DE102009058027B4 - Device for height adjustment of a vehicle body - Google Patents

Abstract

Device for height adjustment of a vehicle body comprising a disposed between the vehicle body and a wheel suspension strut with a tensioned between an upper and a lower spring plate spring, wherein a spring plate or a vehicle body receiving support plate is adjustable in height via an adjusting means, characterized in that the Adjusting means (7) comprises a spatially separated from the strut (3) arranged pump (8) which is operated via a at least one motor (9) driven ball screw (10), wherein the pump (8) via a hydraulic or pneumatic line ( 11) with at least one linearly movably guided support plate (22) or the linearly movably guided spring plate (5) associated receiving space (12) for receiving a hydraulic or pneumatic medium is connected, wherein the ball screw (10) for actuating the piston movement of a piston the pump (8) associated cylinder Piston unit is used and the piston by the spindle (16) or the nut (20) of the ball screw (10) is formed.

Description

Field of the invention

The invention relates to a device for height adjustment of a vehicle body, comprising a arranged between the vehicle body and a wheel strut with a tensioned between an upper and a lower spring plate spring, wherein a spring plate or the vehicle body receiving support plate is adjustable via an adjusting means in its height.

Background of the invention

Height adjustment devices or level adjustments for motor vehicles can be found in the prior art in a variety of configurations and therefore basically known. In particular, in modern motor vehicles can be done on these devices, for example, a suspension adjustment according to the wishes of the driver. For example, the driver can select a so-called sports program in which the vehicle body is lowered.

Structurally, these systems are regularly designed so that the height adjustment causing actuator is located directly on the strut, which can lead to problems in terms of very limited available space.

DE 101 44 111 A1 relates to an electromechanical level control of a motor vehicle with a mounted between a body-side and a Radträgerseitigen contact point spring, wherein the first contact point via one of an electric drive, which cooperates with a spindle drive designed as a screw, with respect to the body height is adjustable. Here, the electric drive is associated with a spindle which meshes with a fixedly arranged at the first contact point spindle nut. The electric drive is located directly on the body-side contact point, thus the system builds up in a horizontal direction.

Out WO 2008/148746 A1 is a height-adjustable spring bearing for a arranged between a vehicle body and a wheel spring with an actuator connected to the spring actuator in the form of an electric motor for height adjustment of the spring bearing, wherein the actuator and the adjustable spring bearing are arranged on the side of unsprung wheel carrier, which also to a problematic arrangement can result in limited space available.

Furthermore, a height adjustment device for wheel suspensions of motor vehicles DE 10 2007 004 747 A1 known. For this purpose, a rotatably mounted on a damper tube, axially non-displaceably held inner sleeve member is provided which displaces an coaxial with the sleeve member arranged outer sleeve at an actuation of the height adjustment so that thus a spring plate is axially adjustable. The inner sleeve member and the outer sleeve are designed in principle as a ball screw, wherein the inner sleeve member serves as a positionally fixed threaded spindle and the outer sleeve as along this movable nut. An electric motor serving as the actuator is similar to the above-mentioned arrangement WO 2008/148746 intended.

However, the European patent application concerns EP 1 970 226 A2 a suspension for motor vehicles with a strut, consisting of a arranged between spring plates spring and a shock absorber, wherein a spring plate is displaceably guided relative to the vehicle body and such an actuator in its axial position is variable. In addition to the actual spring a so-called memory spring is additionally provided, which has a spring force opposite the spring and which is supported on the one hand on the vehicle body and on the other hand on the displaceable spring plate. The arrangement of the actuator is located outside of the shock absorber, nevertheless, the use of two springs with opposite spring forces is very expensive.

