Bending beam of a motor vehicle, motor vehicle and methods for the protection of occupants of a motor vehicle

Abstract

A bending beam of a motor vehicle is described, comprising an extruded profile with a front and a back, wherein at least one chamber is formed between the front and back, wherein an expansion element with a crash surface is arranged in the chamber, wherein at least one cutout is provided in the front of the extruded profile in the area of ​​which the crash surface of the expansion element is arranged, wherein an airbag is arranged in the at least one chamber between the back of the extruded profile and the expansion element, wherein the airbag is configured, after its ignition, to move the expansion element in an expansion direction with the crash surface through the cutout of the front of the extruded profile, so that the crash surface is arranged in the expansion direction in front of the front of the extruded profile, wherein at least one blocking element is arranged in the chamber.which can be placed between the back of the extruded profile and a contact surface of the expansion body, and which provides for the placement of at least one blocking element by means of the airbag.

Description

[0001] A vehicle crossmember of a motor vehicle, a motor vehicle, and a method for protecting the occupants of a motor vehicle are described.

[0002] Vehicle crossmembers, motor vehicles, and methods for protecting the occupants of motor vehicles of the type mentioned at the beginning are known in the prior art.

[0003] Known crossmembers generally have an end face which - when installed as intended in the direction of a vehicle rear or a vehicle front - is generally predominantly vertically oriented in the intended mounting position. The crossmembers have the task of absorbing impact energy during a collision of the motor vehicle with an obstacle or another motor vehicle by means of deformation.

[0004] In motor vehicles, effective overhangs are defined in the front and / or rear area. In this case, the effective overhang, for example at the rear, is the distance between the rear edge of a rear door or trunk lid of the vehicle and the end face of the bending member. The effective overhang is determined in particular so that a rear door or trunk lid is not damaged at low impact speeds. The distances resulting from safety requirements are quite large and crucial for the appearance and design of the vehicle. The greater the effective overhang, the greater the design overhang. The problem is that the large overhangs place severe restrictions on the design of the vehicle.

[0005] Therefore, for reasons of freedom of design, it is desirable if the legal and insurance-related requirements could be combined with a high degree of freedom of design.

[0006] DE 10 2018 205 396 B3 discloses a hollow beam for a body structure of a vehicle, comprising a body-side profiled part, characterized in that the hollow beam has a profiled part facing the crash, which is adjustable in a pre-crash phase and is located in a retracted position with a reduced hollow beam cross-section during normal driving operation, and in the pre-crash phase is adjusted to an extended crash position in which the hollow beam cross-section and the hollow beam deformation path are increased, wherein in the event of a crash, the hollow beam deformation path between the body-side profiled part and the profiled part facing the crash is reduced, specifically with the dissipation of crash energy by deformation of the hollow beam, wherein for increased crash energy dissipation, the hollow beam has at least one locking element which is brought into a locking position in the pre-crash phase and in the event of a crash,in which the locking element additionally stiffens or reinforces a crash load path between the crash-facing profile part and the body-side profile part.

[0007] The disadvantage of this is that the hollow beam cannot be formed as a single piece, which leads to noise and reduced strength, and that a very voluminous airbag is required for deployment.

[0008] DE 10 2012 107 042 A1 discloses a bumper assembly for a motor vehicle, comprising a main cross member that is displaceable in the direction of travel (X) and extends at least partially between two deformation elements. The deformation elements each comprise a displaceable segment and a stationary segment that are movable relative to one another. The displaceable segment is coupled to the main cross member, and the stationary segment can be coupled to the vehicle body directly or via a flange plate.

[0009] The task therefore arises of further developing bending beams of motor vehicles, motor vehicles and methods for protecting the occupants of motor vehicles of the type mentioned above in such a way that they have a higher rigidity.

[0010] The object is achieved by a bending beam of a motor vehicle according to claim 1, a motor vehicle according to the independent claim 5 and a method for protecting the occupants of a motor vehicle according to the independent claim 6. Further embodiments and developments are the subject of the dependent claims.

