Frunk arrangement for a motor vehicle and corresponding motor vehicle

Abstract

The invention relates to a frunk arrangement (10) for a motor vehicle (12) comprising a front trunk (14) which includes a wall assembly (18) enclosing an interior space (16) with an opening (20) and a pivotable frunk cover (22) which covers the opening (20) in a closed position, wherein the wall assembly (18) and the frunk cover (22) are each double-walled and a respective first wall (24) and a respective second wall (26) fluid-tightly enclose a respective cavity (28) and the respective cavity (28) is at least partially filled with a non-Newtonian fluid (30), wherein, when a force acts from the outside on the wall assembly (18) and / or the frunk cover (22), at least part of the force can be absorbed by the non-Newtonian fluid (30) and / or a distribution of the acting force over the front trunk (14) can be initiated. The invention further relates to a motor vehicle (12).

Description

[0001] The invention relates to a frunk arrangement for a motor vehicle, comprising a front trunk according to claim 1. Furthermore, the invention relates to a motor vehicle according to claim 10.

[0002] A front trunk is called a "frunk" in English, a portmanteau of "front" and "trunk" (cargo space) also used in German. A frunk is typically found in electric vehicles because the arrangement and / or size of an electric motor, and the absence of a combustion engine, frees up space in the area of ​​the traditional engine compartment. Thus, electric vehicles lack conventional engine blocks, which can lead to weaker crumple zones and consequently greater structural damage in frontal collisions.

[0003] Current passive safety systems do not offer adaptive impact damping before a collision occurs. Pole and offset crashes concentrate the force on a small area, which can also have a negative impact on structural damage.

[0004] DE 103 05 868 A1 discloses an element for damping the impact of a road user on an inner or outer part of a motor vehicle, consisting of a flexible outer shell that encloses the element gas-tight on all sides and a fluid filling the element, wherein the viscosity of the fluid can be changed by applying an electromagnetic field.

[0005] Furthermore, DE 10 2017 003 013 B4 discloses a bumper arrangement for a motor vehicle, with an absorber element arranged on an outer side of a bumper cross member, which has different deformation behavior in respective sub-areas, wherein at least one of the sub-areas of the absorber element is formed by a receiving element for a non-Newtonian fluid.

[0006] German patent DE 10 2023 115 207 A1 discloses a vehicle battery housing with a housing wall having at least one cavity in which battery cells of the vehicle battery are accommodated, the cavity being filled with a non-Newtonian fluid. The use of non-Newtonian fluids in the front area of ​​motor vehicles for the protection of battery cells is also disclosed in CN 21 8334079 U.

[0007] The object of the present invention is to provide a frunk arrangement and a motor vehicle which provides a demand-dependent, energy-absorbing mechanism that is particularly lightweight, reusable and especially passive, and can therefore be designed, for example, without an active deployment mechanism.

[0008] This problem is solved according to the invention by the subject matter of the independent claims. Advantageous embodiments and further developments of the invention are the subject matter of the dependent claims, the description, and the drawings.

[0009] A first aspect of the invention relates to a frunk arrangement for a motor vehicle. The motor vehicle can, in particular, be an electrically powered passenger car. The frunk arrangement according to the invention comprises a front trunk, which has a wall structure enclosing an interior space and an opening, in particular oriented in the vertical direction of the vehicle in the operating position, and a pivotable frunk cover, which covers the opening in the open or closed position.

[0010] In order to advantageously provide impact protection for the motor vehicle, the invention provides that the wall assembly and the frunk cover are each double-walled, with a respective first wall and a respective second wall fluid-tightly enclosing a respective cavity, and the respective cavity being at least partially filled with a non-Newtonian fluid, wherein, in the event of an external force acting on the wall assembly and / or the frunk cover, at least part of the force can be absorbed by the non-Newtonian fluid and / or a distribution of the acting force over the front trunk can be initiated.

[0011] In other words, both the frunk (front trunk) and its cover are formed from a double-walled structure, creating a cavity within the double-walled structure. Advantageously, both the outer and inner walls are welded together to create a watertight or fluid-tight seal. This cavity is filled with a non-Newtonian fluid, specifically a non-Newtonian liquid, to create a passive energy-absorbing barrier that can dynamically adapt to impact forces. A non-Newtonian fluid behaves in such a way that, under normal conditions, it exhibits a soft, especially liquid, state, which, for example, allows for a lightweight and flexible vehicle design.In the case of sudden stresses, for example during an impact, the liquid solidifies immediately, forming a rigid protective layer that absorbs and / or redistributes impact energy.

