CN110525372B - Damping element and arrangement of a damping element on a body element of a motor vehicle - Google Patents

Abstract

The invention relates to a damping element for a front or rear hood of a motor vehicle and to an arrangement of such a damping element on a body element of a motor vehicle. The invention relates to a damping element (16) for a front cover (10) or a rear cover of a motor vehicle, comprising a base body (30) extending in the longitudinal extension direction, a force-receiving surface (32) arranged at an end of the base body, and a fastening section (36) arranged in a region spaced apart from the end and extending at least partially radially outward relative to the base body, for fastening the base body to an element of the motor vehicle, wherein at least one predetermined breaking point (42) is provided on the fastening section (36) and/or the base body (30) in such a way that it breaks when a limit load is exceeded and allows a relative movement of the base body (30) relative to the fastening section (36). The force receiving surface (32) is designed as a force receiving surface (32) serving as a contact surface (34), and both the force receiving surface (32) and the fastening section (36) having the rated breaking point (42) are designed in one piece with the base body (30).

Description

Damping element and arrangement of a damping element on a body element of a motor vehicle

Technical Field

The invention relates to a damping element for a front or rear hood of a motor vehicle and to an arrangement of such a damping element on a body element of a motor vehicle.

Background

DE 102010026725 a1 discloses a damping element which is composed of a damping body, an outer sleeve, an inner sleeve, a base part and a locking ring in a multi-component manner and requires complex assembly. Optionally, a braking ring and foil arrangement is also described in relation to the cushioning element. Provided on the base part of the damping element are inner, middle and outer predetermined breaking points which should break in succession when a force acts axially on the damping element (as occurs in a pedestrian impact), wherein with each break a partial element of the damping element penetrates into the base part.

DE 102005012773 a1 discloses a stop buffer for a front hood of a motor vehicle, which is plastically deformed in the vertical direction above a defined limit load (as occurs in a pedestrian collision). The stop damper is likewise of multi-part design and essentially comprises a damping element with a threaded rod and a receptacle into which the damping element is screwed. In order to at least partially break the receptacle when the extreme load is exceeded, so that the damping element can be displaced relative to the front cover and no longer acts as a stop for the closed front cover, a predetermined breaking point is provided in the flange-like section of the receptacle. The stop buffer is fixed to the front cover of the vehicle. No damping element is disclosed which interacts with the stop damper.

A disadvantage of the damping elements known from the aforementioned patent documents is that they entail high production, logistics and installation costs due to the multiple component and the required installation effort.

Disclosure of Invention

The object of the present invention is to provide a damping element for a front or rear hood of a motor vehicle, which achieves high-quality pedestrian protection and can nevertheless be produced simply and cost-effectively.

The invention is based on a damping element for a front or rear hood of a motor vehicle and an arrangement of such a damping element on a body element of a motor vehicle.

The invention relates to a damping element for a front or rear cover of a motor vehicle, comprising a base body extending in a longitudinal direction, a force-receiving surface arranged at an end of the base body, and a fastening section arranged in a region spaced apart from the end and extending at least partially radially outward relative to the base body for fastening the base body to an element of the motor vehicle, wherein at least one predetermined breaking point is provided on the fastening section and/or on the base body in such a way that the predetermined breaking point breaks when a critical load is exceeded and allows a relative movement of the base body relative to the fastening section. The force receiving surface is designed as a force receiving surface serving as a contact surface, and the force receiving surface and the fastening section with the rated breaking point are both designed in one piece with the base body. The damping element according to the invention can thus be produced simply and inexpensively, i.e. in particular as a plastic part. This applies primarily to the case where a large number of such damping elements are required and the plastic parts are produced in large quantities by the plastic injection molding method. This eliminates a separate installation process and also simplifies logistics and maintenance, since the damping element can be simply inserted as a whole and replaced again as a whole.

In a further practical embodiment, the fastening section has a fastening ring spaced radially from the base body, and at least one web extending between the fastening ring and the base body is provided as the predetermined breaking point. In this case, the securing ring can advantageously be used not only as a securing element, but, when the predetermined breaking point is appropriately arranged, the securing ring can also be used in the event of a failure as a guide ring, by means of which a base body that is released after the predetermined breaking point has failed and is thus able to move relative to the securing ring is prevented from twisting and thus unlimited penetration of the securing ring can be prevented.

