Sensor arrangement for a motor vehicle bumper

Abstract

A sensor arrangement (18) for a bumper (10) of a motor vehicle is provided, comprising a sensor element (20) for non-contact detection of obstacles (14), a housing (30) for fixed mounting in the bumper (10), a guide arrangement (24) for guiding the sensor element (20) relative to the housing (30) when the sensor element (20) is displaced when the bumper (10) is pushed in, at least one first magnet (32) attached to the housing (30) and at least one second magnet (34) attached to the sensor element (20), wherein the first magnet (32) and the second magnet (34) are aligned with each other to provide a repulsive magnetic force.In the event of an impact, the sensor element (20) can deflect along the impact forces to avoid damage, while simultaneously generating a magnetic restoring force which allows the sensor element (20) to be guided back into its predefined sensor position by the guide arrangement (24) when the front wall (12) of the bumper (10) deforms back to cover the largest possible cone of vision, thereby saving additional sensor elements and the associated installation space and enabling space-saving detection of obstacles (14) in the vicinity of a motor vehicle.

Description

[0001] The invention relates to a sensor arrangement that can be installed in a bumper of a motor vehicle, with the help of which obstacles can be detected without contact, as well as a bumper and a motor vehicle with such a sensor arrangement.

[0002] KR 10 2024 0050941 A shows a bumper of a motor vehicle in which, when the bumper is bumped, two strips carrying permanent magnets are pressed towards each other against a spring force of springs, so that a magnetic restoring force building up between the strips increases the restoring spring force of the springs and can push the bumper back into its original shape.

[0003] DE 10 2019 210 776 A1 shows a sensor arrangement for a fairing part of a motor vehicle, comprising a sensor element for non-contact detection of obstacles, a housing for fixed attachment in the fairing part, and a guide arrangement for guiding the sensor element relative to the housing when the sensor element is displaced in the event of a minor parking bump, wherein the sensor element is biased outwards into a neutral position by coil springs.

[0004] From DE 32 02 641 A1 a low-wear damping, suspension and buffering system for vehicles, machines, machine parts and electronic systems is known, formed by magnets arranged with opposite poles.

[0005] There is a constant need to be able to detect obstacles near a motor vehicle in a space-saving manner.

[0006] The object of the invention is to demonstrate measures that enable space-saving detection of obstacles in the vicinity of a motor vehicle.

[0007] The problem is solved according to the invention by a sensor arrangement with the features of claim 1, a bumper with the features of claim 6, and a motor vehicle with the features of claim 9. Preferred embodiments of the invention are specified in the dependent claims and the following description, each of which can individually or in combination represent an aspect of the invention, the scope of protection being determined by the claims.

[0008] One aspect of the invention relates to a sensor arrangement for a bumper of a motor vehicle, comprising a sensor element for non-contact detection of obstacles, a housing for fixed mounting in the bumper, a guide arrangement for guiding the sensor element relative to the housing when the sensor element is displaced by impact of the bumper, at least one first magnet attached to the housing and at least one second magnet attached to the sensor element, wherein the first magnet and the second magnet are aligned with each other to provide a repulsive magnetic force.

[0009] To prevent damage to a bumper in a minor impact, such as a parking bump, it is possible to design the front wall of the bumper, which faces the obstacle and absorbs the impact forces, to be elastically deformable to a certain extent. This allows the front wall to be indented upon impact without sustaining damage, provided the impact is sufficiently minor. It has been observed that a sensor element intended for non-contact obstacle detection can be damaged if the front wall is rigidly mounted close enough to it.To prevent damage to the sensor element, it is possible to position it further back from the front wall. However, this would restrict the sensor element's field of view and / or range due to other components within the bumper. This would limit the area monitored by the sensor element, necessitating an increase in the number of sensor elements and consequently the required installation space.