[0012] The non-Newtonian fluid is a dilatant fluid and therefore exhibits shear distortion. This is referred to as shear thickening. This occurs due to an increase in viscosity caused by a structural change in the fluid, which leads to stronger interactions between individual fluid particles, causing them to interlock and slide past each other less easily. The viscosity, and thus the resistance to shear, of a dilatant fluid increases with the shear rate, but at a constant shear rate, it does not depend on time.

[0013] One advantage is that the double-walled construction provides exceptionally high structural stability, while the airtight or fluid-tight seal prevents the escape of the non-Newtonian fluid, especially under external forces. Another advantage is that the frunk assembly operates passively and requires no electrical sensors or active release mechanisms, thus ensuring reliability across a wide variety of impact scenarios. The frunk, filled with the non-Newtonian fluid, and its cover absorb and distribute beneficial impact forces, reducing cabin deformation in situations such as frontal, offset, and / or pole crashes. Furthermore, local impacts, such as pole impacts, are mitigated because the fluid immediately solidifies to prevent deep penetration.In the event of offset impacts, the system can dynamically adapt to reinforce the affected side while remaining flexible elsewhere to ensure even energy distribution. In a collision with a pedestrian, the frunk provides a soft initial contact that gradually absorbs energy, thus maximizing impact protection.

[0014] In an advantageous embodiment of the invention, the first wall is welded to the second wall. Additionally or alternatively, the respective cavity is sealed pressure-tight. The weld seam between the first and second walls is designed such that the cavity is completely welded around its perimeter, thereby creating, for example, a pressure-tight or airtight seal. In other words, the entire cavity is sealed, including, for example, a connection between the frunk cover and the vehicle structure, in order to minimize or, in particular, prevent the escape of non-Newtonian fluid, even under the corresponding temperature and / or vibration loads that can occur, for example, during normal operation of the vehicle. This offers the advantage of a particularly reliable frunk assembly.

[0015] In a further advantageous embodiment of the invention, at least one structural element is formed, extending through at least one of the cavities and connecting the first wall and the second wall. This structural element can, in particular, control the energy input and / or energy distribution both into the cavity and / or the second wall, as well as into the non-Newtonian fluid. In other words, the double-walled construction is equipped with struts or similar elements to provide particularly high structural stability. This offers the advantage of, for example, exceptionally high crash stability.

[0016] In a further advantageous embodiment of the invention, the respective first wall forms an outer wall of the front trunk and / or the first wall and / or the second wall at least partially comprises an elastomer, or the first wall or the second wall is at least partially formed from the elastomer. In other words, the second wall faces the interior or is located closer to the interior than the first wall, so that the respective first wall is formed on the outside of the front trunk and in particular forms an outer wall, which may, for example, be further covered. It has proven particularly advantageous for the outer wall if it is at least partially formed from or comprises an elastomer. In particular, an elastomer with a particularly high tensile strength can be used.This offers the advantage that the cavities can be sealed particularly effectively and, furthermore, energy can be advantageously transferred into the non-Newtonian fluid.

[0017] In a further advantageous embodiment of the invention, the elastomer is a thermoplastic polyurethane or comprises at least a portion of a thermoplastic polyurethane. Additionally or alternatively, at least one of the walls is fiber-reinforced, for example, by means of aramid fibers such as Kevlar, for instance in the form of filaments or staple fibers. Furthermore, other fibers, such as carbon fibers or the like, can be used. In particular, individual areas of the respective wall can be formed with the elastomer. This offers the advantage that, due to the thermoplastic polyurethane, particularly low wear and / or high tear strength as well as advantageous tensile strength can be achieved, and, through the fibers or the fiber reinforcement, for example, a particularly high tear strength can also be achieved.

[0018] In an advantageous embodiment of the invention, at least one of the cavities, i.e., the cavity of the wall assembly and / or the cavity of the frunk cover, is subdivided into chambers. In other words, the wall assembly and / or the frunk cover has several, in particular separate, cavities. Thus, the frunk can be subdivided into chambers, which, for example, form a honeycomb structure, in order to selectively retain the non-Newtonian fluid at appropriate locations and / or thus advantageously control or influence the energy distribution.

