Vehicle as well as boundary element and impact element for the vehicle

Abstract

The invention relates to a vehicle with a flexible cross member (1), a bumper fascia (2), an impact element (3) arranged in the vehicle longitudinal direction (X) between the flexible cross member (1) and the bumper fascia (2), a detection unit (4) received by the impact element (3) and extending in the vehicle transverse direction (Y) along the impact element (3) for detecting an impact on the bumper fascia (2) and a limiting element (5) arranged at least in sections in the vehicle longitudinal direction (X) between the impact element (3) and the flexible cross member (1) for limiting the deformation of the impact element (3) when an object impacts the bumper fascia (2).The vehicle according to the invention is characterized in that the limiting element (5), at least viewed in the vehicle vertical direction (Z), runs between the impact element (3) and the bending cross member (1) at the geodetic height (h) at which the detection unit (4) runs, wherein the limiting element (5), viewed in the vehicle transverse direction (Y), is divided into a first edge region (6-1), a second edge region (6-3) and a central region (6-2) arranged between them, wherein a depth (t) of the limiting element (5) in the vehicle longitudinal direction (X) is greater in the central region (6-2) than in the two edge regions (6-1, 6-3).

Description

[0001] The invention relates to a vehicle according to the preamble of claim 1s, a limiting element for the vehicle and an impact element for the vehicle.

[0002] Vehicles such as passenger cars are designed to provide a certain level of accident protection. The aim is to protect both vehicle occupants and those involved in accidents outside the vehicle, especially road users requiring special protection such as pedestrians or cyclists, from injury or to reduce the severity of their injuries in the event of a collision. Passive safety features, such as crumple zones, and active safety features such as airbags, an active hood, and the like, are known for this purpose.

[0003] The accident-safe design of a vehicle's front end is particularly challenging in this respect. A distinction must be made between high-energy and low-energy frontal accidents. A high-energy accident is associated with a high impact speed and / or a high mass of the object impacting the vehicle. For example, the vehicle travels at a high speed against a stationary object, or a massive object such as another vehicle collides head-on with the vehicle. In a low-energy accident, the vehicle collides with a pedestrian or cyclist, for example, particularly at low speeds. To ensure sufficient safety in the event of a high-energy accident, deformations of the vehicle's front end are absorbed by a bending cross member running in the transverse direction of the vehicle in front of the vehicle interior.However, a direct force connection between the front of the vehicle and the flexible cross member is disadvantageous in low-energy accidents. The supporting effect exerted by the flexible cross member would cause the front of the vehicle to form a rigid obstacle, meaning that in a low-energy accident, the corresponding impact energy cannot be sufficiently dissipated by deformation of the vehicle structure. This increases the risk of injury to pedestrians, cyclists, and the like. For this reason, the flexible cross member is mechanically decoupled from the vehicle's front bumper. An impact element, typically made of foam, is provided behind the bumper. This impact element is therefore also referred to as impact foam.The provision of the impact foam enables a support effect on the front bumper, while at the same time providing deformation capacity to reduce the corresponding impact energy.

[0004] To prevent excessive deformation of the impact foam and to enable a frictional connection to the bending cross member in the event of a high-energy accident, so-called limiting elements, also known as pendulum stoppers, are provided on the sides of the impact foam. Such an arrangement is known from DE 10 2013 009 312 B4. Furthermore, a detection unit can be integrated into the impact element for detecting an impact. This detection unit can in particular be designed as a so-called hose sensor. This is a hermetically sealed hose filled with a fluid medium, at at least one end of which a pressure sensor is provided. If an impact occurs on the vehicle, a pressure change in the fluid medium occurs, which can be detected accordingly by the sensor element. This can be used to trigger an active hood.To ensure sufficient detection quality, the detection unit must be able to detect corresponding impulses or impacts even in low-energy accidents. This increases the requirements for the integration of the detection unit into the front of the vehicle. The impact element must be sufficiently soft so that corresponding impacts on the front of the vehicle can be detected by the detection unit, yet sufficiently rigid or hard to ensure a certain degree of support.

[0005] In vehicles with a high structural depth, i.e. a front section that is elongated in the longitudinal direction of the vehicle, the arrangement known from DE 10 2013 009 312 B4 reaches its limits. For example, the flexible cross member only becomes effective as a braking element very late in the event of a crash. The corresponding pendulum stoppers would therefore have to be designed to be comparatively elongated and slim, so that they are prone to buckling under load. The pendulum stoppers would therefore have to be made thicker. This, in turn, would mean that the impact foam would have to be installed in a comparatively narrow groove with the detection unit, which, due to correspondingly unfavorable geometric conditions, would impair the signal quality detectable by the detection unit.

