Deformation element for a motor vehicle

Abstract

A deformation element for a motor vehicle is proposed, consisting of at least two parts whose walls run parallel to each other at least in sections and are in contact at several points. During a collision, the two parts can deform independently, but influence each other. A loose connection allows the two parts to be linked in such a way that they can be marked together during the vehicle's manufacturing process.

Description

[0001] The invention relates to a deformation element for a motor vehicle and to a motor vehicle with such a deformation element. In automotive engineering, it is state of the art to design the motor vehicle, where possible, in such a way that in an accident the vehicle is decelerated in such a way that the acceleration values ​​acting on the vehicle's occupants are as low as possible. For this purpose, plastically deformable, energy-absorbing structures are often used, which are deformable along a collision direction and thereby convert the kinetic energy of the vehicle into deformation energy as uniformly as possible. Such structures can be referred to, for example, as deformation elements, crash elements, or energy-absorbing structures.The aforementioned elements ensure that the motor vehicle has a defined crumple zone which absorbs energy in an accident and decelerates the vehicle as gently as possible without critically affecting the survival space in the passenger compartment.

[0002] The use of so-called large-cast front and rear sections has recently led to the integration of new materials into a vehicle's crash structure. Large castings, for example made of aluminum, are more prone to breakage than deformation. Damage to these very large components can result in very high costs, quickly leading to the vehicle being deemed a total loss. However, large-casting technology offers many advantages in passenger car manufacturing, as the numerous individual sheet metal parts typically required for a steel structure can be consolidated into a few parts requiring minimal tooling. Assembly time can also be reduced, as many of the otherwise necessary joining processes, such as welding, are eliminated.

[0003] When using large cast structures, so-called sacrificial longitudinal beams, also made of a cast material, are sometimes employed according to current technology to protect the expensive structures. Alternatively, classic steel structures with deformable sheet metal are used. In the hypercar sector, carbon fiber monocoques are used, which make repairs virtually impossible.

[0004] US Patent 2007 / 0052258 A1 discloses an energy-absorbing device for a motor vehicle with a reduced initial peak load for improving crash energy management in an end structure. The energy-absorbing device has a deformable structure capable of progressively folding along a longitudinal axis under an oscillating crash load. The oscillating impact load consists of a mean load and a peak load, which is intended to be located in close proximity to the mean load.

[0005] From EP 2 366 591 A1, a device for absorbing impact energy is known, comprising a plurality of absorption phases. The device includes a first deformation part, which undergoes a first plastic deformation due to expansion in order to absorb collision energy generated in the event of a vehicle accident, and a second transformation part, which is arranged in line with one end of the first deformation part, wherein the second transformation part undergoes a second plastic deformation after the first plastic deformation of the first deformation part in order to sequentially absorb collision energy in the event of a vehicle accident. Furthermore, the device includes an expansion induction part, which is combined with one end of the second deformation part and arranged between the first deformation part and the second deformation part to guide the first plastic deformation of the first deformation part.

[0006] Overall, the solutions known from the prior art appear to be in need of improvement with regard to their deformation properties and energy absorption potential. Some of the known solutions consist of several individual parts and are therefore complex to manufacture and assemble in the vehicle.

[0007] It is therefore the object of the present invention to provide a deformation element for a motor vehicle that overcomes the disadvantages known from the prior art, exhibits advantageous deformation behavior and is easy to assemble.

[0008] The problem is solved by a deformation element for a motor vehicle comprising a tubular outer portion and an inner portion, wherein the inner portion overlaps the outer portion by at least 50% of its length along a predetermined impact direction of the deformation element, and wherein an outer surface of the inner portion is at least partially in contact with an inner surface of the outer portion. The problem is further solved by a motor vehicle with such a deformation element. An advantageous embodiment provides that the motor vehicle comprises at least one large cast element.

[0009] A tube-shaped element is understood to be, in particular, a hollow body that has a circumferential surface around its cross-section and a cross-section that remains essentially constant over its length. The cross-section can be, for example, circular, rectangular, polygonal, or oval.

[0010] For the purposes of this description, the overlapping of two elements means, in particular, that the two elements run parallel to each other at a small distance in the overlap area in the direction of a primary expansion direction of the elements, for example, in the longitudinal direction of a pipe. In the overlap area, the resulting overall structure can then be considered to have a two-layer design.