The DE 32 23 195 A1 shows a device for adjusting the height of the bodywork of a motor vehicle, with at least one hydraulic cylinder whose pressureable piston supports at least one suspension spring, wherein the motor vehicle is a hydraulic device with a motor-driven pump and a flow line to a control valve of the open-center design and a Return line to a non-pressurized reservoir, wherein the hydraulic cylinder is connected via an arbitrarily controllable directional control valve to the flow line, the directional valve in a middle position M shuts off the hydraulic cylinder, in a high position H connects this with the flow line and in a low position T with the reservoir.

The DE 44 26 682 A1 shows an electronically controllable brake actuation system for motor vehicles, with an operable by means of an operating pedal master cylinder with controllable by an electronic control unit brake pressure sensors are directly connected to the wheel brakes of the vehicle and can be connected via shut-off by means of valve hydraulic connections to the master cylinder, with at least one sensor device for detecting the driver deceleration request and at least one with the master cylinder interacting simulator chamber. In order to improve the function of such a system, in particular the dynamics of the brake pressure generator while reducing the response time of the entire system, it is proposed that the valve devices are designed as solenoid valves, which are controlled by the electronic control unit time delay, connected to the pressure chambers of the brake pressure generator low-pressure accumulator are in the release position of the brake pressure transducer associated with the wheel brakes.

The DE 101 53 007 A1 shows a device for height adjustment of the structure of a motor vehicle, with a suspension with a suspension spring and shock absorber existing strut, wherein the suspension spring and the shock absorber are supported by damping means on the structure and the suspension spring via a fluid pressure adjustable, arranged on the structure actuator with a movable Piston is adjustable in height relative to the structure, the damper bearing of the shock absorber is integrated into the piston of the actuator to maintain the spatial position between the suspension spring and the piston rod of the shock absorber.

The DE 103 53 025 A1 shows a suspension system for a motor vehicle, with a hydraulic actuator, which influences a body movement of the vehicle and which is connected via a first hydraulic line to a hydraulic pump (which is driven by a motor), and a storage unit which is provided for receiving hydraulic oil and is connected via a second hydraulic line to the hydraulic pump, wherein the motor is designed as an electric motor and this has a rotor which is coupled to the hydraulic pump and which is operable in two rotational directions, so that hydraulic oil in either the hydraulic actuator or in the storage unit is eligible.

Summary of the invention

The invention is therefore based on the problem to provide a device for adjusting the height of a vehicle body, which can also be used in very confined spaces and also has a simple design.

To solve this problem, a device for height adjustment of a vehicle body of the aforementioned type is provided according to the invention, which is characterized in that the actuating means comprises a spatially separated to the strut pump, which is operated via a motor driven via at least one ball screw, wherein the pump is connected via a hydraulic or pneumatic line with at least one linearly movably guided support plate or the linearly movably guided spring plate associated receiving space for receiving a hydraulic or pneumatic medium.

The device according to the invention for height adjustment of a vehicle body thus takes up very little space. The actuating means is associated with a pump, which, however, not in the immediate region of the strut, but spatially separated, in particular to the height-adjustable components, namely the support or spring plate, is arranged. The pump is a hydraulic or pneumatic pump which is connected via a corresponding hydraulic or pneumatic line with at least one receiving or receiving chamber associated with the support or spring plate for receiving the hydraulic or pneumatic working medium. The height adjustment of the support or spring plate via a further detailed below linear guide, which has as an essential element the receiving space for the corresponding hydraulic or pneumatic medium and allows a linear movement of the support or spring plate in the vertical direction along the spring axis.

In principle, the device according to the invention is thus not an electromechanical device in which, as known from the prior art, a spindle-nut drive or ball screw drive, which is usually motor-driven by an electric motor, effects the height adjustment of the vehicle, but instead to a, in particular closed, hydraulic or pneumatic system.

