DE102019212624B3 - Additionally lowerable chassis suspension - Google Patents

Abstract

The invention relates to a lowerable chassis (10; 70) with an additional spring (18) which can be supported against a support section (20). It is provided that an operating configuration (46; 48) of the support section (20) can be changed in binary form, in order to either shorten (54; 56) telescopically (54; 56) in its longitudinal direction (30) or to impart compressive rigidity in its longitudinal direction (30) in an elongated state to the support section (20), bounded by a stop (66).

Description

The invention relates to a lowerable chassis suspension according to the preamble of claim 1, a chassis and a vehicle.

In the technical field of vehicles, in particular land vehicles, a common design consists in mounting a vehicle body on a chassis, via which contact with the ground is established. This is known in rail vehicles and in particular in road vehicles.

The chassis often has resilient properties compared to the ground, with spring force reserves being required from a certain point in the compression travel, usually towards the end of the compression travel. Therefore, such chassis are often designed with an additional spring on a progressive overall spring characteristic.

Often there is an additional requirement to lower the vehicle body via the suspension on the chassis, for example to ensure barrier-free access to the vehicle. Such vehicle bodies can usually be lowered by about 50 mm to 70 mm.

For example, describes the DE 10 2014 206 142 A1 a device for height adjustment of a vehicle body between an upper and a lower adjustment position.

Other known lowerable chassis suspensions include, for example, a spring-damper system in order to achieve the desired spring-damping properties with respect to the ground. In order to realize the lowerability, an air spring, for example, is used in such known lowerable chassis suspension. To implement the progressive overall spring characteristic, for example, an additional spring and a support section are used, with a damper of the spring-damper system being mounted on the support section and the additional spring being mounted between the damper and the support section in such a way that when a defined compression travel of the chassis suspension is reached a flow of force between the damper and the support section via the additional spring is enabled.

However, due to the additional spring, the desired lowerability is subject to technical limits, which can be undesirable with regard to accessibility.

The invention is based on the object of proposing such a lowerable chassis suspension with an additional spring that can be lowered significantly more than known solutions.

The object is achieved by the subject matter of the independent claims 1, 9 and 10. Further preferred embodiments of the invention emerge from the other features mentioned in the subclaims and the description.

• - ein Feder-Dämpfer-System;
• - eine Zusatzfeder; und
• - einen Stützabschnitt, wobei
• - ein Dämpfer des Feder-Dämpfer-Systems an dem Stützabschnitt gelagert ist und die Zusatzfeder derart zwischen dem Dämpfer und dem Stützabschnitt gelagert ist, dass bei Erreichen eines definierten Einfederwegs der Fahrwerksfederung ein Kraftfluss zwischen dem Dämpfer und dem Stützabschnitt über die Zusatzfeder ermöglicht wird.

A first aspect of the invention relates to a lowerable chassis suspension, comprising:

• - a spring-damper system;
• - an additional spring; and
• - A support section, wherein
• - A damper of the spring-damper system is mounted on the support section and the additional spring is mounted between the damper and the support section in such a way that when a defined compression travel of the chassis suspension is reached, a flow of force between the damper and the support section is enabled via the additional spring.

According to the invention it is provided that the support section comprises a contact element for the additional spring and a support element for the contact element, which are mounted with respect to a common longitudinal axis and can adjust the support section between a locked state and an unlocked state by rotating relative to one another around the longitudinal axis, the contact element and the support element can be placed rigidly against one another in the locked state in the direction of the longitudinal axis and, in the unlocked state, can shorten the support section by limited sliding into one another in the direction of the longitudinal axis.

In other words, an operating configuration of the support section can be changed in binary form in order to either shorten the support section, limited by a stop, telescopically in its longitudinal direction or to impart compressive rigidity in its longitudinal direction in an elongated state.

This offers the advantage that towards the end of the compression travel of the chassis suspension, which is normally provided in vehicle operation, when the additional spring is reached, the additional spring normally rests on the damper and the support section and generates a large counterforce, an additional lowering of the vehicle body relative to the ground is made possible by shortening the support section. If, for example, an air spring is used in the spring-damper system, it can simply be relaxed further.

The spring-damper system can, for example, be in the manner of a McPherson strut be formed or also comprise a spring and a damper, which are arranged separately from one another on different sections of a wishbone.

The additional spring is preferably designed for the spring of the spring-damper system in such a way that a progressive overall spring characteristic results.

