Motor vehicle with a sealing arrangement

Abstract

Motor vehicle (1) with a sealing arrangement (3) comprising a sealing element (4) for sealing a joint (5) between a first body part (6) and a second body part (7) movably mounted therein, wherein the sealing element (4) has an inflatable cavity (8) and the sealing arrangement (3) is designed such that it adjusts the amount of air in the cavity (8) of the sealing element (4) and thus the stiffness of the sealing element (4) as a function of a driving speed “v” of the motor vehicle (1), characterized in that the cavity (8) of the sealing element (4) is communicatively connected to a piston-cylinder assembly (10) via a connecting line (9) and that a piston (12) of the piston-cylinder assembly (10) is subjected to back pressure when the motor vehicle (1) is traveling forward, wherein the first body part (6) is a front bumper (16) and the second body part (7) is a hood (14). are,wherein the piston-cylinder assembly (10) is provided on the front bumper (16), and wherein the piston (12) of the piston-cylinder assembly (10) has a return spring.

Description

[0001] The present invention relates to a motor vehicle with a sealing arrangement comprising a sealing element for sealing a joint between a first body part and a second body part movably mounted therein, according to the preamble of claim 1. The invention further relates to a method for operating such a motor vehicle.

[0002] From EP 2 050 607 B1, a motor vehicle of this type is known, comprising a sealing arrangement and a tubular sealing element extending between a hood and the front body of the vehicle. The hood is pivotable relative to the front body between a raised and a closed position, with the hood, in the closed position, simultaneously resting on the tubular seal and a foam block.

[0003] From DE 101 26 195 C1, a front hood arrangement for a motor vehicle is known, which has a lateral separation joint between the front hood and a fender. The front hood has an inner inner hood and an outer outer hood, as well as a stiffening zone which, when the front hood is closed, is directly or indirectly supported by a supporting structure of the vehicle body. The outer hood has a lateral edge region, with at least one connecting web provided, via which the stiffening zone is connected to the edge region of the outer hood. In order to improve the spreading behavior in the event of a vertical impact on the front hood, the stiffening zone is laterally supported outwards by anchor points when the front hood is closed.

[0004] From DE 27 11 339 C3, a pedestrian impact protection device for a motor vehicle is known, comprising a front hood located at pedestrian height, attached to the vehicle by means of bearings, and yielding upon impact. The hood bearing is designed to yield to forces acting on the front hood from the front and / or from above, caused by a pedestrian impact. This is intended to at least reduce injuries in the event of a pedestrian collision.

[0005] A seal for a vehicle is known from DE 10 2004 033 939 A1. This seal serves to seal a movable body component, in particular a door, against an adjacent fixed body structure, is made of an elastic material, and comprises at least one longitudinally extending hollow profile whose shape can be changed during driving. In order to reduce the required amount of pressure medium for a seal of the aforementioned type while maintaining good function, it is provided that only partial areas of the entire longitudinal extent of the hollow profile of the seal are designed to be inflatable during driving.

[0006] Seals in which the pressure can be varied are also known from DE 10 2010 053 830 A1, DE 42 16 692 A1 and US 4 761 917 A.

[0007] From DE 10 2013 213 793 A1, a vehicle with a pedestrian protection device is known which has at least one sensor element in the area of ​​a front bumper for detecting an impact force and at least one actuator which, upon detection of the impact force, lifts the hood from an operating position to an impact position. According to the invention, a force transmission unit is connected between the sensor element and the actuator, with which the impact force exerted on the sensor element can be directly converted into an actuating force for lifting the hood into the impact position, in particular without any further external energy.

[0008] DE 42 39 120 C2 and JP 11048894 A show airbags of a motor vehicle which are inflated by a volume which is compressed in a frontal impact.

[0009] DE 10 2009 023 031 A1 shows a safety arrangement with a pneumatic working element which uses a pressure gradient generated by the airflow of a vehicle to automatically move a locking element into the locked position.

[0010] From EP 1 167 102 A1 a method for operating a motor vehicle is known in which a sealing arrangement adjusts a quantity of air in at least one cavity of a sealing body and thus a stiffness of the sealing body as a function of a driving speed of the motor vehicle.

