DE2736026A1 - ADJUSTABLE WHEEL SUSPENSION SYSTEM FOR VEHICLES - Google Patents

Description

Dipl.-Ing. H. MITSCHERLICH Dipl.-Ing. K. GUNSCHMANN

Dr. ret. not. W. KÖRBER Dipl.-Ing. J. SCHMIDT-EVERS PATENT LAWYERS

D-8000 MÖNCHEN 22 Stei.isdorfstroßelO

If (089) * 29 66 84

10.

IS //

Honda Giken Kogyo Kabushiki Kaisha 27-8, 6-chome, Jingumae Shibuya-ku
Tokyo / Japan

Patent application Adjustable suspension system for

vehicles

809808 / 07A6

The question concerns variable hanging systems. to the Use in vehicles where the spring action of between dam liahons and the corresponding cadres of the vehicle Shock absorbers can be adjusted depending on the driving conditions of the vehicle, including the steering movement, acceleration, deceleration, driving at high speed, driving over irregular surfaces and driving in strong winds belong.

In general, in the suspension system of a motor vehicle, particularly when it is traveling over irregular surfaces, it is desirable that the shock absorbers have a relatively low value of the spring rate in order to exhibit a soft or mild spring action. With such shock absorbers, however, the magnitude of the vertical displacement of the wheels relative to the vehicle frame can reach a permissible maximum, which gives rise to a ground effect or a so-called "full stroke ¹¹ state" when the vehicle is driven over a road surface with particularly severe irregularities In such a condition, the shock absorbers are unable to perform their intended spring function, and not only are the driver's belir.iili chksir.dos badly impaired, but there is also a risk that the vehicle frame and the suspension system will be damaged by the road impacts Therefore, in cases where the amount of vertical displacement of the wheels relative to the vehicle frame is likely to exceed a predetermined V / ert, such as when the vehicle travels over markedly irregular surfaces, it is desirable that the V / the spring constant of the shock absorber is increased in order to make it capable try to show a relatively hard spring action.

; During a steering movement, an acceleration, a ; hesitation, driving with strong V / ind or driving sn at high speed the vehicle tends to lurch

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or to change his driving behavior in any other way under the influence of external forces acting on the vehicle frame, or under the action of violent vibrations of the vehicle frame itself. If in such cases the shock absorbers of the suspension system are in a soft spring operating state and their spring constant is a lower value the change in running behavior or the rolling motion would be of the vehicle considerably, and not only the driving comfort, but also the running stability and controllability of the vehicle are significantly impaired. To avoid such a dangerous condition, it is again It is desirable that the shock absorbers of the suspension system are increased in value of the spring constant and an operational state with harder suspension under such driving conditions as steering movement, acceleration, deceleration, Show driving in strong winds and driving at high speed.

In this context, the use of an anti-roll stick known to be minimized with the lateral oscillation or rolling of the vehicle frame. However it is impossible with simple application of an anti-roll bar in the suspension system, the spring constant of the shock absorbers to be adjusted according to the driving conditions of the vehicle. In addition, with such a system, the wheel movements are at the Vehicle control operation is not always smooth, and driving comfort is hardly satisfactory.

A suspension system is also known, the fluid shock absorber is used and which is provided with a drive unit controlled by a suitable command signal is used to inject the liquid into the system and let it flow out of the system, the spring rate of the shock absorbers to change. However, such an arrangement is not desirable from a structural point of view, since it not only a considerable weight and a complicated structure with it

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, brings, but also a disproportionately large amount of space.

Another known system of shock absorbers uses the
: Spring action of a gaseous fluid and is designed to
that the spring constant by changing the volume of the
Gas-containing xamrner of the system is changed. In the
In practice, however, difficulties encountered before the change
the spring constant is effected with the volume of the gas chamber , because of the compressibility of the gaseous fluid. : In addition, it is not so easy to control such a system, since the medium used is highly temperature-dependent.

j In addition to those described above, various types of shock

J damper systems have been proposed that are designed to ! that the spring constant can be changed as it is a Occasion requires. However, there has been no suggestion of a satisfactory adjustable suspension system in which the spring action of the between the vehicle frame and the rags

arranged shock absorber according to the driving conditions of the vehicle _;

J is adjustable, including steering movement, acceleration, deceleration, '■.

