DE102019218060A1 - Stop buffering device with progressively increasing spring characteristics - Google Patents

Abstract

The invention relates to a stop buffering device (10; 40), in particular for a chassis of a motor vehicle, containing an elastically acting stop buffer element (12; 42) which is intended for attachment to a chassis (60) of a motor vehicle and for arrangement between the chassis (60) and a chassis of a motor vehicle is provided without getting into mechanical contact with the chassis in a normal load condition. According to the invention, the stop buffering device (10; 40) is equipped with a means for limiting an expansion of the stop buffer element (12; 42) in at least one direction which is perpendicular to a direction of action of a mechanical force exerted on the stop buffer element (12; 42) in a high-load state is.

Description

The invention relates to a stop buffering device according to the preamble of claim 1, in particular for a chassis of a motor vehicle, having an elastically acting stop buffer element which is intended for attachment to a chassis of a motor vehicle and for arrangement between the chassis and a chassis of a motor vehicle. The invention further relates to a rear wheel suspension system for the suspension of a rear part of a chassis of a motor vehicle according to the preamble of claim 10 with such stop buffering devices.

In the field of automotive engineering, it is known to use elastic spring elements between a body of a motor vehicle as a sprung object and wheels of the vehicle as unsprung objects in order to increase driving comfort for vehicle occupants by not transferring shocks caused by uneven floors directly to the body. Furthermore, a ground contact of the wheels, which is necessary for a power transmission, can also be ensured in the case of uneven ground. Vibrations of the body caused by uneven ground are dampened in a known manner by using shock absorbers which are arranged between the body and wheel axles. The elastic spring elements can, for example, be formed by elastic cylindrical, conical or barrel-shaped spiral springs and be an integral part of the shock absorber (spring-damper unit, suspension strut).

The elastic spring elements can, for example, also be formed by leaf springs or leaf spring arrangements in wheel suspensions. A leaf spring is generally designed as a curved elongated rod with a rectangular cross-section. For the production of leaf springs or leaf spring arrangements it is known to use steel or, in order to save weight, a composite material in the prior art. The leaf spring or the leaf spring arrangement can be arranged as a transverse leaf spring perpendicular to a straight-ahead driving direction of a vehicle or as a longitudinal leaf spring with its main direction of extent parallel to a straight-ahead driving direction of a vehicle.

One type of such wheel suspensions known from the prior art is the so-called Hotchkiss rear wheel suspension, in which the vehicle chassis and thus the vehicle body are resiliently supported against a rigid axle of a vehicle on both sides by means of longitudinal leaf springs or longitudinal leaf springs. Each of the longitudinal leaf springs is pivotably connected to the vehicle chassis at a front end. At a rear end, the longitudinal leaf springs are often pivotably connected to bracket elements, which in turn are pivotably connected to the vehicle chassis. A first, softer suspension is achieved with individual leaf springs. With the help of leaf spring or wave spring elements that are attached to the body structure, a second, more rigid suspension can be generated.

Regardless of an embodiment, a progressive characteristic curve of the springs used is desired for the suspension of motor vehicles in order to provide a high level of driving comfort with a normal load and a deflection of the suspension up to a deflection of the suspension with a high load, for example with an uneven road surface and / or a high weight load to be able to avoid an end stop so that potholes do not "penetrate" to the vehicle chassis. To achieve a progressive spring characteristic, various solutions have been proposed in the prior art, for example the use of further spring elements and / or elastic stop buffers which are fastened to the frame of the motor vehicle.

In addition, solutions have been proposed in the prior art which provide stop buffer elements for motor vehicles in connection with enabled rotary movements.

For example, describes the WO 2016/030638 A1 a motor vehicle suspension with a suspension stop with a movable sealing element, which is provided in particular for integration into a telescopic strut of a motor vehicle steering wheel.

The motor vehicle suspension stop has an upper shell, a lower shell and roller bodies arranged between the shells to enable their relative rotation, the shells being arranged so that they form at least one annular sealing chamber between them. The suspension stop further comprises a sealing element with two segments which are mounted so that they move within the sealing chamber with respect to a first and a second bearing surface, respectively, which are each formed on a shell. The first segment is attached to the first bearing surface for sliding sealing, the sliding seal being arranged to enable reversible movement of the sealing element into a position in which the second segment comes into sealed contact with the second bearing surface. According to one embodiment, a sliding friction contact can be established between a radial annular groove of an outer annular sealing chamber and the internally arranged second segment of the sealing element.

