducing force of the variable damper/4', the variable damping force A spring force adjusting means for adjusting the spring force of the spring, a steering angle detecting means for detecting the steering angle of the steering wheel, and a steering angle signal outputted by the steering angle detecting means are input, and based on this steering angle signal, A steering angle signal processing means for calculating and outputting a roll angle change rate signal indicating the roll angle change rate and a roll angle change amount signal indicating the roll angle change amount, and inputting the roll angle change rate signal and the roll angle change amount signal. When the roll angle change rate indicated by the roll angle change rate signal is larger than the set value, a variable damper control signal for increasing the damping force of the variable damper is output to the damping force adjusting means, while the roll angle is An automobile suspension comprising control means for outputting a variable spring control signal for increasing the spring force of the variable spring to the spring force adjusting means when the amount of change in roll angle indicated by the amount of change signal is larger than a set value. (2) The rudder angle signal processing means generates a signal based on the difference between a reference rudder angle obtained by averaging the rudder angle signals inputted from the rudder angle detection means by going back a predetermined period of time and the actual rudder angle. , in the averaging process, the roll angle change rate signal is obtained by performing an averaging process in which the actual steering angle is weighted more heavily than the reference steering angle compared to the roll angle change amount signal. Claim 1:
Suspension of the automobile mentioned in section.