According to the invention it is advantageous if the ball screw for actuating the piston movement of a piston of one of the pump associated cylinder-piston unit is used. Sonach the pump is essentially designed as a cylinder-piston unit, wherein the ball screw actuate the associated piston, that is, can move axially. In this way, the hydraulic or pneumatic working medium is moved by the line corresponding to a receiving space or deducted from this, in other words built pressure or flow. For this purpose, between the axially movable portion of the ball screw, which is formed either by nut or spindle, and the piston ensures a suitable, stable connection, which transmits the axial movement of the movable portion of the ball screw on the piston. The respective position-fixed portion of the ball screw is used for coupling with a motor-side output element, for example a shaft. However, it is particularly advantageous if the piston is formed by the spindle or the nut of the ball screw itself, as far as a separate piston can be saved and results in a reduction of components. The arrangement of Sealing elements on the piston or on the piston forming part of the ball screw, which prevent entry of the working fluid in the area behind the piston, this is usually required.

The drive of the pump via at least one motor-driven ball screw, with either the mother or the spindle of the ball screw is connected to a motor associated output shaft depending on the design. Optionally, the pump or the ball screw can also be operated within the pump via multiple motors, if this should be necessary, for example, in an increased power requirement.

The engine can be directly assigned to the pump, so be her own, or be assigned in addition to or other original vehicle components, its operation is controlled by a control device. In the ball screw disposed within the pump is a common ball screw with a spindle and a nut, but which is selected in terms of its material so that it withstands possible interactions, such as a corrosive attack, with the hydraulic or pneumatic working fluid. For this purpose, a protective coating of the working medium exposed areas of the ball screw can serve.

The hydraulic or pneumatic line used is designed with regard to their material and their material thickness so that on the one hand shows no interactions with the respective working medium and on the other hand withstand the pressures occurring during operation of the device.

Optionally, it may also be appropriate to assign both the support plate and the lower spring plate a receiving space for receiving a hydraulic or pneumatic medium, which may result in a total of even greater stroke of the vehicle body. Here, the receiving spaces can be connected via lines to one or each with a motor-driven pump.

In a preferred embodiment of the invention, it is provided that the receiving space is arranged either between the support plate and the upper spring plate, wherein the support plate is guided linearly movable relative to the upper spring plate, or that the receiving space between the lower spring plate and a strut fixedly arranged support plate is arranged, wherein the lower spring plate is guided linearly movable relative to the support leg fixedly arranged on the suspension strut. Thus, this results in two possibilities of height adjustment of the vehicle body, which depend essentially on the positioning of the receiving space. The receiving space is more vehicle body side, ie between support plate and upper spring plate, the height adjustment via an axial movement of the support plate is up, the upper spring plate remains unchanged in its axial position. However, if the receiving space is located in the lower region of the suspension strut, ie if it is arranged fixedly between the lower spring plate and a support plate arranged on the suspension strut, the height adjustment takes place via an axial movement of the lower suspension plate relative to the support plate which is fixedly arranged on the suspension strut and remains unchanged in its axial position , In other words, the receiving space is therefore basically in two places anordbar namely on the one hand in the upper region of the shock absorber and the other in the lower region of the strut, which in each case results in a relative movement of different components, which, however, as a result, either raises or lowers the vehicle body ,

As mentioned above, if necessary, a particularly large stroke of the vehicle body and two receiving spaces in the upper and lower portions of the shock absorber may be appropriate, with respect to their arrangement and operation does not change.

The receiving space is advantageously designed as a cylindrical annular space. Of course, it is also possible to use the receiving space other than circular bases, including, for example, an oval-shaped, therefore distorted, ring shape falls. It is important that a bottom surface of the cylindrical annulus is closed, so in a longitudinal section through this results in a substantially U-shaped, opened in only one direction profile. Of course, the total stroke but is significantly influenced by the height of the cylindrical annulus, which is why at high strokes correspondingly high levels of the cylindrical annulus should be realized.

