Energy absorption device

Abstract

The invention relates to an energy absorbing device (101, 201, 301) for a vehicle (1) having a main direction of extension (A) and an outer surface (103) intended to receive at least one impact, comprising at least a core (113) made of at least one energy absorbing material, the core (113) having a corrugated shape (115) with a succession of crests (117) in an extension direction (E) parallel to said main direction of extension (A), and at least one plastic structure (133) forming an in-piece body together with said core (113), the plastic structure (133) comprising means (153) for attaching the energy absorbing device (101, 201, 301) to an element (3) of the vehicle (1) to be protected.

Description

Technical Field

[0005] ,

[0001] The present invention relates to the field of energy absorption devices equipped on vehicles, particularly automobiles. More specifically, the present invention relates to an energy absorption device disposed on an element to be protected on a vehicle, particularly an automobile. The element to be protected is, for example, the vehicle body or the vehicle's electric battery.

Background Art

[0002] An energy absorption device for an automobile is usually disposed between the bumper and the side member of the vehicle. Whether it is disposed on the front bumper or the rear bumper of the automobile, the energy absorption device has a function of at least partially absorbing the energy transmitted to the vehicle during a potential collision with an external element.

[0003] More specifically, the energy absorption device can prevent this energy from being transmitted entirely to the side member of the vehicle and can limit the deformation of the member during a collision. It should be understood that replacing the side member, which is an important structural element of the vehicle's underbody, would require costly work.

[0004] To achieve the desired collision / impact absorption performance, it is known that an energy absorption device can be composed of a suitable metal and combined with an additional absorber composed of foamed polystyrene or other similar materials.

[0005] These energy absorption devices have the disadvantages of being heavy and bulky. Furthermore, due to the dimensions required for these devices to achieve the required performance, it is difficult to adapt these devices to the overall style and size of the vehicle. Moreover, since the internal structures of these energy absorption devices are substantially the same in all respects, the possibility of adapting the structure to suit a given shape and location, and the possibility of significantly improving the energy absorption capacity of these energy absorption devices are limited and even blocked. [Overview of the project]

[0006] Therefore, an object of the present invention is to mitigate at least one of the aforementioned drawbacks by proposing a novel energy absorption device. The energy absorption device, through its structure and configuration, can absorb force to prevent it from being transmitted to elements of the vehicle that need protection during a collision, and at the same time can be easily integrated into the vehicle and its internal structure can be modified.

[0007] The present invention proposes an energy absorption device for a vehicle having a main extension direction and an outer surface intended to receive at least one impact. The energy absorption device comprises at least a core made of at least one energy absorption material, the core having a corrugated portion having a continuum consisting of a crest in an extension direction parallel to the main extension direction, and at least one plastic structure that together with the core forms a single part, the plastic structure having means for attaching the energy absorption device to an element of the vehicle to be protected.

[0008] Energy absorbers are intended to protect vehicle elements from impacts caused by one or more external objects. The absorbers are designed to extend along the main extension direction. The absorbers also have an outer surface intended to withstand impacts.

[0009] The energy absorption device has the special feature of comprising at least a core and at least one plastic structure that together with the core form a single-part structure. Here, and throughout the following text, the term “single-part” should be understood to mean that the plastic structure and the core form a single object that cannot be separated without damaging at least one of the plastic structure and / or the core. In other words, the plastic structure cannot be removed from the core without damaging either one or the other.

[0010] The core is composed of an energy-absorbing material. This protects the elements to be protected by preventing the spread of energy released following one or more impacts. Furthermore, the core has a corrugated section. The corrugated section is a continuum of at least one peak and at least one trough, also called a crest. Preferably, the corrugated section comprises multiple peaks and troughs. The crests are continuous with each other in an extending direction parallel to the main extension direction of the energy absorber. This arrangement of the corrugated section of the core relative to the entire energy absorber can further improve the energy absorption capacity of the core and, consequently, the energy absorber according to the present invention.

[0011] According to one embodiment, the continuum consisting of the crest extends over at least a portion of the length of the energy absorber in the main extension direction. Preferably, the continuum consisting of the crest extends over the entire length of the energy absorber in the main extension direction. The length of the energy absorber is the distance between the two longitudinal ends of the device, measured in the main extension direction.

[0012] According to one embodiment, the outer surface is formed at least partially by the crest of the corrugated portion of the core, preferably by most of the crest. Thus, a portion of the crest contributes to defining a plane corresponding to the outer surface. As a result, a portion of the crest is positioned to receive energy from one or more impacts.

[0013] This configuration is highly advantageous because it allows for a gradual increase in the reaction force acting on an object colliding with the energy absorber without generating force spikes. Furthermore, the energy absorber can absorb a greater amount of energy for the same level of deformation. Therefore, the present invention makes it possible to achieve the same results with an energy absorber that is both more efficient and lighter.

[0014] According to one embodiment, the outer surface is at least partially formed by segments of the corrugated portion of the core. The segments of the corrugated portion are transverse and vertical planar cross-sections including the direction of extension of the crest, and correspond to the cross-sections of the corrugated portion in the transverse and vertical cross-sections that form a sine wave with a continuous crest falling inside. In other words, the corrugated portion is composed of a plurality of segments stacked longitudinally, and the segments located at the longitudinal ends of this stack contribute to defining the outer surface at least partially. In this context, the upper surface of the absorber is defined by at least a portion of the crest of the corrugated portion. The upper surface is the surface that connects the outer surface to the inner surface on the opposite side of the outer surface. The inner surface is the surface that faces the element to be protected.

