DE1219341B - Pneumatic individual suspension for the two wheels of an ideal vehicle wheel axle - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

Number:
File number:
Registration date:
Display day:

B62d

B60g

German class: 63 c-41

1219 341
S6614411 / 63c
7th December 1959
June 16, 1966

The invention relates to an hydropneumatic individual suspension for the two wheels of an ideal one Vehicle wheel axle consisting of two support devices, each of which except the one above the support piston arranged in the support cylinder hydraulic work space has a hydraulic space below of the support piston is in the support cylinder and is in constant communication with a hydraulic fluid low-pressure tank stands, from which a pump sucks in hydraulic fluid that is constantly fed into the carrying device is promoted. This known single suspension has a disadvantage in that because of the required long oil-carrying lines, which have a relatively small cross-section, when Working of the suspensions pressure drops can occur, leading to a complete blockage of the Suspension can lead.

The suspension according to the invention avoids this disadvantage and is a device that a regular and reliable way of working is guaranteed. The individual suspension according to the invention of the type described above is characterized in that each support device consists of a support cylinder consists, which is so coaxially enveloped by another cylinder that a hydraulic cylinder-piston units known annulus is formed in the control openings for the hydraulic medium of the support cylinder open and that the opening located at the lower end of the support cylinder connects the hydraulic space below the support piston with a hydraulic low-pressure tank, wherein the two openings of the two support devices through a line with one, two support devices common pneumatic-hydraulic compensation accumulator are connected and the clear cross-section of this line is large enough to Hydraulic medium from each lower support cylinder space into the hydraulic space of the equalizing reservoir to let flow back without in the course of medium and fast displacements of the support piston a each support device a significant counter pressure in the hydraulic space below each Generate support piston.

According to another feature of the invention, the two openings are in each support device are connected to the low-pressure tank by a line with a large cross-section, which is at least partially elastic in a manner known per se.

According to a further feature of the invention, each support device comprises a per se known Way a chamber with an elastic wall, in its oleopneumatic individual suspension for the two Wheels of an ideal vehicle wheel axle

Applicant:

Societo d'Etudes et d'Applications Industrielles
Commerciales et Immobilieres
"Inter-Technique", Paris

Representative:

Dipl.-Ing. H. Seiler, patent attorney,

Berlin 19, Oldenburgallee 10

Named as inventor:
Marcel Dangauthier, Paris

Claimed priority:

France of March 11, 1959 (789 022)

Inside the opening located at the lower end of the support cylinder opens.

Another feature is that a further outlet opening for the hydraulic medium each Carrying device with the low pressure tank parallel to the lower hydraulic space through the line large cross-section, hydraulic space of the pneumatic-hydraulic accumulator and return line connected is, the cross section of the return line is dimensioned sufficiently large to allow normal discharge of the hydraulic medium emerging from the outlet opening, its outflow quantity corresponds approximately to the continuous output of the pump.

The drawings show an exemplary embodiment of the invention, and it is

Fig. 1 is a schematic view in elevation with partial sections of an oleopneumatic according to the invention Suspension,

F i g. Figure 2 is a vertical section on an enlarged scale through one of the support and shock absorbing devices this suspension and

F i g. 3 is a longitudinal section along line 3-3 of FIG. 2 of the device of the shock-absorbing valves this support and shock absorbing device.

According to the illustrated embodiment, the suspension according to the invention is used to suspended rear part I of the motor vehicle, which is shown schematically by a small part of the motor vehicle body is indicated with the rear support part

609 579/209

and to connect the motor, which is itself schematically represented by the connectors II, the are connected to the wheels, not shown, of this arrangement.

The suspended part I is connected to each of the components II by means of an oleopneumatic support and shock-absorbing device, which is supplied with oil by means of a hydraulic unit B common to both arrangements A.

In the following, one of these arrangements and then the hydraulic unit are described first.

Each of these support and shock- absorbing arrangements A has a support device a with a cylinder and piston which effectively supports the suspended part of the motor vehicle, a pneumatic energy store b taking on the role of the spring. A shock absorbing arrangement c is also provided.

