Decoupling elements for ultrasonic sensors

Abstract

The present invention provides a decoupling element (8) for an ultrasonic sensor (1) that can be mounted on a two-dimensional part (6) for a vehicle (5) having a notch (7), the decoupling element (8) having a cylindrical ultrasonic transmitting / receiving element (3) that can be introduced into the notch (7). The decoupling element (8) comprises a hollow cylindrical element (15) for surrounding the cylindrical ultrasonic transmitting / receiving element (3) of the ultrasonic sensor (1) and a plurality of support ribs (13) arranged on the outside in the radial direction of the hollow cylindrical element (15) and spaced apart from one another in the circumferential direction of the hollow cylindrical element (15), for supporting the decoupling element (8) outside the notch (7) in the area of ​​the two-dimensional part (6) when an axial end portion of the cylindrical ultrasonic transmitting / receiving element (3) is introduced into the notch (7) together with the hollow cylindrical element (15) surrounding the cylindrical ultrasonic transmitting / receiving element (3). Each support rib (13), when viewed in an axial cross section of the decoupling element (8), is shaped like an arch that opens in the axial direction toward the other axial end of the hollow cylindrical element (15).

Description

[Technical Field]

[0001] The present invention relates to a decoupling element for an ultrasonic sensor that can be attached to a flat part for a vehicle, the flat part having a notch. The present invention also relates to an ultrasonic sensor with a decoupling element, an arrangement having an ultrasonic sensor and a flat part, and a motor vehicle having such an arrangement. [Background technology]

[0002] Ultrasonic sensors are used in vehicles to record information about the vehicle's surroundings using transmitted and received echo ultrasonic pulses, and to transmit information about the vehicle's surroundings to parking assistance systems, driver assistance systems, etc.

[0003] Figure 2 shows a known arrangement 100 with an ultrasonic sensor 1 mounted on a flat part 6. The ultrasonic sensor 1 comprises a sensor housing 2 and a membrane pot 3 protruding therefrom, the membrane pot 3 having a cylindrical wall 4 supporting a membrane 5 used to transmit and receive ultrasonic pulses to and from the surrounding environment 9 of the vehicle (50 in Figure 1). The membrane pot 3 is introduced by its axial end portion (the portion at the end along the axis A) into a recess 7 in a flat part 6, such as a bumper of the vehicle (50 in Figure 1).

[0004] In order to prevent vibrations from being transmitted from the vehicle body via the flat part 6 to the membrane 5 of the membrane pot 3, a known hollow cylindrical decoupling ring 108 is provided. The decoupling ring 108 surrounds the cylindrical wall 4 of the membrane pot 3 and is introduced therewith into the recess 7. In addition to vibration decoupling, the decoupling ring 108 also serves to protect the membrane pot 3 from the ingress of moisture and water.

[0005] The ultrasonic sensor 101 is pressed into the recess 7 by pressing it against the flat part 6 with a predetermined contact pressure. Due to the conical outer surface of the decoupling ring 108, a holding force acts on the decoupling ring 108 at the contact points 11 between the decoupling ring 108 and the edge of the flat part 6. This holding force has a radial and an axial component. The radial component acts inward in the radial direction r and fixes the membrane pot 3 against the decoupling ring 108 in the recess 7. The axial component presses the decoupling ring 108 axially against the sensor housing 2. However, the axial component of the holding force is small, in particular significantly smaller than the radial component. Furthermore, due to manufacturing-related deviations from the desired shape of the recess 7, there may be no contact between the decoupling ring 108 and the flat part 6 at some points 11 along the circumference, and therefore no holding force can be exerted.

[0006] It has been recognized that, in the case of the component 100 of FIG. 2 , water may penetrate between the decoupling ring 108 and the membrane pot 3 and / or between the decoupling ring 108 and the flat part 6, for example, when cleaning the vehicle with a high-pressure washer. Because the axially acting retaining force component is small, the pressure generated here tends to push the decoupling ring 108 axially outward, toward the vehicle's (50 in FIG. 1 ) ambient environment 9. This can lead to water accumulating and freezing in gaps formed between the decoupling element 8 and the sensor housing 2, particularly at the foot points 12. Such ice bridges can adversely affect the function of the membrane pot 3 of the ultrasonic sensor 1. Furthermore, if the decoupling ring 108 protrudes beyond the outer surface of the flat part 6, the decoupling ring 108 can easily break or slip out of the opening.