[0019] In a further advantageous embodiment of the invention, at least one pressure equalization valve for the respective cavity is provided or formed on the wall assembly and / or on the frunk cover. In other words, a venting or pressure equalization valve is provided, particularly in the case of especially high pressure peaks during an impact, which in particular integrates a defined opening threshold, for example comparable to an airbag. This offers the advantage that the frunk assembly can be used particularly advantageously.

[0020] In a further advantageous embodiment of the invention, conductive elements are formed that are connected to or linked with a vehicle body in the operating position, through which the force can be directed into the wall and / or the frunk cover at particularly predetermined locations. The connection is, in particular, an effective connection, so that the forces acting on the vehicle body in the event of an impact, for example on a hood and / or the front of the vehicle, can be advantageously directed into the front trunk in order to dissipate energy there as advantageously as possible, ideally in accordance with the effect of an air cushion.

[0021] In a further advantageous embodiment of the invention, the non-Newtonian fluid contains silica particles and / or polyethylene glycol. Advantageously, the non-Newtonian fluid comprises the silica particles in polyethylene glycol (PEG). The use of silica particles in combination with polyethylene glycol results, for example, in particularly rapid solidification behavior at shear rates such as those expected in a vehicle impact. This offers the advantage that the frunk arrangement enables particularly efficient energy absorption, which therefore does not need to be absorbed by other components of the vehicle.

[0022] A second aspect of the invention relates to a motor vehicle comprising a frunk arrangement according to the first aspect of the invention.

[0023] Advantageous embodiments and further developments, as well as advantages of the first aspect of the invention, are to be regarded as advantageous embodiments and further developments, as well as advantages of the second aspect of the invention, and vice versa.

[0024] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figure alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0025] It shows: Fig. 1 A schematic sectional view of the front of a motor vehicle, comprising a frunk arrangement.

[0026] Fig. Figure 1 shows a schematic sectional view of a vehicle front, comprising a frunk arrangement 10 of a motor vehicle 12, which is to be presented and introduced here by means of the frunk arrangement 10.

[0027] The frunk arrangement 10 and thus the motor vehicle 12 comprise a front trunk 14, which has a wall assembly 18 enclosing an interior 16 with an opening 20 shown here, oriented in the vehicle's vertical direction in the operating position, and a pivotable frunk cover 22, which is pivotable, for example, via an axle, and in a closed position covers the opening 20 to close the interior.

[0028] To make the frunk assembly 10 particularly advantageous for use in, for example, a frontal collision with the vehicle 12, the wall assembly 18 and the frunk cover 22 are each double-walled, with a first wall 24 and a second wall 26 forming or enclosing a cavity 28, which is particularly fluid-tight and at least partially filled with a non-Newtonian fluid 30. Due to the physical properties of the non-Newtonian fluid 30, at least a portion of any external force or impact force acting on the wall assembly 18 and / or the frunk cover 22, especially on their respective first walls 24 (which serve as outer walls), can be absorbed and / or a distribution of the force across the front trunk 14 can be initiated.

[0029] It has proven advantageous if the respective cavity 28 is sealed particularly airtight, which can be achieved, for example, by welding the first wall 24 to the respective second wall 26.

[0030] The sectional view shows that the frunk assembly 10 is embedded in the front of the vehicle between a front panel 32 and is arranged in the vertical direction of the vehicle, for example above a radiator 34 and / or below a hood 36, wherein, for example, the front panel 32 is connected to the front trunk via a conduit element 38, wherein the conduit element 38 is designed, for example, to direct the force into the wall assembly 18 and / or the frunk cover 22 at a predetermined location.

[0031] Furthermore, at least one structural element leading through one of the cavities 28 and connecting the first wall 24 and the second wall 26 can be formed, which can also be used, for example, to direct force into the fluid 30.

[0032] In the vehicle 12 shown and the associated frunk assembly 10, the advantage arises that the non-Newtonian fluid 30 can automatically adapt to different impact intensities, or rather, its viscosity varies or increases according to the impact intensity. This results in the possibility of particularly advantageous impact protection, whereby, for example, deformation or force on other vehicle components, especially the passenger compartment, can be particularly low in high-speed and / or offset accidents.