From the EP 3 219 521 A1 a suspension stop for a strut is known which includes a coil spring. The suspension stop includes a bearing and a cover with an underside having a contact zone with the bearing, the cover being provided with a snap-in zone. The suspension stop also has an integrally formed shell with an upper side which delimits a housing for the bearing with the lower side of the cover, and with a lower side with a circumferential annular support zone for an upper end of the helical spring. The circumferential annular support zone lies radially outside of the locking zone. The suspension stop also includes a mounting ring which is fixedly connected to the one-piece molded shell and has at least one complementary snap-in zone which protrudes radially in the direction of the snap-in zone of the lid in order to snap onto the snap-in zone of the lid. The cover can consist in a first section of a first material, which forms the contact zone with the bearing, and in a second, annular section, of a second material that differs from the first material. For example, a thermoplastic, optionally filled with glass fibers, can be used for the bearing part and a thermoplastic elastomer (TPE), in particular an elastomeric polyurethane (TPU), for the annular latching section. The mounting ring can be attached to the shell in a number of ways. In one embodiment, the mounting ring comprises a base that is molded into the molded plastic material of the shell. Alternatively, the mounting ring carries at least one elastically deformable lower fastening zone which is locked into at least one complementary fastening zone of the shell.

The US 9,010,741 B2 proposes a strut which is provided with a shock absorber comprising a damper rod, a spring, a suspension shock stop mounted around the damper rod and an elastic filter block arranged between the suspension shock stop and the body of a motor vehicle, in which the shock absorber is mounted, and the one May contain elastomer.

The suspension stop device has a roller bearing which forms an axial stop buffer which is equipped with an upper ring, a lower ring and a plurality of rolling elements which are arranged between the rings. The upper and lower rings are each carried by an upper plate and a lower plate, the lower plate forming a bearing means for a suspension spring. At least one sealing lip is provided on one of the plates so that it rests against a bearing surface section of the other plate. The bearing surface section is essentially cylindrical, with the sealing lip facing downward, facing away from the roller bearing, and bearing against said bearing surface section when it is radially influenced. The above-mentioned essentially cylindrical bearing surface section is connected at the top with a shoulder against which the sealing lip can rest when the two cups are radially eccentric to one another.

In one embodiment, the lower plate, which forms a bearing means for a suspension spring, includes a body and a reinforcing insert which is at least partially covered by the body, the body being made of one part made of a rigid material and one part made of a soft material is made, which includes the sealing lip. The soft material can be overmolded at least partially over the rigid material and at least partially over the reinforcement insert and contain an elastomeric material, for example a synthetic rubber such as polyurethane rubber.

The FR 2 899 154 B1 a solution for a suspension stop device for a suspension strut of a vehicle can be found, wherein the suspension strut is provided with a spring and a damping cushion. The device has a thrust bearing with a lower metal disk, which rotates relative to an upper metal disk, and a one-piece, stamped metal plate in which the cushioning pad is accommodated. The metal plate forms, on the one hand, a base which forms a contact surface with the damping cushion, and, on the other hand, an apron with a radial limitation for the damping cushion. The device also includes an intermediate support piece made of a synthetic material to transfer forces exerted by the cushioning pad and the spring to the lower metal disc. The intermediate support piece has an upper side which is equipped with an annular support area for the lower metal disk of the axial bearing. The intermediate support piece furthermore has an underside which forms an outer support shoulder which supports the spring, and an inner transverse shoulder which is connected directly to the bottom of the metal plate. An annular part made of an elastomer material rests on the outer support shoulder as a mechanical filter between the spring and the intermediate support piece.

From the US 7,934,579 B2 a suspension arrangement is known which includes an axle and an elastic element. The axle includes a first end and a second end and is movable with respect to a vehicle frame between an unloaded position and a loaded position. The resilient element is configured such that it is spaced from the axle and / or the frame when the axle is in the unloaded position. The elastic element is also configured to selectively progressively bias the axle towards the unloaded position. The elastic element can have a progressive characteristic curve and contain, for example, a stop buffer with a spring part and a cover part. The spring part can be formed from metal or some other suitable material, and the cover part can be formed from an elastomer (eg rubber) or from another material with elastic properties. The cover portion can define a hollow interior; but it can also be designed as a solid block of material (eg rubber).