[0011] For the purposes of this description, the fact that a structure is at least partially in contact with another structure means, in particular, that there are multiple points or areas where the two structures are in physical contact with each other. For example, two surfaces can be in full contact with each other, but it is equally possible that, due to tolerances, inaccuracies, or an intentionally designed structure, the two surfaces are only in contact at specific points or in sections.

[0012] An advantage of the solution according to the invention is that the outer and inner parts of the deformation element interact with each other during deformation, enabling the deformation element to absorb a relatively large amount of energy, with the energy being absorbed relatively uniformly, thus resulting in a relatively uniform deceleration of the vehicle. Deformation elements consisting of only a single component, for example, a tubular metal element, tend to deform unevenly or in a wave-like manner. In this process, stress is built up in the deformation element in phases until a limit is reached, after which a partial collapse of the structure occurs. The process then begins again with a stress build-up phase until the entire structure is compactly folded.

[0013] According to the invention, the inner and outer components of the deformation element, which interact with each other during deformation, disrupt this regular collapse behavior. This reduces the peak loads acting on the vehicle occupants. Furthermore, compared to deformation elements known from the prior art, it is advantageous that the inner and outer components can be installed together in the vehicle. For this purpose, the inner and outer components can be joined together before installation in the vehicle. A friction-fit connection between the inner and outer components can be sufficient to achieve sufficient structural stability for assembly. Therefore, the inner and outer components do not need to be screwed, welded, or connected in a similar manner.However, it is also possible to provide such a connection between the inner part and the outer part.

[0014] The solution according to the invention also allows for flexible adaptation to the specific application, since there are a large number of parameters that can be used to influence the deformation behavior, as will be explained below.

[0015] As already mentioned, it can be advantageous for the inner part to be loosely connected to the outer part. The inner and outer parts can be connected in such a way that they can be mounted as a single unit in the vehicle. For example, the inner part can be connected to the outer part via a plug-in connection. The inner part can be inserted into the outer part, for instance. The inner and outer parts can be designed to work together in such a way that the loose connection creates a sufficiently stable overall structure to allow the deformation element to be mounted as a single unit in the vehicle.

[0016] Such a connection can be achieved simply if the outer surface of the inner part, within an overlapping area and within a production-related tolerance range, has the same shape as the inner surface of the outer part. In other words, a basic shape of the inner part can partially or completely correspond to a basic shape of a cavity within the outer part. For example, the inner part can have sections whose outer diameter or outer circumference corresponds to an inner diameter or inner circumference of a corresponding section of the outer part. When the inner and outer parts are joined, for example, by inserting the inner part into the outer part, the corresponding sections then come into direct contact with each other, creating a friction-fit connection between the inner and outer parts.

[0017] For this purpose, it can be advantageous if the inner and outer parts are connected by a transition fit. Depending on the specific application, it can also be advantageous if the inner and outer parts are connected by an interference fit, particularly a light interference fit.

[0018] A simple method for manufacturing the deformation element according to the invention arises when the outer portion has a cylindrical or prismatic basic shape. For example, the outer portion can be a tube with a circular, rectangular, or oval cross-section, or a base body with a corresponding shape. The inner portion can be adapted accordingly and also be a tube with such a circular, rectangular, or oval cross-section. The inner diameter of the outer portion can correspond to the outer diameter of the inner portion.

[0019] Advantageously, the inner portion overlaps the outer portion over a large area. Accordingly, it can be provided that the inner portion overlaps the outer portion by at least 70% of its length, preferably at least 85%, along the intended impact direction of the deformation element. The intended impact direction typically corresponds to the longitudinal direction of the deformation element. It is also possible for the inner portion to overlap the outer portion along its entire length along the intended impact direction of the deformation element. By adjusting the overlap area, the deformation behavior of the deformation element can be influenced.If there is no complete overlap between the inner and outer sections, a force acting on the deformation element in the direction of deformation or impact may result in a deformation phase in which the inner section shifts relative to the outer section. It is possible that no plastic deformation of either the inner or outer section occurs during this phase. However, at least a frictional force acts between the inner and outer sections, and depending on the design, the outer section may expand due to the relative movement, or the inner section may be compressed. This elastic deformation can then compensate for even small impacts without causing permanent damage to the vehicle.If the inner and outer components completely overlap, plastic deformation can occur in the first deformation phase. Such a design can be advantageous when a highly compact deformation element is required, for example, because the available installation space is severely limited.