[0033] Furthermore, the use of the non-Newtonian fluid 30 requires no additional sensors, electronics, or active components, so the frunk assembly 10 shown is always ready for operation in terms of crash safety and impact protection. The non-Newtonian fluid 30 is, in particular, a shear-thickening suspension and is based, for example, on silica particles in polyethylene glycol (PEG). This fluid remains liquid under normal conditions, even with minor vibrations and / or slow movements. Only when a sudden shear load occurs, such as during an impact, does the material solidify abruptly and behave accordingly, similar to a solid. After the load is removed, it automatically returns to its original state.This ability can be particularly advantageous for absorbing and / or redistributing energy in impact situations, or when a force is applied where the load can change rapidly and / or locally. Tests show that a suitable non-Newtonian fluid 30 exhibits solidification behavior at shear rates above 1000 / s, meaning it could also be used, for example, in ballistic protection systems.

[0034] In pole crashes, the fluid hardens precisely where the pole impacts, thus preventing penetration into the vehicle. In an offset frontal crash, stiffening can occur asymmetrically depending on the force applied, offering an advantage over the rigid structures of conventional vehicles. Furthermore, pedestrian protection is particularly high, as initially soft structures and controlled energy absorption during a collision with a pedestrian can be achieved. In summary, dynamic damping and distribution upon impact, as well as local stiffening thanks to the corresponding fluid reaction, are possible, allowing adaptive stiffening to occur precisely where needed.

[0035] Furthermore, at least one pressure equalization valve can be provided for at least one of the cavities 28, which in particular has a defined opening threshold so that, for example, in the case of particularly high pressure peaks or acting forces, a corresponding pressure equalization is possible. In addition, the respective cavity 28 can be subdivided into several chambers, for example by means of a honeycomb structure, in order to selectively retain the non-Newtonian fluid 30 and / or to control the energy distribution. Furthermore, a corresponding structural element can be provided between the respective first wall 24 and the second wall 26, for example for stiffening or for directing the force into the non-Newtonian fluid.

[0036] The frunk arrangement 10 and the motor vehicle 12 shown demonstrate a frunk concept for particularly good crash performance.

Claims

[1] Frunk arrangement (10) for a motor vehicle (12) comprising a front trunk (14) which includes a wall assembly (18) enclosing an interior space (16) with an opening (20) and a pivotable frunk cover (22) which covers the opening (20) in a closed position, wherein the wall assembly (18) and the frunk cover (22) are each double-walled and a respective first wall (24) and a respective second wall (26) fluid-tightly enclose a respective cavity (28) and the respective cavity (28) is at least partially filled with a non-Newtonian fluid (30), wherein, in the case of a force acting from the outside on the wall assembly (18) and / or the frunk cover (22), at least part of the force can be absorbed by the non-Newtonian fluid (30) and / or a distribution of the acting force over the front trunk (14) can be initiated. [2] Frunk arrangement (10) according to claim 1, characterized by, that the first wall (24) is welded to the second wall (26) and / or the respective cavity (28) is sealed pressure-tight. [3] Frunk arrangement (10) according to claim 1 or 2, characterized by , that at least one structural element is formed which leads through at least one of the cavities (28) and connects the first wall (24) and the second wall (26). [4] Frunk arrangement (10) according to any one of the preceding claims, characterized by , that the respective first wall (24) forms an outer wall of the front trunk (14) and / or the first wall (24) and / or the second wall (26) is at least partially made of and / or includes an elastomer. [5] Frunk arrangement (10) according to claim 4, characterized by that the elastomer comprises a thermoplastic polyurethane and / or at least one of the walls (24, 26) is fiber-reinforced. [6] Frunk arrangement (10) according to any one of the preceding claims, characterized by, that at least one of the cavities (28) is subdivided into chambers. [7] Frunk arrangement (10) according to any one of the preceding claims, characterized by that the wall assembly (18) and / or the frunk cover (22) include at least one pressure equalization valve for the respective cavity. [8] Frunk arrangement (10) according to any one of the preceding claims, characterized by , that in the operating position connected to a vehicle body, conduit elements (38) are formed through which the force can be directed to the wall device (18) and / or the frunk cover (22) at predetermined points. [9] Frunk arrangement (10) according to any one of the preceding claims, characterized by , that the non-Newtonian fluid (30) contains silica particles and / or polyethylene glycol (PEG). [10] Motor vehicle (12) comprising a frunk arrangement (10) according to one of the preceding claims.

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