The KR 20030006654 A describes a bumper of a vehicle suspension system which can achieve an excellent driving feeling by causing a soft contact of a bumper member and can improve durability by controlling the movement of the rear wheels. The bump stop of the vehicle suspension system includes a first bump stop element made of a soft material and a second bump stop element made of a material that is harder than the material of the first bump stop element. The second stop buffer element is shorter than the first stop buffer element and is arranged close to the first stop buffer element. When the rear wheels compress, the rear wheels contact the first bumper element. The first bumper element is deformed and the rear wheels touch the second bumper element. This prevents further compression of the rear wheels.

The US 8,505,887 B2 provides a microcellular polyurethane elastomer ("MCU") bumper / spring post that has a plurality of struts that are adjusted to provide consistent spring characteristics when sections are laid one on top of the other. MCU bumpers / spring supports are well known in the art to support vehicle suspension systems. In particular, bumpers / spring supports are often used in vehicle suspension systems in conjunction with shock absorbers and strut assemblies. In addition to influencing the control and driving behavior of the vehicle, these assemblies offer a pleasant driving experience. The struts are arranged around the perimeter of the MCU bumper / spring post. The additional struts between the undercuts partially support the outer surfaces of the MCU stop buffer / spring support. Struts are generally formed between the outer surfaces, but can also be molded onto an inner surface.

In the specialist article by John Miles, Insights into bump-stop tuning (available at https://www.vehicledynamicsinternational.com/features/insights-into-bump-stoptuning.html), February 01, 2018, is one of the greatest advantages of microcellular polyurethane elastomer (PU) has been described as having progressive and non-linear compressibility properties that allow greater travel for a given damper stroke and therefore the potential for efficient and minimal use of vertical packing space for struts and dampers.

In view of the state of the art shown, the area of stop buffering of wheel suspensions for motor vehicles still offers room for improvement.

The invention is based on the object of providing a stop buffering device, in particular for a chassis of a motor vehicle, which has a simplified structure and a progressive spring characteristic in order to enable a high level of driving comfort with low to normal mechanical loads and as a stop buffering in the case of high mechanical loads to serve that effectively and reliably prevents deflection of a suspension of the chassis up to a chassis of the motor vehicle.

According to the invention, the object is achieved by a stop buffering device with the features of claim 1. The object is also achieved by a rear wheel suspension system for the suspension of a rear part of a chassis of a motor vehicle according to claim 10. Further, particularly advantageous configurations of the invention are disclosed in the dependent subclaims.

It should be pointed out that the features and measures listed individually in the following description can be combined with one another in any technically meaningful manner and show further embodiments of the invention. The description additionally characterizes and specifies the invention, in particular in connection with the figures.

The stop buffering device according to the invention includes an elastically acting stop buffer element which is intended for attachment to a chassis of a motor vehicle and for arrangement between the chassis and a chassis of a motor vehicle without coming into mechanical contact with the chassis in a normal load condition. In the context of the invention, it should also be ruled out that the stop buffer element indirectly comes into mechanical contact with the chassis by means of an object arranged in between.

In this case, the stop buffering device is provided with a means for limiting an expansion of the stop buffer element in at least one Direction equipped, which is arranged perpendicular to a direction of action of a mechanical force exerted on the stop buffer element in a high load state.

In the context of the invention, a “normal load condition” is to be understood in particular as a load condition in which the chassis is statically loaded by the weight of the chassis and the body as well as by the driver and any vehicle occupants and luggage. In the context of the invention, a “high load state” is to be understood as meaning, in particular, a load state in which the chassis is deflected in a static or dynamic manner by the weight of the chassis and the body as well as by the driver and any vehicle occupants and luggage that may be present in the vehicle such that the stop buffer element and the chassis are in mutual mechanical system. In the context of the invention, it should also be included that the stop buffer element is indirectly in mutual mechanical contact with the chassis by means of an object arranged in between. In the context of the invention, the term “intended for this purpose” is to be understood in particular as being specifically designed or arranged.

Due to the limitation of the expansion of the stop buffer element in at least one direction perpendicular to the direction of action of a mechanical force exerted on the stop buffer element, a progressively increasing spring characteristic of the stop buffer element can be achieved.

The proposed stop buffering device can advantageously be used in particular for stop damping of a chassis of a motor vehicle. In the context of this invention, a “motor vehicle” is to be understood as meaning, in particular, a passenger car, a truck, a tractor or a bus.