The support device α thus has a cylinder 1, in which a piston 2 is movably arranged. The cylinder 1 stands at its outer upper End via a seal 3 (Fig. 2) with a component 4 in engagement. Over this component is an enveloping Cylinder 5 attached coaxially to the cylinder 1, which together with the cylinder 1 annular space 6 forms.

Above the component 4, a frustoconical part 7 is arranged on the outside, on which the part I of the Motor vehicle by means of an annular buffer 8 made of rubber or similar material and a frustoconical sleeve 9 is elastically supported. The cuff 9 is on the Part I of the motor vehicle attached.

The piston 2 is connected to the component II (carriage axle or other) via a piston rod 10, this component II is firmly connected to the corresponding wheel. The piston rod 10 is elastic on this component z. B. by means of two rubber washers 11 and 12 (Fig. 1) attached between the component II and metal washers 13 and 14 are fastened by means of a nut 15, which is attached to the outer threaded end of the piston rod is screwed, which passed through the component Π with play is.

The piston 2 must be completely sealed, at least when the motor vehicle stops, and the intended Sealing arrangement must not cause any noticeable sliding friction, so no reduction the great flexibility required for the suspension takes place. This result is z. B. thereby obtained that on the piston 2 a sealing ring 16 (F i g. 2) made of Tetrafiuoräthylen is provided is that against the cylinder 1 by means of a seal 17 made of elastic material such as rubber, is pressed.

The piston rod 10, the pressure of the piston 2 transfers to the wheel, is guided at the lower end of the cylinder 1 by a bearing support 18, which is provided with a seal 19, the function of which, as can also be seen from the other Executions results, is to allow movement without pressure. This seal 19 is supported by means of a spring 20 on an enclosure 21 which is arranged in the casing 5.

The interior of the cylinder 1 is in communication with the annular space 6 by means of a discharge opening 22 with a fairly small cross-section, so in a certain height of the cylinder to enable a delivery of the liquid of the suspension device, and on the other hand consists a connection between the cylinder 1 and the annular space 6 at the lower end of the cylinder by means of one (or more) large opening 23 the permanent connection with the Room 24 represents.

The opening or openings 23 have an overall cross section for the passage of liquid in of the order of a third or a quarter of the cross section of the space 24.

A further chamber 25, which is referred to as the “carrier chamber”, is arranged above the piston. This chamber is connected via the shock-absorbing arrangement c with the memory b , which is under a high gas pressure. This creates the suspension of the suspension.

This memory b has a storage container which is preferably formed spherically from two parts 26 and 27, the part 26 z. B. is attached to the component 4 by screwing. The part 26 has a hole which is formed by an opening 28 which establishes a connection with the interior of the component 4 and thus with the cylinder 1. On the other hand, the part 27 is provided with an opening 29 through which gas can be refilled. After filling the gas, this opening is closed by a closure 29 α .

The memory is made by a flexible membrane 30 made of rubber or similar material divided into two chambers 31 and 32, the Chamber 32 contains a constant amount of gas under pressure when in communication with cylinder 1 standing chamber 31 is filled with oil. The volume of the memory is chosen so that always under the Membrane 30 is present regardless of the prevailing operating conditions oil.

In order to prevent this membrane from tearing, its radius is preferably smaller than that of the reservoir, so that the membrane can be easily stretched, thereby increasing its surface area without the risk of this membrane wearing out and being destroyed.

Furthermore, the shock-absorbing arrangement c (FIG. 2), supported on an inner projection 33 of the component 4, has a perforated disk 34 (FIGS. 2 and 3) with two rows of connecting openings 35 and 36, each row having at least one opening and preferably has several such openings. On each of these openings, a flap valve 37 or 38 is supported in the opposite direction of the individual rows to one another and is returned to its seat by means of a spring 39 or 40. The spring is supported on a component 41 or 42. The two components 41 and 42 are fastened to one another by a screw 43 on the disk 34.

It should be noted that when several ports and flap valves are arranged in series, the Cross-sections of the openings, the valve lifts of the flap valves and / or the spring forces of the springs are preferably set so that a successive opening of the various openings is achieved, d. H. for different prints.