\ Driving in strong winds and driving at high speed '

'and belong over irregular surfaces, and that a little '

Has weight and is easy to assemble, limited space requirements,

ι easy to control, reliable in operation and extremely valuable '

too practical to use. \

In these circumstances, the subject of the invention is the) Creation of an adjustable wheel suspension system for ver j

application in vehicles that is able to adjust the spring action ι

that between the vehicle frame and the corresponding wheels j

arranged shock absorber according to the driving conditions of the j

to adjust stuff, including steering movement, acceleration, ver j

lag, driving in strong winds and driving at high speeds !

and over irregular surfaces, and that one ^! has a low weight and is easy to assemble, takes up space

is limited, reliable in operation and of high usability. i

I 809808/0746

'Ζ ± \\ :: 2 ±: 3Τϋ'Γ subject of / τϊ indvng is ·. ", The,' Jcho.flunj of an adjustable": adaur ^v i ^: incungs3ystc: ns of the kind described, which iot designed so that εο often as the spring constant of the shock absorbers changes according to the load and driving conditions of the vehicle, the loss effect on the relative movement between the railroad and the rags of the driver is also changed to an ontinal level that the new value the spring constant.

Embodiments of the invention are given below with reference to of the drawings. It shows:

Figure 1 'is a schematic diagram showing the general Figure 3 illustrates an arrangement of an adjustable wheel suspension system for vehicles according to the invention;

^; FIG. 2 shows a partially schematic partial longitudinal section of an exemplary embodiment of one used in the system

; Wheel suspension;

; Figure 3 is a block diagram of an embodiment of the in

your system used signal generator; Figure Zf a partial cross section of an embodiment of the

? η '■ "en .System vo ^ v.'eiv.ibo.rer. Ä.orkwinkeldatoktors; Figure 5 is an elevation, partly in section, of an embodiment

', example of a brake detector that can be used in the system;

ί Figure 6 is an explanatory diagram showing the load / lift curves I represents the shock absorber used in the system and shown in FIG. 2;

! Figure 7 is a timing diagram showing the mode of operation of a ; Application of the delay switch I suitable in the invention represents circle;

ί Figure 3 is a partially cut away, similar to Figure 2 i view that another practical embodiment shows a wheel suspension that can be used in the system;

: Figure 9 operating curves of the wheel shown in Figure 8!

I used fluid dampers for suspension. I.

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Under 3ozug on the drawings is z'j.nLi.chi-.t Ln Figure 1 a adjustable ^ adaufhö.njungssystö-n scheiiiacinch a ^ rgoo ^ ellh, -Va 3 in the dargDS ^ ellton versionaforu four i ~! Nd additions 6a, Gb, 6c and 6: 1 auxv / eist, which lead to two pairs 3η iüi anterior and rear section ds 3 vehicle are arranged. .Jode dor Tlaiauihr.nvr-.ingen uniaß an otoßdännfor A, a conveyor belt 5 to 'adjusting the ^ edervrirl-zu the; assigned Shock absorber and a ge.neinsansn oisnaläoneracor 1 for control the activity of spring adjuster J.

As shown, "/ eist the signal generator 1 detectors 2a, 2Ό, Zc and 2d, which determine the driving conditions of the vehicle," when it is, for example, steered, accelerated, decelerated or at strong V / ind or at high speeds drives, and generate inverted output signals, furthermore a manual switch 2e for generating an inverted output signal similar to that of the detectors, a comparison circuit 3 for comparing the output values of some of the detectors, namely 2a and Zo, with a predetermined reference value, delay circuitry Jfa , / fb and Lc, which act upon receipt of the corresponding output signals from the comparison circuit \ :: '\ · ~ ^ e. " ^1. r ^^ lrvcUon T ^^ Vitor τ: ΐ 2c and 2d v.rsrJon, ur: i To generate corresponding output signals that last a predetermined duration of a delay time after the signals from the comparison circuit 3 and the detectors 2c and 2d have been terminated, an AND-C-atcer 5, which at dnpfang the Output signals from the delay circuits ifa, Zfb and ifc and from the manual switch 2e in action, and amplifiers pa, 5'o, 5c and 5d for amplifying the output signal of the UIID-Gattei-3 5 · The amplified signals from the jev / Urgent amplifiers 5a, 5b, 5c and 5d are given to corresponding switching valve devices (3o), which are provided in the spring force adjusters 1>, and serve as 3efaultsignal for oils? vcn ': iVjoti ^: .tig'j.ng.

