System for protecting pedestrians during impact with a vehicle, use of the system and vehicle with such a system

Abstract

System for protecting pedestrians during impact with a vehicle, use of the system and vehicle with such a system - the plastic support (4) consists of a fixed part (4.1) and several elements (4.2) which can be moved towards the fixed part (4.1), - the elements (4.2) each have several hollow segments (5.1, 5.2, 5.3), - the fixed part (4.1) carries on the side of the elements (4.2) an absorption foam (6) and a return spring (7) directed coaxially to the latter and is traversed by a first channel (8) for a fluid (9), - the plastic carrier (4) is traversed by a second channel (9.1) connected to the first channel (8) for discharging the fluid (9) and - the segments (5.1, 5.2, 5.3) are each provided with a circumferential seal (10) and are inserted into one another in such a way that the impact of the pedestrian (5) pushes them together, compresses the absorption foam (6) against the force of the return spring (7) and displaces the fluid (9) through the second channel (9.1) from the system in a volume flow which is limited by the cross-section (18) of the first channel (8).

Description

[0001] The present invention relates to a system for protecting pedestrians during a collision with a vehicle. The present invention further relates to the use of such a system and a motor vehicle with such a system. State of the art

[0002] In the field of pedestrian protection in motor vehicles, various technologies have been established to minimize the risk of injury to pedestrians in a collision with a vehicle. These technologies are regulated by law in both the European Union and other regions, including the United States, and require continuous development to meet growing safety requirements.

[0003] To protect pedestrians from serious head injuries that occur in collisions when the pedestrian's head comes into contact with the hood or windshield, vehicles are often equipped with deformable hoods. This design allows for effective absorption of impact energy, thus reducing the impact forces acting on the pedestrian. To further protect the pedestrian's legs, the front of the vehicle is also designed to be flexible.

[0004] In addition, modern vehicles utilize active protection systems. These systems include airbags that deploy above the hood and adjustable hoods that lift in the event of an impact, creating greater deformation space. These active systems complement passive safety with structural measures and further contribute to reducing the risk of injuries in accidents involving pedestrians.

[0005] Another aspect of pedestrian protection is the early detection of a pedestrian impact. Contact-based sensor systems are primarily used for this purpose. These systems typically consist of a rubber hose mounted along the front of the vehicle and equipped with pressure sensors at its ends. In the event of an impact, the rubber hose deforms, causing the internal pressure to rise. This pressure increase is detected and evaluated by the sensors, triggering safety systems such as airbags.

[0006] In the United States, vehicles must also meet the requirements of the US Part 581 standard, known as the pendulum test. This test involves subjecting the front of the vehicle to the force of a pendulum with the same mass as the vehicle itself. After the impact, there must be no obvious damage to the vehicle, and all assistance systems must still be functional. For this test, a stiffer absorption foam is often placed in front of the crash management system itself to protect the vehicle structure and reliably meet the standard requirements.

[0007] DE 10 2012 221 438 A1, CN 1 04 999 977 A, CN 1 10 641 405 A, and WO 2000 / 039 479 A1 each disclose a system for protecting a pedestrian during an impact with a vehicle. The system comprises a plastic carrier to be attached to the vehicle's crash management system. The carrier consists of a fixed part and several elements, each of which has several hollow segments and is movable toward the fixed part. The fixed part carries an absorption foam on each of the elements, as well as a return spring directed coaxially to the latter, and is traversed by a first channel for a fluid. A second channel connected to the first channel for discharging the fluid passes through the plastic carrier.The segments are each provided with a circumferential seal and are inserted into one another in such a way that the impact of the pedestrian pushes them together, compresses the absorption foam against the force of the return spring and displaces the fluid from the system through the second channel in a volume flow that is limited by the cross-section of the first channel.

[0008] DE 10 2009 000 112 A1 shows a deformation element for partner protection (vehicle-to-vehicle and / or vehicle-to-pedestrian crash). Energy absorption is also achieved by a telescopic structure, which is also filled with a medium, which in turn is discharged through a first channel into a second channel in the event of a crash.

[0009] FR 2 161 308 A5 relates to a motor vehicle comprising a bumper connected to the free ends of two long elements extending parallel to the axis of the vehicle, each of which engages at its other end in a tubular assembly containing springs counteracting the inward telescopic movement of the long element, and in that the tubular assembly is mounted in a box which can be fixed to the body of the vehicle, the tubular assembly being able to slide axially in the box against the resistance of a friction means arranged between the inner surface of the box and the outer surface of the tubular assembly.