The common hydraulic arrangement B will now be described. The same has a

I 219 341

5 6

Pump 44 (Fig. 1), which a certain liquid 44 must have a very short length, otherwise due to the loss of the feed pressure caused by the calving due to the suspension different pressure. th oil may have a value in the order of magnitude

When dispensing the amount of liquid, reach the voltage of 1 kg / cm ² , whereby a given pump with a value q for the smallest occurrence, if the pump runs empty,

tend pressure, d. H. when the motor vehicle is empty, the reservoir 46 is under the pressure of the

is cross-section of the outlet opening 22 of each support pump 44, whereby the suction through this

and shock-absorbing device A is dimensioned in such a way that the pump is facilitated, which is

the amount of liquid dispensed through this follows. This storage container can hold up to one

Opening 22 pass through without pressure increase io not shown here, level be filled in such a way

can. that in a new motor vehicle such

The pump 44 is continuously z. B. by the level shows that there is enough oil for the working camshaft 45 of the motor vehicle's engine, as instructed by the suspension, remains after all operated. The same sucks from a container 46, the written components and lines are filled, is under low pressure, by means of a line 47 15 The arrangement of the hydraulic device the liquid and then presses it into the is preferably continued by the following Line 48. The line 48 is completely connected to the component 49 described additional devices, which contains a check valve 50 and is permanent.

is connected to two lines 51, the flexible In the suction line 47 is a pump nozzle or

or have flexible parts. Each of these lines 20 diaphragm 62 is provided, which allows the from

51 is attached to a connection point 52, the amount of liquid indicated on the pump to almost

the hemisphere 26 of the memory c of the one or the other to set a constant value, though

other of the support and shock-absorbing devices have fluctuations in their speed of rotation

Gen A is provided so that the chambers 31 are the reason for the transmission of power to this pump

Memory c persistently occur with the outflow side of the pump 25 high speed range of the engine.

44 to contact. In line 48 through which the liquid comes out

The reduction of the liquid is on the load end of the pump hindurchgepreßt, is a small, the pressure, the return of the liquid that is, in hitting the fluid regulating device e the container 46 is inserted from the annular space. 6 The same is formed by a spherical each of the carrying devices A through a single body made of two parts 63 and 64, in the line 53 and then through a common line a membrane 65 made of rubber or similar material 54 brought about. The lines 53 have a largely arranged, which forms two chambers 66, 67, ßen cross section in the order of magnitude of the transverse The chamber 66 contains a gas which has previously been introduced under section of the annular space 5 and the pressure . The chamber 67 ent cross-section of the openings or the openings 35 keeps the oil in free communication with the discharge line in the chamber 24, in which a low pressure of the pump. The prevailing in this chamber 67, arranged, has like the common pressure is lower than that in the chambers 32 line 54 has a smaller cross section. The support device A. Nevertheless, the pressure in the connection between these lines is sufficiently high due to the device e to cause the volume attachment 55 of a reservoir d , which is used to store 40 men of the high pressure gas To keep fluctuation in volume of the lower ring-shaped at impact sufficiently large.
Chambers24 of the two devices A to be A safety branch line / to a Kugel68 chen. and spring 69 which is set to a pressure that

This memory d has two capsules 56 and 57 above the highest possible pressure of the carrying device, the second being fixed to the extension 55 of the 45 gene and being connected to the supply and discharge lines of the connecting piece. This capsule pump connected in order to prevent destruction of the line holding pressed between the edge of an elasystem in the event of a blockage of the line with elastic membrane 58 made of rubber or corresponding high pressure,
the materials, through the two chambers 59 and 60. In the following, the same will be formed one after the other. 50 weight of the vehicle when stopping, the process

The chamber 59 has a relatively large volume rensweise the suspension when driving and the

with respect to that of the lower ring-shaped chamber- equalization of the volume fluctuation under the column-

mern24 of devices A. This volume ben each device A and also the role of

is approximately four times the total maxi- various additional devices of the hy-

paint volume of the two chambers. 55 discussed hydraulic arrangement.