[0015] In this embodiment, it should be noted that the outer surface is at least partially formed by the longitudinal edges of the corrugated portion that forms sharp edges, and these sharp edges are embedded in the plastic structure. The plastic material used may have, in particular, a low stiffness of less than 2 GPa and ductility of more than 20% elongation at break. This allows the plastic material to deform under the measured load without exposing these sharp edges.

[0016] According to one embodiment, the crest of the corrugated portion has a radius of curvature that changes in the direction of extension of the continuum formed by the crest. The radius of curvature of the crest corresponds to the radius of a circle that the crest can inscribe in, as viewed in a plane containing the direction of extension of the continuum formed by the crest. Therefore, the crest may have different rounded shapes depending on their position within the energy absorption device. This improves the effectiveness of the crest during collisions.

[0017] According to one embodiment, the crests of the corrugated portion have a radius of curvature that is substantially constant in the direction of extension of the continuum formed by the crests. Here, and throughout the following text, the term “substantially” should be understood to mean within manufacturing tolerances and any assembly tolerances that may exist therein. In other words, all crests have the same radius of curvature in the direction of extension of the continuum formed by the crests.

[0018] According to one embodiment, the radius of curvature of the crest of the corrugated portion varies depending on the material used and its thickness, but it can have an inner diameter of at least 5 millimeters.

[0019] According to one embodiment, the corrugated portion has an amplitude that varies in the extending direction of the continuum consisting of the crests. The amplitude is the distance between the projections of two consecutive crests onto a plane perpendicular to the extending direction of the continuum consisting of the crests. Therefore, in the first portion of the corrugated portion, the amplitude has a first value, and in the second portion of the corrugated portion, the amplitude has a second value different from the first value. This feature contributes to adapting the core structure to the overall shape of the energy absorption device while appropriately maintaining the energy absorption characteristics of the core.

[0020] According to one embodiment, the waveform-shaped portion has an amplitude that is substantially constant in the direction of extension of the continuum consisting of the crest.

[0021] As a non-limiting example, the amplitude of the waveform shape may specifically fall within the range of 5 mm to 50 mm.

[0022] According to one embodiment, the corrugated portion has a pitch that varies in the direction of extension of the continuum consisting of crests. The pitch is the distance between two consecutive pattern units of the corrugated portion, measured in the direction of extension of the continuum consisting of crests. Each pattern unit comprises two adjacent crests. Thus, it is possible to have zones within the core, each having a different pitch, and the characteristics of the corrugated portion can be adapted according to the location of the zones within the core of the energy absorber.

[0023] According to one embodiment, the corrugated portion has a pitch that is substantially constant in the direction of extension of the continuum made up of crests.

[0024] As a non-limiting example, the pitch of the waveform shape may specifically fall within the range of 50 mm to 200 mm.

[0025] The width of the energy absorber is the distance between the outer surface of the energy absorber and the inner surface of the energy absorber opposite to the outer surface, and is measured in directions perpendicular to the extending direction, perpendicular to the inner surface, and perpendicular to the outer surface.

[0026] The height of the energy absorber is the distance between the top surface of the energy absorber and the bottom surface of the energy absorber, which is opposite the top surface, and is measured in directions perpendicular to the extending direction, perpendicular to the top surface, and perpendicular to the bottom surface. The top and bottom surfaces connect their outer surfaces to their inner surfaces. In this context, it will be understood that, in some cases, the height of the energy absorber, or the width of the energy absorber, is substantially equal to the pitch of the corrugated portion.

[0027] According to one embodiment, the waveform-shaped portion has a variable shape that changes along the extension direction of the energy absorption device, and has a shape having at least a first portion and a second portion. The first portion of the waveform-shaped portion has a configuration different from that of the second portion of the waveform-shaped portion. It should be noted that the individual portions of the waveform-shaped portion can have particularly different configurations as long as the value of the pitch, the value of the amplitude, and / or the value of the radius of curvature are different between the portions. Therefore, by changing the pitch within the waveform-shaped portion, the amplitude within the waveform-shaped portion, and / or the radius of curvature of the crest within the waveform-shaped portion, the internal structure of the energy absorption device can be changed. Thereby, in the waveform zone, a plurality of zones can be created that conform to the desired technical and aesthetic characteristics of the energy absorption device. Thus, the energy absorption device can be arbitrarily changed and adapted. It should be noted that it is particularly the structure of the energy absorption device, in which its core and its plastic structure form a single part body, that enables such adaptability.

[0028] According to one embodiment, the energy absorption device includes an inner surface opposite to the outer surface, and the mounting means projects from the inner surface and includes a connection interface extending in the main extension plane of the inner surface. It will be understood that the inner surface is intended to face the element to be protected, while the outer surface opposite to the inner surface is intended to at least partially absorb the energy transmitted to the vehicle during a potential collision with an external object.

[0029] According to one embodiment, the mounting means is integrated within a volume defined by a surface of the plastic structure. The mounting means includes a barrel formed within the plastic structure.