[0011] From DE 10 2015 121 360 A1, a motor vehicle door with an exterior mirror attached to it and with at least one expandable hollow profile made of an elastic polymeric material arranged on the motor vehicle door is known, wherein the hollow profile forms a seal or part of a seal of the motor vehicle door for sealing with components adjacent to it, and wherein the fluid enclosed by the hollow profile is connected via a fluid line to at least one pressure-dependent pressure-generating element, so that an overpressure generated by the pressure-generating element increases the fluid pressure inside the hollow profile.

[0012] From DE 100 23 193 A1 a vehicle body for a front section of a motor vehicle is known, in which a support structure is provided which essentially consists of a fender support and a fender panel, wherein the fender panel can optionally be replaced by another fender panel so that a changed joint profile between the front flap and the fender can be achieved.

[0013] From DE 10 2011 056 049 A1, a hinge device for the movable connection of a vehicle flap to a vehicle body part is known, comprising a first hinge part connected to the vehicle flap and a second hinge part connected to the vehicle body part, wherein two pivoting elements are provided, each pivotally connected to the first and second hinge parts, and wherein an adjusting element is provided, which is also pivotally connected to the first and second hinge parts.

[0014] Especially with electric vehicles, noise comfort is increasingly coming into focus, as the elimination of the combustion engine and the associated reduced noise emissions increase general noise reduction requirements in all areas. Particularly at higher vehicle speeds, airflow can whistle through a relatively narrow gap between the hood and a fender or front bumper, generating increased and, in particular, disturbing noise. This can be remedied, for example, by using existing rubber bladder seals that seal the gap when the hood is closed.A disadvantage of this type of bladder seal, however, is that it mounts the hood relatively rigidly in the event of a pedestrian impact, making it less deformable and less able to absorb impact energy. This is because, upon impact, the pedestrian, and especially their head, must first compress the bladder seal, and even in its compressed state, the seal still acts as a rubber abutment.

[0015] The present invention therefore deals with the problem of providing an improved or at least an alternative embodiment for a motor vehicle of the generic type, which is characterized in particular by improved pedestrian impact protection and reduced noise.

[0016] This problem is solved according to the invention by the subject matter of independent claim 1 and the method described in claim 8. Advantageous embodiments are the subject matter of the dependent claims.

[0017] The present invention is based on the general idea of ​​providing a pneumatic system for the speed-dependent inflation of a sealing element of a sealing arrangement for sealing a joint between a first and a second body part of a motor vehicle which is movably mounted thereto, which at higher speeds enables inflation of the at least one sealing element and thus a reliable and noise-optimized sealing of the joint, and at lower speeds enables deflation of the sealing element of the sealing arrangement, which in this case then provides increased pedestrian impact protection.The motor vehicle according to the invention has a sealing arrangement with at least one sealing element for sealing a joint between a first body part and a second body part movably mounted therein, wherein the sealing element of the sealing arrangement has a cavity and is inflatable, and the sealing arrangement is simultaneously designed such that it adjusts the amount of air in the at least one sealing element, and thus the stiffness of the sealing element, depending on the driving speed of the motor vehicle. As will be explained below, this can be achieved in different ways, but in all cases it ensures that at comparatively low driving speeds, for example at a driving speed v < 40 km / h of the motor vehicle, no inflation occurs.The sealing element, at least one of which is emptied, is designed so that in the event of a pedestrian collision, and especially if the pedestrian's head strikes the second body panel (the hood), the deceleration of the pedestrian's head is reduced, thus lowering the risk of injury. Because the sealing arrangement does not seal the gap at the relatively low speeds of the vehicle, a pedestrian's head striking the second body panel in an accident no longer needs to compress the sealing arrangement or its sealing element, as it is already compressed due to its uninflated cavity and therefore offers no resistance.At higher speeds, where whistling noises can occur in the joint due to the wind, the sealing arrangement according to the invention increases the amount of air in the cavity of the sealing element and thus its rigidity, thereby reliably sealing the joint and preventing, or at least reducing, disruptive whistling noises. This is particularly advantageous in electric vehicles, which completely lack the usual noise emissions of an internal combustion engine and thus have an overall lower noise level. Furthermore, the cavity of the sealing element is connected to a piston-cylinder assembly via a connecting line. Depending on the vehicle's speed, the piston-cylinder assembly causes the sealing element to inflate.