The other chamber 60, which can have a very small The suspended part I when held by cross-section, which in the rest position carries the pressure effect, which can be zero from the pressure of itself, contains the oil under oil in the chamber 25 of each device A from a pressure which is applied equal to atmospheric pressure. This pressure is equal to the pressure in addition to the loss of feed in which 60 is that in the chambers 31 and 32 of the corresponding common return line 54. The transverse gas-filled energy store b prevails,
As soon as the motor vehicle is loaded when stopping than that of the lines 53, this line must be sufficient, although the same is smaller, with the engine not running, so that the pressure in the chamber 60 shifts each piston 2 in the upward direction in winter remains weak when the oil is thick. 65 mer 25, whereby its shift due to the

The reservoir 46 consists of sheet iron. The oil flows out of this chamber 25 in the direction of

and is in the engine compartment of the motor vehicle to the chamber 31 via the shock absorption

orderly. The supply line 47 to the pump device c is braked.

As soon as the engine is started, the pump 44 pushes oil through the lines 48 and 51 towards the chambers 31 of the devices ^ i and through the devices c. This oil enters the chamber 25 and leads the pistons back down again until each of them clears the outlet opening 22, through which the oil discharged by the pump through the annular space 6 and the lines 53 and 54 in the direction of the reservoir 46 can flow.

Thus, the suspended part I is again by means of the combination of the pistons 2 and the drainage hole 22 returned to a constant height above the non-suspended part II.

The vibrations of the suspended part of the motor vehicle with respect to the wheels and the unevenness of the road are dampened by the shock absorbing device c , the oil in each device A of the chamber 25 passing towards the chamber 31 when the motor vehicle drives over a bump in the road and if, conversely, the path leads through a hole in the pavement or if the body rebounds. By suitable selection of the openings 35, 36 and the return springs 39, 40 of the flap valves 37, 38, the suspension is set up in such a way that the vibrations of the body 1 are almost aperiodic. For this purpose, it is sufficient to set the devices c almost to the critical damping.

When the road is completely smooth, the suspension practically does not move, and the pistons 2 are at such a level that all of the liquid dispensed by the pump 44 into the storage container 46 through the openings 22, the annular chambers 6 and the lines 53 and 54 returns.

Provided that each opening 22 has a diameter such that the entire The amount of liquid dispensed by the pump through these openings is less than the smallest possible Pressure can pass, the entire amount of liquid dispensed by this pump is in the closed working circuit of the reservoir 46 returned.

The seal 19 of the shaft 10 of the piston moves without pressure because the annular space 6 is constantly emptied.

As soon as the piston 2 moves in the downward direction in the cylinder 1 (expansion) takes place the volume of the annular chamber 24 around the shaft 10 decreases. At high and medium piston speeds this corresponds to considerable quantities of oil dispensed, which represent a multiple of that which is dispensed by the pump 44.

Merely for the sake of explanation it should be stated that with an annular area of 5 cm ² and a speed of 1.5 m / s a downward movement of the wheel, this corresponds to an outflow of liquid of 0.75 l / s and this approximately thirty times that Mege, which the pump 44 delivers, which preferably operates ^{on the order of 25 cm 2.} With a small cross-section of the lines returning the liquid, outflowing amounts of liquid of this order of magnitude would lead to increased losses of the working pressure of the carrying device, and there would be the risk that the piston would be blocked in the relaxed position and thus no longer be suspended.

A remedy is created in that the storage d , which brings about the compensation, is connected to the supporting devices by the relatively short pipe system 53 having a large diameter.

At the time of the rapid downward movement of the piston 2, a lot of the occurs

ίο Oil, which corresponds to the reduction in the annular volume around the shaft, immediately through the openings 23, the annular spaces 6 and the conduit 53. The chamber 60 of the equalizing reservoir d causes a continuous compression of the gas in the other chamber 59 of this reservoir d. The base pressure in the lower annular chamber 24 caused by the downward movement of the piston remains small and negligible compared to the pressure in

ao of chamber 25 prevails.