[0020] As previously indicated, it can be provided that the inner portion does not overlap with the outer portion over a length of at least 5%, preferably at least 10%, for example between 5% and 20% of the length of the inner portion. This area, in which the inner and outer portions do not overlap, can then be used, as previously described, to absorb minor impacts without plastic deformation of the deformation element.

[0021] The deformation element may have a front end element and / or a rear end element. The front end element and / or the rear end element may, for example, be plate-shaped. The front end element and / or the rear end element may, for example, close off a cross-section of the inner or outer portion. The front end element and / or the rear end element may be designed to connect the deformation element to other structures of the vehicle, such as the body or other load-bearing elements. Similarly, the entire deformation element may be designed to be mounted on a longitudinal member of a vehicle. For this purpose, the deformation element may also be designed as a so-called sacrificial longitudinal member. The deformation element can then replace a section of a longitudinal member in a vehicle.

[0022] In an alternative embodiment, the inner portion can have a cross-sectional shape that differs from that of the outer portion. For example, the inner portion can have several wall sections extending perpendicular to the direction of impact and through a central axis of the outer portion. Accordingly, the inner portion can, for example, have a cruciform or star-shaped cross-section. A combination of these embodiments is also possible, such that the inner portion can have a tubular base body in which the wall sections described above can be arranged, or a central element with a cruciform or star-shaped cross-section can be arranged.

[0023] A further development of the invention provides that the deformation element includes a spring element configured to dampen relative movement of the inner portion with respect to the outer portion. Such an embodiment can be particularly advantageously combined with the feature that the inner and outer portions do not completely overlap. The spring element can be arranged in the region of a front end element or a rear end element. If the deformation element is used in the front of a vehicle, the front end element can, for example, correspond to an impact-side end element, and the rear end element can correspond to a body-side or interior-side end element. In particular, the spring element can be arranged in a region where the inner and outer portions do not overlap.The spring element can be positioned between an end face of the inner or outer section and an end element or another non-moving component of the vehicle. When the inner section moves relative to the outer section, particularly along the direction of impact, the spring element can compress and absorb kinetic energy. This allows small impacts to be absorbed without causing permanent damage to the vehicle.

[0024] According to a specific design, the inner and / or outer portion can have a target deformation zone, which includes structurally weakening elements. Such structurally weakening elements can be, for example, recesses, milled areas, or bores. Accordingly, the structurally weakening elements can be areas of reduced material thickness. These target deformation zones allow the deformation behavior of the deformation element to be further adapted to the specific application. In this way, the deformation profile over time can be flexibly adjusted to different requirements.

[0025] It is also possible for the inner section to have a wall thickness that differs from that of the outer section. For example, the inner section can have a wall thickness that is between 20% and 100% greater than the wall thickness of the outer section. It is also possible for the inner section to have a wall thickness that is, for example, between 15% and 50% less than the wall thickness of the outer section. Furthermore, the inner section can be made of a different material than the outer section. In this way, the deformation behavior of the deformation element can also be influenced by selecting a suitable combination of materials.

[0026] A further development of the invention provides that a third part of the deformation element is arranged within the inner part. This third part can function as a reinforcing structure. The third part of the deformation element can be rigidly connected to the inner part. Alternatively, it is possible that the third part of the deformation element is also only loosely connected to the inner part. The third part of the deformation element can be inserted into the inner part. The third part of the deformation element can, for example, be tubular in shape. The third part can partially or completely overlap with the inner part. It is possible that the third part has end walls that partially or completely enclose a cross-section of the third part.In principle, all previously described design variants of the inner part can also be used for the third part, provided there are no obvious reasons against it. Likewise, it is generally possible to arrange a fourth part of the deformation element within the third part, which in turn can exhibit the previously described characteristics.