[0018] It is further according to the invention that a piston of the piston-cylinder assembly is subjected to back pressure when the motor vehicle is traveling forward. For this purpose, the piston can, for example, have a pressure-bearing surface pointing forward in the direction of travel. This offers the significant advantage that inflation of at least one sealing element of the sealing arrangement occurs solely due to the airflow generated by the driving motion, through the application of back pressure to the piston of the piston-cylinder assembly. This eliminates the need for additional pumps, such as electric air pumps, which would require additional connections and an electrical power supply. The piston of the piston-cylinder assembly is spring-loaded into a starting position, preventing deflation or...Air can be automatically extracted from the cavity if the spring force of the return spring is greater than the dynamic pressure or force exerted on the contact surface by the airflow. The advantage of such a piston-cylinder assembly with a return spring lies particularly in its design and operation, which is completely independent of an external electrical power supply. Of course, instead of the return spring, the expanding sealing element alone, when inflated, can also cause the air to be expelled from the cavity of at least one sealing element, provided the pressure in the cavity of the sealing element is greater than the dynamic pressure acting on the piston's contact surface.

[0019] The inflation behavior of at least one sealing element can be controlled relatively easily by the design of the piston-cylinder assembly, the size of the forward-facing impact surface, and / or the design of the return spring for the piston, or by the choice of material for the sealing element.

[0020] In a further particularly preferred embodiment of the motor vehicle according to the invention, an electric air pump is provided which is communicatively connected to the connecting line and the cavity of the at least one sealing element. Such an electric air pump offers the particular advantage of being able to be arranged at virtually any location, for example, even at a point in the motor vehicle not subject to back pressure, and to be controlled by a corresponding control device depending on the speed. A further advantage of such an electric air pump lies in its comparatively low manufacturing costs and its particularly individual programmability.For example, a sensor in the vehicle could detect an impending impact, especially of a pedestrian, whereupon the electric air pump immediately begins to extract air from the cavity of at least one sealing element, so that it is emptied much faster and pedestrian impact protection can be significantly improved once again.

[0021] In a further advantageous embodiment, the sealing element is designed as a bladder seal having at least one cavity. Such bladder seals are already widely used in the field of joint seals in motor vehicles, whereby the bladder seal used for the invention can have significantly thinner walls, since the sealing effect is achieved by the air pressure prevailing in the cavity of the at least one sealing element of the bladder seal. The reduced material thickness also allows for weight savings and resource conservation.

[0022] In a motor vehicle according to the invention, the first body part is a front bumper and the second body part is a hood. The piston-cylinder unit is arranged on the front bumper. In this configuration, the invention can fully develop its effect, since unpleasant noises, such as whistling, are avoided at higher speeds, and optimal pedestrian impact protection is achieved at lower speeds.

[0023] In a further advantageous embodiment of the motor vehicle according to the invention, it is designed as an electric vehicle. Compared to vehicles powered by internal combustion engines, electrically powered vehicles emit significantly less noise while driving due to the absence of a combustion engine. This means that even disturbing noises, such as whistling in the gaps between two body panels, are more readily perceived as bothersome. By using the sealing arrangement in this context, the noise emissions of electric vehicles in particular can be significantly improved, thereby considerably increasing driving comfort.

[0024] The present invention is further based on the general concept of providing a method for operating the motor vehicle described in the preceding paragraphs, in which a sealing arrangement adjusts the amount of air in a cavity of at least one sealing element of the sealing arrangement, and thus the stiffness of the sealing element, depending on the vehicle's speed. In the method according to the invention, at low speeds, for example, at speeds of v < 40 km / h, the sealing element of the sealing arrangement does not inflate, which means that in the event of a pedestrian collision, a pedestrian's head may penetrate deeper into the hood, since the sealing element of the sealing arrangement no longer provides any support in this state.At higher vehicle speeds, particularly electric vehicles, for example at speeds of v ≥ 40 km / h, the amount of air in the cavity of the at least one sealing element, and thus its stiffness, is increased. This closes the gap between two body parts that the at least one sealing element is intended to seal, thereby preventing unpleasant noises such as whistling. The method according to the invention thus improves both pedestrian impact protection and driving comfort.