In a further development of the invention, the cylindrical annular space extends from the support plate in the direction of the upper spring plate, wherein the upper spring plate engages at least partially piston-like in this. In addition, however, it may also be that the cylindrical annular space extends from the upper spring plate in the direction of the support plate and a piston-like projection assigned to the support plate engages at least partially in the latter, wherein it is a 180 ° rotated arrangement. In other words, it is possible, the cylindrical annular space with its opening in the direction of the upper spring plate or the To arrange support plate. It also follows that the cylindrical annular space can be considered preferably as a cylinder cylinder-piston unit, the cylinder by itself and the cylinder in the axially movable piston depending on the arrangement either by the upper spring plate or by a on the support plate of the Vehicle structure protruding projection, each partially engaging in the cylinder formed by the annulus, may be formed. These statements relate respectively to the aforementioned arrangement of the receiving or annular space in the upper region of the strut.

Alternatively, it is conceivable that the cylindrical annular space extends from the strut fixedly arranged support plate in the direction of the lower spring plate and the lower spring plate engages at least partially piston-like in this, or that arranged the cylindrical annular space from the lower spring plate in the direction of the strut fixed Support plate extends and a the bearing pin fixedly arranged support plate associated piston-like projection engages at least partially in this. From this development of the invention, the arrangement of the receiving or annulus is affected in the lower region of the strut. Again, the cylindrical annulus is to be regarded as a cylinder cylinder-piston unit. The opening of the cylindrical annular space can therefore point in the direction of the lower spring plate, with the lower spring plate extending at least in sections like a piston into the cylindrical annular space. Alternatively, the cylindrical annular space can be arranged rotated by 180 °, whereby its opening in the direction of the strut fixed positionally arranged support plate shows. In this case, a piston-like protrusion correspondingly arranged on the shock absorber is formed, which protrudes at least in sections into the cylinder space.

According to another embodiment of the invention, the motor, which is particularly preferably designed as an electric motor, can be blocked via at least one blocking means. The at least one blocking means engages, for example, on the motor-side output element, for example a shaft, which is either blocked or decoupled from the motor-side drive element by a clutch or the like. Due to the blocking of the output element, the cylinder-piston unit associated with the pump is also blocked in the following, since the piston, as described above, is in connection with the ball screw drive or is itself formed by parts thereof. As a result of the closed nature of the hydraulic or pneumatic system and the connection of the pump to the receiving space or spaces via the corresponding lines, the support plate or the lower spring plate can no longer be moved in this way, thus blocking the entire device. Of course, several, possibly even different locking means for blocking the engine may be provided. Particularly preferably, the blocking means blocking the engine is designed as a wrap spring lock or roller freewheel.

It is expedient, moreover, to interpose a transmission between engine and ball screw. For this purpose, all known types of transmission in question, where only by way of example and not exhaustive planetary or worm gear, spur gears and belt or chain drives are listed. By using a transmission gear, for example, the axial displacement of the piston of the pump-side cylinder-piston unit can be accelerated and thus the height adjustment of the vehicle body done faster. Similarly, a fine adjustment of the height adjustment can be made possible or facilitated via a transmission gear as well.

It is also particularly advantageous to design the hydraulic or pneumatic line flexibly, since this results in even greater degrees of freedom with regard to the arrangement of the pump. Thus, the pump may be located at a suitable length of the hydraulic or pneumatic line, for example, in the engine compartment, which may continue, as mentioned above, the opportunity to drive this with another, additionally driving another device engine. Thus, it is not absolutely necessary that the pump itself includes its own engine. As eligible, the line forming material are mainly but not exclusively sufficient elastic rubber compounds can be led.