In preferred embodiments of the stop buffering device, the stop buffer element is designed in the form of a straight truncated pyramid with a rectangular base and top surface which, when installed, faces the chassis of the motor vehicle. In this way, an effective stop buffer element with a particularly compact geometry can be achieved. Furthermore, because the stop buffer element first comes into mechanical contact with the chassis with the smaller top surface of the truncated pyramid when the mechanical load on the chassis increases, a particularly soft spring characteristic of the stop buffer element and thus a particularly high level of driving comfort can be achieved.

In other embodiments of the stop buffering device for applications in which saving installation space is not a priority, the stop buffer element can also be designed in the form of a straight truncated cone with a circular base, which, when installed, faces the chassis of the motor vehicle.

The means for limiting an expansion of the stop buffer element is preferably formed by an upwardly open cup element with a side wall, which is provided for attachment to the chassis of the motor vehicle. In this case, the opening of the cup element faces the stop buffer element in an installed state. The lateral dimensions of the wall of the cup element are matched to the lower lateral dimensions of the stop buffer element. For example, one lateral dimension or several lateral dimensions of the wall of the cup element can correspond to the lower lateral dimension or the lower lateral dimensions of the stop buffer element.

The terms “above” or “below” used in this application and word forms derived therefrom relate to an installed state of the buffer stop device.

Due to the lateral wall of the cup element, a lateral expansion of the stop buffer element is limited in the high-load state, as a result of which a desired, non-linearly progressive spring characteristic can be amplified.

The cup element and the stop buffer element are preferably arranged concentrically in an installed state, as a result of which a particularly simple installation position can be achieved. The cup element can preferably be made of a resistant metal, for example steel.

In preferred embodiments of the stop buffering device, the stop buffer element contains a predominant portion of a rubber-elastic material. Rubber-elastic materials naturally have a non-linear spring characteristic, so that the stop buffer element contributes to a desired, non-linear progressive spring characteristic in driving situations in which a particularly large deflection depth is achieved. Examples of rubber-elastic materials are elastomers, rubbers, natural and synthetic rubber and silicone rubber.

In the context of the invention, a “predominant proportion” should in particular mean a proportion of more than 50% by volume, preferably more than 70% by volume. % and, particularly preferably, more than 90% by volume. In particular, the term is intended to include the possibility that the stop buffer element consists completely, ie 100% by volume, of the rubber-elastic material.

A dimension of the cup element parallel to the direction of action of a mechanical force exerted on the stop buffer element in the high-load state preferably corresponds to a predominant proportion of the dimension of the stop buffer element in this direction and in the normal operating state. In this way, when the lateral dimensions or the lateral dimensions of the wall of the cup element are suitably matched to the lower lateral dimensions of the stop buffer element, an outside of the stop buffer element can be achieved before the high-load state is reached, ie in a load state in which the stop buffer element and the chassis are not yet in mutual mechanical contact, come into sliding contact with the wall of the cup element. Due to the then effective sliding friction on the wall of the cup element, the stop buffer element can contribute to a desired, non-linearly progressive spring characteristic.

Furthermore, an edge region of the opening of the cup element is preferably designed as a guide element for guiding a movement of the stop buffer element in the operating state. Centering of the stop buffer element during a movement in the operating state can thus be achieved in a structurally simple manner.

In preferred embodiments of the stop buffering device, the means for limiting an expansion of the stop buffer element is formed by at least one section which is connected in the direction of action of a mechanical force exerted on the stop buffer element in the high-load state and which contains an auxetic material.

In the context of the invention, an “auxetic material” should be understood to mean a material with a negative Poisson's number (Poisson's ratio). In the case of materials of this type, a surface pressure acting on a cross-sectional area causes a reduction in the cross-sectional area instead of an increase in cross-section which occurs with conventional materials.

If the stop buffer element comes into mechanical contact with the chassis with increasing mechanical load on the chassis and a surface pressure is effective on the cross-sectional area of the stop buffer element, the cross-sectional area is reduced, which results in a desired harder spring characteristic of the stop buffer element.

The at least one contiguous section preferably contains a multiplicity of layers made of the auxetic material. As a result, the auxetic property of the stop buffer element can be produced in a comparatively simple manner. In the context of the invention, the term “multiplicity” is to be understood in particular as a number of at least two.

The number of the multiplicity of layers made of the auxetic material is preferably between ten and 200, as a result of which a good compromise can be found between the desired auxetic properties of the stop buffer element and the effort required for production.