[0030] According to one feature of the present invention, the mounting means can be arranged such that the energy absorption device is mounted on a plane that substantially coincides with the plane defined by the inner surface of the energy absorption device. Therefore, the installation area, that is, the longitudinal dimension of the vehicle on which such an energy absorption device is mounted, is significantly reduced. This is because there is no energy absorber interposed between the vehicle structure and the lateral unit forming the energy absorption device. In this context, it can be assumed that at least the inner surface of the energy absorption device has a certain curvature, and by conforming to the curvature of the vehicle, it is possible to closely press the energy absorption device against the vehicle structure.

[0031] According to an embodiment of the present invention, the energy absorption device includes a central energy absorption zone arranged between two mounting zones. These are each defined, for example, by mounting plates that form a mounting interface. The dimension of the central absorption zone in the main elongation direction is at least twice as large as the corresponding dimension of the mounting zone. For this reason, what is produced is a single component body that absorbs force uniformly, and the absorption is uniformly distributed over a large lateral range on the mounting zone.

[0032] According to an embodiment, the mounting means is integrally formed with the plastic structure. Here, and throughout the following text, the term "integrally formed" should be understood to mean that the integrally formed elements form a single part and thus they are composed of the same single or multiple materials. This part, for example, can be obtained by molding or injection molding. Therefore, this part is different from elements joined together integrally by welding or adhesion. Integrally formed elements cannot be separated without destroying one and / or the other of these elements.

[0033] According to an embodiment, the energy absorption material can particularly consist of a mixture of continuous fibers including glass fibers, carbon fibers, or any synthetic or natural fibers, and a thermoplastic resin or a thermosetting resin.

[0034] According to one embodiment, the energy-absorbing material is different from a plastic skeleton. For example, the plastic skeleton may consist of an unreinforced or discontinuously reinforced thermoplastic or thermosetting material.

[0035] The present invention also relates to a vehicle, particularly an automobile, comprising at least one element to be protected from impact, and at least one energy absorbing device having at least one of the features described above, wherein the energy absorbing device is mounted to the element to be protected using the mounting means such that its outer surface is on the opposite side of the element to be protected, and the inner surface of the energy absorbing device, opposite to the outer surface, faces the element to be protected.

[0036] According to one embodiment, the elements to be protected are the vehicle body and / or the vehicle's electric battery.

[0037] According to one embodiment, the energy absorption device is located in the underbody structure of the vehicle body.

[0038] According to one embodiment, the energy absorption device is placed on the wall of the vehicle's electric battery.

[0039] Further features and advantages of the present invention will become clearer from the following description and from the multiple exemplary embodiments shown non-limitingly with reference to the accompanying schematic drawings. [Brief explanation of the drawing]

[0040] [Figure 1] Figure 1 is a schematic diagram of the rear of a vehicle body equipped with an energy absorption device according to the first embodiment of the present invention. [Figure 2] Figure 2 is an enlarged view of the energy absorption device shown in Figure 1. [Figure 3] Figure 3 is a schematic diagram of the pattern formed within the plastic structure of the absorbent device according to the first embodiment. [Figure 4]Figure 4 is a schematic diagram of a pattern formed within a plastic structure in an alternative embodiment of the first embodiment shown in Figure 3. [Figure 5] Figure 5 is a schematic diagram of a pattern formed within a plastic structure in an alternative embodiment to the embodiments shown in Figures 3 and 4. [Figure 6] Figure 6 is a schematic diagram of a vehicle body equipped with multiple energy absorption devices, in which one of the energy absorption devices according to the third embodiment is interposed between two energy absorption devices according to the second embodiment of the present invention. [Figure 7] Figure 7 is an enlarged view of the energy absorption device according to the second embodiment shown in Figure 6. [Figure 8] Figure 8 is an enlarged view of the energy absorption device according to the third embodiment shown in Figure 6. [Figure 9a] Figure 9a shows the energy absorbed and the reaction force during the collision process for the energy absorption device. [Figure 9b] Figure 9b shows the energy absorbed and the reaction force during the collision process for another energy absorption device. [Modes for carrying out the invention]

[0041] The drawings provide details for carrying out the present invention, but it should be noted that they can, of course, be used to more clearly define the invention as needed. It should also be noted that in all drawings, similar elements and / or elements performing the same function are indicated by the same number.

[0042] In the following explanation, the longitudinal, transverse, and vertical directions are defined as functions of the three faces L, V, and T shown in the diagram. The longitudinal direction L is defined as the direction in which a vehicle, especially an automobile, travels in a straight line. By convention, the direction perpendicular to the longitudinal direction and located in a plane parallel to the ground is called the transverse direction T. The third direction perpendicular to the other two directions is called the vertical direction V. The forward direction corresponds to the direction in which a vehicle normally travels in the longitudinal direction L, and is opposite to the rearward direction.

[0043] The automobile 1 shown in Figure 1 comprises a main body 3 and at least one energy absorption device 101. The energy absorption device 101 is illustrated in this example according to a first embodiment of the present invention and is located on a portion of the main body 3. The energy absorption device 101 extends in a principal extension direction A parallel to the lateral direction T of the vehicle 1 as defined earlier. In this first embodiment, the energy absorption device 101 extends over the entire lateral length W of the vehicle 1. The lateral length W is measured in the lateral direction T between a first lateral end and a second lateral end of the vehicle 1.