The support section can preferably serve to connect the chassis to the vehicle, for example to the vehicle structure or a body. The damper can preferably be coupled to a wishbone of the chassis.

In a preferred embodiment of the lowerable chassis suspension of the invention, it is provided that the contact element and the support element abut one another at the ends in the locked state and can engage in one another like a claw in the unlocked state.

In other words, the contact element and the support element can, for example, comprise mutually complementary shaped features or also shaped recesses, wherein the shaped features can also be formed, for example, by the respective sections between the shaped recesses.

The shaped features of the contact element can, for example, engage in the shaped recesses of the support element or vice versa. The support section is brought into the unlocked state by the rotational movement of the contact element and / or the support element by aligning the respective moldings and mold recesses with one another so that they can be pushed into one another in the direction of the longitudinal axis. If, on the other hand, the respective shaped features and shaped recesses are not aligned with one another in this way, the respective end faces of the contact element and support element rest against one another and give the support section compressive rigidity in this locking state.

Preferably, the contact element and the support element are each designed like a sleeve. The shaped features and shaped recesses can then be produced simply by means of clearances in the respective jacket volume of the contact element and support element, which are preferably arranged at the same angular intervals in the jacket volume.

In the locked state, the contact element and support element are then supported on one another via a base or top surface of the respective sleeve shape. In the unlocked state, which can be assumed by rotating the base or top surfaces that are preferably in contact with one another, still existing shell volume sections of the contact element can dip into the complementary clearances of the support element (or vice versa) and the contact element and support element can thus be pushed axially into one another in sections. Corresponding form-fit surfaces, for example on the base of the clearances, are preferably used as stops.

Such an interaction, which is similar in principle to a claw coupling, can be achieved technically with little effort. At the same time, the support section can be subjected to extreme pressure loads both in its unlocked state and in its locked state and a change between the states can be easily achieved at the same time. The contact element and the support element are preferably secured in a suitable manner against undesired relative rotation in the locked state.

Thus, in a further preferred embodiment of the lowerable chassis suspension of the invention, it is provided that the support element has an external toothing by means of which it can be rotationally adjusted.

This enables not only a simple and precise adjustment, but at the same time also a protection against unwanted relative rotation, as mentioned above.

In a further preferred embodiment of the lowerable chassis suspension of the invention, it is provided that a pinion is provided which is in engagement with the external toothing.

In this way, the adjustment can be carried out simply, safely and precisely.

In a further preferred embodiment of the lowerable chassis suspension of the invention, it is provided that the pinion is adjustable by a motor or includes a tool attachment.

Both variants offer individual advantages. Adjustment using a tool is more cost-effective. Adjustment by means of a motor is, however, extremely flexible and, in particular, is to be regarded as preferred in connection with barrier-free vehicles, especially since vehicles are often not easily accessible from below in order to apply a tool.

In a further preferred embodiment of the lowerable chassis suspension of the invention, it is provided that the support section comprises a housing in which the contact element and the support element are mounted.

In this way, by suitable mounting, the support element and the contact element can advantageously be rotated relative to one another and axially displaced to one another to the extent described above without the two components being able to fall apart. In conjunction with a pinion for driving one of the two components, the housing can also be used to ensure that the driven part remains axially stationary and is securely in engagement with the pinion. The support element is preferably driven in rotation and the contact element is axially displaced.

When using a McPherson strut, the housing can preferably include the strut bearing. In addition to the additional spring, the contact element can preferably comprise a bearing, preferably a rubber bearing, for the damper piston. The bearing can preferably allow cardanic movements.

In a further preferred embodiment of the lowerable chassis suspension of the invention it is provided that a return spring is arranged between an inner wall of the housing and the contact element, which is able to apply a restoring force to the contact element in the direction of the longitudinal axis.

This offers the advantage that the shortening of the support section is reliably reversed when the vehicle body is raised again, so that the support section can be brought back into the locked state.

In a further preferred embodiment of the lowerable chassis suspension of the invention, it is provided that the chassis suspension can be lowered by at least 120 mm by shortening the support section.

By shortening the support section, a significantly greater lowering of the vehicle body is possible than in the prior art.

Another aspect of the invention relates to a chassis comprising a lowerable chassis suspension according to the invention according to the preceding description.

A further aspect of the invention relates to a vehicle comprising a chassis according to the invention according to the preceding description or a lowerable chassis suspension according to the invention according to the preceding description.

The vehicle is preferably a motor vehicle, particularly preferably an automobile and very particularly preferably a barrier-free accessible automobile. The term automobile includes both passenger and truck.