[0025] In an advantageous further development of the method according to the invention, the at least one sealing element is inflated in a pressure-dependent manner by means of a piston-cylinder unit connected to the cavity of the sealing element via a connecting line, or by means of an electric air pump. The piston-cylinder unit offers the significant advantage of being energy self-sufficient, i.e., requiring no additional externally supplied electrical energy, which in particular reduces wiring effort and thus also assembly costs. In the additional or alternative embodiment using the electric air pump, inflation and deflation of the cavity of the at least one sealing element can be carried out particularly quickly, which, especially when deflating the cavity in the event of an impending pedestrian impact, provides increased pedestrian impact protection.Another advantage of such an electric air pump is that it can be installed almost anywhere in the vehicle, thus achieving significantly increased flexibility in the assembly process.

[0026] In a further preferred embodiment of the method according to the invention, the sealing element is only inflated when the vehicle's speed exceeds v ≥ 40 km / h. Only above this speed are increasingly louder noises, such as whistling, to be expected, whereas at lower speeds such noises do not occur or only occur to a tolerable degree. At lower speeds, i.e., v < 40 km / h, increased pedestrian impact protection is desirable, which can be achieved by using a deflated sealing element.

[0027] It is of course clear that the sealing arrangement used in the motor vehicle according to the invention can have not only one sealing body with one cavity, but also several sealing bodies with multiple cavities that are interconnected and communicate with each other.

[0028] Further important features and advantages of the invention will become apparent from the dependent claims, the drawings and the associated description of the figures based on the drawings.

[0029] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention as defined by the claims. Components of a higher-level unit, such as a device, apparatus, or arrangement, mentioned above and those to be mentioned below, which are designated separately, can form separate parts or components of this unit or be integral areas or sections of this unit, even if this is depicted differently in the drawings.

[0030] Preferred embodiments of the invention are shown in the drawings and are explained in more detail in the following description, wherein identical reference numerals refer to identical or similar or functionally identical components.

[0031] They show, schematically, Fig. 1 a sectional view through a motor vehicle according to the invention in the area of ​​an invention measured sealing arrangement, with the sealing body not inflated, Fig. 2 a representation as in Fig. 1, however, with inflated sealing bodies.

[0032] According to the Fig. 1 and Fig. Figure 2 shows a motor vehicle 1 according to the invention, which can, for example, be designed as an electric vehicle 2, comprising a sealing arrangement 3 with a sealing element 4 for sealing a joint 5 between a first body part 6 and a second body part 7 movably mounted therein. According to the invention, the sealing element 4 has an inflatable cavity 8 (compare Figure 2). Fig. 2), wherein the sealing arrangement 3 is also designed such that it adjusts the amount of air in the at least one sealing body 4, i.e., in its cavity 8, and thus the stiffness of the sealing body 4 as a function of the driving speed v of the motor vehicle 1. It is of course clear that the sealing arrangement 3 can have not only a single sealing body 4 with a single cavity 8, but also several sealing bodies 4 with several cavities 8.

[0033] The cavity 8 of the sealing body 4 is designed according to the Fig. 1 and Fig. 2 is connected to a piston-cylinder assembly 10 via a connecting line 9. The piston-cylinder assembly 10 has a cylinder 11 in which a piston 12 is mounted so as to be adjustable translationally, in this case usually in the longitudinal direction 13 of the vehicle.

[0034] At comparatively low driving speeds v, for example, at a driving speed v of the motor vehicle 1 of less than 40 km / h, the cavity 8 and thus at least one sealing element 4 of the sealing arrangement 3 is not inflated, meaning that the sealing element 4 does not form a support for the second body part 7, for example, a hood 14. In the event of a pedestrian impact on the hood 14, the pedestrian's head can therefore more easily depress or dent the hood 14, thereby reducing the deceleration speed and thus directly mitigating the consequences of the accident for the pedestrian. Such a situation is present in Fig. 1 shown. At a driving speed of v < 40 km / h, even disturbances such as whistling due to the airflow 15 through the joint 5 are not perceptible or at least tolerable.