After the pistons have returned upwards, at least part of the oil flows under the pistons return.

With regard to the diaphragm 62, the nozzle or any other device which causes a load drop on the sealing component of the pump, since a limitation of the amount of liquid dispensed by the pump in the ranges of medium and high speed (e.g. from 2000 rev / min of the engine) enables the exhaust ports 22 to be reduced in size. This results in a considerable advantage, since it avoids that the pressure in the chamber or chambers 24 does not suddenly drop, which for example at the end of the braking process would lead to a rapid lowering of the suspended part of the motor vehicle as soon as the opening 22 of one or the other two carrier devices A is no longer covered, which z. B. occurs during prolonged braking, which causes a lifting of the rear part of the vehicle.

As already stated in the introduction to the description, the arrangement of thick and short tubes 53 and the compensating force storage device d can be replaced by all other equivalent devices, namely e.g. B. one can connect each port 46 directly to the low pressure container 46 by a thick pipe, provided that it is not too long. On the other hand, you can let the opening 23 open more or less directly into the reservoir, so that the same then z. B. is arranged concentrically around the cylindrical container 5 of the device ^. On the other hand, an elastic membrane can be provided directly on the support and shock absorbing device A in the form of a part of its casing 5.

Parts of the description of the exemplary embodiment that go beyond the wording of the claims and the drawings are for explanatory purposes only and are not part of the invention.

Claims (4)

Patent claims: 1. Individual hydropneumatic suspension for the two wheels of an ideal vehicle wheel axle, which consists of two support devices, each of which except the one above the support piston in the Hydraulic working space arranged in the support cylinder has a hydraulic space which is located below the support piston in the support cylinder and which is in constant communication with a hydraulic medium low-pressure container from which a pump draws in hydraulic medium which is constantly conveyed into the support devices, characterized in that each support device (A; A) consists of a support cylinder (1) which is coaxially enveloped by a further cylinder (5) in such a way that an annular space (6), known per se in hydraulic cylinder-piston units, is formed in the control openings (22, 23 ) open for the hydraulic medium of the support cylinder and that the opening (23) located at the lower end of the support cylinder connects the hydraulic space (24) below the support piston (2) with a hydraulic low-pressure container (46), the two openings (23; 23) of the two carrying devices (A; A) through a line (53) with such a pneumatic-hydraulic balancing device common to both carrying devices hsspeicher (d) are connected and the clear cross-section of this line (53) is large enough to allow hydraulic fluid to flow back from each lower supporting cylinder space (24) into the hydraulic space (60) of the equalizing reservoir (d) without medium and fast displacements of the support piston (2) of each support device (A) to generate a significant counter pressure in the hydraulic space (24) below each support piston. 2. Suspension according to claim 1, characterized in that the two openings (23) of each support device (A; A) are connected to the hydraulic space (60) of the common pneumatic-hydraulic compensating accumulator (d) by a line (53) of large cross-section which is at least partially elastic in a manner known per se. 3. Suspension according to claim 1, characterized in that each supporting device (4, 4; A ) comprises, in a manner known per se, a chamber with an elastic wall (e.g. wall 5), into the interior of which the opening (23) opens. 4. Suspension according to claim 1, characterized in that a further outlet opening (22) for the hydraulic means of each support device ^; A) is connected to the low-pressure tank (46) parallel to the lower hydraulic space (24) through the line (53) of large cross-section, hydraulic space (60) of the pneumatic-hydraulic accumulator (d) and return line (54), the cross-section of the return line ( 54) is dimensioned sufficiently large to allow normal discharge of the hydraulic medium emerging from the outlet opening (22), the outflow quantity of which corresponds approximately to the continuous output of the pump (44). Considered publications: German Patent Nos. 650 188, 945 674; French patents No. 1112 916,
849; U.S. Patents Nos. 2,492,990, 2,620182,
023, 2 802 674, 2857171, 2861794; Automobile Engineer magazine, August 1955, p. 328. 1 sheet of drawings 609 579/209 6.66 © Bundesdruckerei Berlin