[0044] The energy absorption device 101 shown in Figure 1 forms part of the rear bumper of vehicle 1 and is intended to protect victims and / or the vehicle body and / or objects by at least partially dissipating the energy generated in a collision between the vehicle and an object. Victims of a collision may be, for example, the car's user or a pedestrian.

[0045] More generally, the energy absorption device according to the present invention can be incorporated into any vehicle body element, such as a front bumper or side bumper. Furthermore, to protect one or more specific elements of a vehicle, such as an electric battery, the energy absorption device according to the present invention can be integrated with a protective device installed on the vehicle.

[0046] The energy absorber 101 comprises at least an outer surface 103 intended to at least partially absorb the energy transmitted to the vehicle during a collision, and at least an inner surface 105 opposite the outer surface 103, which in this example faces the rear of the main body 3 of the vehicle 1 and faces toward the center of the vehicle. More generally, regardless of the application of the energy absorber, if the energy absorber 101 is mounted on the vehicle 1, the inner surface 105 is intended to at least partially face the element to be protected.

[0047] Referring to Figure 1, particularly when the energy absorber is positioned to form the front or rear bumper, the outer surface 103 and inner surface 105 each extend in a plane perpendicular to the longitudinal axis L of the vehicle 1 as defined earlier.

[0048] As is clearly visible in Figure 2, the outer surface 103 and the inner surface 105 are connected to each other by the upper surface 107 and the lower surface 109 opposite the upper surface 107, and by the two side surfaces 111. The upper surface 107 and the lower surface 109 extend in a plane perpendicular to the vertical axis V of the vehicle 1, respectively. The side surfaces 111 extend in a plane perpendicular to the lateral direction T of the vehicle 1, respectively. Thus, in this first embodiment, it will be understood that the energy absorption device 101 has the shape of a parallelepiped.

[0049] Therefore, the length U of the energy absorber 101 can be defined as the distance between the two lateral ends of the energy absorber 101, which are measured in the main extension direction A and correspond to the side surface 111.

[0050] Furthermore, the width Pd of the energy absorption device 101 can also be defined as the distance between the outer surface 103 and the inner surface 105 of the energy absorption device 101, measured perpendicular to the elongation direction A, perpendicular to the inner surface 105, and perpendicular to the outer surface 103 in the longitudinal direction L.

[0051] Furthermore, the height H of the energy absorber 101 is measured perpendicular to the extension direction A and perpendicular to the upper surface 107 and the lower surface 109 in the vertical direction V, and can also be defined as the distance between the two vertical ends of the energy absorber 101 corresponding to the upper surface 107 and the lower surface 109.

[0052] The length, width, and height dimensions can all be determined according to the volume allocated to the energy absorber in the vehicle and / or according to the defined impact zone and desired absorption level. It is noteworthy that, according to the present invention, the presence of the corrugated core and the plastic structure that together with the core form a single-piece structure allows for easy adaptation of the shape and dimensions to meet the required specifications, depending on what is feasible in terms of space.

[0053] The energy absorber 101 is equipped with mounting means 153 for fixing it to the body 3 of the vehicle 1. The mounting means 153 shown in Figure 1 extends from the inner surface 105 facing the element to be protected. The mounting means 153 is equipped with a connection interface that can cooperate with a retaining means (not visible in Figure 1) belonging to the body 3 of the vehicle 1. As shown, the connection interface protrudes particularly vertically from the parallelepiped forming the energy absorber.

[0054] The connection interface extends in a plane parallel to the main extension plane 200 of the inner surface 105. When the energy absorption device 101 is mounted on the vehicle body 3, the connection interface makes direct contact with the receiving surface of the vehicle 1. This configuration is particularly advantageous because it eliminates the need for the impact absorption block and the parallelepiped shape of the energy absorption device that are normally interposed between the vehicle body and the side rail members in particular.

[0055] The energy absorption device 101 comprises at least a core 113 made of at least one energy absorbing material and a plastic structure 133 that together with the core 113 form a single component. The core 113 and the plastic structure 133 can partially define the surfaces 103, 105, 107, 109, and 111 of the energy absorption device 101, more specifically the outer surface 103 and the inner surface 105, respectively.

[0056] The core 113 is intended to absorb energy, and the plastic structure 133 serves to support and reinforce the core 113. However, it should also be noted that the plastic structure 133 can contribute to all the properties of the energy absorber 101, as will be described in more detail below.

[0057] The energy-absorbing material of the core 113 is different from that of the plastic structure 133. The energy-absorbing material may consist of a mixture of continuous fibers, including glass fibers, carbon fibers, or any synthetic or natural fibers, and a thermoplastic or thermosetting resin.

[0058] The shape of the core 113, and the material comprising it, contribute to the energy absorption characteristics of the core. Therefore, the core 113 is special in that it has a corrugated section 115, the details of which are shown particularly in Figure 2. The corrugated section 115 is a continuum of at least one peak 117 and at least one valley 117, also referred to as a crest. For the remainder of this specification, the reference numeral 117 is used interchangeably for crests, peaks, and valleys.

