JPS5973309A - Suspension of car - Google Patents

Abstract

PURPOSE:To provide manipulating characteristic matching a load, by constituting a device such that, through installation of a spring means, having variable characteristic, to a damper which is positioned parallel to the spring means, a constant ratio between a front and a rear suspension is variable according to a car body load detecting signal. CONSTITUTION:A load signal, detected by a load sensor 4, is inputted to a controller 3. In the case of a high load signal, a signal is inputted through lead wires 3b and 3c to actuators 1a and 2a of accumulators 1A and 2A of suspensions 1, 1 and 2, 2 of front and rear wheels on both sides, a spring constant KF of a spring 1b of each of front wheels is set to a high value, a spring constant KR of a spring 2b of each of rear wheels to a low value, and a spring constant ratio KF/KR between both springs to a high value. This enhances understeer characteristic and strengthens the suspensions. Conversely, in the case of a low load, the understeer characteristic is lowered. This provides manipulating characteristic matching a load.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a suspension of an automobile, and particularly to an automobile suspension which is provided with a spring means having variable spring characteristics in parallel with a tamper, and whose spring characteristics can be controlled according to the situation. It is something that can be done.

For automobile suspensions, it has been proposed to control the damping force of the tamper depending on the situation. For example, as shown in Utility Model Application No. 55-109008, C It is known that J, which always obtains favorable handling characteristics by liquefying the damping force, strengthens the understeer characteristics at high speeds, and weakens it at low speeds. The steering characteristic (q) is such that tl is 1!:i when the vehicle is controlled with excellent control depending on the change in vehicle speed.

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

For example, changes in piston weight are also closely related to maneuvering characteristics.
When the load changes, the handling characteristics change.

In other words, the understeer characteristics become weaker when the load is high and become stronger when the load is low. Therefore, it is not possible to achieve sufficient running stability with only intermediate control.

For example, if the load increases due to an increase in the number of passengers in a car or an increase in the amount of luggage carried on the vehicle's throat, the characteristics will be weakened and the oversteer tendency will approach. The understeer characteristic is particularly effective in correcting disturbances when the car is subjected to external disturbances, and this 1.1+ f'l
が'r)S) ;I, then (self-propelled stable f1 or 1st generation [・shi, especially (8 speed 11.), a dangerous car screams.

However, if the understeer characteristic becomes strong, the response during steering becomes dull and the maneuverability becomes poor, so it is desirable to simply strengthen it: LL/<', x
stomach. Therefore, when the load changes, it is desirable to always be able to obtain appropriate understeer characteristics accordingly.

The present invention has focused on this point and aims to provide an automobile suspension that can always obtain desirable handling characteristics in response to changes in load.

In order to achieve this objective, the respension of the present invention makes it possible to vary the spring characteristics of the spring means provided in parallel with the damper.
), this is controlled according to changes in load so that the desired l is always maintained.
This vehicle is characterized by providing excellent handling characteristics.

That is, the suspension of the present invention is provided with a spring means that changes the spring characteristic each time the spring constant is changed on at least one of the back of the suspension of the front and rear wheels, the front wheel, and the rear wheel, and the spring constant of the spring means is adjusted. When a signal is input from a load sensor that detects a medium load (r+ and outputs a high i+: + medium 114 day signal), the front wheel A control signal is input to the adjustment means so as to change the ratio of the spring constant of the suspension to the spring constant of the rear wheel suspension to a greater extent than when the load is low.

Here, setting the ratio of the spring constant of the front wheel suspension to the spring constant of the rear wheel suspension to be larger when the load is high than when the load is low means that when the spring constant of the front wheel is constant, the spring constant of the rear wheel when the load is high. When reducing the spring constant of
There are three cases when both are changed in opposite directions, i.e., when the front wheel side is made larger and the rear wheel side is made smaller (in each case, when the load is low, the spring constant (
1), a simple explanation 1Ilfi (For H, the spring constants of the spring means of the suspension PI of the front and rear wheels are each 1〈[, 1〈).
It is shown in zede. The ratio of 1<1- to K R is K F /
Since it is expressed as +<[, the above three cases mean that KF/K[ma during steering is smaller than KF/KR when not steering. This can be expressed as shown in Table 1.