[0010] US 2009 / 0 322 107 A1 discloses a vehicle bumper structure comprising a bumper cover arranged on an outermost side of a vehicle and extending in the vehicle width direction, a bumper reinforcement member arranged at a distance from the bumper cover toward the interior of the vehicle and extending in the vehicle width direction, a load detection unit for detecting an impact load arranged on an outer or inner surface of the bumper reinforcement member in the vehicle longitudinal direction, a bumper impact absorbing member arranged between the bumper cover and the bumper reinforcement member, extending in the vehicle width direction and having a substantially uniform thickness across the entire width of the bumper, and a load transmission member,which is arranged between the bumper impact-absorbing component and the bumper reinforcement part or between the bumper cover and the bumper impact-absorbing component, is harder than the bumper impact-absorbing component and is thicker in the vehicle longitudinal direction in a central region of the bumper as seen in the vehicle width direction and thinner in the vehicle longitudinal direction or tapers off at the bumper corner regions in order to reduce fluctuations in the output of the load sensing unit in the vehicle width direction. Disclosure of the invention

[0011] A problem in the current design of vehicle safety systems, especially in the area of ​​pedestrian protection, arises from the need to meet both the strict safety requirements for protecting pedestrians in the event of an accident and the legal requirements for the vehicle structure in the event of minor collisions (so-called parking bumps). This dual requirement clearly leads to a conflict of objectives in vehicle design.

[0012] For example, using a rigid foam carries the risk that it may not compress sufficiently in an actual pedestrian collision to prevent leg injuries. This inability to cushion the pedestrian impact and, if necessary, initiate additional protective measures poses a significant safety risk.

[0013] The described problem is solved by a system for protecting pedestrians during impact, a method for using this system and a motor vehicle with such a system according to the independent claims.

[0014] This approach resolves the conflicting objectives described above by enabling improved sensitivity and adaptability to various impact situations. The system is capable of reliably cushioning pedestrian impacts without undermining the vehicle's structural protection, as required by the stringent "pendulum test."

[0015] The new system is characterized by increased flexibility in absorbing impact energy. It is capable of responding to the specific characteristics of various impact situations, whether the impact of a human leg or a parking bump. This adaptability contributes to optimizing the protection of both pedestrians and vehicle components.

[0016] Another advantage of the system is that it requires no additional installation space. This is particularly important for vehicle design, as the available space in the front of the vehicle is limited. The system thus allows manufacturers to increase pedestrian safety without having to compromise on vehicle design.

[0017] Further advantageous embodiments of the invention are specified in the dependent patent claims. Short description of the drawings Fig. Figure 1 shows a conventional vehicle with rigid foam in front of the crash management system. Fig. 2 shows the vehicle colliding with a pedestrian on the front end and bonnet. Fig. 3 shows a perspective view of the plastic carrier of a system according to the invention. Fig. 4 shows a cross-section of the plastic support mounted behind an attachment. Fig. Figure 5 shows the corresponding cross-section of the beam after impact of a leg. Fig. Figure 6 shows a longitudinal section of the system during impact of the leg and another vehicle. Embodiments of the invention

[0018] Fig. 1 illustrates a conventional vehicle (1) with a crash management system (3) provided with foam (2) of a thickness x (2.1). Fig. Figure 2 shows the impact of a pedestrian (5) against the front end and hood of the vehicle (1). The foam (2) is compressed in the conventional manner (Figure 2.2) by this impact.

[0019] Fig. Figure 3, on the other hand, shows the plastic support (4) of a system according to the invention. The plastic support (4) consists of a fixed part (4.1) and several movable elements (4.2). Each element (4.2) consists of three telescopically movable segments: a first segment (5.1), a second segment (5.2), and a third segment (5.3). The segments are arranged so that they can be compressed in the event of an impact.

[0020] The Fig. Figure 4 shows a cross-section of the plastic support (4) of a system according to the invention, which is mounted behind an attachment (11). The plastic support (4) consists of a fixed part (4.1) and several movable elements (4.2). The fixed part (4.1) is attached to the crash management system (3).

[0021] Within the movable element (4.2) are several telescopic segments (5.1, 5.2, 5.3) that fit together. These segments are designed to be pushed together in the event of an impact. The circumferential seal (10) ensures a fluid-tight connection between the segments and prevents air (9) from escaping from the elements (4.2) without passing through a channel (8) connected to the cavity of all segments (5.1, 5.2, 5.3).

[0022] An absorption foam (6) is arranged inside the movable elements (4.2). This foam serves to absorb the kinetic energy in the event of an impact and is surrounded by a return spring (7), which causes the system to return to its original position after an impact.

