JPS5973310A - Suspension of car - Google Patents

Abstract

PURPOSE:To provide manipulating characteristic matching a steering angle, by constituting a device such that a spring means, having variable spring constant, is installed parallel to a damper, a steering angle is detected, and according to the change in the steering angle, a spring constant ratio between a front and a rear wheels is varied. CONSTITUTION:A steering angle, detected by a steering angle sensor 5, is inputted to a controller 3, and when the steering angle exceeds a set value, the controller 3 outputs a signal to actuators 1a and 2a, a spring constant KF of each of front wheels is reduced, and a spring constant KR of each of rear wheels is increased. Thus, KF/KR is lowered. Similarly, when a steering angle is below the set value under a straight running condition, each of the actuators 1a and 2a is operated so that KF/KR is increased, and the understeer characteristic is enhanced. This obtains optimum manipulating characteristic matching a steering angle.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to suspension systems for automobiles, and particularly to automobile suspensions that are equipped with a spring means having variable spring characteristics in parallel with a damper, and whose spring characteristics are controlled according to the situation. It's something to do with.

A suspension system for automobiles has been proposed in which the damping horn of a damper can be controlled according to the situation. For example, as shown in Japanese Utility Model Application No. 55-109008, a vehicle is known in which the damping force is changed according to the vehicle speed so as to always maintain favorable handling characteristics. This strengthens the 7-under steer characteristic at high speeds, and provides neutral steer or weak over steer characteristics at low speeds, so that stable steering characteristics are always maintained in response to changes in vehicle speed.

However, there are other important factors other than vehicle speed as changes in the situation that require changes in handling characteristics.

For example, the magnitude of the j-beam steering angle is closely related to the required steering characteristics, and it is desirable that the understeer characteristics be weaker when the steering wheel is turned significantly. That is, it is desirable that the understeer characteristic be weakened when the steering angle is large, and strengthened when the steering angle is small. However, sufficient running stability cannot be ensured only by control according to vehicle speed.

For example, when the steering wheel is suddenly turned and the direction of travel of the car is changed significantly, the understeer characteristic is weakened and the response is better when the steering wheel is moved closer to A-birthday, resulting in better steering. However, when the vehicle is traveling straight without turning the steering wheel, it is desirable to have strong understeer characteristics because it improves straight-line performance. The understeer characteristic is particularly effective in correcting disturbances when the car is subjected to disturbances, and when this characteristic weakens, the straight-line stability decreases, making the car dangerous especially at high speeds. Therefore, when the steering angle changes, it is desirable to always be able to obtain an appropriately strong understeer characteristic.

The present invention has focused on this point and aims to provide a suspension for an automobile that can always provide desirable handling characteristics in response to changes in the steering angle.

In order to achieve this objective, the steering wheel of the present invention makes the spring characteristics of the spring means provided in parallel with the damper variable, and controls this according to changes in the steering angle so as to always obtain desired steering characteristics. It is characterized by:

That is, in the suspension of the present invention, a spring means is provided for changing the spring characteristic by changing the spring constant on at least one of the front wheel and the rear wheel among the front and rear wheels, and the spring constant of the spring means is controlled by the adjusting means. When a steering signal is input from a steering sensor that detects steering and outputs a steering signal during steering, this adjusting means adjusts the spring constant of the front wheel suspension to the rear wheel suspension during steering. The controller includes a controller that inputs a control signal to the adjustment means such that the ratio to the steering constant is smaller than when the steering is not performed.

Here, when we say that the ratio of the spring constant of the front wheel suspension to the spring constant of the rear wheel suspension is 1' smaller than when steering and when not steering, we mean that the spring constant on the front wheel side is constant.
When steering, there are cases where the spring constant of the rear wheels is increased, and conversely, cases where the spring constant of the rear wheels is kept constant and the spring constant of the front wheels is decreased, and cases where both are changed in the opposite direction. (In each case, when not steering, the direction opposite to the above (this (imitation constant)
is caused to change).

Hereinafter, in order to simplify the explanation, the spring constants of the front and rear suspension spring means are 4t, KF, respectively.
K R0 surface tension. The ratio of K "to K I-< is K"
/' is represented by a single prong, so the above three platforms and (ma,
K F / K R when steering I12 and K F when not steering
, /K means to be smaller than R. This can be expressed as in Table 1.