The auxetic material also preferably contains a predominant proportion of a polymeric plastic. In particular, the polymeric plastic can be designed as a thermoplastic plastic and / or as an elastomer.

As a result, the auxetic material of the stop buffer element or the entire stop buffer element can be produced by means of an additive manufacturing process, for example by 3D printing.

The layers of the plurality of layers made of auxetic material can preferably be designed as flat diamond fold structures. Preferably, the layers of the plurality of layers of auxetic material can have a 2.5-dimensional microstructural texture.

In a further aspect of the invention, a rear wheel suspension system is provided for the suspension of a rear part of a chassis of a motor vehicle, the motor vehicle including a rigid rear axle with a wheel carrier at each end of the rear axle. The rear wheel suspension system is equipped with an embodiment of the stop buffering device according to the invention arranged in an area of each of the rear wheels between the chassis and the rear axle of the motor vehicle, the respective stop buffer element being attached to the chassis of the motor vehicle. The advantages described in connection with the proposed stop buffering device can be fully transferred to the rear wheel suspension system.

• 1 eine schematische Darstellung einer Anschlagpufferungsvorrichtung eines Fahrwerks eines Kraftfahrzeugs in einem normalen Belastungszustand in einer geschnittenen Vorderansicht,
• 2 eine schematische Darstellung der Anschlagpufferungsvorrichtung gemäß der 1 in einem Hochlastzustand in derselben Ansicht,
• 3 eine schematische Darstellung einer alternativen Ausführungsform einer Anschlagpufferungsvorrichtung in einem normalen Belastungszustand und in einem Hochlastzustand in einer geschnittenen Vorderansicht, und
• 4 eine schematische, vergrößerte Darstellung des auxetischen Materials der Anschlagpufferungsvorrichtung gemäß der 3 in derselben Ansicht.

Further advantageous embodiments of the invention are disclosed in the subclaims and the following description of the figures. Show it

• 1 a schematic representation of a stop buffering device of a chassis of a motor vehicle in a normal load condition in a sectional front view,
• 2 a schematic representation of the buffer stop device according to FIG 1 in a high load state in the same view,
• 3rd a schematic representation of an alternative embodiment of a buffer stop device in a normal load condition and in a high load condition in a sectional front view, and
• 4th a schematic, enlarged representation of the auxetic material of the buffer stop device according to FIG 3rd in the same view.

In the different figures, the same parts are always provided with the same reference numerals, which is why they are usually only described once.

1 shows a schematic representation of a possible embodiment of a buffer stop device 10 of a chassis of a motor vehicle in a normal load condition in a sectional front view. The buffer stop device 10 is part of a rear wheel suspension system (not shown) for the suspension of a rear part of a chassis 60 of a motor vehicle. The motor vehicle includes a rigid rear axle with a wheel carrier at each end of the rear axle and each of the rear wheels is in an area with one between the chassis 60 and the stop buffering device arranged on the rear axle of the motor vehicle 10 according to the 1 fitted.

The buffer stop device 10 contains an elastic stop buffer element 12th . The stop buffer element 12th is in the form of a straight truncated pyramid with a rectangular base 14th and top surface 16 formed, the base area 14th in an installed state the chassis 60 of the motor vehicle is facing. The stop buffer element 12th is made entirely of a rubber-elastic material. Suitable materials are, for example, elastomers, rubbers and natural and synthetic rubber such as polyester-urethane rubber.

The stop buffer element 12th is by means of a fastening device on the chassis 60 of the motor vehicle attached. The fastening device includes a downwardly open shell element 18th with a rectangular inner base and a short side wall that protrudes essentially at right angles from the base. The shell element 18th is fixed to the chassis in this position 60 of the motor vehicle attached, for example by means of a welded connection. The stop buffer element 12th is with its base 14th in mechanical contact with the bottom of the shell element 18th and can for example be attached to the floor by an adhesive connection.

The buffer stop device 10 also has an upwardly open and upwardly widening cup element 20th with side wall 22nd and rectangular inner bottom 24 on. The cup element 20th is made of steel and firmly attached to the chassis (not shown) of the motor vehicle, for example by a welded connection. The opening 26th of the cup element 20th is in the in the 1 and 2 shown installed condition of the stop buffer element 12th facing. The cup element 20th and the bump stop element 12th are arranged concentrically. Lateral dimensions of the wall 22nd of the cup element 20th like the mutual distance between opposite sides of the wall 22nd and a width of the inner bottom 24 in the lateral Y-direction are on the lower lateral dimensions of the stop buffer element 12th matched in the X and Y directions. In the 1 and 2 two axes of a right-handed Cartesian coordinate system are given.