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BATH ORIGINAL

The delay circuits 4a, 4b and 4c are used for compensation the time delay in the movement of the vehicle frame compared to the actuation of the vehicle control device such as the steering system and the braking system of the Vehicle and the deceleration of the movement of the wheels. It should be noted that by the action of the delay circuits 4a, 4b and 4c smooth the running behavior of the vehicle, which has considerable dimensions and a large inertial mass is controlled.

Incidentally, they are assigned to the corresponding wheels 12 Spring force adjuster B is only shown schematically in FIG. 1 and, as is easy to see, basically have same structure. The structure of one of the spring force adjusters is described in detail below with reference to FIG described.

In FIG. 2, a link 9 is rotatable at one end by means of a pin 10 on a carrier 8 of the vehicle frame 7 arranged, and at the other end of the link 9, the axle 11 of the wheel 12 is mounted. A hydraulic cylinder 16 is fixed to the by fasteners 15a, 15b, 15c and 15d adjacent side of the vehicle frame 7 mounted, with a Piston 17 is slidably received in the cylinder. A piston rod 14 is rotatable with the piston at one end 17, as shown at 18, and at its lower end to the central portion of the handlebar 9, as shown at 13. The interior space in the cylinder 16 above the upper surface of the piston 17 is filled with pressure fluid and serves as variable-volume pressure fluid chamber 19. The cylinder 16 and the piston 17 cooperate to provide the shock absorber A to form between the vehicle frame 7 and the wheel 12.

The pressure fluid chamber 19 is in fluid communication with a fluid pressure adjusting chamber 22 of a main fluid spring 20 over

80 9 808/07

a connecting channel 24 which is provided with an opening 24 'serving as a damper for the fluid spring. The fluid pressure adjustment chamber 22 is one of two chambers 22, 23, into which the interior of the fluid spring 20 is connected by an elastic Partition wall 21 is divided. The other chamber 23 in the fluid spring 20 is a sealed gas chamber in which one appropriate amount of gas is included. The reference numeral 25 denotes an auxiliary fluid spring, which is by an elastic Partition wall 26 is divided into two chambers, namely a liquid pressure adjusting chamber 27 and a sealed gas chamber 28. The fluid pressure adjusting chamber 27 is in fluid communication with the pressurized fluid chamber 19 via a Connection channel 29 in which a switching valve 30 with a solenoid 31 for the switching process and an opening 29 · is provided which serves as a damper for the fluid spring 25.

Although in Figure 2 the main and auxiliary fluid springs 20 and 25 are each shown in a single unit, it is understood that one or both of the fluid springs can also be used in a plurality of units can be provided if required.

The solenoid 31 is fed to the switching valve 30 at Receipt of a command signal from the signal generator 1 to operate, which is shown in FIG. When the switching valve, When viewed in Figure 2, is operated downward, the pressurized fluid chamber 19 becomes in fluid communication with the fluid pressure adjusting chamber 27 of the auxiliary fluid spring 25 as well as with the fluid pressure adjustment channel 22 of the main fluid spring 20 is set, with the result that the spring constant of the shock absorber Ά is reduced and the shock absorber A is put into its operating state with soft suspension. if on the other hand, the switching valve 30, viewed in Figure 2, is actuated upwards, the connecting channel 29 is closed, to interrupt the connection of the auxiliary fluid spring 25 with the pressure fluid chamber 19, which is now only with the fluid pressure adjusting chamber 22 of the main fluid spring 20 is in communication. This will

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^: the, Vert of the spring constant dos shock absorber A increases so that it works in an operating state with hard suspension. The operating state with hard suspension of the shock absorber A is desirable if the size of the stroke, i.e. the relative movement between the wheel and the vehicle frame, is increased, for example, during a steering movement, acceleration, deceleration and when driving the vehicle at high speed or over irregular surfaces. Obviously, in these cases, the signal generator 1 sends such a command signal to the switching valve 3 °> when this is actuated upwards, viewed in FIG.