[0059] In the first embodiment, particularly shown in Figures 1 and 2, the corrugated portion 115 advantageously comprises a plurality of crests 117 that are continuous with each other in an extending direction E parallel to the main extension direction A of the energy absorber 101. The corrugated portion 115 of the core 113 extends along the entire length U of the energy absorber 101, thereby ensuring continuous energy absorption over substantially the entire lateral length W of the vehicle 1.

[0060] The crests 117 of the corrugated portion 115 are oriented such that a portion of them defines the outer surface 103 of the energy absorber 101. Therefore, the crests 117 are entirely contained within the plane on which the outer surface 103 extends. More specifically, in Figure 2, the majority of the crests 117 define the outer surface 103. As a result, a portion of the crests 117 is positioned to receive energy from one or more impacts.

[0061] In the first embodiment shown in Figures 1 and 2, the upper surface 107 and lower surface 109 of the energy absorber 101 are at least partially formed by at least one segment of the corrugated portion of the core 113. The segment of the corrugated portion corresponds to the cross-section of the corrugated portion in the lateral and vertical planar sections and forms a sine wave with a continuous crest falling inside. Advantageously, the longitudinal edges of the corrugated portion that form sharp cutting edges are thus oriented to form at least partially the upper and / or lower surfaces, i.e., surfaces that do not directly face elements to be protected from impact, or external elements that the vehicle will collide with.

[0062] Therefore, the energy absorption characteristics of the energy absorber 101 depend not only on the material used but also on the characteristics of the corrugated portion 115. These characteristics include the amplitude AMPc of the crest 117, the radius of curvature Rc of the crest 117, the pitch PASc of the crest, and the thickness EPAc of the corrugated portion 115.

[0063] These features may differ from one lateral end to the other. In this context, as shown in Figure 2, the energy absorber may exhibit a longitudinally and vertically symmetrical plane 300.

[0064] The amplitude AMPc is defined as the distance between the projections of two consecutive crests 117 in a direction perpendicular to the extending direction E of the continuum consisting of crests 117, and is contained in a plane parallel to the plane on which the upper surface 107 extends.

[0065] As shown in Figure 2, the amplitude AMPc of the crest 117 is substantially constant in the extending direction E. It can also be seen that the amplitude AMPc is substantially equal to the width Pd of the energy absorber 101, and that the crest is alternately flush with the outer surface 103 and the inner surface 105.

[0066] The radius of curvature Rc of the crest 117 corresponds to the radius of a circle that the crest 117 can be inscribed in, in a plane containing the extension direction E of the continuum consisting of the crest 117, and parallel to the plane on which the upper surface 107 extends. Since the crest 107 may have a radius of curvature that changes from one lateral end to the other lateral end of the energy absorber 101, it has a rounded shape that changes depending on their positions within the energy absorber 101.

[0067] In the example specifically shown in Figure 2, the crest of the first portion 119 of the waveform-shaped section 115 has a radius of curvature Rc of value R1, and the crest 117 of the second portion 121 of the waveform-shaped section 115 has a radius of curvature Rc of value R2. In this example, the first portion 119 is a central portion surrounded on both sides in the lateral direction by two second portions 121. The first radius of curvature Rc, R1 is larger than the second radius of curvature Rc, R2. As a result, the crest 117 located in the center of the energy absorption device 101 has a more rounded shape than the crests 117 located on both sides in the lateral direction of the second portion 121.

[0068] The corrugated portion 115 shown in Figure 1 or Figure 2 may comprise at least one other portion. In this portion, the crest 117 has a radius of curvature Rc that is different from the first radius of curvature Rc, R1 and also different from the second radius of curvature Rc, R2.

[0069] More specifically, the radius of curvature Rc of the crest 117 of the corrugated portion 115 can vary uniformly in the extending direction E, such that the radius of curvature Rc of the crest 117 is at its maximum value in the center of the device and decreases in both directions E toward the lateral ends of the device.

[0070] The pitch PASc is defined as the distance between two crests 117 of the corrugated shape section 115 that are continuous with each other and located on the same plane defining the energy absorption device, coplanar with the outer surface 105 in the example shown in Figure 2. The pitch is measured in the direction E of the continuum consisting of the crests 117. In other words, the pitch PASc is the lateral distance, i.e., the distance between two continuous pattern units in the direction E of the continuum consisting of the crests 115, where each pattern unit comprises two adjacent crests 117, i.e., a peak and a valley.

[0071] As specifically shown in Figure 2, the pitch PASc changes in the extending direction E of the continuum consisting of the crest 115. More specifically, the crest 117 of the first part 119 of the corrugated section 115 has a first pitch PASc, PAS1, and the crest 117 of the second part 121 of the corrugated section 115 has a pitch PASc, PAS2. The first pitch PASc, PAS1 is larger than the second pitch PASc, PAS2. As a result, in this example, the crests 117 of the first part 119, which is the central part of the device, are spaced further apart from each other than those of the second part 121, which are the measuring parts located on both sides laterally of the central part in this example.