Locking means may be provided, preferably as electromagnetically controllable valves, advantageously also within the hydraulic or pneumatic line, wherein it is conceivable to arrange a plurality of locking means within the conduit. Through the use of such blocking means, the flow in the line can be interrupted or stopped, which further hinders the piston from axial movement. In addition, in this way the reflux of the working medium in the receiving space into the pump can be controlled or prevented. It is important that the blocking means in the form of valves are so-called two-way valves. Especially electromagnetically controllable valves are particularly useful because they are characterized by fast reaction times. Optionally, can be dispensed with by the use of blocking means within the line even on the above-mentioned, the motor associated locking means.

list of figures

• 1 eine teilweise geschnittene Prinzipdarstellung einer erfindungsgemäßen Vorrichtung zur Höhenverstellung eines Fahrzeugaufbaus mit dem Fahrzeugaufbau in einer ersten Höhenlage,
• 2 eine teilweise geschnittene Prinzipdarstellung einer erfindungsgemäßen Vorrichtung zur Höhenverstellung eines Fahrzeugaufbaus mit dem Fahrzeugaufbau in einer zweiten Höhenlage,
• 3 eine teilweise geschnittene Prinzipdarstellung einer dem Stellmittel zugeordneten Pumpe, und
• 4 eine dreidimensionale Ansicht einer erfindungsgemäßen Vorrichtung zur Höhenverstellung eines Fahrzeugaufbaus.

An embodiment of the invention is illustrated in the drawing and will be described in more detail below. Show it:

• 1 1 is a partially sectioned schematic representation of an inventive device for height adjustment of a vehicle body with the vehicle body in a first altitude,
• 2 1 is a partially sectioned schematic representation of a device according to the invention for adjusting the height of a vehicle body with the vehicle body in a second altitude,
• 3 a partially sectioned schematic representation of the adjusting means associated pump, and
• 4 a three-dimensional view of a device according to the invention for height adjustment of a vehicle body.

Detailed description of the drawings

1 represents a partially sectioned schematic representation of a device according to the invention 1 for height adjustment of a vehicle body 2 with the vehicle body 2 in a first altitude. The device 1 includes a between the vehicle body 2 and a not shown wheel carrier arranged strut 3 with one between an upper spring plate 4 and a lower spring plate 5 arranged spring 6 , The height adjustment of the vehicle body 2 is about an actuating means 7 , Which is a spatially separated from the strut hydraulic pump 8th includes, via an electrically powered engine 9 driven ball screw 10 operated, accomplished. The pump is visible 8th over a line 11 with a support plate 22 associated, between this and the upper spring plate 4 arranged recording room 12 connected to receive a hydraulic medium, which in all figures a common hydraulic oil is meant. The support plate 22 is about the actuating means 7 adjustable in height because it is linearly guided and relative to the upper spring plate 4 is movable, resulting in a total height adjustment of the vehicle body 2 results.

The recording room 12 is as a cylindrical annulus 14 formed, whose one bottom surface is closed. Therefore, the cylindrical annulus has 14 in the partially sectioned view according to 1 and 2 in the section shown here on a U-shaped profile. In the 1 and 2 extends the cylindrical annulus 14 from the support plate 22 in the direction of the upper spring plate 4 , where the upper spring plate 4 engages at least partially piston-like in these, which is why the cylindrical annulus 14 can also be understood as a cylinder of a cylinder-piston unit.

Under additional reference to 3 which is a partially sectioned schematic representation of the adjusting means 7 associated pump 8th shows, the inventive principle of operation of the device 1 for height adjustment of a vehicle body described in more detail. Inside the pump is the ball screw 10 , which a position-fixed, rotatable spindle 16 with a piston-like section 15 having. The piston-like section 15 can act as a piston of one of the pump 8th associated cylinder-piston unit to be understood, whose cylinder through one in the pump 8th slidably arranged cylindrical sleeve 17 is formed. At the engine ( 9 ) facing the end of the cylindrical sleeve ( 17 ) is rotatably on the inner wall of the ball screw 10 also associated mother 20 appropriate. Of course, the ball screw includes 10 continue between threads 16 and mother 20 rolling rolling elements 23 , Which are always located on a required return for the operation of a return line, not shown here. At the piston-like section 15 of the thread 16 is circumferentially arranged a sealing element in the form of an O-ring 18 For example, made of rubber, which prevents hydraulic oil can get behind the piston.