[0006] The present invention is therefore based on the object of providing a vehicle that is improved compared to the prior art.

[0007] According to the invention, this object is achieved by a vehicle having the features of claim 1. Advantageous embodiments and further developments as well as a limiting element and impact element that can be used to form the vehicle according to the invention result from the claims dependent thereon.

[0008] A generic vehicle with a flexible cross member, a bumper fascia, an impact element arranged in the vehicle longitudinal direction between the flexible cross member and the bumper fascia, a detection unit received by the impact element and extending in the vehicle transverse direction along the impact element for detecting an impact on the bumper fascia and a limiting element arranged at least in sections in the vehicle longitudinal direction between the impact element and the flexible cross member for limiting the deformation of the impact element in the event of an impact of an object on the bumper fascia, is further developed according to the invention in that the limiting element runs between the impact element and the flexible cross member at least when viewed in the vehicle vertical direction at the geodetic height at which the detection unit runs, wherein the limiting element, when viewed in the vehicle transverse direction, extends into a first edge region,a second edge region and a central region arranged between them, wherein a depth of the boundary element in the vehicle longitudinal direction is greater in the central region than in the two edge regions.,

[0009] By providing the limiting element between the impact element and the bending cross member at least at the geodetic height at which the detection unit runs, the detection unit is shifted forward in the vehicle's longitudinal direction, toward the front of the vehicle. The detection unit is thus closer to the bumper fascia provided at the front of the vehicle than without such a forward shift. If an impact occurs on the front of the vehicle, the corresponding forces, impulses, and impact energy are transmitted to the detection unit with less attenuation. This also makes the detection unit more reliably able to detect the corresponding impact. This improves the signal quality of the signals generated by the detection unit.

[0010] By providing a greater depth in the central region, the detection unit can be positioned even further toward the front of the vehicle in the direction of the vehicle's longitudinal axis than with a constant depth across the entire width of the boundary element. This further improves the detection quality of the detection unit. In the two edge regions, the detection unit is located closer to the flexible cross member, and in the central region, it is further away from it. The depth of the two edge regions can be different.

[0011] In particular, the sections of the limiting element that serve as a support for the impact element can be designed such that the cross-section viewed in the vehicle's longitudinal direction increases in the direction of the flexible cross member. This can improve the buckling behavior. However, this leads to a corresponding decrease in the cross-section of the impact element in the direction of the flexible cross member. By shifting the arrangement position of the detection unit forward towards the front of the vehicle, the detection unit can be provided at points on the impact element that are characterized by a comparatively larger cross-sectional area. This can further improve the detection quality of the detection unit. In particular, with a detection unit designed as a hose sensor, the corresponding hose diameter can be made larger, which further contributes to an improvement in the signal detection quality.

[0012] An advantageous development of the vehicle according to the invention provides that the detection unit extends essentially across the entire width of the flexible cross member, viewed in the transverse direction of the vehicle. This makes it possible to detect an impact on the front of the vehicle not only at one or a few locations, but across the entire width of the vehicle.

[0013] According to a further advantageous embodiment of the vehicle according to the invention, the limiting element extends only over a partial width of the flexible cross member, viewed in the vehicle's transverse direction. This arrangement may already be sufficient to position the detection unit forward toward the front of the vehicle. Thus, the detection unit extends relatively close to or even on the flexible cross member in the vehicle's transverse direction at those locations where the limiting element is not yet provided, and is positioned forward toward the front of the vehicle at those locations where the limiting element is provided.

[0014] Preferably, the depth of the first and second edge regions is equal. This further improves the signal quality of the detection unit due to the symmetrical design of the boundary element.

[0015] A further advantageous embodiment of the vehicle according to the invention further provides that the depth increases continuously from the first and second edge regions toward the center region. A sudden change in depth would result in inadequate detection of pressure fluctuations in the tube sensors. A continuous change in depth prevents kinks in the detection unit, which further improves the detectable signal quality.

[0016] The depth change is preferably linear or harmoniously curved. With a linear depth change, each edge region is connected to the central region via a straight ramp. With a harmoniously curved depth change, however, the ramp is curved. A linear depth change is characterized by its geometric simplicity. At the corresponding transition points from the edge regions to the central region, however, there is a kink, albeit a comparatively slight one. If the depth change is harmoniously curved, the corresponding transition points are rounded so that any angulation can be avoided. This is therefore a particularly preferred design variant.