The link 9 is at a point adjacent to its pin 1o provided with a curved arm 32 which extends vertically upward from the handlebar. On the outer hand of the self

'■■ horizontally extending portion of the arm 32, a pressure part 33 is attached, which has a certain horizont3.1e length. The carrier plate 34 is on the side of the vehicle frame 7

; fastened in a position which is below the pressure part 33 opposite this in the vertical direction, and carries a front and rear actuators 35a and 35a, respectively. 35b. The order is made such that when the vertical distance

, between the Vlau 12 and the vehicle frame 7 aui aine Limit is increased, the pressure part 33 to one of the

: Actuator, namely ^> 3 ^a > acts and pushes it down. When the vertical distance between the Sad 12 and the vehicle frame is reduced to a predetermined limit, the pressing part 33 acts in a similar way on the other actuator 35b and depresses it. The actuators 35a and 35b are constructed in such a way that when one of them is depressed, it becomes active and gives the switching valve 3o a signal which causes it to be actuated upwards, as viewed in FIG. In this .Veise the pressure member 33 and the paired actuators 35a and 35b cooperate to form a stroke detector 39 z ", and when a vertical stroke is detected, the

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-13-

■ Exceeds the limit distance between the wheel 12 and the frame 7,

the switching valve 3o is activated by the command signal from the stroke detector 39 in poetry of the Isrhöhuns of the spring constant of Shock absorber A actuated so that it is in its operating state r.works with hard suspension. It goes without saying that in this example the stroke detector 39 is connected to the signal generator 1 (FIG. 1) heard.

In Figure 3 is another embodiment of the signal generator ; shown, which has a number of detectors on v / e, all of them

are designed to generate an inverted output signal after scanning a predetermined parameter value, including \ a driving speed detector 36, a steering angle detector 37, a braking detector 38, a stroke detector 39 ', a crosswind detector l ± o, a driving force detector ^ 1 and a manual switch LZ. The output of the vehicle speed detector 36, which relates to the cruising speed of the

Vehicle is referred to a comparison circuit LJ, Zug-; leads to be compared with a reference signal for the vehicle speed. The output signal of the comparison switching

Circuit LJ is fed to a UTID gate k 5 via a delay circuit / | 4a.

ι The output signal of the steering / ink detector 37 »which is related to the given Lenlcv / inlcel, the comparison switching! circuit LJ, supplied v / o it is converted into a corresponding lateral acceleration signal to be compared with a reference signal for lateral acceleration. The output signal from the comparison circuit LJ is fed to the AND gate via the delay circuit if ^ a.

The output signal from the brake detector 38, which is based on the 3rems-; activity related is v / ird via another delay; circuit ψ-χο given to the UIID gate l \ 5 . Ί

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The output signal from the stroke detector 39 '' which is on a a predetermined limit exceeding stroke or down. stood between dor.i assigned rlad and your frame of the vehicle is supplied to the AND gate 45 through a delay circuit 44c.

The output of the crosswind detector 40, which is on a crosswind intensity exceeding a predetermined value is obtained via a delay circuit given to the AND gate 45.

j In a similar manner, the output signal of the driving force detector becomes 4I based on motorized acceleration

which exceeds a specified acceleration value ^; rises, fed to the AND gate j 45 through a delay circuit 44e.

■ A manual signal generated by the hand switch 42,

Anyone actuated directly by the driver is directly linked to the AND gate 45 supplied. It will be understood that the hand switch 42

'against a malfunction or failure of one of the detectors 36, 37, 38, 39' » ho or 41, of the pre-equalization circuit '+3 or one of the delay circuits 44a, Wb» hhc, Wd or hk & is provided and based on the Manual operation instead of the! disturbed detector or circuit is effective.

The AND gate 45 is the product of the inputs from the j delay circuits 44a, 44b, 44c, 44d, 44e. and the j manual switch 42 received, and the output from AND gate 45 is provided by the ones provided for the corresponding wheels 12

Amplifiers 46a, 46b, 46c and 46d are amplified and, by these, the switching valves 3o assigned to the respective wheels 12 J fed. Each of the switching valves 3o switches upon receipt ι the signal from the associated amplifier 46a, 46b, 46c or 46d in viewing the increase in the spring constant of the associated

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I shock absorber A so that it is in its operating condition: .iit

i!