[0027] Exemplary embodiments of the invention are explained in more detail with reference to the drawings and the following description. The drawings show: Fig. 1: Parts of a motor vehicle according to the state of the art, Fig. 2: a section of a motor vehicle in accordance with the state of the art, Fig. 3: a schematic representation of a first embodiment of a deformation element according to the invention in a perspective exploded view, Fig. 4: a longitudinal section through the first embodiment , Fig. 5: a section of a second embodiment of a deformation element according to the invention after the application of a force, Fig. 6: a longitudinal section through a third embodiment of a deformation element according to the invention, Fig. 7: a longitudinal section through a fourth embodiment of a deformation element according to the invention, Fig. 8: a longitudinal section through a fifth embodiment of a deformation element according to the invention, Fig. 9: a longitudinal section through a sixth embodiment of a deformation element according to the invention, Fig. 10: a longitudinal section through a seventh embodiment of a deformation element according to the invention, Fig. 11: a longitudinal section through an eighth embodiment of a deformation element according to the invention, Fig. 12: a longitudinal section through a ninth embodiment of a deformation element according to the invention, Fig. 13: a longitudinal section through a tenth embodiment of a deformation element according to the invention, Fig. 14: a longitudinal section through an eleventh embodiment of a deformation element according to the invention, Fig. 15: a longitudinal section through a twelfth embodiment of a deformation element according to the invention, Fig. 16: a longitudinal section through a thirteenth embodiment of a deformation element according to the invention, Fig. 17: a cross-section through a fourteenth embodiment of a deformation element according to the invention, Fig. 18: a cross-section through a fifteenth embodiment of a deformation element according to the invention, Fig. 19: a cross-section through a sixteenth embodiment of a deformation element according to the invention, Fig. 20: a cross-section through a seventeenth embodiment of a deformation element according to the invention, and Fig. 21: a cross-section through an eighteenth embodiment of a deformation element according to the invention.

[0028] Fig. Figure 1 shows parts of a motor vehicle 2 according to the prior art. The figure depicts a body 4 which has a large cast element in both the front and rear sections, each of which in turn comprises two longitudinal members 6. If a sufficiently large impact strikes one of these longitudinal members 6, for example in a frontal crash or a rear-end collision, the longitudinal members 6 are only able to absorb the crash energy to a very limited extent, so that the large cast element can quickly break. Such damage often results in the total loss of the motor vehicle, as the affected elements are very expensive and difficult to replace. It is therefore known from the prior art how, in Fig. Figure 2 shows that the longitudinal members 6 of the large cast element are designed to be shortened and lengthened with so-called sacrificial longitudinal members 8. The sacrificial longitudinal members 8 are designed as separate, replaceable elements that absorb the crash energy in minor and moderate accidents, thus protecting the expensive large cast structure. The sacrificial longitudinal members 8 can be replaced separately later, so that in some cases an economically viable repair of the vehicle becomes possible. The deformation element according to the invention can replace such a sacrificial longitudinal member 8.

[0029] Fig. Figure 3 shows a schematic representation of a first embodiment of a deformation element 10 according to the invention in a perspective exploded view. The deformation element 10 essentially consists of an outer part 12 and an inner part 14. The inner part 14 is inserted into the outer part 12. The outer part 12 is attached at a body-side end to the body-side end element 16. In the illustrated embodiment, the body-side end element 16 is simplified to a rectangular plate or sheet metal and can, in principle, have any suitable configuration. The inner part 14 has an impact-side end 18, which is connected to an impact-side end element 20. Fig. For clarity, the impact-side end element 20 is shown in exploded view, not connected to the inner portion 14. The impact-side end element 20 can have the same properties as the body-side end element 16. The impact-side end element 20 typically faces an outside of the vehicle, whereas the body-side end element 16 faces an inside. If the deformation element 10 is used in the area of ​​the front of the vehicle, the impact-side end element 20 can correspond to a front end element, and the body-side end element 16 can correspond to a rear end element.

[0030] It can also be seen that a gap exists between the body-side end 22 of the inner portion and the body-side end of the outer portion 14 along the direction of impact. In other words, in the illustrated embodiment, the body-side end 22 of the inner portion 14 does not rest against the body-side end element 16. Similarly, a gap exists between the impact-side end 24 of the outer portion 12 and the impact-side end element 20.If a force acts along the longitudinal axis of the deformation element 10, or along the direction of impact, on the inner portion 14 or on the impact-side end element 20, the inner portion 14 is initially pushed further into the outer portion 12 until the body-side end 22 of the inner portion 14 comes into contact with the body-side end element 16 and / or until the impact-side end 24 of the outer portion 12 comes into contact with the impact-side end element 20. In the next phase, plastic deformations of the outer portion 12 and / or the inner portion 14 then occur. It is possible that the distance between the body-side end 22 of the inner portion and the body-side end element 16 corresponds to the distance between the impact-side end 24 of the outer portion 12 and the impact-side end element 20.However, it is also possible that the two described distances are different from each other, so that a total of three phases of deformation can be distinguished: in a first phase, the outer part 12 and the inner part 14 slide into each other; in a subsequent second phase, primarily the part of the deformation element 10 that is already in contact with the end elements 16, 20 on both sides deforms; and in a third phase, both the outer part 12 and the inner part 14 deform plastically.