[0072] The thickness EPAc of the corrugated portion 115 can be defined as the distance between the two ends of the corrugated portion 115, measured along an axis perpendicular to the extending direction E, and may be contained in a plane parallel to the main elongation plane 200 of the inner surface 105. More specifically, in the example shown herein where the crest 117 contributes to defining the outer surface 103, the thickness is the distance between two opposing segments of the corrugated portion that each form the edge of the corrugated portion. In Figures 1 and 2, the thickness EPAc of the corrugated portion 115 is substantially constant along the extending direction E. In this specific example, the thickness EPAc of the corrugated portion 115 corresponds to the height H of the energy absorber 101.

[0073] Therefore, the configuration can differ with respect to the values ​​of pitch, amplitude, and / or radius of curvature. Thus, it will be understood that by changing one or more characteristics of the waveform shape, the energy absorber can exhibit desired technical and aesthetic characteristics.

[0074] As described above, the energy absorption device according to the present invention is configured such that the core and the plastic structure form a single component. More specifically, the core 113 of the energy absorption device 101 is installed inside a mass made of the plastic structure 133. The plastic structure 133 can be, for example, overmolded onto the core 113.

[0075] The plastic structure 133 comprises multiple walls, including outer walls that define the outer shell in which the core 113 is inscribed, and inner walls 135 that extend across the plastic structure and connect the outer walls to each other.

[0076] The inner wall 135 has a longitudinal edge portion at the first longitudinal end of the device that defines at least a portion of the outer surface 103. This complements at least a portion of the crest 117 of the corrugated portion 115 of the core. Furthermore, the longitudinal edge portion of the inner wall may define at least a portion of the inner surface 105 at the second longitudinal end of the device. This complements at least a portion of the crest 117 of the corrugated portion 115 of the core.

[0077] The inner wall 135 is positioned such that its longitudinal edges are near the outer surface 103 and the inner surface 105, respectively, to integrally form a pattern 137 when viewed in the main extending planes of the outer surface 103 and the inner surface 105 of the energy absorber.

[0078] As shown in the figure, the pattern 137 formed by the longitudinal edge of the inner wall 135 of the plastic structure 133 near either the outer or inner surface of the energy absorption device 101 is a set of lines that extend from one outer wall to the other of the outer shell of the plastic structure and intersect each other when viewed in the main extending plane of the outer surface 103.

[0079] In the first embodiment shown in Figures 1 to 3, the pattern 137 formed by the plastic structure 133 on the outer surface 103 comprises a plurality of rhombic shapes of different dimensions. These dimensions vary in the main extension direction A of the energy absorber 101. In an embodiment not shown, the pattern formed by the plastic structure on the outer surface of the energy absorber is a grid.

[0080] The pattern 137 can be altered by changing the arrangement of the walls of the plastic structure 133, particularly the inner walls 135. In a first modification of the first embodiment, as shown in Figure 4, the inner walls 135 are arranged such that the pattern 137 exhibits a honeycomb structure.

[0081] In a second modification of the first embodiment, as shown in Figure 5, the inner wall 135 of the plastic structure 133 is arranged to have a rectangular shape in which the pattern 137 is arranged in a staggered configuration.

[0082] Note that in each of these modifications, the intrinsic thickness of the inner wall is shown to be constant throughout the inner wall. Here, intrinsic thickness is understood as the minimum dimension of the sheet forming the corresponding inner wall, independent of the concept of the thickness EPAc of the corrugated portion measured in the vertical direction. Furthermore, the intrinsic thickness of the inner wall is the same throughout the modifications. Alternatively, although not shown, it may be conceivable to change, for example, increase, the intrinsic length of at least one inner wall to improve the force absorption characteristics of the apparatus according to the present invention. Furthermore, it may be conceivable to change the absorption characteristics depending on the exposure of the corresponding zone of the apparatus according to the present invention by having an inner wall located in a first part of the plastic structure have a different intrinsic thickness than the inner wall located in a second part of the plastic structure in the same apparatus.

[0083] In Figures 1 to 5, the pattern is placed only on the outer surface 103, but it is also possible to place it similarly or alternatively on one or more other surfaces of the energy absorber 101. Typically, this feature of the plastic structure can be used to modify the energy absorption characteristics of the energy absorber 101.

[0084] Furthermore, the plastic structure 135 also offers the advantage of being integrally formed with the mounting means 153. Therefore, the mounting means 153 can be manufactured at the same time that the plastic structure 133 is overmolded onto the core 113. This makes it easier to attach the device according to the present invention to the body 3 of the vehicle 1.

[0085] Furthermore, the vehicle 1 may be equipped with multiple energy absorption devices according to the present invention. These energy absorption devices can be placed together on the vehicle element to be protected. This allows the energy absorption devices to be placed only at mechanically significant vulnerable points on the element to be protected. Moreover, this may facilitate the integration of these devices with the element to be protected.

[0086] This possibility is illustrated in Figure 6 by a vehicle 1 comprising two energy absorbers 201 according to a second embodiment of the present invention and one energy absorber 301 according to a third embodiment of the present invention. The energy absorbers 201 and 301 are intended to form part of the rear bumper. However, they can also be placed on other elements of the vehicle 1, such as the electric battery, for the purpose of protecting it.

[0087] The energy absorbers 201 and 301 are positioned at the rear of the vehicle body 3. Referring to Figure 6, each of the energy absorbers 201 and 301 has a length U that is smaller than the lateral length W of the vehicle 1 in the lateral direction, as mentioned earlier. Furthermore, the main extension directions A of the energy absorbers 201 and 301 are parallel to each other. Preferably, the main extension directions A of the energy absorbers 201 and 301 coincide.