¹ hard suspension is used. ^;

An example of a steering / ink detector 52 is shown in Figure 1+ ^;

placed, in which the reference numeral 1 + 7 denotes a pinion,!

which is operatively connected to the steering wheel of the vehicle and
! is in mesh with a rack 1 + 3 , which is through
i a transmission housing 1 + 9 extends in the transverse direction of the vehicle. . _;

ι!

\ Two connecting rods 5oa and 5ob are with the rack l + o i

hinged at their opposite ends. Further '

i is in the hit te of the rack ^ 8 on its top a ■. Formed recess 51, and extends into this recess

; An actuator 53 of the steering angle detector 52, which is fixed;

! i

■ is mounted on the gear housing 1 + 9. When the steering wheel is in

^! is rotated in either direction, the pinion becomes 1 + 7 ■

I rotated and drives the rack ^ 8 to the right or left, i

and an end wall of those formed in the rack

I recess 51 comes under the actuator 53, this is after!

I printed above and the steering angle detector 52 actuated. j

^: An example of a brake detector 59 is shown in Figure 5;

in which the reference numeral 55 is rotatable at 5A- on the vehicle frame ^!

A mounted brake pedal and 58 denote a brake cylinder,

_; which is provided with a rod 57 which at its outer j

ι end at 56 with the brake pedal 55 is rotatably connected. Dar j

I brake detector 59 v / eist an actuator 6o, the normal-;

j v / else in contact with a j formed on the brake pedal arm ! Projection 61 stands. When the brake pedal 55 is depressed,

the projection 61 is moved so that it is away from the actuator

6o releases and the brake detector 59 is actuated. ^!

ι It is evident to the person skilled in the art that in the invention;

I each of the detectors can be implemented in various ways as required j i can be and the steering angle and brake detectors are not on the

i in the embodiments shown in Figures 1+ and 5 limited j

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^: are. Similarly, the stroke detector is not limited to the embodiment shown in Fig. 2. ^!

Figure ο shows a diagram that the rait the shock absorbers; represents stable load / lift curves, and in which the abscissa!

the size of the stroke odor distance "vertical expansion and ■ contraction of the shock absorber and the ordinate the size of the indicates the load absorbed by the shock absorber. If the vehicle i

drives straight over flat or moderately rough surfaces, Is j

. i

'the shock absorber reduced in value of its spring constant and J : works, as indicated by curve a in Figure 6, in its |

Operating condition with soft suspension. If on the other hand that!

Vehicle is being steered, accelerated or decelerated or with i

'Driving at high speed, the shock absorber will be in its

• Operating state with hard suspension offset, where the value ι ι ι

! its spring constant is increased, and works, v / ie with I.

' Curve b indicated in FIG. In this context is too; Note that even if the vehicle is bumpy <

! Drives roads or such very irregular surfaces,

; the shock absorber works with reduced spring constant and consequently in its operating state with soft suspension, following curve a in Figure 6 as long as the stroke or distance of a vertical displacement of the JSade relative to the vehicle frame is in a predetermined range, or in other words as long as the shock absorber expands or contracts only within the stroke range from S. to Sp (Figure 6). But when

! the shock absorber is forced to move beyond the range of S.

until S ~ expand and contract, he will be in his j 2

Operating state with hard suspension, that is offset with increased spring constant and follows c the curves and c ¹ 6 in FIG It is understood that such different by the curves a, b, c and c ¹ indicated operating states of the shock absorber all by the switching action of the Switching valve 3o can be selected.

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; FIG. 7 is a timing diagram which shows the timing of the; Change of the ßre / iiswert, the BremsdeteVrtorv / artos, the deceleration value, the switching valve position and the Scoßdätnpfer- ■ spring characteristics of the wheel suspension system, -vaan the vehicle is braked. In this representation generated under the assumption that the rireas force in the one represented by the; The continuous line 1 indicated sequence is exerted by the braking detector, an output signal in the form of a reversal of the braking force line 1, as indicated by the solid line 2. In this example, the output signal of the delay circuit takes the form:; i of the solid line 3 ^a n> since it is delayed by the time Δt compared to the input signal of the delay circuit. The switching valve works through the control on the part of the delay signal, v / ie indicated by the solid line 1+ , so that the spring characteristics of the shock absorber vary in the form indicated by the solid line 5. It should be noted that, in this example, the spring characteristic or spring constant of the shock absorber is increased at the moment the braking force is applied,

and remains, when the braking force is eliminated, continuously increased over a certain period of time At.