A marginal area 28 the opening 26th of the cup element 20th is used as a guide element for guiding a movement of the stop buffer element 12th formed in the operating state by being attached to the wall which initially widens obliquely upward 22nd of the cup element 20th an outward-facing, curved section 30th is integrally formed.

The stop buffer element 12th is between the chassis 60 and the chassis of the motor vehicle arranged without being in the normal load condition, which is in the 1 is shown with the chassis or the cup element 20th to get into mechanical system.

In the event of a static increase in the mechanical load acting vertically, ie parallel to the Z direction, on the chassis 60 , for example due to an increased payload, or in the event of a dynamic increase in the mechanical load on the chassis, for example when cornering, the distance in the vertical (Z) direction between the stop buffer element becomes 12th and the cup element 20th lower, and the bump stop element 12th first comes into mechanical contact with the wall 22nd of the cup element 20th . The one between the stop buffer element 12th and the wall 22nd of the cup element 20th occurring sliding friction contributes to a desired, non-linearly progressive Suspension characteristics of the buffer stop device 10 at.

A dimension of the cup element 20th parallel to the direction of action of the stop buffer element 12th The mechanical force exerted corresponds to a predominant proportion of the dimensions of the stop buffer element 12th in this direction and in normal operating condition. By designing the dimensions of the cup element 20th a contribution of the sliding friction to a desired, non-linearly progressive suspension characteristic of the stop buffering device 10 being controlled.

With a further increase in the mechanical load on the chassis 60 or the undercarriage reaches the deck 16 of the stop buffer element 12th finally in mechanical contact with the inner floor 24 of the cup element 20th . This high load state of the buffer stop device 10 is in the 2 shown. If the mechanical load is continuously increased parallel to the Z-direction, the cup element is used 20th as a means for limiting an expansion of the stop buffer element 12th in lateral directions that are perpendicular to a direction of action of the stop buffer element 12th exerted mechanical force are arranged, ie in both the X and Y directions.

Due to the limitation of the lateral expansion of the stop buffer element 12th a reinforcement of the desired, non-linear progressive spring characteristic is achieved.

3rd shows an alternative embodiment 40 the buffer stop device according to the invention in a normal load condition and in a high load condition in a sectional front view.

To avoid repetition, only differences between the alternative embodiment are described below 40 to the embodiment of the buffer stop device according to the invention 10 according to the 1 and 2 described.

The stop buffer element 42 the alternative stop buffering device 40 is made in its entirety from an auxetic material. The auxetic material has a plurality of layers 50a, 50b, 50c, of which in FIG 4th three layers are provided with reference numerals by way of example. The layers 50a, 50b, 50c can be produced, for example, from a thermoplastic material such as polyoxymethylene (POM) or acrylonitrile-butadiene-styrene (ABS) and, for example, individually by means of an additive manufacturing process such as a 3D printing process. The individual layers 50a, 50b, 50c are used to build the stop buffer element 42 firmly connected to one another at connection points 52a, 52b, 52c, which can be achieved, for example, by means of an adhesive process. In the 4th three of the connection points are provided with reference numerals by way of example. Each of the layers 50a, 50b, 50c has a 2.5-dimensional microstructural texture. The layers 50a, 50b, 50c are connected to one another by the connection points 52a, 52b, 52c in such a way that they form a plurality of diamond fold structures 54 form, whereby the auxetic property of the material can be achieved.

The stop buffer element 42 is thus formed from a continuous section of the auxetic material. In the normal load condition, the stop buffer element 42 the same shape as the embodiment 12th according to the 1 and 2 on. The stop buffer element 42 is by means of a fastening device on the chassis 60 of the motor vehicle attached. The fastening device includes a downwardly open shell element 48 with side walls and a rectangular inner bottom. The shell element 48 is fixed to the chassis in this position 60 of the motor vehicle attached, for example by means of a welded connection. The stop buffer element 42 is located with its base 44 in mechanical contact with the bottom of the shell element 48 and can be attached to this, for example, by an adhesive connection.