In connection with this, it is also pointed out that a damping element for a front or rear cover of a motor vehicle is also claimed, comprising a base body extending in a longitudinal direction, a force-receiving surface arranged at an end of the base body, and a fastening section arranged at a distance from the end and extending at least partially radially outward relative to the base body for fastening the base body to a body element of a motor vehicle, wherein at least one predetermined breaking point is formed on the fastening section and/or the base body, such that the predetermined breaking point breaks when a limit load is exceeded and the base body is allowed to move relative to the fastening section, with the proviso that the fastening section has a fastening ring spaced radially from the base body, and at least one web extending between the fastening ring and the base body is provided as a predetermined breaking point. In this case, it is not necessarily required that the force receiving surface is designed as a force receiving surface serving as a contact surface and that the force receiving surface and the fastening section with the rated breaking point are designed in one piece with the base body. It is therefore also possible to additionally arrange a separate element, for example in the form of a rubber buffer, in the region of the force-receiving surface in order to locally increase the damping in the region of the contact surface of the buffer element at the end of the bearing element facing the front or rear cover and thus to improve the acoustic operating performance and to reduce component vibrations. This applies analogously to the fastening region, in particular in the region of contact with the body element of the motor vehicle, i.e. in the region of the fastening section which is permanently in contact with other elements or which may be in contact with other elements when the motor vehicle is used as intended, for example in the case of poor road sections or when strong body vibrations occur temporarily due to uneven traffic lanes.

In a further practical embodiment of the damping element according to the invention, the fastening ring and the at least one predetermined breaking point are formed integrally with the base body. Reference is again made to the advantages associated therewith, in particular when the plastic part is produced in one piece, which have already been explained above.

Further advantages with regard to the installation of the damping element according to the invention can be achieved if at least one guide rib extending in the longitudinal direction is formed on the base body at least over a part of its length. Preferably, a plurality of guide ribs are distributed in the circumferential direction of the base body and are each designed parallel to one another. The guide ribs can advantageously be used to adapt the outer geometry of the base body in the region below the securing ring to the contour of the opening in which the damping element is to be secured. Preferably, a rib is provided which extends in the longitudinal direction of the damping element and whose outer dimensions are adapted to the inner contour or inner dimensions of the respective opening. Such a guide rib preferably extends only over a portion of the length of the damping element according to the invention, said portion being oriented from the fastening ring in the direction of the end opposite the force receiving surface.

In principle, any fastening element can be provided on the damping element, in particular on its base body, in order to fasten the base body and/or the fastening section to a body element of the motor vehicle. Preferably, at least one elastically designed clamping element is designed on the base body, which clamping element allows a simple latching of the damping element to a body element of the motor vehicle. Preferably, two or more clamping elements are provided distributed over the outer circumference of the base body of the damping element according to the invention, wherein preferably only two clamping elements are provided on opposite sides of the base body.

In a further practical embodiment, the base body of the damping element according to the invention has a circular cross-sectional geometry in a direction transverse to the longitudinal extension. A circular cross-sectional geometry is to be understood to mean, in particular, a circular, oval or otherwise shaped cross-sectional shape, i.e. a cross-sectional shape which does not contain mathematical discontinuities, i.e. only curves and no edges. This configuration has the advantage that, in particular after failure of at least one or more predetermined breaking points and subsequent penetration of the base body by the securing ring, the risk of the damping element being deflected and the resulting risk of the base body becoming stuck relative to the securing ring can be reduced or almost completely avoided.

In a further practical embodiment of the damping element according to the invention, a rotation-blocking element projecting in the longitudinal direction of extension is formed on the base body or on the fastening section. In this case, these may be, in particular, corresponding recesses which interact with complementarily designed recesses or complementarily designed projections in the openings of the body element. This has the advantage that, in particular in the case of damping elements having a circular or oval cross-sectional geometry, torsional installation of the damping element according to the invention can be effectively avoided. This is important in particular if the elements are not of symmetrical design and therefore, when the component is inserted in a twisted manner, an incorrect orientation of the force receiving surface or of the force receiving surface serving as a contact surface occurs.

As already mentioned, the base body of the damping element according to the invention is preferably made of plastic. This applies in particular to the fastening portion and the force receiving surface when the damping element according to the invention is produced in one piece.