^ s is v / UnacherioV / Grt that everyone who rj _t itektur'e; i is designed to produce an output signal that is opposite to his

! Input signal is inverted, v / ie above in the case of the brake detector shown. It can be seen that with such a

ι Detector, if the 3actuator and the one provided for the detector The circuit seen is faulty or does not work properly and no input signal is fed to the detector, the spring constant of the shock absorber is always kept increased and the j Driving safety is ensured even if the driving comfort may be impaired to a certain extent. Further j makes it providing delay circuits possible on the output side of the respective detectors, the Time lag in the movement of the vehicle body opposite

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the movement of the vehicle control devices such as the steering or braking system and in relation to the movement of the To compensate wheels so that the behavior of the vehicle body of considerable size and inertia are smoothly controlled can.

The use of a liquid as a fluid medium to adjust the spring constant of the shock absorber eliminates all difficulties which would otherwise occur due to temperature fluctuations when adjusting the shock absorber constants. Further sets the fact that the switching valves and the signal generator provided for them are integrated into the system in a coordinated manner, the shock absorbers are able to operate in the manner described above with reference to FIG. 6, so that not just any Damage to the vehicle is effectively prevented, but also the driving comfort and stability in the control of the vehicle can be significantly improved.

FIG. 8 illustrates a second embodiment of the invention which is a modification of the wheel suspension shown in FIG and has substantially the same construction and arrangement as the embodiment previously described with reference to Figure 2, with the exception that fluid dampers or viscous Damper 62 and 69 in the corresponding connecting channels 24 and 29 of the spring force adjuster B instead of the openings 24 · and 29 'are inserted to reduce the damping effect at relative Movement between the associated wheel and the frame of the vehicle according to the change in the value of the spring constant of the shock absorber A. In FIG. 8, the same reference numerals are used as in FIG. 2 for similar parts with the same Function used.

In the embodiment of FIG. 8, the fluid damper 62, which is inserted into the connecting channel 24, is the pressure fluid chamber 19 connects to the fluid pressure adjusting chamber 22 of the main fluid spring 20 through a partition wall 63 in two Divided compartments, the partition wall having an opening 64 and a

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other opening 65 with a smaller diameter than that of the opening 64 has. The opening 64 is provided with a one-way valve 67, which is arranged on the side of the partition which defines the compartment communicating with the main fluid spring 20. The one-way valve 67 has the shape of a flexible lamella, which at one end of the partition wall 63 with a fastening part 66 is attached. In the same way, the opening 65 is provided with a one-way valve 68, which is on the opposite side of the partition wall 63 is arranged. The one-way valve 68 has the shape of a flexible lamella that with the same fastening part 66 as the one-way valve 67 is fastened at one end to the partition wall.

With this arrangement, when the wheel 12 is pushed up and the piston 17 is pushed up in the cylinder 16, the liquid medium in the system is forced through the connecting channel 24 and the opening 64 in the direction of the pressurized fluid chamber 19 to the fluid pressure adjusting chamber 22 against the bias of the sealed gas chamber 23 with a relatively high flow velocity flow. The liquid once forced into the liquid pressure adjusting chamber becomes under the increased gas pressure in the gas chamber 23 and flows to the pressure fluid chamber 19 through the connecting channel 24 and this time through the opening 65, which has a smaller diameter than the opening 64, with a relatively small diameter Flow rate, so that the piston 17 is forced downwards and causes the wheel 12 to be relatively smaller Speed bounces back.

The inserted into the connecting channel 29 other fluid damper 69 is between the switching valve 30 of the electromagnetic Type and the auxiliary fluid spring 25 are arranged and divided into two compartments by a partition wall 70, which is provided with an opening 71 and another opening 72 is provided, which is a smaller one

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Has diameter than the opening 71. The opening 71 is with a one-way valve 74 in the form of a flexible lamella is provided, which is fastened at one end by a fastening part 73 to the side of the partition wall 70 which is that of the two compartments defined that with the auxiliary fluid spring 25 in Connection. On the other hand, the opening 72 is provided with a one-way valve in the form of a flexible lamella, which is fixed at one end to the other side of the partition wall 70 by the same fixing part 73.