[0017] It is also possible for the depth change to be linear from the first edge area to the center area and harmoniously curved from the second edge area to the center area, or vice versa. This provides even greater design freedom for adapting the geometric configuration of the boundary element to the specific vehicle geometry. The depth of each edge area could also not be constant across the width, but also increase toward the center area.

[0018] A further advantageous embodiment of the vehicle according to the invention further provides that the limiting element is arranged centrally in the vehicle's transverse direction opposite the flexible cross member. As a result, the detection unit is displaced centrally toward the front of the vehicle, as viewed in the vehicle's transverse direction. The respective areas at which the detection unit again approaches the flexible cross member in the vehicle's longitudinal direction are equidistant from the vehicle center, as viewed in the vehicle's transverse direction. Thus, a symmetrical arrangement position is achieved. This further improves the detection quality of the detection unit.

[0019] According to a further advantageous embodiment of the vehicle according to the invention, it is provided that the first and second edge regions or the sections with a depth change from the respective edge region to the central region, viewed in the vehicle's transverse direction, are arranged at those width positions of the flexible cross member at which the longitudinal members connecting the flexible cross member to the remaining vehicle frame are located. In other words, the limiting element thus runs, viewed in the vehicle's transverse direction, between the two longitudinal members connecting the flexible cross member to the remaining vehicle frame. This ensures a particularly robust design of the vehicle front.

[0020] A further advantageous embodiment of the vehicle according to the invention further provides that the limiting element is monolithic, in particular made of plastic. In other words, the limiting element consists of a single part. This ensures simple and cost-effective production of the limiting element and also facilitates its integration into the vehicle. Plastic has proven particularly suitable as a manufacturing material. Plastic is comparatively inexpensive and allows the mass of the limiting element to be reduced compared to, for example, a metal embodiment. The limiting element can be made of solid material, hollow material, or even foam. Mixed forms are also conceivable, for example a sandwich design.

[0021] A delimiting element according to the invention for a vehicle as described above has a shape that, when properly mounted on the vehicle, is capable of displacing the detection unit, at least in sections, toward the front of the vehicle, as viewed in the vehicle's longitudinal direction. For this purpose, the delimiting element is subdivided into a first edge region, a second edge region, and a central region arranged between them, with the depth of the delimiting element being greater in the central region than in the two edge regions. Thus, correspondingly designed delimiting elements fall within the scope of protection of the invention in and of themselves.

[0022] An impact element according to the invention for a vehicle described above is characterized by a shape adaptation to a limiting element described above. Thus, a correspondingly designed impact element also falls within the scope of protection of the invention. "Shape adaptation" means that the respective limiting element and the respective impact element bear against one another at least in a form-fitting manner when properly mounted on the vehicle. In addition, the limiting element and the impact element can also bear against one another in a force-fitting and / or material-fitting manner. Furthermore, it is also possible for the limiting element and the impact element to be spaced apart from one another.The respective side facing the other element is designed to match the geometric shape of the opposing element, so that the limiting element and the impact element can move toward each other in the event of an accident and can be accommodated in a correspondingly designed receptacle in the other element. This allows the elements to be configured to follow a corresponding movement trajectory in the event of a crash.

[0023] The limiting element can be attached to the flexible cross member or mounted on the vehicle independently of it. When attached to the flexible cross member, this attachment can be friction-locked, form-locked, and / or bonded.

[0024] To support the impact element, the limiting element can have projections projecting beyond the impact element in the direction of the vehicle's longitudinal axis.

[0025] These are provided at least on an upper and / or lower peripheral side of the impact element.

[0026] Further advantageous embodiments of the vehicle, limiting element and impact element according to the invention also emerge from the exemplary embodiments which are described in more detail below with reference to the figures.

[0027] Showing: Fig. 1 a schematic side view of a vehicle front end known from the prior art; Fig. 2 a schematic side view of a vehicle front end according to the invention; Fig. 3 a schematic plan view of the vehicle front end according to the invention; Fig. 4 a schematic plan view of a limiting element according to the invention according to a first embodiment; and Fig. 5 a schematic plan view of a limiting element according to the invention according to a second embodiment.

[0028] Identical parts are provided with the same reference symbols in the figures, so that reference is made to the description of the previous figures.

[0029] Fig. Figure 1 shows a vehicle front end known from the prior art, which provides a certain degree of accident protection in the event of an impact with the front of the vehicle. It depicts a flexible cross member 1 of a bumper assembly extending in the vehicle's transverse direction Y and a bumper fascia 2, also referred to as the outer bumper skin, arranged in front of the cross member in the vehicle's longitudinal direction X toward the front of the vehicle.