In a preferred embodiment of the damping element according to the invention, the length of the base body extending in the longitudinal direction corresponds to a multiple of the length of the fastening ring extending in the same direction. In this case, a large deformation path can be provided by the base body, in particular for receiving forces in the event of a pedestrian collision, in particular if the base body extends from the fastening ring mainly in the longitudinal direction in the direction of the force receiving surface.

The invention also relates to an arrangement of a damping element, in particular as described above, on a body element of a motor vehicle, having a fastening opening, wherein the damping element has a clamping element and a fastening ring, wherein the clamping element and the fastening ring form a fastening region extending over a fastening height F, which fastening region is adapted to the material thickness of a wall of the body element surrounding the fastening opening in such a way that the wall is enclosed by the clamping element and the fastening ring and the damping element is held in a rotationally fixed manner (drehstab) relative to the body element. This makes it possible to achieve a simple assembly in a simple and cost-effective manner and at the same time a reliable arrangement of the damping element according to the invention on the motor vehicle. In a suitable embodiment, the mounting can be achieved in particular by inserting the lower section of the base body into the fastening opening of the body element until at least one clamping element, preferably two clamping elements or more clamping elements, snap-lock with the fastening opening. For this purpose, it is sufficient in a suitable embodiment for the damping element according to the invention to be introduced into the fastening opening with a sufficiently high force in the longitudinal extension direction thereof until the clamping element or the clamping elements are elastically deflected and latched with the fastening opening. By body element is meant in particular body elements other than front covers or rear covers, which serve as a support for the front covers or rear covers, for example a carrier element, such as a lock bracket or a cross member, in the region of the front compartment or rear compartment of the motor vehicle.

Drawings

Other practical embodiments of the present invention will be described below with reference to the accompanying drawings. In the drawings:

fig. 1 shows a front hood of a motor vehicle from below, with a transverse member arranged on the front side and two support elements arranged on the transverse member;

fig. 2 shows a detail of a front compartment of a motor vehicle, on which the front cover shown in fig. 1 can be mounted, in a perspective view from diagonally in front and above, with a cushioning element corresponding to the support element, but without the front cover shown in fig. 1;

fig. 3 shows only the lock frame with two damping elements in a perspective view from obliquely in front and above;

fig. 4 shows a detail of a front cover with a bearing element arranged thereon, which bearing element rests on a damping element in the closed state of the front cover;

FIG. 5 illustrates an exemplary view of the failure characteristics of the cushioning element of FIG. 4;

fig. 6 shows a perspective view of a first embodiment of the damping element according to the invention;

FIG. 7 illustrates the cushioning element of FIG. 6 in a side view;

fig. 8 shows the damping element of fig. 6 and 7 in a view from above;

fig. 9 shows a second embodiment of the damping element according to the invention from below;

fig. 10 shows the damping element from fig. 9 in a view from above;

fig. 11 shows the damping element from fig. 9 and 10 in a perspective side view;

fig. 12 shows a lock bracket with a recess for a damping element according to the invention and

fig. 13 shows the region of the lock holder with the recess, which region is designated XIII in fig. 12, in an enlarged view.

Detailed Description

Fig. 1 shows a front hood 10 of a motor vehicle, not shown, from below. The longitudinal direction of the vehicle is indicated by x in fig. 1 and in all other figures, the transverse direction of the vehicle is indicated by y and the height direction of the vehicle is indicated by z. Correspondingly, the terms x-direction, y-direction and z-direction are also used analogously to the terms vehicle longitudinal direction, vehicle transverse direction and vehicle height direction.

As can be seen from fig. 1, a transverse member 12 is arranged on the motor vehicle front side of the front flap 10 and is fixedly connected to the front flap 10. Two support elements 14 can be seen on the outside of the transverse beam 12. The support element 14 and also two further support elements 14, which are arranged directly on the front hood 10 and are arranged further to the rear and further to the outside on the front hood 10, as viewed in the vehicle longitudinal direction (x direction) and the vehicle transverse direction (y direction), interact with a damping element 16 designed according to the invention, the position of which damping element 16 on a front compartment 18 of the vehicle being visible in fig. 2.

The damping element 16, which is further arranged on the front side of the motor vehicle, is arranged on a lock bracket 20, which is arranged behind a bumper cross member 22 in the region of the front compartment 18.