Table 1 When K F , -' K R are made smaller, the understeer characteristics are weakened, so it is possible to weaken the understeer characteristics during steering and improve steering control.

According to the present invention (as described above, KF' and -'KR are changed depending on the magnitude of the steering angle), it is possible to always obtain desirable understeer characteristics, and to maintain good O/O.
It is possible to achieve excellent maneuverability and driving stability.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
t Za.

FIG. 1 shows a car equipped with 1)-spendidine according to an embodiment of the present invention, and FIG. 2 shows a system diagram of one essential part of the system shown in FIG. In this example, the front wheel lease pension 1
, 1 and the rear wheel suspension 2.degree. 2 are provided with Akicomulators 1A and 2.DELTA. for changing the spring constant, and these are controlled by controllers 1 to rollers 3. The roller 3 to the controller 1 is installed on the steering wheel 4 (
A steering angle sensor 5 detects the magnitude of the steering angle.
1'4 force 1) is input through the i'J-to' line 3a to change the spring constant of the front and rear wheel suspensions 1,
1; A control signal is sent to the Akicomulators 1△ and 2△ of 2 and 2 with the lead wires 3, b, and 3C at an angle of j. In addition, in this implementation, the output from the speedometer 6 is inputted at the same time as the output from the speedometer 6.The manual changeover switch 7 is connected to the controller 3 through the lead wire 3e. It is connected to the.

As shown in FIG. 2, each respension 1, 1. ;2.
2 includes actuators 1a, 1a consisting of electromagnetic means;
:2a, 77 key 1 muller IAI, 2A that can read 2a
is connected to 1, and this t-eye exposure means causes the no.l accumulator 1△ to be connected.

Each respension 1,1: 2,2
By communicating with the j '7/to' in the 1-A spring, the air (, the spring constant iQ K F, KR can be changed (1, steering angle 1, 5) The 11j force of (]tan]ton1~(]-ra3/)~1) which receives the signal from is,
Lead wires 3t], 3c through the left and right front and rear wheel respensions 1, 1; 2, 2 Akicomulators 1Δ, 2Δ
Actuators 1a, la: 2a, 2a are manually operated. The actuators 1a, la which received (-) this output, that is, the steering signal; 2a, 2a are the air bones Ib
, lb: Control the spring constants of 2b and 2b to be small or to override them.

For example, the steering angle sensor 5 detects a steering angle equal to or greater than a predetermined value and generates a signal indicating that the steering angle is large (predetermined value 11i').
i or more electromagnetic), the receiver 5 or controller 3 outputs this to the actuators 1a, 1a: 2a, 2a
Drive the front wheel Eno7 spring ib, reduce the spring constant (KF) of ib, and reduce the rear wheel air spring 2 +1, 211.
by increasing the spring constant (K, I) of KF
/ Decrease KR.

Specifically, for example, as shown in Figure 3. I J: Sea urchin, steering angle 1? If the output of pin 'lJ5 is less than a predetermined value,
The positive input of the comparator 3Δ of the inverter 3 becomes large, outputting a high output (+-1>), and this inverter 3A
By lowering the base mJ, 1,000 of 1- transistor 3C connected to the output of 1 through inverter 3B,
At the same time as turning off C, transistor 1 to transistor 3 connected to the output of inverter 3A is turned off.
is set high to turn on this transistor 3D. Respension 1. ′
The spring constant (KF) of 1 is reduced, and the rear wheel side actuators 2a, 2a (solenoids of electromagnetic means) connected to the [rector side of the rear right 1-' run raster 3D] are driven. It is possible to increase the spring constant (KR) of the suspensions 2, 2, thereby decreasing KF/KR and weakening the understeer characteristics.

In the straight-ahead state, the output of the steering angle sensor 5 is less than the predetermined value, so the output of the comparator 3△ becomes a low output ([), and transistors 1 to 3C connected via the inverter 31.3 are turned on and the front wheel side is turned on. By increasing the spring constant (K F ) of the rear wheel and decreasing the spring constant (K R) of the rear wheel,
By increasing the F/K l, the understeer characteristics are strengthened.

a3, speedometer 6 (Fig. 1,
In addition to the output of the steering angle sensor 5, the output of the steering angle sensor 5) is input to the 71 to 11-ra 3, and in addition to the above-mentioned spring constant control by the steering angle sensor 5, the output is This control according to the vehicle speed is, for example, as known in the art, for example, control for reinforcing understeer characteristics at high speeds, and control for the steering angle (θ). ＼/) 24 control in the opposite direction, and control to weaken the understeer characteristic where the vehicle speed is high during steering. ψ) is the steering angle (θ)
℃ depending on the size of (θ x V2)
Two types of control are possible to weaken the understeer characteristics.