In the open state of the electromagnetic switching valve 30, it becomes in the system including the pressurized fluid chamber 19, the connecting channels 24 and 29 and the fluid pressure adjusting chamber 27 filled fluid when the wheel 12 is pushed up and the piston 17 is forced to rise is forced through the connecting channels 24 and 29 and the opening 71 with the larger diameter in the Direction from the pressure fluid chamber 19 to the auxiliary fluid spring 25 to flow. The liquid is thus against the bias of the sealed gas chamber 28 in the liquid pressure one Partial chamber 27 pushed but immediately pushed back and flows in the opposite direction through the connecting channels 29 and 24 and the opening 72 with the smaller diameter with a relatively low flow velocity to in to return the pressurized fluid chamber 19 so that the piston 17 is pushed downward and a gentle spring back of the wheel 12 causes.

It can be seen that the fluid connection between the fluid damper 69 and the pressure fluid chamber 19 is interrupted when the electromagnetic switching valve 30 closes is operated.

In the second embodiment according to FIG. 8, which according to the above Description is constructed, it can be seen that when an operating condition with a relatively soft or gentle suspension

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and a corresponding lower spring constant of the shock absorber depending on the load and driving conditions of the vehicle are required, the electromagnetic switching valve 30 is operated downward, so that both the main fluid spring 20 as also the auxiliary fluid spring 25 work to collectively a gentle To give spring action. On this occasion, practice in the corresponding connection channels 24 and / or. 29 provided Fluid dampers 62 and 69 have an adequate damping effect the flow of liquid into and out of the liquid pressure adjusting chambers 22 and 27. Since this in particular Fluid dampers are designed so that they have a relatively high flow rate from the pressurized fluid chamber to the corresponding fluid pressure adjusting chambers and 27 and allow only a relatively low flow rate in the opposite direction, the upward movement of the pushed wheel is offered only relatively little resistance, while the subsequent rebound of the wheel is effectively slowed down, and any pulsating flow of liquid will be prevented.

FIG. 9 shows the operating curves of the fluid dampers 62 and 62, the abscissa being the liquid flow rate through the connection channels 2 4 and 29, while the The ordinate indicates the fluid pressure difference occurring at each of the fluid dampers 62 and 69. Also in this representation it is assumed that the liquid flow rate from the pressurized liquid chamber 19 to the liquid pressure adjusting kairaner 22 or 27 is positive and negative in the opposite direction. The fluid pressure differential is considered positive assumed when the pressure is on the side of the fluid damper 62 or 69 that communicates with the pressurized fluid chamber 19 stand is higher than the pressure on the opposite side of the fluid damper. The solid line X represents the working curve obtainable with only the fluid damper 62 in operation; the dashed Line Y represents the working curve that is obtainable when the other fluid damper 69 alone is operated

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is; and the dash-dotted line Z is the working curve ι again, which is available when both fluid dampers 62 and

are in operation. As can be seen, the value of the liquid pressure difference, which is indicated by the curve Z, is '; essentially equal to the sum of the pressure differential values indicated by the curves X and Y, since the fluid pressure ' difference occurring at each of the fluid dampers 62 and 69 corresponding to the load received by the vehicle frame 7.

As can be clearly seen from FIG. 9, when the electromagnetic switching valve 30 is in its position closing the connection channel j and only the fluid damper 62 is working in the connection channel 24, the fluid pressure difference that occurs at the fluid damper 62 varies in the range of P ₁ to -Pl when the speed of the liquid flowing through the connecting channel 24 varies _{in the range from V 1} to -V _1. On the other hand, when the electromagnetic switching valve 30 is in its open position and thus both fluid dampers 62 and 69 are operating, the velocity of the fluid flowing through each of the fluid dampers 62 and 69 varies only in the range of V ₂ to -V ₂ / the narrower than the range is from V ₁ to -V ₁ , the fluid pressure difference occurring at the fluid damper 62 and 69 varying in a correspondingly reduced range from P ₂ to -P ₂ *. This means that the two fluid dampers 62 and 69 work together to produce an overall damping effect which corresponds to the reduced spring constant of the shock absorber A.