Fig. 3 shows only in an enlarged view the lock bracket 20 with two damping elements 16, which are arranged on the front side of the motor vehicle and are shown in fig. 2. In fig. 3, it can be seen that the lock bracket 20 is formed in the embodiment shown from a metal profile 24 which comprises a sprayed-on plastic element 26. A fastening opening 28 is provided in the plastic element 26 of the lock frame 20, said fastening opening 28 being clearly visible in fig. 12. In each fastening opening 28, a damping element 16 is inserted, wherein the arrangement of the damping element 16 relative to the lock frame 20 and the front cover 10 with the support element 14 can be clearly seen in fig. 4 and 5. Before describing the arrangement in detail, some geometrical details of the damping element 16 according to the invention are described with reference to fig. 6 to 8.

As can be seen particularly clearly in fig. 6 and 7, the damping element 16 according to the invention comprises a base body 30 which extends in the longitudinal extension direction L, a force receiving surface 32 which is arranged at the upper end of the base body 30 in fig. 6 and 7 and serves here as a contact surface 34 with the bearing element 14, and a fastening section 36 which extends radially outward relative to the base body 30 and serves for fastening the base body 30 to a body element, for example the lock bracket 22 shown in fig. 2 to 5. The fastening section 36 is designed here as a circular fastening ring 38 and is connected to the main body 30 by four webs 40 distributed over the circumference and designed as predetermined breaking points 42.

As can be seen from fig. 6 to 8, guide ribs 44 which extend downward from the fastening ring 38 and are oriented in the longitudinal direction of the main body 30 are also formed on the main body 30. The guide ribs 44 extend radially outward from the base body 30. The guide ribs serve to center the base body 30 relative to the fastening opening 28 when the damping element 16 is installed, i.e., when it is inserted into the fastening opening 28, and thus to improve the orientation of the damping element 16 relative to the lock bracket 20 or other body elements of the motor vehicle.

As can be seen clearly in fig. 6 and 8, the base body 30 has a circular cross-sectional geometry with a radius r perpendicular to the longitudinal extension direction L.

In the region below the fastening ring 38, two clamping elements 48 are provided on opposite sides of the base body 30, one of the clamping elements 48 being visible in each case in fig. 6 and 7.

Extending longitudinally downward from the securing ring 38 is a rotation-blocking element 50 which interacts with a recess 52, which is shown in fig. 13 as a detail of the securing opening 28. This ensures that the damping element 16 is only correctly oriented and mounted in the fastening opening 28 and that incorrect arrangements are reliably avoided.

Fig. 9 to 11 show a further embodiment of a damping element 16 according to the invention, wherein the same reference numerals are used for identical or at least functionally identical elements as in the other figures. The main difference between the further embodiments shown in fig. 9 to 11 is that the base body 30 has an oval or elliptical cross-sectional geometry. Furthermore, the webs 40 designed as the rated breaking points 42 are not distributed uniformly in the circumferential direction, but rather the rated breaking points 42 are each arranged in the region of a long side of the oval basic body 30.

It should also be noted that in the embodiment of the damping element 16 shown in fig. 9 to 11, four guide ribs 44 are arranged approximately uniformly distributed in the circumferential direction. The guide ribs 44 are provided in the lower region with chamfers 46 for easier insertion of the base body 30 into the fastening opening 28.

As can be seen in fig. 4, the support element 14 rests on the contact surface 34 of the damping element 16 when the front flap 10 is closed and the motor vehicle is used as intended.

If, for example, in the event of a pedestrian collision, the force acting on the front cover 10 increases from above in the direction of the damping element 16, the predetermined breaking point 42 is designed in the damping element 16 according to the invention in such a way that it fails and the base body 30 of the damping element 16 can move relative to the fastening ring 38. The base body 30 can then be lowered downward through the retaining ring 38 as shown in fig. 5 (see the position of the base body 30' shown in dashed lines). This results in a large deformation path which is advantageous for absorbing energy and reducing the load on the head of the pedestrian.

The invention is particularly suitable for arrangements with a front cover which is of three-component or multi-component design and has a reinforcing element, in particular a cross member, as a separate element in the region of the front side of the motor vehicle in order to increase the rigidity of the front cover 10.