[0007] EP 2 616 836 B1 therefore proposes an arrangement as shown diagrammatically in FIG. 3 . The decoupling element 208 has a number of spacer elements 213 arranged radially outward from the cutouts. The upper surfaces 214 of the spacer elements 213 of the decoupling element 208 form a support platform for the flat part 6. In this way, the flat part 6 can exert a holding force with a large force component in the axial direction. This holding force presses the decoupling element 208 against the sensor housing 2 even if the hollow cylindrical part 215 of the decoupling element 208 and the flat part 6 are not in close contact, for example due to the out-of-roundness of the cutouts 7. In principle, this prevents the decoupling element 208 from being pressed axially upward in FIG. 3 , creating gaps at the foot points 12 where water could accumulate and ice bridges could form.

[0008] However, the teachings of EP 2 616 836 B1 require relatively precise adjustment of the axial dimension of the spacer element 213, the axial thickness of the flat component 6, and the mounting position of the sensor housing 2 relative to one another. However, the thickness of the flat component 6 may vary between different vehicle models and between different locations on the same vehicle model. At the same time, it is desirable for the membrane 5 and the flat component 6, which face the ambient environment 9, to always be flush with each other. If the same type of decoupling element 208 is used for flat components 6 of different thicknesses and is always press-fit to ensure that the membrane 5 and the outer surface of the flat component 6 are flush with each other, the contact pressure exerted on the spacer 213 in the axial direction will vary according to the force-displacement curve of the spacer element 214. Although the decoupling element 208 has a certain flexibility, the contact pressure required to flush the membrane 5 with the outer surface of the flat component 6 is very high, especially for very thick flat components 6, making assembly difficult or impossible. Furthermore, the high pressure caused by the thick flat component 6 may compress the spacer element 213 and tilt it outward. In this case, the decoupling element 208 may be forced upwards, creating gaps at the foot points 11 where water may collect and ice bridges may form.

[0009] WO 2015 / 104094 A1 and EP 2 812 723 are further examples of the prior art. Summary of the Invention

[0010] Against this background, the present invention is based on the object of providing an improved decoupling element.

[0011] According to a first aspect, to achieve this object, a decoupling element for an ultrasonic sensor that can be mounted on a flat part for a vehicle, the flat part having a cutout, is proposed. The decoupling element for the ultrasonic sensor has a cylindrical ultrasonic transmitting / receiving element that can be inserted into the cutout. The proposed decoupling element includes a hollow cylindrical element for surrounding the cylindrical ultrasonic transmitting / receiving element of the ultrasonic sensor, and a plurality of support ribs arranged radially outward from the hollow cylindrical element and spaced apart from each other in the circumferential direction of the hollow cylindrical element, for supporting the decoupling element outside the cutout in the area of ​​the flat part when the cylindrical ultrasonic transmitting / receiving element and the surrounding hollow cylindrical element are inserted into the cutout by their end portions at the axial ends. In an axial cross section of the decoupling element, each support rib has an arch shape that opens in the axial direction toward the other axial end of the hollow cylindrical element.

[0012] The support rib has an arch shape in axial cross section, which may be particularly described as an arch shape that is open on one side or a hollow arch shape, or as a rib shape that is open on one side or a hollow rib shape. Advantageously, the open or hollow support rib can be more easily compressed compared to a solid support rib (i.e., not open and not hollow, e.g., having a convex cross section), and therefore can be flexibly used on a wide range of flat parts with different thicknesses, i.e., has a more favorable force-displacement curve.