Will now be the engine 9 driven, this transmits over the drive shaft 19 a torque on the spindle 16 , this causes an axial, the pump room 21 decreasing movement of the mother 20 including cylindrical sleeve 17 along the rotating spindle 16 , The hydraulic oil gets out of the pump room 21 through the pipe 11 in the cylindrical annulus 14 pressed, causing the recording room 12 increases, causing an axial movement of the support plate 22 relative to the stationary upper spring plate 4 pulls. The vehicle construction 2 thus moves upwards. This position is in 2 shown, which is a partially sectioned schematic representation of a device according to the invention 1 for height adjustment of a vehicle body 2 with the vehicle body 2 in a second altitude, the second altitude being the vehicle body 2 higher than the first altitude. An even higher positioning of the vehicle body 2 is no longer possible, since it looks like 2 the bottom surface of the cylindrical sleeve can be seen 17 already up to the piston-like section 15 the pump 8th has moved.

Based on this, only a reduction of the vehicle body 2 respectively. This is achieved by the drive shaft 19 in opposite direction, causing the bottom surface of the cylindrical sleeve 17 from the spindle 16 or their piston-like section 15 away, the pump room 21 enlarging, is moved and it so to a return flow of the hydraulic oil from the cylindrical annulus 14 in the pump room 21 comes.

The device according to the invention 1 allows a stepless height adjustment of the vehicle body 2 , For this purpose, suitably not shown in detail, serving as a blocking means electromagnetically controllable valves in the line 11 arranged at any time via a corresponding control device, the flow of hydraulic oil from or into the pump room 21 can prevent, resulting in a determination of the vehicle body 2 at a desired height.

The engine 9 are also blocking means in the form of Schlingfedersperren not shown belonging to the associated output shaft 19 can block and thus the ball screw 10 or the axially displaceable piston-like portion 15 To block. This blocking means turns off the engine 9 the stroke set at that moment is immutable. In principle, it is expedient if the blocking means when the engine is switched off 9 blocking effect.

Between engine 9 and ball screw 10 is a preferred not shown in detail, serving as a transmission gear planetary gear, whereby a certain translation can be realized, which is particularly suitable when the engine 9 can not make enough or not enough speed.

A specific gear ratio of pump 8th to the actuating means 7 can also be adjusted or varied via the respective pump and adjusting means side cross sections. For example, with a particularly wide cross-section of the pump 8th or the pump room 21 compared to the adjusting means 7 associated cylindrical annular space 14 already a small axial adjustment of the piston-like section 15 inside the pump room 21 suffice for a comparatively large stroke of the vehicle body 2 in positive or negative direction, depending on the spindle 16 to effect applied torque.

Finally shows 4 a three-dimensional view of a device according to the invention 1 for height adjustment of a vehicle body 2 , based on which the physical separation of pump 8th to the strut 3 or the actuating means 7 is shown again clearly. The connection of the pump 8th with the actuating means 7 over the flexible line 11 allows the pump 8th basically freely selectable to arrange at a variety of locations within the vehicle and so to solve the problem of limited space in the area around the strut. Furthermore, it can be seen that the device according to the invention 1 is simple and largely no special, especially space-consuming, requires components.

Although not shown in the figures, it is also conceivable, in addition or alternatively, a receiving space between the lower spring plate 5 and one on the strut 3 positionally arranged support plate 13 to arrange and a line, not shown, with the pump 8th or a separate, again not shown pump to connect such that the lower spring plate 5 relative to the strut 3 positionally arranged support plate 13 is guided linearly movable, resulting in equal or additional height adjustment of the vehicle body 2 results.