With regard to the overall height H of the damping element 16, reference is made to a preferred height of between 20 and 80mm, in particular between 20 and 60 mm. Particularly preferred are heights H of about 30mm + -5 mm and about 40mm + -5 mm. In practice, it has been found that with these two dimensions, the damping element 16 can be realized for almost all vehicle types of vehicle manufacturers. In the region of the force application surface, in particular when the force application surface is designed as a contact surface, the material thickness of the damping element 16 according to the invention is at least 2mm, preferably at least 2.5mm and particularly preferably at least 3 mm. In the remainder, the material thickness is preferably between 1mm and 3mm, particularly preferably less than 2 mm. For example, the material thickness may be 1.8mm in all other regions. In the region of the intended breaking point, a smaller material thickness is preferred, in particular a value of 1.5mm or less.

As dimensions of the force-receiving surface, in particular when the force-receiving surface is used as a contact surface, values between 20 × 20mm and 60 × 60mm are particularly preferred. Values of, in particular, 30X 50mm have proven particularly suitable here.

The features of the invention disclosed in the description, the figures and the claims can be essential for the implementation of the invention in its different embodiments, individually or in any combination. The invention may vary within the scope of the claims and taking into account the knowledge of a person skilled in the art.

List of reference numerals

10 front cover

12 crossbeam

14 support element

16 buffer element

18 front carriage

20 lock rack

22 Bumper Beam

24 shaped part

26 Plastic element

28 fixed opening

30 base body

32 force bearing surface

34 contact surface

36 fixed section

38 fixed ring

40 lath

Rated fracture site of 42

44 guide rib

46 chamfered edge

48 clamping element

50 torsion stop element

52 recess

Claims (8)

1. A damping element for a front cover (10) or a rear cover of a motor vehicle, having a base body (30) extending in a longitudinal extension direction, a force receiving surface (32) arranged at an end of the base body (30), and a fastening section (36) arranged at a distance from the end and extending at least partially radially outward relative to the base body (30) for fastening the base body (30) to a body element of the motor vehicle, wherein at least one predetermined breaking point (42) is designed on the fastening section (36) and/or on the base body (30) such that it breaks when a limit load is exceeded and allows a relative movement of the base body (30) relative to the fastening section (36), wherein the force receiving surface (32) is designed as a force receiving surface (32) serving as a contact surface (34), and the force-receiving surface (32) and the fastening section (36) with the predetermined breaking point (42) are designed in one piece with the base body (30),

the fastening section (36) is designed as a fastening ring, and the base body (30) has a length extending in the longitudinal direction which corresponds to a multiple of the length of the fastening ring extending in the same direction, wherein at least one guide rib (44) extending in the longitudinal direction is formed on the base body (30) at least over a part of its length, said guide rib extending downward from the fastening ring so that the base body is centered relative to the fastening opening when a base body region located below the fastening ring is inserted into the fastening opening.

2. The damping element according to claim 1, characterized in that the fastening section (36) has a fastening ring (38) which is radially spaced apart from the base body (30) and at least one web (40) which extends between the fastening ring (38) and the base body (30) is provided as a predetermined breaking point (42).

3. The damping element according to claim 2, characterized in that the fastening ring (38) and the at least one predetermined breaking point (42) are designed in one piece with the base body (30).

4. Damping element according to claim 1, characterized in that at least one elastically designed clamping element (48) is designed on the base body (30).

5. Cushioning element with retaining ring (38) according to claim 4, characterized in that the base body (30) has a circular cross-sectional geometry in a direction transverse to the longitudinal extension.

6. The damping element according to claim 1, characterized in that a rotation-blocking element (50) projecting in the longitudinal direction of extension is formed on the base body (30) or on the fastening section (36).

7. Cushioning element according to claim 1, characterized in that the base body (30) is made of plastic.

8. Arrangement of a damping element (16) on a body element (20) of a motor vehicle according to one of the preceding claims, having a fastening opening (28), wherein the damping element (16) has a clamping element (48) and a fastening ring (38), characterized in that the clamping element (48) and the fastening ring (38) form a fastening region extending over a fastening height f, which fastening region is adapted to the material thickness of a wall of the body element surrounding the fastening opening (28) in such a way that the wall is enclosed by the clamping element (48) and the fastening ring (38) and the damping element (16) is thereby held in a rotationally fixed manner relative to the body element, wherein at least one longitudinally extending guide rib (44) is formed on the base body (30) at least over a partial length, said guide rib extending downward from the fastening ring, so that the base body is centered relative to the fastening opening when the base body region lying below the fastening ring is inserted into the fastening opening.

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