Table 1 K F / K Since increasing R increases the understeer characteristics, it is possible to prevent the understeer characteristics from being weakened by high loads. In the present invention, as mentioned above, KF/KR is changed by Jζ depending on the magnitude of the vehicle body load, so it is possible to always have the desired under-daring characteristics, and to achieve good handling and running ( j Stability can be achieved.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows an automobile equipped with a suspension according to an embodiment of the present invention, and FIG. 2 shows a system diagram of its main parts. In this embodiment, front wheel suspension 1,
1 and the rear wheel suspension 2゜2, Akicomulators IIA and 2A are installed to change the spring constant (
], these are controlled by controller 3. The output from the load sensor 4 that detects the magnitude of the vehicle body load is input to the roller 3 through the lead wire 3a, and the front and rear wheel suspensions for changing the spring constant 1° 1; 2, 2 Akicomulator 1A, 2
△Niri-l: 粍) The control signal is 1ff through 3b and 3c.
I will be beaten. In addition, in this embodiment, a manual switch 5 for switching the lυ width of the entire suspension between A-mode and soft 1- is connected through a lead wire 3d to a controller I-IJ-
La 3 (This is connected.

As shown in Figure 2, each suspension circle 1, 1; 2.2
an actuator 1a consisting of a solenoid valve;
Akicomulators 1△ and 2△ equipped with 2a are connected, and these solenoid valves control the air chambers in accumulators IA and 2A, respectively. By communicating with the air bubbles, the spring constant of the air bubbles B can be changed.

The output from the controller 3 that received the signal from the electric power station 4 is the lead wire 3b.

Respension of left and right front and rear wheels through 3C 1, 1; 2
．． It is input to the actuators la, 2a of the horns 1-, 1,/-\actuators IA, 2A of 2. This output indicates a high load and receives a signal I, =? coutuator 1a,
2a is an air spring lb; 11+: 2b, the spring constant of 2b is controlled to be small or d;

When the high-level No. 45 is input to the actuators la and 2a and the solenoid is driven, the air chambers of the actuators 1Δ and 2Δ are activated by the air chambers of each suspension. It is communicated with the air chamber of the spring, the spring constant is small, and the lease pension becomes soft 1~.

On the other hand, when the signal is low level, the solenoid
A, the solenoid valve is closed and the spring constant of the suspension increases, becoming a heart.

This is shown in the table below.

Table 2 For example, if the load sensor 1) 4 detects a load greater than a predetermined value and outputs a signal (voltage greater than a predetermined value) indicating that the load is high, the controller 3 that receives this outputs a signal (voltage greater than a predetermined value) to actuators la, 2a. to increase the spring constant (1〈de) of the front wheel air springs 1b, lb, and the rear wheel air springs 2b, 2.
The spring constant (KR) of No. 11 is made smaller, thereby increasing the king/KR.

Specifically, as shown in FIG. 3, for example, the load sensor 4
When the output of is equal to or higher than the predetermined value 1ItI,
The power of comparator 3A became too strong, and Takayama 7J
(1-1), and lowers the base voltage of transistor 3C connected to the output of comparator 3 via inverter 3B to turn off transistor 3C, and transistor 3I connected to the output of comparator 3A. ) by increasing the base voltage of this I~ transistor 3.
Turn on Z to turn on D, and turn on the former 1 to transistor 3C.
Demagnetize the solenoid of the front wheel side 1 cutuator 1a connected to the collector side of the front wheel side respension 1, 1.
At the same time as increasing the spring constant (K It is possible to reduce the spring constant (KR) of spring 2.2 and increase J, short, /KR to strengthen the undersubstrate characteristic ↑1.

In a state of low load, if the output of the load cylinder 4 is less than the predetermined value, the output of the inverter 3A is low (L
) and 1. The transistor 3C connected via the inverter ζ)B is turned on to decrease the spring constant (K[-) of the front wheel and increase the spring constant (K[?) of the rear wheel].
By making K l-/K R smaller, J, S, Anders der Tokutake is weakened.