Figure 3C is a diagram using the output of vehicle speed 1, and is shown in Figures 4 and 5. An example of this type of control will be explained. (Control in the opposite direction for the former steering angle and vehicle speed
cK Umono in Figure 5 1t[l! For example, the control for 0xV2 will be explained with reference to the embodiment shown in FIG. ) In addition to the above-mentioned automatic automatic control, the 7I-1 ~ manifold knob changeover switch 7 can be used to manually change the spring constants (KF, KR) of the front and rear wheels at will. It allows manual control.

Next, FIG. 4 shows a second embodiment. In this embodiment, the output 0 of the steering angle sensor 5 and the output S of the vehicle speed sensor (3), which are manually input to the roller 30, are the same as the steering angle θ, and the vehicle speed V is the output S of the medium speed sensor. is converted into electromagnetic J by the converter 31. -The output V is converted into V2 by the multiplier 32, and then input to the multiplier 33 to obtain θ×V1''. This output θ×V2 is transmitted to the front and rear wheel actuators la, 21) via the Balanor 371a and the amplifier 341) to control the spring constant.In other words, the medium speed (V) is squared. According to the magnitude of the value obtained by multiplying the steering angle (0) by the steering angle (It), the front and rear wheel ratio of the spring constant K F ,,='KR is set to this value (θ×v2) or the larger the culm becomes smaller. This makes it possible to control the spring constant by multiplying the steering angle by the influence of centrifugal force, which is proportional to the square of the vehicle speed, by λ·j.

Next, depending on the combination of vehicle speed and steering angle, t of the front and rear wheels;
An example of controlling the fta constant will be described.

This 33rd embodiment covers the basic control of slightly distorting the magnitude of KF/K) in steering 11), while roughly distorting the magnitude of Kl-',/KR depending on the vehicle speed. It is something that can be changed. 1lJ4c Straw, increase K F /' K R at high speed throat than at low speed throat to increase the undersudder characteristic at high speed. [Strengthen jl J
, sea urchin.

This relationship can be expressed as shown in Table 2.

Table 2.
R) means small, and heart means large. Therefore, Table 1 shows that the spring constant (K R) of the rear wheels is changed from soft to hard when steering at both low speeds and high speeds, weakening the under steer characteristic. From low to high 4r, the spring constant of the front wheel (
KF) is set to hard from Sono to strengthen the understeer characteristics.

A circuit diagram of such an embodiment is shown in FIG.

As is clear from FIG. 5, the output from the vehicle speed sensor 6 is input to the first comparator 36 of the controller 35, which turns on and off the first transistor 37 connected to the output of the first comparator 36. Actico 1-Yu 1a of connected front wheel suspension 1 Aki 1 muleta 1A.

1a. (At the time of steering, the first) output of the energizer 36 is H (I decided to turn on -9 after turning on, and set the soft to hard), while the steering angle was set to -9.
The output is input to the second comparator 38, which turns on and off the second transistors 1 to 39, and controls the actuators 2a, 2a of the accumulator 2Δ of the rear wheel suspension 2 connected thereto. (Second
21 The output of the inverter 38 becomes H, and the actuator is turned on, thereby making the software hard. ) Next, a specific example of an air spring suspension with a variable spring constant will be explained in detail with reference to FIG.