[0011] A bending beam of a motor vehicle is described, comprising an extruded profile with a front side and a rear side, wherein at least one chamber is formed between the front side and the rear side, wherein an expansion body with a crash surface is arranged in the chamber, wherein at least one cutout is provided in the front side of the extruded profile, in the region of which cutout the crash surface of the expansion body is arranged, wherein an airbag is arranged in the at least one chamber between the rear side of the extruded profile and the expansion body, wherein the airbag is designed, after its ignition, to move the expansion body in an expansion direction with the crash surface through the cutout in the front side of the extruded profile, so that the crash surface is arranged in front of the front side of the extruded profile in the expansion direction.

[0012] Such an extruded profile is usually made of aluminum for weight and rigidity reasons. The extruded profile has a back and a front, with the back typically facing the vehicle and the front facing outward, away from the vehicle. Between the back and front, one or more additional sides may be provided that connect the front and back sides, for example, a bottom and a top.

[0013] The chamber is formed by the corresponding sides. The chamber can be open toward the end faces, with the end faces defining an extrusion direction, or the end faces can be closed, for example, by caps.

[0014] At least one cutout is provided on the front side of the extruded profile, which opens the chamber to the outside.

[0015] The expansion body arranged in the chamber can also be designed as an extruded profile or manufactured using another manufacturing process, for example, as a cast body. The expansion body can be made of aluminum or another metal, and in some embodiments, even of plastic.

[0016] The expansion body has a crash surface designed for initial contact with another vehicle or an obstacle. In the event of contact with another vehicle or an object, the flexural beam first impacts with the extended crash surface. In the retracted state, with the airbag deactivated, the crash surface is set back relative to the front of the extruded profile, allowing the expansion body to be inserted laterally during assembly of the flexural beam.

[0017] The crash surface of the expansion body is positioned relative to the cutout in the extruded profile so that the crash surface can protrude or be pushed through the cutout. The crash surface is therefore slightly smaller than the cutout to prevent the crash surface of the expansion body from getting caught in the cutout.

[0018] The airbag can be tubular in design and extend transversely to the expansion direction along the extrusion direction of the extruded profile. The airbag can have a fabric casing. The airbag can be secured in the flexible beam by a material connection, for example, glued. The airbag can be folded when not in use and expanded by means of at least one ignitable gas generator or gas reservoir.

[0019] The airbag is arranged between the clamping profile and the expansion body and, depending on the specific design, can be fixed at the back of the clamping profile in the area of the chamber.

[0020] In certain designs, multiple airbags may be provided. If multiple expansion bodies are provided, one or more airbags can be used for each expansion body.

[0021] By igniting the airbag, the expansion body can be expanded in an expansion direction that points from the back of the clamping profile to the front of the clamping profile, with the crash surface of the expansion body being pressed through the cutout. The first contact with the obstacle or the other motor vehicle then occurs with the crash surface of the expansion body, achieving an earlier first contact than if a corresponding expansion body were not present.

[0022] As a result, the bending beam can be designed more compactly overall, which increases the design freedom of the vehicle designers.

[0023] In certain embodiments, it is possible to increase a depth measured from the back of the extruded profile to the area of ​​the first contact, i.e. either the front of the extruded profile according to the prior art or the crash surface according to the bending beam described above, by up to 40%.

[0024] The bending beam described above allows for more intrusion travel and reduces the loads on the vehicle and, in particular, its occupants. The decisive factor here is that, in the load case of the deformation occurring here, the gained height is multiplied by the cube.

[0025] In the embodiment according to the invention, it is provided that at least one blocking body is arranged in the chamber, which blocking body can be placed between the rear side of the extruded profile and a contact surface of the expansion body.

[0026] Depending on the design, it may be useful to provide two or more blocking bodies.

[0027] In its final position, the at least one blocking body is located in the load path between the extruded profile and the expansion body. Thus, the expansion body can be supported by the at least one blocking body on the rear side of the extruded profile, so that in the event of a collision, the expansion body initially deforms until the colliding object reaches the extruded profile. From then on, the extruded profile is deformed. The blocking bodies can also be deformed and designed as energy-absorbing deformation bodies.

[0028] In an embodiment according to the invention, it is provided that the movement of the at least one blocking body is provided by means of the airbag.

[0029] In this embodiment, the airbag can be expanded in two stages: once in particular in the expansion direction and once in particular transversely to the expansion direction. In the first stage, the expansion body is pushed outward. In the second stage, the blocking body(s) are then brought into their locking position, in particular pushed, in which the expansion body is supported on the rear side of the extruded profile by means of the at least one blocking body.