[0010] It was recognized that damage to the sensor element in a position favorable to its field of view, as close as possible to the front wall, can be achieved by ensuring that the sensor element does not remain rigidly in its predefined sensor position, but rather follows the deformation of the indented front wall and is carried along by it. To allow the sensor element to return to its predefined sensor position after the front wall of the bumper has been deformed, a repulsive magnetic force is generated by the stationary first magnet and the moving second magnet. This force pulls the sensor element back towards the vicinity of the now undepressed front wall. A separate energy source for moving the sensor element is not required.Furthermore, spring elements for providing a restoring force can be avoided, as these could jam and / or become misaligned due to the unpredictable force directions during an impact. To ensure that the repulsive magnetic force presses the sensor element into the correct, predefined sensor position, the guide arrangement directs the sensor element's return movement in such a way that it arrives back in the predefined sensor position at the end of its return movement and is not forced into a position displaced from the predefined sensor position.In the event of an impact, the sensor element can deflect along the impact forces to avoid damage, while simultaneously generating a magnetic restoring force. This force guides the sensor element back into its predefined sensor position when the front wall of the bumper deforms to cover the largest possible field of view, thus saving additional sensor elements and the associated installation space, and enabling space-saving detection of obstacles near a vehicle.

[0011] The sensor array can, for example, be part of a parking assistance system and / or a LiDAR system of the vehicle. Preferably, several sensor arrays are provided for the respective bumper in order to cover a sufficiently large detection area. The larger the respective field of view of each sensor array, the fewer sensor arrays are required to cover a given detection area. The sensor array can be located in the front of the vehicle, in particular in a front bumper, and / or in the rear of the vehicle, in particular in a rear bumper.

[0012] The sensor element can be designed for non-contact distance measurement. For example, the sensor element can emit electromagnetic beams, such as in an infrared, ultraviolet, and / or radar frequency range, and measure the travel time of reflected beams arriving at a detector in order to determine the distance of the reflecting obstacle from this travel time. The sensor element can be connected to lines for supplying electrical power and / or for data exchange, wherein the lines, particularly in a cable configuration, are flexible enough to accommodate any displacement of the sensor element when the bumper is compressed.

[0013] The guide arrangement can align the return movement of the sensor element to the predefined sensor position. For this purpose, the guide arrangement can, for example, have a funnel-shaped design that tapers towards the predefined sensor position. The guiding action of the guide arrangement can be magnetic and / or mechanical. For example, the guide arrangement enables a component connected to the sensor element to slide in a directed manner along a corresponding sliding surface of the guide arrangement.

[0014] The housing can be attached at a point where it experiences little or no movement when the bumper is compressed upon impact, thus ensuring relative movement of the sensor element to the housing. In particular, the housing can fully or partially enclose the sensor element when the bumper is compressed, thereby protecting the sensor element from damage caused by forces from various directions. The housing can be made of a plastic material, especially hard plastic and / or thermoplastic polymer.Since the sensor can be positioned completely outside the housing in its predefined sensor position, it is even possible in this case to manufacture the housing from a metallic material, especially steel and / or sheet steel, since a shielding effect of the metallic material ("EMI protection") of the housing would only come into play when the bumper is indented.

[0015] The first magnet and / or the second magnet can be made of a magnetized ferromagnetic material. The first magnet and / or the second magnet can be designed as permanent magnets, or alternatively, as electromagnets. The first magnet and the second magnet are aligned relative to each other such that their south poles or north poles point towards each other to provide the repulsive magnetic force, which increases when the magnets are brought close together. Since the first magnet is connected to the housing and the second magnet to the sensor element, the relative position of the first magnet to the second magnet corresponds to the relative position of the housing to the sensor element.Preferably, several first magnets and / or several second magnets are provided, resulting in a better defined and more stable direction of the repulsive magnetic force as well as the return movement of the sensor element supported by the guide arrangement.

[0016] In particular, the repulsive magnetic force is dimensioned to push the sensor element away from the housing when the bumper is not depressed. Even when the bumper is not depressed, the first magnet can interact with the second magnet to provide the repulsive magnetic force, thus pressing the sensor element against the front of the bumper with a contact force applied by the repulsive magnetic force. This magnetically generated contact force increases the frictional contact of the sensor element, preventing it from slipping when the bumper is struck. This improves the correct positioning and retention of the sensor element in the predefined sensor position.