As shown in FIG.
12, a lower case 16 consisting of an outer cylinder 14 and an inner cylinder 15, which are assembled so that the upper end goes in and out of the lower end of the upper case, and upper and lower cases 13.16.
A connection that airtightly connects and covers the inside of the drum (1) coaxially penetrates the inside of the upper and lower darts 13.1G;
8, a main valve 19 fixed to the F end of this piston rod °18, and 1. Bottle 1 fixed to the lower end of the inner cylinder 15
The main valve 19 controls the oil chamber in the inner cylinder 15 between the upper and lower [Δ] of the main valve 19.
Furthermore, the oil chamber C between the outer cylinder 14 and the inner cylinder 15 is communicated with the upper end of the chamber A at one end, and the lower end of the oil chamber C is communicated with the lower end of the chamber B. In addition, a screw 21 passes vertically through the center of the screw 1 to the rod 18, and this control j'' cut 21 is controlled by the rotation when the upper end 21a is rotated by the outer knob j. It is engaged with the key 22 so that rotational force can be transmitted.The lower end of the control rod 2 is provided with a hole in the lower end 18a of the piston rod 18 to communicate the Δ chamber and the B chamber. An orifice 211) is provided that communicates with the communicating hole 181) in the lower end portion 18a of the piston rod.
) is now turned on and off.

Details of the structure of the lower end J5 of the screws 1 to 18 including the lower ends of the connectors 1 to 21, the main valve 19, and the bottom valves 1 to 20 will be omitted.

The relative vertical movement of the upper case 13 and the lower case 16 is caused by the air spring provided by the air chamber 12 as well as by the upper and lower cases 13.1.
Upper and lower sublink cases 13a and 16a fixed to 6
It is elastically absorbed by the spring 30 held between them. Brackets l~1 fixed to the outer surface of the lower case 16
Reference numerals 6b and 16c are used to fix the wheel support structure including the wheel hub that supports the wheels, and the wheels are thereby held on the part 10 of the vehicle body so as to be movable up and down.

That is, the vehicle body is suspended on wheels and is elastically supported by L downward movement. Parts of the peripheral walls of the air chambers 12 and 72 have a frontage 12a extending from the crotch i.
, )l r leak, and during this time r'+ 128 is connected to one end of a pneumatic pipe 23 for communicating the Akicomulator 2Δ and this machine j' shaft 12. This pneumatic piping 2.3
The other end is the solenoid valve (
The solenoid valve 2a is electrically connected to the T1 lead wire 3ci from the roller 3.

This solenoid valve 2a is closed by the output of the controller J1 or 1-'1 as described above, and the air chamber '1' is closed.
2. Separate the air chamber of the 2nd Aki R, l\Rator 2A, and increase the spring constant KR of the lower A spring. In other words, this -
If spring 11 is for rear wheel respension 2,
During steering, the solenoid valve 2'al of the controller 2A is opened by the output from the controller 3, and the volume of the air chamber 12 is reduced.
;The spring constant of the r spring becomes larger. As the spring constant increases, the soft near spring becomes harder (KR), and as is clear from Table 2, the understeer characteristics of the car are weakened and the responsiveness increases.

In the case of the front wheels, contrary to the above control, when a steering signal during steering is manually input to the controller 3, the controller 3
acts to open the solenoid valve (actuator >la) of accumulator 1A, and opens the front wheel suspension 1.
, 1 by decreasing the spring constant KF of the near spring, and moving up to Sono 1~.

The respension of an automobile according to the present invention uses a spring means with a variable spring constant as shown in -L, and controls this according to changes in the steering angle (by reducing KF/KR during steering). As a result, the understeer characteristic, which is weakened by non-steering wheels, can be maintained at a desired level, and stable driving can always be achieved regardless of changes in the steering angle.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an automobile equipped with a suspension system according to the present invention, Fig. 2 is a system diagram of an embodiment of a four-booth pension according to the present invention, and Figs. FIG. 6 is a sectional view showing an example of a spring means used in the respension of the present invention. 1.2... Eggplant pension 1a, 2a... Actuator 1Δ, 2A... Accumulator 3... Controller 1-Roller 5... Steering angle sensor 6
...Vehicle speed sensor 7...7I-1-MAR-7A changeover switch 12...
・Air chamber 13... Upper case 14... Outer cylinder 1j)... Inner cylinder 16... Lower case 1
8... Screws 1 to 1'' 18b... Connection
1 hole... Main valve 20... Bom valve 21... Control 1~Roll rod 21b... Δ refit 22... Rotary key Fig. 1 Fig. 2

Claims (1)

[Claims] At least 0 deviation of the front and rear wheels' 1 nose suspension bl A variable spring constant (copying means) provided in parallel with the damper on one side, an adjusting means for changing the spring constant of this spring means, detects the steering, and controls the IC when the steering is steered.
a steering sensor that outputs a steering signal when the steering signal is input; Automobile suspension consists of a human-powered controller.