[0031] Fig. Figure 4 shows a longitudinal section through the first embodiment. Fig. 3. It is clearly evident that the outer portion 12 and the inner portion 14 overlap over a large area and are in direct contact with each other. If a force is applied in the direction of impact, i.e., from the left in the figure, to the impact-side end element 20, the inner portion 14 is pushed further into the outer portion 12. When further insertion of the inner portion 14 into the outer portion 12 is no longer possible because the body-side end 22 of the inner portion 14 is in contact with the body-side end element 16 and / or the impact-side end 24 of the outer portion 12 is in contact with the impact-side end element 20, the plastic deformation of the deformation element 10 begins. The force required to move the two portions 12 and 14 relative to each other can be adjusted by fine-tuning the shapes of the inner portion 14 and the outer portion 12.In this way, a frictional force existing between the two parts 12, 14 can be influenced, and it can also be determined by the type of fit with which the outer part 12 and the inner part 14 are connected to each other whether deformations, in particular elastic deformations of one of the parts 12, 14, are already caused by the displacement movement.

[0032] Fig. Figure 5 shows a section of a second embodiment of a deformation element 10 according to the invention after an impact in which the deformation element 10 absorbed energy and plastically deformed, for example, after an accident. It can be seen that the inner portion 14 and the outer portion 12 have deformed in a similar manner. Both the outer portion 12 and the inner portion 14 have undergone compression, such that the respective walls of the outer portion 12 and the inner portion 14 now run partially perpendicular or obliquely to their original direction of extension along the direction of impact. This results in a zigzag shape for both portions 12 and 14, whereby the outer portion 12 is now no longer in contact with the inner portion 14 in certain sections.Since the two components 12 and 14 deform similarly but not identically, the overall result is a smoothing of the deceleration value over time, thus reducing peak loads experienced by the vehicle occupants. If one of the two elements is in a collapse phase, characterized by very rapid deformation, the other element is often in a slower deformation phase, allowing the energy to be absorbed more evenly by both elements.

[0033] Fig. Figure 6 shows a longitudinal section through a third embodiment of a deformation element 10 according to the invention. The third embodiment corresponds essentially to the first embodiment from Figure 6. Fig. 4. However, in the third embodiment shown, there is a complete overlap between the outer portion 12 and the inner portion 14. In other words, the inner portion 14 is completely inserted into the outer portion 14, so that no relative movement between the outer portion 12 and the inner portion 14 is possible without deformation of the outer portion 12 and the inner portion 14. Accordingly, the body-side end 22 of the inner portion 14 rests against the body-side end element 16, and the impact-side end 24 of the outer portion 12 rests against the impact-side end element 20.

[0034] Fig. Figure 7 shows a longitudinal section through a fourth embodiment of a deformation element 10 according to the invention. The fourth embodiment is constructed similarly to the third embodiment from Fig. 6 and differs from this essentially by a reinforcing structure 28 arranged within the inner portion 14. The reinforcing structure 28 can be considered the third part of the deformation element 10. In the illustrated embodiment, the reinforcing structure 28 is attached to the body-side end element 16. It projects in the direction of impact or in the longitudinal direction of the deformation element 10 to approximately the middle of the deformation element 10 into the cavity within the inner portion 14. The reinforcing structure 28 is also tubular and has a circumferential outer wall 30 and an end wall 32.

[0035] Fig. Figure 8 shows a longitudinal section through a fifth embodiment of a deformation element 10 according to the invention. The fifth embodiment shown is constructed similarly to the first embodiment. It differs from the first in that a spring element 34 is arranged in a region between the body-side end 22 of the inner portion 14 and the body-side end element 16. This spring element can absorb minor impacts so that they can be reversibly cushioned. The filter element 34 is arranged completely within the outer portion 12. Ideally, the deformation element 10 can thus withstand a minor impact without permanent changes.

[0036] Fig. Figure 9 shows a longitudinal section through a sixth embodiment of a deformation element 10 according to the invention. The sixth embodiment is similar in structure to the first embodiment and differs from it by an internal reinforcement structure 28, which is tubular in shape and covers the entire inner cavity of the deformation element 10 in the longitudinal direction. The reinforcement structure 28 thus rests with its end faces against both the body-side end element 16 and the impact-side end element 20. This results in an overall structure in which, during the initial phase of an impact, the outer portion 12 and the inner portion 14 move or shift relative to each other, while the reinforcement structure 28 already undergoes plastic deformation.