In the event of a static increase in the mechanical load acting in the Z direction on the chassis 60 or a dynamic increase in the mechanical load on the chassis first reaches the top surface 46 of the stop buffer element 42 in mechanical contact with the chassis (not shown), so that a surface pressure on the stop buffer element 42 acts whose amount depends on the top surface 46 up to the base 44 steadily decreases. Due to the auxetic properties of the bumper element 42 the surface pressure causes one of the top surface according to its amount 46 to the base 44 decreasing reduction in cross-sectional area. In the 3rd is the bump stop element 42 shown in a high load state with dashed lines.

The the bump stop element 42 The contiguous section formed from auxetic material thus constitutes a means for limiting an expansion of the stop buffer element 42 in lateral directions that are perpendicular to a direction of action of the stop buffer element 42 mechanical force exerted F. are arranged, ie in both the X and Y directions.

Due to the limitation of the lateral expansion of the stop buffer element 42 becomes a desired, non-linear progressive spring characteristic achieved.

List of reference symbols

10

Stop buffer device

12th

Bump stop element

14th

Floor space

16

Deck area

18th

Shell element

20th

Cup element

22nd

Wall

24

ground

26th

opening

28

Edge area

30th

curved section

40

Stop buffer device

42

Bump stop element

44

Floor space

46

Deck area

48

Shell element

50

layer

52

Junction

54

Diamond fold structure

60

chassis

F.

force

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• WO 2016/030638 A1 [0007]
• EP 3219521 A1 [0009]
• US 9010741 B2 [0010]
• FR 2899154 B1 [0013]
• US 7934579 B2 [0014]
• KR 20030006654 A [0015]
• US 8505887 B2 [0016]

Claims (10)

Stop buffering device (10; 40), in particular for a chassis of a motor vehicle, containing an elastically acting stop buffer element (12; 42) which is used for attachment to a chassis (60) of a motor vehicle and for arrangement between the chassis (60) and a chassis of a motor vehicle is provided without coming into mechanical contact with the chassis in a normal load state, characterized by a means for limiting an expansion of the stop buffer element (12; 42) in at least one direction which is perpendicular to a direction of action of a in a high load state on the stop buffer element ( 12; 42) exerted mechanical force is arranged. Stop buffering device (10; 40) according to Claim 1 , characterized in that the stop buffer element (12; 42) is designed in the form of a straight truncated pyramid with a rectangular base area (14; 44) which, when installed, faces the chassis (60) of the motor vehicle. Stop buffer device (10) according to Claim 1 or 2 , characterized in that the means for limiting an expansion of the stop buffer element (12) is formed by an upwardly open cup element (20) with a side wall (22) which is provided for attachment to the chassis of the motor vehicle, the opening (26 ) of the cup element (20) faces the stop buffer element (12) in an installed state, and the lateral dimensions of the wall (22) of the cup element (20) are matched to the lower lateral dimensions of the stop buffer element (12). Stop buffering device (10) according to one of the preceding claims, characterized in that the stop buffer element (12) contains a predominant portion of a rubber-elastic material. Stop buffering device (10) according to one of the preceding claims, characterized in that a dimension of the cup element (20) parallel to the direction of action of a mechanical force exerted on the stop buffer element (12) in the high load state is a predominant part of the dimension of the stop buffer element (12) in this direction and corresponds in normal operating condition. Stop buffering device (10) according to one of the preceding claims, characterized in that an edge region (28) of the opening (26) of the cup element (20) is designed as a guide element for guiding a movement of the stop buffer element (12) in the operating state. Stop buffering device (40) according to Claim 1 or 2 , characterized in that the means for limiting an expansion of the stop buffer element (42) is formed by at least one section which is connected in the direction of action of a mechanical force exerted on the stop buffer element (42) in the high-load state and which contains an auxetic material. Stop buffering device (40) according to Claim 7 , characterized in that the at least one contiguous portion includes a plurality of layers (50a, 50b, 50c) of the auxetic material. Stop buffering device (40) according to Claim 7 or 8th , characterized in that the auxetic material contains a predominant proportion of a polymeric plastic. Rear wheel suspension system for the suspension of a rear part of a chassis (60) of a motor vehicle, the motor vehicle including a rigid rear axle with a wheel carrier at each end of the rear axle, characterized by one in a region of each of the rear wheels between the chassis (60) and The stop buffering device (10; 40) arranged on the rear axle of the motor vehicle according to one of the preceding claims, the respective stop buffer element (12; 42) being fastened to the chassis (60) of the motor vehicle.

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