Likewise in the 1 . 2 not shown, but conceivable, it may, as mentioned above, also be possible, a cylindrical annular space 14 alternatively or additionally between the lower spring plate 5 and one on the strut 3 positionally arranged support plate 13 to arrange. Accordingly, it would be conceivable in this case that the cylindrical annular space 14 from the strut 3 positionally arranged support plate 13 in the direction of the lower spring plate 5 extends and the lower spring plate 5 engages at least partially piston-like in this. Analogous to the above, a corresponding rotated by 180 ° arrangement would be possible, after which the cylindrical annulus 14 from the lower spring plate 5 towards the strut 3 positionally arranged support plate 13 extends, and one on the strut 3 positionally arranged support plate 13 associated piston-like projection at least in sections in the lower spring plate 5 intervenes.

Also, although not shown, based on the support plate side arrangement of the actuating means, rotated by 180 ° arrangement of the cylindrical annular space 14 conceivable, according to which the cylindrical annulus 14 from the upper spring plate 4 in the direction of the support plate 22 , opening to this, extends. In this case, one would be the support plate 22 associated piston-like projection at least in sections from above into the cylindrical annulus 14 intervention. The same applies to the arrangement of the actuating means between the lower spring plate and the suspension strut fixedly arranged support plate.

LIST OF REFERENCE NUMBERS

1

contraption

2

vehicle body

3

strut

4

spring plate

5

spring plate

6

feather

7

actuating means

8th

pump

9

engine

10

Ball Screw

11

management

12

accommodation space

13

Support plate

14

annulus

15

section

16

spindle

17

shell

18

O-ring

19

drive shaft

20

mother

21

pump room

22

Support plate

23

rolling elements

Claims (8)

Device for adjusting the height of a vehicle body comprising a arranged between the vehicle body and a wheel strut with a tensioned between an upper and a lower spring plate spring, wherein a spring plate or the vehicle body receiving support plate is adjustable in height via an adjusting means, characterized in that the Adjusting means (7) comprises a spatially separated from the strut (3) arranged pump (8) which is operated via a at least one motor (9) driven ball screw (10), wherein the pump (8) via a hydraulic or pneumatic line ( 11) with at least one linearly movably guided support plate (22) or the linearly movable guided spring plate (5) associated receiving space (12) for receiving a hydraulic or pneumatic medium is connected, wherein the ball screw (10) for actuating the piston movement of a piston the pump (8) associated cylinder R piston unit is used and the piston by the spindle (16) or the nut (20) of the ball screw (10) is formed. Device after Claim 1 , characterized in that the receiving space (12) either between the support plate (22) and the upper spring plate (4) is arranged, wherein the support plate (22) relative to the upper spring plate (4) is guided linearly movable, or the receiving space (12 ) between the lower spring plate (5) and a spring leg (3) fixedly arranged support plate (13) is arranged, wherein the lower spring plate (5) relative to the strut (3) fixedly arranged support plate (13) is guided linearly movable. Device according to one of the preceding claims, characterized in that the receiving space (12) as a cylindrical annular space (14) is formed. Device after Claim 3 , characterized in that the cylindrical annular space (14) from the support plate (22) in the direction of the upper spring plate (4) and the upper spring plate (4) engages at least partially piston-like in this, or that the cylindrical annular space (14) from upper spring plate (4) in the direction of the support plate (22) and a support plate (22) associated piston-like projection at least partially engages in these. Device after Claim 3 , characterized in that the cylindrical annular space (14) from the shock absorber (3) fixedly arranged support plate (13) in the direction of the lower spring plate (5) extends and the lower spring plate (5) engages at least partially piston-like in this, or that the cylindrical annular space (14) from the lower spring plate (5) in the direction of the strut (3) fixedly arranged support plate (13) and a the strut (3) fixedly arranged support plate (13) associated piston-like projection at least partially engages in these. Device according to one of the preceding claims, characterized in that the motor (9) via at least one blocking means, in particular a Schlingfedersperre or roller freewheel, can be blocked. Device according to one of the preceding claims, characterized in that between the motor (9) and ball screw (10) a transmission gear is interposed. Device according to one of the preceding claims, characterized in that the hydraulic or pneumatic line (11) at least one Blocking means, in particular an electromagnetic controllable valve comprises.

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