[0035] At higher driving speeds, for example v ≥ 40 km / h, the airflow 15 generates noise when passing through the joint 5. This noise can be particularly bothersome in electric vehicles 2 due to the absence of a combustion engine and the associated lack of its noise emissions. At such speeds, the sealing element 4 is inflated by the ram air pressure exerted on the piston 12 of the piston-cylinder assembly 10. This causes the piston to move rearward in the direction of travel, forcing air from the cylinder 11 through the connecting line 9 into the cavity 8 of at least one sealing element 4 of the sealing arrangement 3. This inflates the sealing element 4 and increases its rigidity.The inflation of the sealing element 4 causes the joint 5 to close, so that the airflow 15 flows over the first body part 6, for example a front bumper 16, then over the joint 5 and not through it, to the second body part 7, i.e., in this case to the hood 14. The inflation of the sealing element 4 is thus dependent on the stagnation pressure by means of the piston 12.

[0036] In addition to or as an alternative to the piston cylinder assembly 10, an electric air pump 18 can also be provided (compare Fig. 2), which is due to the optional possibility in Fig.Figure 2 is shown only with a dashed line. The electric air pump 18 is also connected to the cavity 8 of the sealing body 4 via the connecting line 9. Such an electric air pump 18 offers the significant advantage of being extremely flexible in its placement within the motor vehicle 1. At the same time, it allows for the rapid emptying of the cavity 8 and thus compression of the sealing body 4 in the event of an impending pedestrian collision. If only a piston-cylinder assembly 10 is provided, the cavity 8 can be emptied, for example, due to an air pressure present there that is greater than the dynamic pressure acting on the piston 10 or its forward-facing contact surface 17. According to the invention, the piston 12 of the piston-cylinder assembly 10 also has a return spring.

[0037] All in all, the inventive method and the inventive motor vehicle 1 can achieve a significant increase in driving comfort due to reduced noise pollution while simultaneously improving pedestrian impact protection.

Claims

[1] Motor vehicle (1) with a sealing arrangement (3) with a sealing element (4) for sealing a joint (5) between a first body part (6) and a second body part (7) movably mounted therein, wherein the sealing element (4) has an inflatable cavity (8) and the sealing arrangement (3) is designed such that it adjusts a quantity of air in the cavity (8) of the sealing element (4) and thus a stiffness of the sealing element (4) as a function of a driving speed “v” of the motor vehicle (1), characterized by, that the cavity (8) of the sealing body (4) is communicatively connected to a piston-cylinder assembly (10) via a connecting line (9) and that a piston (12) of the piston-cylinder assembly (10) is subjected to back pressure when the motor vehicle (1) is driven forward, wherein the first body part (6) is a front bumper (16) and the second body part (7) is a hood (14), wherein the piston-cylinder assembly (10) is provided on the front bumper (16), and wherein the piston (12) of the piston-cylinder assembly (10) has a return spring. [2] Motor vehicle (1) according to claim 1, characterized by , that the piston (12) has a forward-facing impact surface (17) in the direction of travel. [3] Motor vehicle (1) according to any of the preceding claims, characterized by , that an electric air pump (18) is provided which is communicatively connected to the connecting line (9) and the cavity (8) of the sealing body (4). [4] Motor vehicle (1) according to any of the preceding claims, characterized by , that the sealing body (4) is designed as a bladder seal having at least one cavity (8). [5] Motor vehicle (1) according to any of the preceding claims, characterized by , - that the motor vehicle (1) is designed as an electric vehicle (2). [6] Method for operating a motor vehicle (1) according to one of claims 1 to 5, wherein a sealing arrangement (3) adjusts an air quantity in at least one cavity (8) of a sealing body (4) and thus a stiffness of the sealing body (4) depending on a driving speed “v” of the motor vehicle (1). [7] Method for operating a motor vehicle (1) according to claim 6, characterized by, that the sealing element (4) is inflated depending on the stagnation pressure by means of a piston-cylinder assembly (10) connected to the cavity (8) of the sealing element (4) via a connecting line (9) and / or by means of an electric air pump (18). [8] Method for operating a motor vehicle (1) according to claim 6 or 7, characterized by , that the sealing element (4) only inflates when the motor vehicle (1) travels at a speed “v” of “v” ≥ 40 km / h.

Images