[0030] An impact element 3 is arranged in the vehicle's longitudinal direction X between the flexible cross member 1 and the bumper fascia 2, comprising a groove 8 in which a detection unit 4 is arranged or partially received, running in the vehicle's transverse direction Y. The detection unit 4 can particularly preferably be a so-called hose sensor system. This comprises a hermetically sealed hose filled with a fluid medium, with a pressure sensor for registering pressure differences being arranged at at least one end of the hose. At least one limiting element 5 is provided laterally above or below the impact element 3, which limits the freedom of movement of the impact element 3 in the event of an accident. The limiting element 5 can run above and / or below the impact element 3 in the vehicle's vertical direction Z.

[0031] The limiting element(s) 5 can be connected to the flexible cross member 1 in a form-fitting, force-fitting, and / or material-fitting manner. The impact element 3 is comparatively soft, in particular made of a deformable foam, while the limiting element 5 consists of or comprises a comparatively stiffer material. If an object strikes the bumper fascia 2, a force is first introduced into the impact element 3, which then deforms. These deformations are impressed on the detection unit 4 running in the groove 8 and can be detected by it. This makes it possible to detect the impact of objects with comparatively low energy, for example, if a pedestrian or cyclist strikes them at a slow vehicle speed.In the event of an accident with high energy, for example when a foreign vehicle hits the vehicle head-on, the bumper fascia 2 is deformed more strongly, so that the impact element 3 and / or the bumper fascia 2 come into contact with the limiting element 5, whereby a force flow is ultimately established to the bending cross member 1.

[0032] Disadvantageous in the Fig. 1 is that, in vehicles with a particularly elongated front section in the vehicle's longitudinal direction X, the bumper fascia 2 is moved correspondingly far away from the flexible cross member 1, so that comparatively long limiting elements 5 and impact elements 3 must be provided. To prevent the limiting elements 5 from buckling laterally in an accident, they must have a sufficient cross-sectional width.

[0033] Accordingly, the extension of the impact element 3, viewed in the vehicle's vertical direction Z, must become increasingly smaller in the direction of the bending cross member 1, so that ultimately the size of the groove 8 and thus also the cross-sectional area of ​​the detection unit 4 decreases. In addition, the distance between the bumper fascia 2 and the detection unit 4 increases in the vehicle's longitudinal direction X. This leads to a decrease in the detection quality of the detection unit 4.

[0034] Fig. Figure 2 shows an embodiment of a vehicle according to the invention, in which the limiting element 5 is arranged or runs between the impact element 3 and the bending cross member 1 at least at the geodetic height h at which the detection unit 4 runs. Furthermore, the limiting element 5 has a special shape, which will be described in more detail in Fig. 3. As a result, the detection unit 4 is positioned further forward in the vehicle's longitudinal direction X, towards the front of the vehicle, and thus virtually shifted towards the bumper fascia 2. This reduces the distance between the bumper fascia 2 and the detection unit 4, so that corresponding accident forces or impulses are less strongly dampened. This also allows them to be better detected by the detection unit 4. In addition, the cross-sectional narrowing of the impact element 3 and thus the groove reduction are less pronounced, so that a corresponding hose diameter can be made larger. This also improves the detection quality.

[0035] Fig. Figure 3 shows a top view of the vehicle front end according to the invention. In the embodiment shown here, the detection unit 4 extends across the entire width b of the flexible cross member 1. The limiting element 5, however, only extends across a partial width of the flexible cross member 1. Furthermore, the limiting element 5 is aligned centrally relative to the flexible cross member 1, as viewed in the vehicle transverse direction Y, which is illustrated by a dashed line.

[0036] According to the invention, the boundary element 5 is divided into a first and second edge region 6-1, 6-3 and a central region 6-2 arranged between these regions. The respective regions have a depth t in the vehicle's longitudinal direction X, with the depth t in the central region 6-2 being greater than in both edge regions 6-1 and 6-3. Fig. 3 shows a particularly preferred embodiment in which the depth t increases continuously in the edge regions 6-1 and 6-3 and then transitions into the depth t of the central region 6-2 in a ramp-like, harmonious curve. This provides a particularly advantageous supporting effect and an advantageous profile for the detection unit 4.

[0037] Particularly preferably, the respective edge regions 6-1, 6-3 or the corresponding depth transitions, viewed in the vehicle transverse direction Y, are arranged at those positions at which longitudinal members 7 connecting the bending cross member 1 to the remaining vehicle body shell are provided.