[0088] The second embodiment of the energy absorption device according to the present invention, shown in detail in Figure 7, differs from the first embodiment in that the amplitude AMPc of the corrugated portion 115 of the core 113 changes in the extending direction E of the continuum consisting of the crest 117 of the corrugated portion 115. The same reference numerals are used for elements identical to those in the first embodiment. For further details regarding these identical elements, please refer to the above description.

[0089] Referring to Figure 7, the inner surface 105 of the energy absorption device 201 extends in the main extension plane 200, while the outer surface 103 extends in multiple planes, at least one of which is parallel to the main extension plane 200.

[0090] More specifically, the first part of the outer surface 103 extends in a first plane, the second part of the outer surface 103 forming the central part of the outer surface extends in a second plane parallel to the main extension plane 200, and the third part extends in a third plane. The first and second planes intersect and do not coincide with each other, and they also intersect and do not coincide with the main extension plane 200.

[0091] As a result, the width Pd of the energy absorber 201 changes in the main extension direction A, that is, in the extension direction of the continuum consisting of the crest 117 of the corrugated portion 115 of the core 113 that forms the energy absorber 201. Therefore, the energy absorber 201 has a first part having a width Pd of a first value P1 and a second part having a width Pd of a second value P2. In the exemplary embodiment shown in Figure 7, the width Pd, P1 of the first part of the device 201 is smaller than the width Pd, P2 of the second part of the device 201.

[0092] The height H of the energy absorption device 201, as defined earlier, is constant in the extension direction A of the energy absorption device 201.

[0093] According to the embodiment described above, the crests 117 of the core 113 shown in Figure 7 are oriented such that a portion of them defines the outer surface 103 of the energy absorber 201. Furthermore, another portion of the crests 117 of the corrugated portion 115 defines the inner surface 105 of the energy absorber 201.

[0094] In this context, it will be understood that the amplitude AMPc of the previously defined waveform-shaped portion 115 changes in the main extension direction A of the energy absorption device 201, that is, in the extension direction E. More specifically, the waveform-shaped portion 115 has a first portion 119 having an amplitude AMPc of a first value AMP1, and a second portion 121 having a width AMPc of a second value AMP2. In the exemplary embodiment shown in Figure 7, the width amplitude APc,AMP1 of the first portion 119 of the waveform-shaped portion 115 is smaller than the amplitude AMPc,AMP2 of the second portion 121 of the waveform-shaped portion 115.

[0095] In this second embodiment, it should be noted that the first part of the device 201 corresponds to the first part 119 of the waveform shaping section 115, and the second part of the device 201 corresponds to the second part 121 of the waveform shaping section 115. As a result, the amplitude AMPc of the waveform shaping section 115 corresponds to the width Pd of the energy absorption device 201.

[0096] In this second embodiment, the change in the width of the energy absorber from one longitudinal end to the other longitudinal end is achieved by changing the amplitude of the wave-shaped portion in this way.

[0097] Referring to Figure 7, the crest 117 of the corrugated portion 115 of the core 113 has a substantially constant radius of curvature Rc in the extending direction E.

[0098] Similar to the embodiments shown in Figures 1 to 5, in the energy absorption device 201 according to the second embodiment, the height EPAc of the corrugated portion 115 is substantially constant in the extending direction E and corresponds to the height H of the energy absorption device 201. Furthermore, the pitch PASc of the corrugated portion 115 changes in the extending direction E, and therefore in the main extension direction A. In addition, the energy absorption device 201 has a longitudinal and vertically symmetrical plane 300.

[0099] The third embodiment of the energy absorption device according to the present invention, shown in Figure 8, differs from the second embodiment in that the outer surface 103 of the energy absorption device 301 is formed at least partially by segments of the corrugated portion 115 of the core 113, rather than by the crest 117 as described in the second embodiment.

[0100] As could have been explained earlier, the segments of the corrugated portion 115 correspond to the cross-sections of the corrugated portion in the lateral and vertical planar sections. As a result, the straight edges contribute to defining the outer surface 103, and a portion of the crest 117 at least partially defines the upper surface 107 of the energy absorber 301 in a plane substantially perpendicular to the main extension plane 200.

[0101] Elements identical to those in the first and second embodiments are denoted by the same reference numerals. For further details regarding these identical elements, please refer to the description above. However, it should be noted that the energy absorber according to this third embodiment, having an outer surface at least partially defined by segments of the corrugated portion of the core, which is described here only in the context of applications having multiple energy absorbers, can be implemented on its own.

[0102] Similar to the second embodiment, in this third embodiment shown in Figure 8, the width Pd of the energy absorber 201 changes in the main extension direction A, that is, in the extension direction E of the continuum consisting of the crest 117 of the corrugated portion 115 of the core 113 that forms the energy absorber 301.

[0103] Referring to Figure 8, the pitch PASc of the waveform-shaped portion 115 is substantially constant in the extending direction E. The amplitude AMPc of the waveform-shaped portion 115 is also substantially constant. The amplitude AMPc of the waveform-shaped portion 115 corresponds to the height H of the energy absorption device 301.