The various embodiments of the invention mentioned in this application can be advantageously combined with one another, unless stated otherwise in the individual case.

• 1A-B eine erfindungsgemäße absenkbare Fahrwerksfederung;
• 2A-B die prinzipielle Funktionsweise der absenkbaren Fahrwerksfederung aus den 1A und 1 B; und
• 3 ein erfindungsgemäßes Fahrzeug.

The invention is explained below in exemplary embodiments with reference to the accompanying drawings. Show it:

• 1A-B a lowerable chassis suspension according to the invention;
• 2A-B the basic functionality of the lowerable chassis suspension from the 1A and 1 B ; and
• 3 a vehicle according to the invention.

1A shows a lowerable chassis suspension according to the invention 10 . The chassis suspension 10 includes a spring-damper system 12 , where in 1A only its damper 14th is shown. The associated spring can for example be parallel to the damper 14th between vehicle body 16 (compare 3 ) and a wishbone, not shown, act or with the damper 14th cooperate in the manner of a McPherson strut.

The lowerable chassis suspension 10 furthermore comprises an auxiliary spring 18th and a support portion 20th .

The damper 14th is on the support section 20th stored and the additional spring 18th is between the damper 14th and the support section 20th stored.

Here is, purely as an example, the additional spring 18th on a damper piston 22nd pushed up and up through the support section 20th limited in their movement and downwards by a piston plate 24 limited in their movement. Also, purely by way of example, one on the support section can also be used 20th attached additional spring 18th be provided.

The support section 20th includes a contact element 26th for the additional spring 18th and a support member 28 for the investment element 26th . The investment element 26th and the support element 28 are with respect to a common longitudinal axis 30th stored and can be rotated relative to each other around this.

The investment element is purely exemplary 26th and the support element 28 executed like a sleeve here. In the present case, only the support element is purely exemplary 28 rotatable.

The rotating support element here 28 has an external toothing 32 on, over which it is rotatably adjustable.

The following is based on 1B Reference where the same lowerable chassis suspension 10 is shown as in 1A .

In addition to the in 1A components shown is in 1B a pinion 34 shown that with the external teeth 32 is engaged. The pinion 34 can take a tool approach 36 or, as in this example, via a motor 38 be adjustable.

In addition, in 1A an additional housing 40 shown. The investment element 26th and the support element 28 are with the engine 38 and the pinion 34 in the case 40 stored in such a way that the interactions described above are possible. The case 40 is illustrated transparently to represent these components.

The case 40 can preferably have a connection 42 to the vehicle body 16 include. The 2A and 2 B now show the principle of operation of the lowerable chassis suspension according to the invention 10 from the 1A and 1 B . To simplify the illustration, the housing is 40 in the 2A and 2 B Not shown.

The investment element 26th and the support element 28 can by relative rotation 44 around the longitudinal axis 30th cause the support section 20th between a locked state 46 ( 1A , 1B , 2A) and an unlocked state 48 is adjusted.

In the locked state 46 ( 1A , 1B , 2A) are the investment element 26th and the support element 28 in the direction of the longitudinal axis 30th rigidly attached to each other. This is the support section 20th in the direction of the longitudinal axis 30th very rigid. In the example shown, the contact element is located 26th and the support element 28 face to face. The contact element which is designed like a sleeve here 26th and support element 28 are correspondingly each with a base area 50 to each other.

In this locked state 46 can do the spring-damper system 12 work conventionally and, for example, until a defined compression travel is reached 52 deflect or be lowered. When reaching the defined compression travel 52 hits the piston plate 24 on the additional spring 18th . This creates a flow of force between the damper 14th and the support section 20th via the additional spring 18th enables. Cushions the chassis suspension 10 then even further along the compression travel 52 one or the vehicle body 16 lowered further, the additional spring leads 18th to a changed overall spring characteristic or a counterforce.

Should the vehicle body 16 are nevertheless further lowered, this can be achieved by the invention in that the support section 20th in the unlocked state 48 is brought ( 2 B) .

To achieve this, we proceed from the locked state 46 ( 2A) , here the support element 28 around the longitudinal axis 30th to the rotationally immobile contact element 26th twisted. The engine is an example of this 38 driven.