In addition to the automatic control 71-1/control 011 described above, the manual changeover switch 5 is used to manually change the spring constants (KF, KR) of the front and rear wheels as a whole. It allows manual control.

Next, a second embodiment will be explained with reference to FIG.

In this embodiment, the (ljl, mani) of the load sensor 4 is
j? A selector switch 5 is used. This changeover switch 5 allows the driver to change the spring constant of the front and rear wheels → the suspension as a whole according to his/her preference, that is, to change the spring constant of the suspension between hard and soft. Guaru.

The output of the cart sensor 4 is input to the comparator 31, and when the load is greater than a predetermined value (high load), the comparator 1 outputs a signal indicating the high load. That is, the output level of the comparator becomes (1).

The output of this comparator 31 is connected to one input of the NOR circuit 32 and to the non-inverting input of the OR circuit 33.

On the other hand, the output of the manual changeover switch 5 is
The other inputs of the R circuit 32 are connected to the inverting input of the OR circuit 33. The output of the NOR circuit 32 is applied to the accumulator 1A of the front wheel suspension 1.1 in order to change the spring coefficient of the spring of the front wheel suspension 1.1.
transistor 34 that drives the 7) Cuzino L-tactor 1a.
Also, the output of the OR circuit 33 is the rear wheel suspension 2,
It is connected to the 1-non-register 35 that drives the actuator 2a of the 2nd accumulator 2A.

-1- The operation of the circuit shown in Figure 4 is explained using Table 3.

Friend 3 First, the driver wants to harden the entire suspension, so when he selects J: Rehard (large spring constant) on the manual changeover switch 5, the output of the switch 5 is (Ll).
g, 1" roars, and "1" is output to one input of NORMMa2O and the inverted input of the OR circuit 33. At this time, if the vehicle body load is high, the output of the load sensor 4 becomes the output (+- 1) -d rope I, II I ++
This signal is input to the other input of the NOR circuit 32 and the non-inverting input of the OR circuit 33.

Therefore, the output of the NOR circuit 32 becomes '0', and the output of the OR circuit 33 becomes 4 to rr 1 ++.As a result, the front wheel side transistor 34 is turned off, the front wheel actuator 1a is demagnetized, and the C spring constant ( K F ) is large (hard), while the rear wheel side 1 to 35
2a is driven to open the valve of the Ayayumulator 2Δ, and the spring constant (K R) is
Write small. (Sono 1-) Therefore, the ratio of the spring constants of the front and rear wheels (KF/KR) becomes large, and the under (-sudare) characteristic is strengthened.

Next, when the vehicle load decreases in the state shown in "-" (hard selection), the output of the load sensor 4 becomes rr O++ and 4T, so
The output of comparator 31 is 110 ++, O-R
The output of the circuit 33 becomes 0''.Then, the rear wheel actuator 2a is also demagnetized, the spring constant (KR) of the rear wheel suspension becomes crowded (hard), and the understeer characteristics are weakened to the C standard. become a state.

Furthermore, when the driver selects Sono 1 to Spense 3 and the output of the selector switch 5 becomes "0", one input of the NOR circuit 32 becomes "0", and the output from the comparator 1 becomes "0". When high load r ``1'' (1, N
OR1ljl ill 320) If O+1
Then, with a low load, the sharpening of "'0" will move this to "1". On the other hand, the inverting input of the 8H OR circuit c') x3 is always "0" and the output of the 16 to 0 circuit 33 is always '1'.

Actuator 2++ of the two-wheel suspension is driven by 71f, and the spring constant (K
R) is always small, and the spring constant (Kl'') of the front wheel 1 north suspension is high 61J, small (hard) (strengthens the understeer characteristics, and becomes small (sono[・) under low loads). to weaken understeer characteristics.