[0030] The second stage can be achieved, for example, by a suitable folding of the airbag and / or by a separate ignition using an additional propellant gas generator or propellant gas provider.

[0031] The two-stage deployment of the airbag is useful to move the expansion body into its deployed position as quickly as possible.

[0032] In a further advanced embodiment, it is provided that the expansion body and / or the at least one locking body are each fixed to the back of the extrusion profile by means of at least one explosive fixation.

[0033] The corresponding explosive fixations can in particular be explosive screws, which can be designed either passively or actively.

[0034] In the case of passive explosive elements, the connections can be designed such that they break under the force exerted by the airbag, for example by forming the connecting elements from plastic and / or each having at least one predetermined breaking point that breaks under a defined load.

[0035] Active explosive elements can be detonated by a blasting signal, which releases the connection to the extruded profile.

[0036] By detonating the explosive bodies, the connections between the expansion body and / or blocking body to the extruded profile can be removed so that the expansion body and / or blocking body can be moved.

[0037] By providing a corresponding explosive fixation, expansion bodies and / or blocking bodies can be firmly arranged on the extruded profile of the bending beam, which can prevent noise generation such as rattling.

[0038] To connect these connections or explosive elements, such as explosive screws, holes can be drilled on the back of the extruded profile.

[0039] In a further further embodiment, it is provided that the at least one expansion body has at least one stop surface which is intended to stop against the front side of the extruded profile.

[0040] The corresponding expansion body can be substantially L- or T-shaped in side view, with the crash surface located on the narrow, protruding part of the profile. The stop surface(s) are located on one side of the crash surface in the case of an "L" shape, or above and below and / or to the left and right of the crash surface in the case of a "T" shape, and strike the inner side of the front side of the extruded profile facing the chamber, so that the expansion body is precisely aligned relative to the extruded profile when the expansion body is extended.

[0041] In a further refinement, it is provided that an expansion channel is provided on the expansion body for guiding the airbag.

[0042] By providing a corresponding expansion channel, the deployment of the airbag is defined and a smaller airbag can be used, since it only has to fill the channel and not the majority of the chamber.

[0043] A first independent subject matter relates to a motor vehicle having at least one bending beam of the type described above.

[0044] A further independent subject matter relates to methods for protecting occupants of a motor vehicle of the type described above, wherein a crash or an impending crash is detected, wherein the airbag is ignited, whereby the expansion body of the airbag is moved forward in the expansion direction in a first stage.

[0045] Using the method described here, the effectively available depth of a corresponding bending beam can be increased considerably, depending on the design by approximately 40% compared to the depth of the extruded profile alone.

[0046] In a first further embodiment, it is provided that the airbag moves the blocking body or bodies between the extruded profile and the expansion body in a second stage.

[0047] By providing a second stage, where the first stage serves to deploy the expansion body, it is possible to first move the expansion body to its required position as quickly as possible. Then, in a second step, as soon as the appropriate space within the chamber between the extruded profile and the expansion body has been cleared, the blocking body(s) are moved into their blocking position. The blocking body(s) and the expansion body can be moved by linear displacement.

[0048] In a further refinement, it is provided that the second stage is activated by a second ignition of the airbag.

[0049] This allows for optimal time coordination.

[0050] In the case of an active explosive fixation, a further embodiment may provide that the active explosive fixation is released simultaneously with the ignition of the airbag or before the ignition of the airbag.

[0051] To coordinate the processes, a control device can be provided which is autonomous or which is integrated into a motor vehicle control system.

[0052] Further advantages, features, and details will become apparent from the following description, in which at least one embodiment is described in detail—possibly with reference to the drawings. Identical, similar, and / or functionally equivalent parts are provided with the same reference numerals.

[0053] They show schematically: Fig. 1 a perspective view of a front side of a bending beam; Fig. 2 a perspective view of one side of the bending beam from Fig. 1; Fig. 3 a perspective view of a rear side of the bending beam from Fig. 1, and Fig. 4A - 4C perspective views of one side of the bending beam from Fig. 1 in different phases of the release of an expansion body.

[0054] In the exemplary embodiments described below, identical or equivalent components or elements are provided with the same reference numerals for better readability.