[0017] Preferably, the guide arrangement includes a cage that can be supported against the housing. The cage allows the sensor element to tilt and / or shift, and prevents the second magnet from moving out of the direction of the repulsive magnetic force by striking the housing. The cage can, for example, be positioned at a considerable distance on an outer and / or inner side of the housing, allowing the cage and sensor element to tilt by a certain angle until the cage strikes the housing. This also allows the sensor element to tilt, while the limitation of the tilt angle achieved by the cage striking the housing ensures that the sensor element returns to its original position.A relative position in which the second magnet is positioned so far laterally offset from the first magnet that the direction of the repulsive magnetic force does not point towards the predefined sensor position, but instead pushes the sensor element laterally and does not return it to the predefined sensor position, can be avoided. This allows the sensor element to follow a multitude of possible directions of movement when the bumper is depressed, while simultaneously ensuring the sensor element returns to the predefined sensor position.

[0018] The guide arrangement preferably forms a linear guide for the sensor element on the housing. For example, the guide arrangement can have a guide carriage longitudinally guided in a guide opening to form the linear guide. Tilting by a limited angular amount is permitted via the play of the guide carriage in the guide opening. The linear guide prevents the second magnet from migrating out of an area where the repulsive magnetic force is directed towards the predefined sensor position. If the dented bumper exerts an impact force oblique to the longitudinal direction of the linear guide, the sensor element can be provided to slide off the dented front wall of the bumper during displacement along the longitudinal direction of the linear guide.

[0019] In particular, several first magnets and / or several second magnets are provided, the arrangement of which causes the sensor element to self-center magnetically relative to the housing. For example, several first or second magnets can be arranged in a circle, with the other magnet or the majority of the other magnets positioned within this circle. This results in a mutually reinforcing repulsive magnetic force upon lateral displacement, leading to self-centering of the sensor element relative to the housing.

[0020] Another aspect concerns a bumper for a motor vehicle, with a retractable front panel and a sensor assembly that can be designed and further developed as described above, wherein the sensor element is positioned so that it can be displaced when the front panel is retracted and / or wherein the sensor element is displaced from the front panel when the front panel is retracted. The sensor element of the sensor assembly is positioned so close to the front panel to provide a good field of view that, when the front panel is retracted, it can carry the sensor element along with it onto the housing of the sensor assembly.In the event of an impact, the sensor element, along with the dented front wall, can deflect along the impact forces to avoid damage, while simultaneously generating a magnetic restoring force. This force guides the sensor element back into its predefined sensor position as the front wall of the bumper deforms, thus covering the largest possible cone of vision. This eliminates the need for additional sensor elements and the associated installation space, enabling space-saving detection of obstacles near a vehicle.

[0021] Preferably, at least one magnetizable metal body that interacts magnetically with the second magnet and / or at least one third magnet that interacts magnetically with the second magnet is provided to magnetically hold the sensor element in a defined relative position to the front wall in its normal, unpressed state. The correct positioning of the sensor element in the predefined sensor position is thus ensured not only by the repulsive magnetic force between the first magnet and the second magnet, but alternatively or additionally by an attractive magnetic force of the second magnet. Due to its magnetic force, the second magnet tends to approach the magnetizable, particularly ferromagnetic, metal body, thereby establishing a lateral relative position for the predefined sensor position. This effect can be further enhanced by an attractive magnetic force from the third magnet.

[0022] A load-bearing cross member is particularly preferred for supporting impact forces, wherein the housing of the sensor assembly is attached directly or indirectly to the load-bearing cross member. The housing can thus be supported on a component that is unlikely to deform even under significant impact forces, allowing the housing to be essentially fixed in position within the vehicle. Since displacement of the housing during a bumper impact can be avoided, the guidance of the sensor element during impact and rebound is simplified.

[0023] Another aspect concerns a motor vehicle with at least one bumper, which can be designed and further developed as described above. In particular, a front and / or a rear bumper is provided, which can be designed and further developed as described above. In the event of an impact, the sensor element can deflect along the impact forces to avoid damage, while simultaneously generating a magnetic restoring force. This force guides the sensor element back into its predefined sensor position when the front wall of the bumper deforms. This allows the sensor element to cover the largest possible field of view, thus saving additional sensor elements and the associated installation space, and enabling space-saving detection of obstacles near a motor vehicle.