[0037] Fig. Figure 10 shows a longitudinal section through a seventh embodiment of a deformation element 10 according to the invention. The seventh embodiment is designed similarly to the sixth embodiment and differs from it by a second reinforcing structure 36, which is arranged within the first reinforcing structure 28. The second reinforcing structure 36 is spaced apart from both the body-side end element 16 and the impact-side end element 20, but can alternatively also abut one of the two end elements 16, 20. The second reinforcing structure 36 is designed in a hollow cylindrical shape and has two end walls 32. The second reinforcing structure 36 can be loosely inserted or plugged into the first reinforcing structure 28. Alternatively, it can also be firmly connected to it, for example by a positive-locking connection, by a welded connection, or by bonding.

[0038] Fig. Figure 11 shows a longitudinal section through an eighth embodiment of a deformation element 10 according to the invention. The eighth embodiment is constructed similarly to the third embodiment from Fig. 6 and differs from this by a reinforcement structure 28, which is identical to the reinforcement structure 28 of the in Fig. is designed as shown in the sixth embodiment shown in 9.

[0039] Fig. Figure 12 shows a longitudinal section through a ninth embodiment of a deformation element 10 according to the invention. Fig. Figure 13 shows a longitudinal section through a tenth embodiment of a deformation element 10 according to the invention. Fig. Figure 14 shows a longitudinal section through an eleventh embodiment of a deformation element 10 according to the invention. Fig. Figure 15 shows a longitudinal section through a twelfth embodiment of a deformation element 10 according to the invention. The ninth to twelfth embodiments are each similar in construction to the first embodiment. They differ from it by means of predetermined deformation zones 38, each designed as circumferential milled grooves. In the predetermined deformation zones 38, the wall thickness of the respective outer portion 12 or inner portion 14 is reduced by indentations or milled grooves, so that the structure is weakened at this point. In the illustrated embodiments, there are two zones, each with three circumferential milled grooves, arranged at different positions in the longitudinal direction and in the impact direction, respectively.

[0040] The target deformation areas 38 can of course also be formed using other forms or numbers of structural weaknesses.

[0041] In the Fig. In the ninth embodiment shown in Figure 12, the intended deformation areas 38 have recesses pointing towards the outside of the inner portion 14. In the Fig. In the tenth embodiment shown in Figure 13, the intended deformation areas 38 have recesses pointing towards the inside of the outer portion 12. In the Fig. In the eleventh embodiment shown in Figure 14, the intended deformation areas 38 have recesses pointing towards the inside of the inner part 14. In the Fig. In the twelfth embodiment shown in 15, the intended deformation areas 38 have recesses pointing towards the outside of the outer portion 12.

[0042] Fig. Figure 16 shows a longitudinal section through a thirteenth embodiment of a deformation element 10 according to the invention. The thirteenth embodiment is similar to the one in Figure 16. Fig. The fifth embodiment shown in Figure 8 is constructed in the same manner and also features a spring element 34. However, unlike the fifth embodiment, the spring element is arranged between an end region of the outer portion 12 and the impact-side end element 20. It rests on an outer surface of the inner portion 14, so that the spring element 34 extends around the outer portion 14. At its body-side end, the spring element 34 abuts a flange element 40, which forms an impact-side end of the outer portion 12.

[0043] In all illustrated embodiments, the inner and outer sections can, in principle, be interchanged such that the outer section can also be attached to the impact-side end element, while the inner section is then attached to the body-side end element. This results in a reversal of the kinematic relationships between the inner and outer sections. The embodiments described so far each assume inner and outer sections that are simple tubes with a circular cross-section. Various variations with cross-sections deviating from these circular cross-sections are shown below. In principle, all types of cross-sections can be combined with all the other features described above.

[0044] Fig. Figure 17 shows a cross-section through a fourteenth embodiment of a deformation element 10 according to the invention. The cross-section of both the outer portion 12 and the inner portion 14 corresponds to a rectangle with rounded corners. The inner portion 14 rests with its outer side against the inner side of the outer portion 12 along its entire perimeter. Various aspect ratios of the rectangle are possible; for example, the perimeter can correspond to a square with rounded corners.