[0055] Fig. 1 shows a perspective view of a front side of a bending beam 2.

[0056] The bending beam 2 is designed for use in the area of ​​a rear bumper (not shown) of a motor vehicle (not shown).

[0057] The bending beam 2 comprises an extruded aluminum profile 4 with a front side 4.1, a back side 4.2, a top side 4.3, and a bottom side 4.4. The sides 4.1 to 4.4 enclose a chamber 6 open toward the end faces of the extruded profile 4.

[0058] An expansion body 8 is arranged in the chamber 6. From the expansion body 8, Fig. 1 only one crash surface 10 can be seen. The crash surface 10 is arranged in a cutout 12 of the front side 4.1 of the extruded profile 4.

[0059] The crash surface 10 is located behind a plane of the front side 4.1 so that the expansion body 8 can be pushed laterally into the chamber 6 of the extruded profile 4 during assembly of the bending beam 2.

[0060] The crash surface 10 is smaller than the cutout 12 so that the expansion body 8 can be moved through the cutout 12 of the front side 4.1, as shown below.

[0061] The extruded profile 4 is slightly curved in this case in order to follow the shape of the motor vehicle (not shown).

[0062] Fig. 2 shows a perspective side view of the bending beam 2 from Fig. 1.

[0063] The expansion body 8 is essentially T-shaped in cross-section and has projections 14, which are arranged at the top and bottom, respectively, in the vertical orientation of the bending beam 2 shown here. The crash surface 10 is arranged by means of a web at the end of an expansion channel 16.

[0064] An airbag 18 is arranged on the rear side 4.2 of the extruded profile 4 and is glued in place. Fig. Figure 2 shows the airbag 18 in a folded configuration. The airbag 18 is tubular and made of a fabric material.

[0065] Blocking bodies 20, 22 are provided above and below the airbag 18 and can be moved upwards and downwards, as described in connection with the Fig. 4A to 4C is explained.

[0066] The expansion body 8 is secured by means of several explosive screws 24, of which Fig. 2, only two pieces are visible, are fixed to the rear side 4.2 of the extruded profile 4 of the bending beam 2. The explosive screws 24 are designed in such a way that they break when a certain load is exceeded, which is exceeded when the airbag 18 is deployed, but during normal operation of the motor vehicle they securely fix the expansion body 8 to the rear side 4.2.

[0067] When broken, the explosive screws 24 release the connection between the expansion body 8 and the extruded profile 4, so that in this case the expansion body 8 is freely movable relative to the extruded profile 4.

[0068] The blocking bodies 20, 22 are also each fastened with corresponding snap screws to the back 4.2 of the extruded profile 4, but these are in Fig. 2 not shown.

[0069] Fig. 3 shows a perspective view of the rear side 4.2 of the extruded profile 4 of the bending beam 2. On the rear side 4.2 of the extruded profile 4, a plurality of bores 26 are formed, in which no explosive screws are shown in the illustration described here.

[0070] The Fig. 4A to 4C show different phases of the triggering of the expansion body 8 in a crash situation.

[0071] In Fig. 4A is essentially the configuration of Fig. 2. If a crash or an impending crash is detected, e.g. by sensor systems of the motor vehicle, e.g. ultrasonic sensors, radar sensors, cameras or the like, the expansion body 8 is to be propelled outwards in an expansion direction x so that the crash surface 10 lies in front of the front side 4.1 of the extruded profile 4.

[0072] As in Fig. As shown in FIG. 4B, for this purpose, the airbag is inflated by triggering a first ignition stage, and the airbag 18 is pressed into the expansion channel 16 of the expansion body 8. As a result, the airbag 18 first completely fills the expansion channel 16, then exerts an overload on the explosion bolts 24, causing the explosion bolts 24 to break and releasing the expansion body 8 relative to the extrusion profile 4 to enable a subsequent relative movement between the expansion body 8 and the extrusion profile 4. Due to this, the expansion body 8 is pressed outward relative to the extrusion profile 4 in the expansion direction x, and the crash surface 10 penetrates through the cutout 12 forward, with the crash surface 10 finally coming to rest in front of the front side 4.1 of the extrusion profile 4.