[0023] Fig. Figure 5 shows the corresponding cross-section of the plastic support (4) after impact with a leg (100) of the pedestrian (5). The impact compresses the elements (4.2), compressing the absorption foam (6) (30) and the return spring (7). The volume of fluid (9 - 100) displaced by this process Fig. 4) can exit through the channel (8) in a flow which is essentially only limited by the cross-section (18) of the latter.

[0024] Fig. 6 highlights this aspect of venting the system in detail, where instead of air a viscous fluid (9 - Fig. 4) such as oil. The ratio of the piston areas as well as the cross-section of the channels (9.1) and outlet opening (105) are selected so that in the event of an impact limited to the circumference (101) of the leg (100) and thus only compresses individual elements (4.2), the correspondingly small amount ΔV of displaced fluid escapes quickly and without resistance via the outlet opening (105). On the other hand, the cross-section is sufficiently narrow that the larger amount ΔV displaced in the event of a large-area impact from the circumference (301) of another vehicle (300) - for example, in the case of a "parking bump" - does not escape so quickly that the damping foam (6 - Fig. 4) compressed (30 - Fig. 5) would. 1 vehicle 2 Foam in its initial state 2.1 Thickness x of the foam 2.2 compressed foam 3 Crash Management System (CMS) 4 plastic supports 4.1 fixed part (of the plastic carrier) 4.2 (sliding) element (of the plastic carrier) 5 pedestrians 5.1 first segment (of the element) 5.2 second segment (of the element) 5.3 third segment (of the element) 6 Absorption foam in its initial state 7 Return spring 8 first canal (connected to the cavity of all segments) 9 Fluid 9.1 second channel (connected to first channel) 10 circumferential seal 11 Attachment (of the vehicle) 18 Cross section (of the first channel) 20 cavity 30 compressed absorption foam 60 Width of the movable elements 100 Pedestrian's leg 101 Leg circumference 105 Main channel outlet 300 additional vehicles 301 Scope of the additional vehicle

Claims

[1] System for protecting a pedestrian (5) during an impact with a vehicle (1) having the following features: - the system comprises a plastic carrier (4) to be attached to a crash management system (3) of the vehicle (1), - the plastic support (4) consists of a fixed part (4.1) and several elements (4.2) which can be moved towards the fixed part (4.1), - the elements (4.2) each have several hollow segments (5.1, 5.2, 5.3), - the fixed part (4.1) carries on the side of the elements (4.2) an absorption foam (6) and a return spring (7) directed coaxially to the latter and is traversed by a first channel (8) for a fluid (9), - the plastic carrier (4) is traversed by a second channel (9.1) connected to the first channel (8) for discharging the fluid (9), - the segments (5.1, 5.2, 5.3) are each provided with a circumferential seal (10) and are fitted into one another in such a way that the impact of the pedestrian (5) pushes them together, compresses the absorption foam (6) against the force of the return spring (7) and displaces the fluid (9) through the second channel (9.1) from the system in a volume flow which is limited by the cross-section (18) of the first channel (8), - on the side of the fixed part (4.1), each element (4.2) has a cavity (20) delimited by its segments (5.1, 5.2, 5.3) and fluidically connected to the first channel (8), and - the plastic carrier (4) is shaped in such a way that the cavity (20) is emptied when the absorption foam (6) is compressed, characterized by following features: - the segments (5.1, 5.2, 5.3) comprise a first segment (5.1), a second segment (5.2) and a third segment (5.3), - the fixed part (4.1) of the plastic carrier (4) is mechanically connected to the first segment (5.1), - the return spring (7) is a spiral spring (7) supported on the one hand on the fixed part (4.1) and on the other hand on the respective element (4.2), - the absorption foam (6) is arranged inside the spiral spring, - opposite the fixed part (4.1), each element (4.2) has a rectangular pressure plate, - each element (4.2) is shaped in such a way that the pressure plate receives its segments (5.1, 5.2, 5.3) when the respective spiral spring (7) is fully compressed, - the elements (4.2) are each of such a small width (60) that compression occurs when the impact is limited to a circumference corresponding to a human leg (100), - the plastic carrier (4) has, on the side of its fixed part (4.1), an outlet opening (105) fluidically connected to the second channel (9.1) and - the outlet opening (105) is so narrow that compression does not occur if the impact assumes a circumference corresponding to another vehicle (300). [2] Use of a system according to claim 1, characterized by at least one of the following characteristics: - the elements (4.2) are filled with air or - the elements (4.2) are filled with oil. [3] Motor vehicle (1), characterized by following features: - the motor vehicle (1) has a flexible bonnet and an attachment (11) sloping down in front of the bonnet and - the motor vehicle (1) contains a crash management system (3) and a system according to claim 1 arranged between the crash management system and the attachment part (11).

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