Next, a specific example of the air splash suspension with a variable spring constant ii, in which the spring constant is reduced by driving the actuator as described above, will be explained in detail d1 in FIG. (
Suspension 2 for the rear wheel What is the sign f maj? Io) As shown in FIG.
'N! The upper case 13 forming the upper case 12, the upper case 1G consisting of an outer cylinder 14 and an inner cylinder 15 assembled into the lower end of the case so that the lower end can go in and out, and the inside of the upper and lower cases 13 and 16 are airtight. A thick connection 1
17, screws 1 to 18 coaxially pass through the interiors of the upper and lower cases 13 and 16 and are movable up and down relative to the inner cylinder 15 of the case 1G;
The main valve 10 fixed to the lower end and the bolts 20 fixed to the lower end of the inner cylinder 15 are 1! The main valve 19 divides the core palm in the inner cylinder 15 into -(-Δ seedlings of the main pulp 19 and the lower 13 chambers), and further divides the core palm in the inner cylinder 15 into the outer cylinder 1/I and the air chamber between the inner cylinder 15. A with C at the top
The upper end of the chamber is communicated with the lower end of By through d3 at the lower end. Also, tighten the center of the screw 1-rod 18.
The F end 21a is connected to the rotary key 22 whose F end 21a is rotated by an external force. are combined. At the lower end of this control rod 21, there is a screw 7F connected to the lower end 18a of the rod 18 so as to communicate the A chamber with the end 3. An orifice 211 which communicates with the communication hole 18b provided in the piston L1 is provided, and by rotation of the control rod 21, communication between this A refill 21b and the communication hole 181) of the piston L1 end 18a is established. It is set to be turned on and off.

The screw 1 including the lower end of the control rod 21 [1
The lower end of the tube 18 and the main valve 19 ports 1 to 1\
Details of the structure of the valve 20 will be omitted.

-1-The relative vertical movement of the case 13 and the lower case 1G affects the air chamber 12] -1 In addition to the spring, the upper and lower spring cases 13 fixed to the upper and lower cases 1ζ3 and 16
between a and 16a (resiliently absorbed by the two clamped springs 30); brackets h fixed to the outer surface of the lower case 16; This is for fixing the wheel support structure, so that the wheels are held in place 10 on the part 10 of the vehicle body so that they can move downwards. Possibly elastically supported.

An opening 12a is provided in a part of the peripheral wall of the air chamber 12, and one end of a pneumatic pipe 23 for communicating the accumulator 2A and the air chamber 12 is connected to the opening 12a. The other end of this pneumatic pipe 23 is the accumulator 2
A solenoid valve 2a (connected to the actuator 28) is electrically connected to a lead wire 3C from the controller 3.

As mentioned above, this solenoid valve 2a is opened and closed by the output from the controller 1-○-3 to communicate or separate the C1 earth chamber 12 and the air chamber of the accumulator 2A.
7'1; Reduce or increase the spring constant K R of the r spring.

The automobile suspension according to the present invention uses a spring means with a variable spring constant as described above, and controls this according to changes in the vehicle body load to increase 1<F/KR when the load is high. It is possible to maintain the desired strength of the Anders Dare Tokuchiku, which weakens under high loads, and it is possible to always achieve stable running regardless of changes in the vehicle body load.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a schematic diagram of an automobile equipped with a suspension according to the present invention; FIG. 5 is a circuit diagram showing a specific example, and FIG. 5 is a cross-sectional view showing an example of a spring means used in the suspension of the present invention. 1.2... Suspension 1a, 2a... Actuator 1A, 2△...Akicomulator 3...-1-1-11-RA 4...Load sensor 5...Mani switch switch 12...Air chamber 13...Upper case 14...
・Outer cylinder 1j)...Inner surface 16...Lower case 18...Screws 1~Rods Fig. 1 Fig. 2 Fig. 3

Claims (1)

[Scope of Claims] i) A spring means with a variable spring constant provided in parallel with the damper on at least one of the "lambda vents 1" of the rear wheel, an adjusting means for changing the spring constant of the spring means; Detects the vehicle load and outputs a signal when the load is high.When the signal from the load fin 4, 113J, and BI' is input, the front wheel suspension spring 7y' + %Q O) Rear wheel suspension spring Inu-Kizuru Ratio to Constant 1li
ll cylinder II 1 August is inputted into the adjustment means 21 + Ti! +1 car rental. 2) The spring means is a solenoid valve that connects and disconnects the air chamber of the air spring station n and the air chamber of the accumulator. A resuspension of a motor vehicle according to claim 1.