[0073] As shown in Fig. As shown in Figure 4C, after the expansion body 8 is fully extended, a second stage of the airbag 18 is ignited, so that the airbag 18 also expands in and against the transverse direction z, whereby the airbag 18 presses against the blocking bodies 20, 22. As a result, corresponding explosive screws 24, which fix the blocking bodies 20, 22 to the rear side 4.2 of the extruded profile 4, are exploded, so that the blocking bodies 20, 22.

[0074] As the airbag 18 continues to expand in and against the transverse direction z, it displaces the blocking bodies 20, 22. The blocking bodies 20, 22 then come to rest between the rear side 4.2 of the extruded profile 4 and a contact surface 8.2 of the expansion body 8, thus forming part of a force path for a force introduced into the bending beam 2 via the crash surface 10. The blocking bodies 20, 22 are accordingly designed as deformation bodies. The airbag 18 thus acquires a T-shaped cross-section.

[0075] The deployment of the airbag 18 and thus the displacement of the expansion body 8 and the blocking bodies 20, 22 takes only a few hundredths to tenths of a second.

[0076] In the Fig.In the configuration shown in Figure 4C, the bending beam 2 is prepared for an impending crash with an obstacle or another motor vehicle, whereby the available deformation path is greater than with a conventional bending beam.

[0077] Although the invention has been illustrated and explained in detail by preferred embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. It is therefore clear that numerous variations exist. It is also clear that exemplary embodiments are truly only examples and should not be construed as limiting the scope, possible applications, or configuration of the invention in any way.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without departing from the scope of protection defined by the claims and their legal equivalents, such as a further explanation in the description. List of reference symbols 2 bending beams 4 extruded profile 4.1 Front 4.2 Back 4.3 Top 4.4 Bottom 6 chamber 8 expansion bodies 8.1 Stop surface 8.2 Contact surface 10 Crash area 12 Excerpt 14 Overhang 16 Expansion channel 18 airbags 20, 22 blocking body 24 explosive screw 26 Hole x Expansion direction z transverse direction

Claims

[1] Bending beam (2) of a motor vehicle, with an extruded profile (4) with a front side (4.1) and a rear side (4.2), wherein at least one chamber (6) is formed between the front side (4.1) and the rear side (4.2), wherein an expansion body (8) with a crash surface (10) is arranged in the chamber (6), wherein at least one cutout (12) is provided in the front side (4.1) of the extruded profile (4), in the region of which the crash surface (10) of the expansion body (8) is arranged, wherein an airbag (18) is arranged in the at least one chamber (6) between the rear side (4.2) of the extruded profile (4) and the expansion body (8), wherein the airbag (18) is designed, after its ignition, to move the expansion body (8) in an expansion direction (x) with the crash surface (10) through the cutout (12) of the front side (4.1) of the extruded profile (4), so that the crash surface (10) is arranged in front of the front side (4.1) of the extruded profile (4) in the expansion direction (x), characterized by , that at least one blocking body (20, 22) is arranged in the chamber (6), which blocking body can be placed between the rear side (4.2) of the extruded profile (4) and a contact surface (8.2) of the expansion body (8), and the placement of the at least one blocking body (20, 22) is provided by means of the airbag (18)... [2] Bending beam (2) according to the preceding claim, characterized by that the expansion body (8) and / or the at least one blocking body (20, 22) are each fixed to the rear side (4.2) of the extruded profile (4) by means of at least one explosive fixing (24). [3] Bending beam (2) according to one of the preceding claims, characterized by that the at least one expansion body (8) has at least one stop surface (8.1) which is provided for abutment against the front side (4.1) of the extruded profile (4). [4] Bending beam (2) according to one of the preceding claims, characterized bythat an expansion channel (16) for guiding the airbag (18) is provided on the expansion body (8). [5] Motor vehicle with at least one bending beam (2) according to one of the preceding claims. [6] Method for protecting the occupants of a motor vehicle according to claim 5, characterized by that a crash or an impending crash is detected, wherein the airbag (18) is ignited, whereby the expansion body (8) is moved forward by the airbag (18) in the expansion direction (x) in a first stage. [7] Method according to claim 6, characterized by that the airbag (18) in a second stage moves the blocking body or bodies (20, 22) between the extruded profile (4) and the expansion body (8). [8] Method according to claim 7, characterized by that the second stage is activated by a second ignition of the airbag (18).

Images