[0104] The radius of curvature Rc of the crest 117 of the corrugated portion 115 is substantially constant in the extending direction E of the corrugated portion 115. Here, the radius of curvature Rc of the crest 117 corresponds to the radius of a circle that the crest 117 can be inscribed in, in a plane that includes the extending direction E of the continuum consisting of the crest 117, and is parallel to the principal elongation plane 200 of the inner surface 105.

[0105] The thickness EPAc of the corrugated portion 115 varies in the extending direction E. Here, the thickness is defined as the distance between the two ends of the corrugated portion 115, measured along an axis perpendicular to the extending direction E, and is contained in a plane parallel to the main elongation plane 200 of the inner surface 105.

[0106] Due to the shape of the energy absorption device 301 and the arrangement of the corrugated portion 115 of the core 113 within the energy absorption device 301, it will be understood that the thickness EPAc of the corrugated portion 115 corresponds to the width Pd of the energy absorption device 301.

[0107] In this third embodiment, the change in the width of the energy absorber from one longitudinal end to the other longitudinal end is achieved by changing the thickness of the corrugated portion in this way.

[0108] In the second and third embodiments, the mounting means 153, which is integrally formed with the plastic structure 133, is a barrel (not shown) integrated with the volume portion defined by the surface of the plastic structure 133.

[0109] Figure 9 is a set of drawings 9a and 9b showing the test results of two different energy absorption devices.

[0110] The curves labeled "1" correspond to the absorption device according to the present invention (hereinafter referred to as "device 1") in which the outer surface 103 is at least partially formed by the crest 117 of the corrugated portion 115 of the core 113. The curves labeled "2" correspond to the absorption device (hereinafter referred to as "device 2") in which the outer surface 103 is at least partially formed by at least one segment of the corrugated portion 115 of the core 113.

[0111] As shown in Figure 9a, if the front surfaces of each device are displaced by the same distance during impact, device 1 according to the present invention can absorb more energy than device 2.

[0112] Figure 9b shows the reaction force measured when the impact tool used in the test struck the energy absorber. As shown in Figure 9b, at the start of the impact, when the front of device 2 was displaced by approximately 10 mm, a reaction force spike of approximately 10,500 N was measured at the impact tool. In contrast, the reaction force measured for device 1 consistently increased during the collapse. This reaction force always remained below the peak value measured for device 1.

[0113] In particular, the present invention can achieve its described objectives as long as it can provide the following energy absorption devices: namely, energy absorption devices can be used in particular to form the bumpers of automobiles, and can provide energy absorption zones between mounting zones for elements to be protected from collision, the pattern units of which can be easily modified to suit, for example, the energy absorption requirements of a vehicle, and can distribute force toward these mounting zones for transmission to the vehicle body structure.

[0114] Naturally, the present invention is not limited to the examples described above, and numerous modifications can be made to these examples without departing from the scope of the present invention.

Claims

1. An energy absorption device (101, 201, 301) for a vehicle (1), having an outer surface (103) intended to receive at least one impact, and extending in a principal extension direction (A), The energy absorbing device (101, 201, 301) comprises at least one core (113) made of an energy absorbing material, the core (113) having a corrugated portion (115) having a continuous body consisting of a crest (117) in an extending direction (E) parallel to the main extension direction (A), and at least one plastic structure (133) forming an integral with the core (113), the plastic structure (133) having mounting means (153) for attaching the energy absorbing device (101, 201, 301) to an element (3) of the vehicle (1) to be protected, The outer surface (103) is at least partially formed by the crest (117) of the corrugated portion (115) of the core (113), The mounting means (153) is integrally formed with the plastic structure (133), The plastic structure (133) is made of a different material from the core (113). The plastic structure (133) is overmolded onto the core (113). Energy absorption devices (101, 201, 301).

2. The continuous body consisting of the crest (117) extends along the entire length (U) of the energy absorbing device (101, 201, 301) in the main extension direction (A). The energy absorption device (101, 201, 301) according to claim 1.

3. The waveform-shaped portion (115) has an amplitude (AMPc) that changes in the extending direction (E) of the continuum consisting of the crest (117). The energy absorption device (101, 201, 301) according to claim 1.

4. The waveform-shaped portion (115) has a pitch (PASc) that changes in the extending direction (E) of the continuum consisting of the crest (117). The energy absorption device (101, 201, 301) according to claim 1.

5. The waveform-shaped portion (115) has a variable shape that changes along the main extension direction (A) of the energy absorbing device, and has a shape comprising a first portion (119) and a second portion (121). The first portion (119) of the waveform-shaped portion (115) has a configuration different from that of the second portion (121) of the waveform-shaped portion (115). The energy absorption device (101, 201, 301) according to claim 1.

6. The energy absorbing material is glass fiber reinforced plastic. The energy absorption device (101, 201, 301) according to claim 1.

7. A vehicle (1) comprising at least one element (3) to be protected from impact, and at least one energy absorbing device (101, 201, 301) according to any one of claims 1 to 6, The energy absorbing devices (101, 201, 301) are attached to the element (3) to be protected using the mounting means (153) such that the outer surface (103) is on the opposite side of the element (3) to be protected, and the inner surface (105) of the energy absorbing devices (101, 201, 301) on the opposite side of the outer surface (103) faces the element (3) to be protected. Vehicle (1).

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