[0024] The invention is now explained by way of example with reference to the accompanying drawings and preferred embodiments, wherein the features shown below can represent an aspect of the invention, either individually or in combination, and the scope of protection is defined by the claims. The drawings show: Fig. 1: A schematic cutaway top view of a bumper and Fig. 2: a schematic diagram of a sensor arrangement for the bumper made of Fig. 1.

[0025] The in Fig. The bumper 10 shown in Figure 1 can be installed at the front or rear of a motor vehicle. The bumper 10 has a front panel 12 attached to a cross member 11, which can impact an obstacle 14 and be thereby depressed. The front panel 12 can have a sensor opening 16 through which a sensor arrangement 18 can monitor an area in front of the front panel 12 with the largest possible field of view. Depending on the deformation behavior of the front panel 12, the front panel can press against the sensor arrangement 18 and push a sensor element 20 of the sensor arrangement 18 inwards.

[0026] As in Fig.As shown in Figure 2, the sensor element 20 can be enclosed in a holder 22, which is part of a guide arrangement 24. In the illustrated embodiment, the guide arrangement 24 has a linear guide in which a guide rod 26 connected to the holder 22 is guided linearly in a guide opening 28 of a housing 30, which is preferably fixed in a location. Limited tilting of the sensor element 20 relative to the housing 30 is also permitted by allowing some play in the guide rod 26 within the guide opening 28. The housing 30 incorporates several first magnets 32 arranged in a circle, which can interact with corresponding second magnets 34 to provide a repulsive magnetic force that increases as the second magnets 34 approach the first magnets 32.

[0027] When the front wall 12 is pressed in, the sensor element 20 can be pushed more firmly into the housing 30, thereby building up the repulsive magnetic force. When the front wall 12 is no longer pressed in, the repulsive magnetic force can push the sensor element 20 back into the predefined sensor position, possibly even pressing the sensor element 20 firmly into place in the predefined sensor position. Furthermore, it is possible to ensure the correct position of the repressed sensor element 20 by means of an attractive magnetic force, provided that third magnets 36 interact with the second magnets 34.

Claims

[1] Sensor arrangement (18) for a bumper (10) of a motor vehicle, comprising a sensor element (20) for non-contact detection of obstacles (14), a housing (30) for fixed mounting in the bumper (10), a guide arrangement (24) for guiding the sensor element (20) relative to the housing (30) when the sensor element (20) is displaced when the bumper (10) is pressed in, at least one first magnet (32) attached to the housing (30) and at least one second magnet (34) attached to the sensor element (20), wherein the first magnet (32) and the second magnet (34) are aligned towards each other to provide a repulsive magnetic force. [2] Sensor arrangement (18) according to claim 1, wherein the repulsive magnetic force is dimensioned to push the sensor element (20) away from the housing (30) in the unpressed normal state of the bumper (10). [3] Sensor arrangement (18) according to claim 1 or 2, wherein the guide arrangement (24) has a cage that can be supported on the housing (30), wherein the cage allows tilting and / or displacement of the sensor element (20) and blocks the second magnet (34) from moving out of the direction of the repulsive magnetic force by striking the housing (30). [4] Sensor arrangement (18) according to one of claims 1 to 3, wherein the guide arrangement (24) forms a linear guide of the sensor element (20) on the housing (30). [5] Sensor arrangement (18) according to one of claims 1 to 4, wherein several first magnets (32) and / or several second magnets (34) are provided, wherein the arrangement of the several magnets (32, 24) causes a magnetic self-centering of the sensor element (20) relative to the housing (30). [6] Bumper (10) for a motor vehicle, with a retractable front wall (12) and a sensor arrangement (18) according to one of claims 1 to 5, wherein the sensor element (20) is positioned displaceably when the front wall (12) is retracted. [7] Bumper (10) according to claim 6, wherein at least one magnetizable metal body magnetically interacting with the second magnet (34) and / or at least one third magnet (36) magnetically interacting with the second magnet (34) is provided to hold the sensor element (20) magnetically in a defined relative position to the front wall (12) in the normal, unpressed state. [8] Bumper (10) according to claim 6 or 7, wherein a load-bearing cross member (11) is provided for supporting impact forces, wherein the housing (30) of the sensor arrangement (18) is attached indirectly or directly to the load-bearing cross member (11). [9] Motor vehicle with at least one bumper (10) according to any one of claims 6 to 8.

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