In the unlocked state 48 are the support element 28 and the investment element 26th rotated into a relative orientation in which they are no longer rigidly attached to one another. If you compare the 2A and 2 B , it can be seen that this is achieved in the present example in that the support element 28 and the investment element 26th in 2 B no longer on the face with their base 50 lie against each other. Rather, the support element 28 and the investment element 26th in the direction of the longitudinal axis 30th by nesting 54 to shift towards each other (see 2 B) . The support section 20th can thereby be shortened and one of the shortening 56 corresponding additional lowering of the vehicle body 16 enable.

The investment element 26th and the support element 28 are designed here so that they are in the unlocked state 48 can interlock like claws. For this purpose, the sleeve-like contact element 26th and support element 28 mutually complementary shaped recesses 58 and shapes 60 on. An angular offset 62 between the alternating recesses 58 and shapes 60 that both on the plant element 26th as well as on the support element 28 are provided corresponds to the rotation 44 . One twist 64 of the motor 38 may differ due to the translation.

The shortening 56 is limited by the shape characteristics 60 when sliding into one another 54 at some point on land 66 of the complementary shaped recesses 58 to meet.

In this example the shortening is 56 of the support section 20th and thereby the lowering of the chassis suspension 10 at least 120 mm.

To return safely from the in the right part of the 2 B shortened condition shown in 2A To ensure the initial state shown, can preferably between an inner wall of the housing 40 out 1B and the here axially displaceable contact element 26th a return spring can be arranged in the direction of the longitudinal axis 30th a restoring force on the contact element 26th able to muster.

In 3 is a vehicle according to the invention 68 shown that a lowerable chassis suspension according to the invention 10 includes, which is part of a chassis here 70 is.

List of reference symbols

10

Chassis suspension

12

Spring damper system

14th

mute

16

Vehicle body

18th

Additional spring

20th

Support section

22nd

Damper piston

24

Piston plate

26th

Investment element

28

Support element

30th

Longitudinal axis

32

External toothing

34

pinion

36

Tool approach

38

engine

40

casing

42

Connection

44

rotation

46

Locking state

48

Unlocked state

50

Floor space

52

Suspension travel

54

Push into one another

56

Shortening

58

Form recess

60

Shape expression

62

Angular misalignment

64

rotation

66

Floor space

68

vehicle

70

landing gear

Claims (10)

Lowerable chassis suspension (10), comprising: - a spring-damper system (12); - An additional spring (18); and - a support section (20), wherein - a damper (14) of the spring-damper system (12) is mounted on the support section (20) and the additional spring (18) in this way between the damper (14) and the support section (20) ) is mounted so that when a defined compression travel (52) of the chassis suspension (10) is reached, a flow of force between the damper (14) and the support section (20) via the additional spring (18) is enabled, characterized in that the support section (20) a contact element (26) for the additional spring (18) and a support element (28) for the contact element (26), which are mounted with respect to a common longitudinal axis (30) and by relative rotation (44) about the longitudinal axis (30) Support section (20) between a locked state (46) and an unlocked state (48) can be adjusted, wherein the contact element (26) and the support element (28) in the locked state (46) can be placed rigidly against one another in the direction of the longitudinal axis (30) and in the unlocked state can shorten the support section (20) by limited sliding one inside the other (54) in the direction of the longitudinal axis (30). Lowerable chassis suspension (10) according to Claim 1 , characterized in that the contact element (26) and the support element (28) in the locked state (46) abut one another at the front and can engage in one another like a claw in the unlocked state (48). Lowerable chassis suspension (10) according to one of the preceding claims, characterized in that the support element (28) has an external toothing (32) by means of which it can be rotationally adjusted. Lowerable chassis suspension (10) according to Claim 3 , characterized in that the one pinion (34) is provided which meshes with the external toothing (32). Lowerable chassis suspension (10) according to Claim 4 , characterized in that the pinion (34) is adjustable by a motor (38) or comprises a tool attachment (36). Lowerable chassis suspension (10) according to one of the preceding claims, characterized in that the support section (20) comprises a housing (40) in which the contact element (26) and the support element (28) are mounted. Lowerable chassis suspension (10) according to Claim 6 , characterized in that a return spring is arranged between an inner wall of the housing (40) and the contact element (26), which is able to apply a restoring force to the contact element (26) in the direction of the longitudinal axis (30). Lowerable chassis suspension (10) according to one of the preceding claims, characterized in that the chassis suspension (10) can be lowered by at least 120 mm by shortening (56) the support section (20). Chassis (70), comprising a lowerable chassis suspension (10) according to one of the preceding claims. Vehicle (68) comprising a chassis (70) according to Claim 9 or a lowerable chassis suspension (10) according to one of the Claims 1 to 8th .

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