[0038] The Fig. 4 and Fig. 5 show alternative embodiments of the limiting element 5 according to the invention. In general, it is possible for the depth t to be constant in the two edge regions 6-1 and 6-3 or to also increase continuously towards the central region 6-2 (preferably monotonically or strictly monotonically). It would also be possible for the depth t 2 in the mid-range 6-2 increases continuously up to the middle of the mid-range (not shown).

[0039] Fig. 4 shows an embodiment with constant depth gradients along the edge regions 6-1 and 6-3, wherein the depth t changes following a harmonically curved ramp function to the central region 6-2.

[0040] Fig. Figure 5 shows an embodiment in which the depths t 1 , t 3 constant, while the depth transition to the midrange 6-2 follows a linear ramp function.

[0041] In Fig. 3 takes the depth t 1 , t2 in the edge areas 6-1, 6-2 continuously, followed by a harmoniously curved transition to the middle area 6-3 with the depth t 3 .

[0042] The vehicle according to the invention is characterized by a limiting element 5 according to the invention (as well as an impact element 3 according to the invention), which advances the detection unit 4 toward the bumper fascia 2. This improves the detection quality of the detection unit 4. Furthermore, the path of the detection unit 4 can thus be adapted to the geometric design of the bumper fascia 2, i.e., the front of the vehicle, which would not be possible if the contour of the bending cross member 1 were followed alone. Thus, the shape of the bending cross member 1 often cannot follow the corresponding geometry of the vehicle front section with sufficient accuracy due to the manufacturability of the corresponding geometry, a problem that can thus also be overcome. QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] DE 10 2013 009 312 B4 [0004, 0005]

Claims

[1] Vehicle with a flexible cross member (1), a bumper fascia (2), an impact element (3) arranged in the vehicle longitudinal direction (X) between the flexible cross member (1) and the bumper fascia (2), a detection unit (4) received by the impact element (3) and extending in the vehicle transverse direction (Y) along the impact element (3) for detecting an impact on the bumper fascia (2), and a limiting element (5) arranged at least in sections in the vehicle longitudinal direction (X) between the impact element (3) and the flexible cross member (1) for limiting the deformation of the impact element (3) when an object impacts the bumper fascia (2), characterized bythat the limiting element (5), at least viewed in the vehicle vertical direction (Z), runs between the impact element (3) and the bending cross member (1) at the geodetic height (h) at which the detection unit (4) runs, wherein the limiting element (5), viewed in the vehicle transverse direction (Y), is divided into a first edge region (6-1), a second edge region (6-3) and a central region (6-2) arranged between them, wherein a depth (t) of the limiting element (5) in the vehicle longitudinal direction (X) is greater in the central region (6-2) than in the two edge regions (6-1, 6-3). [2] Vehicle according to claim 1, characterized by that the detection unit (4) extends essentially over the entire width (b) of the bending cross member (1) when viewed in the vehicle transverse direction (Y). [3] Vehicle according to claim 1, characterized by that the limiting element (5) extends only over a partial width of the bending cross member (1) when viewed in the vehicle transverse direction (Y). [4] Vehicle according to one of claims 1 to 3, characterized by that the first and second edge area (6-1, 6-3) have the same depth (t 1 , t 3 ). [5] Vehicle according to one of claims 1 to 4, characterized by that the depth (t 1 , t 3 ) increases continuously from the first and second edge region (6-1, 6-3) towards the central region (6-2). [6] Vehicle according to claim 5, characterized by that the depth change is linear or harmonically curved. [7] Vehicle according to one of claims 3 to 6, characterized by that the limiting element (5) is arranged centrally in the vehicle transverse direction (Y) opposite the bending cross member (1). [8] Vehicle according to one of claims 1 to 7, characterized bythat the first and second edge regions (6-1, 6-3) or the sections with a change in depth from the respective edge region (6-1, 6-3) to the central region (6-2) viewed in the vehicle transverse direction (Y) are arranged at those width positions of the bending cross member (1) at which longitudinal members (7) connecting the bending cross member (1) to the rest of the vehicle frame are located. [9] Vehicle according to one of claims 1 to 8, characterized by that the limiting element (5) is monolithic, in particular made of plastic. [10] Limiting element (5) for a vehicle according to one of claims 1 to 9, characterized by a subdivision into a first edge region (6-1), a second edge region (6-3) and a central region (6-2) arranged between them, wherein a depth (t) of the boundary element (5) in the central region (6-2) is greater than in the two edge regions (6-1, 6-3). [11] Impact element (3) for a vehicle according to one of claims 1 to 9, characterized by a shape adaptation to a limiting element (5) according to claim 10.

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