[0045] Fig. Figure 18 shows a cross-section through a fifteenth embodiment of a deformation element 10 according to the invention. In the illustrated embodiment, the outer portion 14 has a square cross-section with rounded corners, and the inner portion 12 has a circular cross-section. The inner section 12 is therefore only in contact with the outer portion 14 in sections, specifically in the central areas of the side walls.

[0046] Fig. Figure 19 shows a cross-section through a sixteenth embodiment of a deformation element 10 according to the invention. The sixteenth embodiment is designed similarly to the fourteenth embodiment. Both the inner portion 12 and the outer portion 14 have rectangular cross-sections with rounded corners. However, the inner portion 12 has a larger radius of curvature, so that there are areas in the corners where the outside of the inner portion 12 is not in contact with the inside of the outer portion 14.

[0047] Fig. Figure 20 shows a cross-section through a seventeenth embodiment of a deformation element 10 according to the invention. In this embodiment, the outer portion 14 again has a square cross-section with rounded corners. The inner portion 12 is a complex component comprising a tubular central portion 42 with a circular cross-section and a plurality of radial portions 44, 46 extending radially from the central portion 42. A total of eight radial portions 44, 46 are present, of which four radial portions 46 are in contact with central areas of the inner surfaces of the side walls of the outer portion 14. The four radial portions 44 are each oriented towards a corner of the cross-section of the outer portion 14. They have the same length as the radial portions 46 and are therefore not in contact with the outer portion 14.

[0048] Fig. Figure 21 shows a cross-section through an eighteenth embodiment of a deformation element 10 according to the invention. The illustrated embodiment has an outer portion 14 in the form of a simple tube with a circular cross-section. The inner portion corresponds essentially to the inner portion of the Fig. The seventeenth embodiment shown in Figure 20 also has a total of four first radial sections 44 and four second radial sections 46. In this embodiment, however, all eight radial sections 44, 46 are identically designed and are all in contact with the inner surface of the outer section 14. Unlike the inner section of the seventeenth embodiment, the central section 42 in this embodiment is solid. The central section 42 is therefore not a tube, but rather a solid cylinder; for example, it is rod-shaped. Reference symbol list 2 motor vehicles 4 Bodywork 6 longitudinal beams 8 sacrificial longitudinal beams 10 Deformation element 12 outer share 14 inner part 16 body-side end element 18 impact-side end of the inner part 20 impact-side end element 22 Body-side end of the inner part 24 impact-side end of the outer portion 26 Body-side end of the outer portion 28 Reinforcement structure 30 shell wall 32 Front wall 34 Spring element 36 second reinforcement structure 38 Target deformation range 40 Flange element 42 Central share 44 first radial component 46 second radial component QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2007 / 0052258 A1

[0004] EP 2 366 591 A1

[0005]

Claims

[1] Deformation element (10) for a motor vehicle comprising a tubular outer portion (12) and an inner portion (14), wherein the inner portion (14) has an overlap of at least 50% of its length with the outer portion (12) along a foreseen impact direction of the deformation element (10), and wherein an outer surface of the inner portion (14) is at least partially in contact with an inner surface of the outer portion (12). [2] Deformation element (10) according to claim 1, wherein the inner part (14) is inserted into the outer part (12). [3] Deformation element (10) according to one of the preceding claims, wherein the inner part (14) and the outer part (12) are connected to each other in such a way that they can be assembled as a unit. [4] Deformation element (10) according to one of the preceding claims, wherein the deformation element (10) has a front end element and / or a rear end element. [5] Deformation element (10) according to one of the preceding claims, wherein the inner part (14) and the outer part (12) are connected to each other by an interference fit or by a transition fit. [6] Deformation element (10) according to one of the preceding claims, wherein a third part of the deformation element (10) in the form of a reinforcement structure (28) is arranged within the inner part (14). [7] Deformation element (10) according to one of the preceding claims, wherein the inner portion (14) has a cross-shaped or star-shaped cross-section. [8] Deformation element (10) according to one of the preceding claims, wherein the deformation element (10) has a spring element (34) which is designed to cushion a relative movement of the inner part (14) relative to the outer part (12). [9] Deformation element (10) according to one of the preceding claims, wherein the inner part (14) and / or the outer part (12) has a desired deformation area (38), wherein the desired deformation area (38) comprises structure-weakening elements. [10] Motor vehicle with a deformation element (10) according to one of the preceding claims.

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