Although in the illustrated embodiments the main and auxiliary fluid springs are each provided in a single unit it is understood that either or both of them can be provided in a variety of units as desired can. In these cases, the fluid springs should be individually provided with a fluid damper. It should be clearly noted

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I that the different in connection with the corresponding fluid springs

; ordered flux ddäinp far in their combination an optimal;

: Create a dampening effect, because the spring cone of the otoüdäm-

I fers corresponds while the, Gchv / ingbev / egung of the vehicle frame

v: during the spring and return spring actuation of the struck wheel

is minimized.

Although some embodiments of the invention are shown and be j

ι have been written, it is apparent to the expert _:

^! Many changes and modifications have been made in it

! v / be able to ground without being diverted from the thought or the framework of the Sr-:

! deviate from the invention as defined in the claims. ^;

The patent attorney

I.

809808/0746

Claims (8)

Expectations 1. ) Adjustable wheel suspension system for vehicles, with ^^ shock absorbers, which are arranged to absorb jerky relative movements between the frame and the corresponding wheels of the vehicle and each have a volume-variable pressure fluid chamber, characterized by a large number of volume-variable fluid pressure adjustment chambers (22, 27) are in communication with the pressurized fluid chamber (19) through corresponding connecting channels (24, 29) and are elastically variable in volume according to the fluid pressure present therein, by a switching valve device (30) which is assigned to at least one of the connecting channels (24,29) and is to be actuated in order to selectively close or open the associated connecting channel (24 or 29), and by a signal generator (1), which is to be actuated according to the driving conditions of the vehicle, in order to give a command signal to the switching valve device (30). 2. Adjustable wheel suspension system according to claim 1, characterized characterized in that the signal generator (1) has a plurality of detectors (2a-2d, 36-41) which work automatically, to determine the respective driving condition on the vehicle, and that the signal generator (1) has a plurality of delay circuits (4a-4c, 44a-44c) corresponding to the respective ones Detectors (2a-2d, 36-41) are assigned to based on output signals of these to act, so that the command signal that an increase in the spring constant of the shock absorber (a) is constantly given to the switching valve device (30), even after the output signal has ended of the detector for a further predetermined period of time. 809808/0746 ORIGINAL INSPECTED 3. Adjustable wheel suspension system according to claim 1, characterized in that the shock absorber (A), the signal generator (1) the fluid pressure adjusting chamber (22, 27) and the switching valve device (30) together adjustable wheel suspensions (6a-6d), which are provided for each one of the wheels (12), and that the signal generator (1) with a Stroke detector (39) is provided, which is used to determine a relative vertical movement between the wheel (12) and the frame (7) the vehicle is used, which exceeds a predetermined amount. 4. Adjustable wheel suspension system according to claim 1, characterized in that the fluid pressure adjustment chamber (22, 27) corresponding sealed gas chambers (23, 28) via corresponding elastic partition walls (21, 26) are adjacent. 5. Adjustable wheel suspension system according to claim 1, characterized in that the switching valve device (30) is a is normally closed switching valve. 6. Adjustable wheel suspension system according to claim 1, characterized in that the signal generator (1) with a Detector or any combination of detectors is provided, which consists of a vehicle speed detector (36) a steering angle detector (37), a brake detector (38), a lift detector (39,39 *) / a crosswind detector (40) and a driving force detector (41) and / or is provided with a manual switch (42). 7. Adjustable wheel suspension system according to claim 1, characterized in that it comprises fluid dampers (62, 69), which are inserted into the corresponding connecting channels (24, 29) which the pressure fluid chamber (19) with the Connect the corresponding fluid pressure adjustment chambers (22,27). 809808/0746 8. Adjustable wheel suspension system according to claim 7 ,. characterized in that each of the fluid dampers (62, 69) one provided with a one-way valve (67, 74) first opening (64, 71) to allow a flow of liquid only in the direction of the pressurized liquid chamber (19) to the associated fluid pressure adjustment chamber (22, 27) to allow when the wheel (12) is pushed and goes up, as well as one with a one-way valve (68, 75) provided second opening (65, 72) to a flow of liquid only in the direction from the associated fluid pressure adjusting chamber (22, 27) to the pressurized fluid chamber (19) to allow when the wheel (12) springs back. 809808/0746