[0013] In particular, when the proposed decoupling element is used with a first flat component in which the axial dimension of the support rib, the axial thickness of the flat component, and the mounting position of the ultrasonic sensor are precisely adjusted, the arch-shaped support rib provides high stability and can withstand the force exerted by the flat component on the support rib as the decoupling element is fixed and pressed against the sensor housing. When the proposed decoupling element is used with a second flat component that is thicker than the first flat component, particularly 1.5 to 1.6 times thicker, the hollow support rib can be compressed without requiring very high contact pressure. Even in this case, the ring remains pressed against the sensor and does not tilt outward in the radial direction.

[0014] Therefore, the same decoupling element can be used to mount the ultrasonic sensor to flat components of different thicknesses, making assembly easier. Advantageously, the arch shape can also resist outward tilt of the support ribs. At high contact pressures, the arch shape is advantageously compressed or pressed inward axially against the sensor housing and radially against the ultrasonic transmitting and receiving element. This prevents the decoupling element from being pressed axially upward or outward, and prevents water from accumulating between the decoupling element, the sensor housing, and the ultrasonic transmitting and receiving element, which could cause ice bridges to form.

[0015] Due to the fact that the multiple support ribs are arranged at intervals in the circumferential direction of the hollow cylindrical element, water that has entered between the hollow cylindrical element and the cylindrical ultrasonic transmitting / receiving element, for example when cleaning with a high-pressure washer, can be drained in the circumferential area where no support ribs are arranged.

[0016] In particular, "decoupling element" should be understood to mean an element that has the ability a) to dampen the transmission of vibrations from flat parts of the vehicle body to the membrane of the ultrasonic transmitting and receiving element, and b) to protect the ultrasonic transmitting and receiving element from moisture and water.

[0017] Examples of flat parts include vehicle body panels, bumpers, interior trim panels, and the like.

[0018] A "cylindrical shape" here should be understood to mean any geometric shape formed by two mutually geometrically similar end faces and a side face connecting the end faces. Preferably, the two end faces can coincide with each other. Preferably, the two end faces can be transformed into each other by displacement. Preferably, the end faces can be circular or elliptical. Particularly preferably, the cylindrical shape along a plane intersecting at least two axial directions can be mirror symmetric. Particularly preferably, the cylindrical shape can be rotationally symmetric or substantially rotationally symmetric about its axis. The "axis" of a "cylindrical shape" defining the "axial direction" should be understood to mean an axis connecting the geometric centers of the end faces with each other.

[0019] Thus, the term "cylindrical ultrasonic transmitting and receiving element" should be understood to mean an ultrasonic transmitting and receiving element whose outer surface forms a cylindrical shape as a whole. For example, the ultrasonic transmitting and receiving element may be what is called a membrane pot. The term "hollow cylindrical element" should be understood to mean an element that encloses an empty space that is cylindrical in shape as a whole. A decoupling element having a hollow cylindrical element may be what is called a decoupling ring, for example. The term "having a cylindrical shape as a whole" should be understood to mean that grooves, flutes, burrs, ribs, etc. on the side surface that are inclined from a strictly geometric cylindrical shape by up to 10°, preferably up to 5° (which in the strictly geometric sense approximates a conical shape rather than a cylindrical shape) are also intended to be included in the term "cylindrical shape."

[0020] "Axial end" is to be understood to mean, in particular, an end in the direction of the axis of the cylindrical shape. "Axial cross section" is, in particular, a cross section through the cylindrical shape that includes the axis of the cylindrical shape (see axis A in Figures 2 to 4).

[0021] In the case where the decoupling element is attached to an ultrasonic sensor with the hollow cylindrical element of the decoupling element surrounding the cylindrical ultrasonic transmitting and receiving element, "one axial end" should be understood to mean the end of the cylindrical ultrasonic transmitting and receiving element and the end of the hollow cylindrical element of the decoupling element at which the membrane of the ultrasonic transmitting and receiving element is arranged to transmit and receive ultrasonic waves. Accordingly, "the other axial end" should be understood to mean the end opposite the one axial end in the axial direction.

[0022] In this specification, the side where "one axial end" is located is also referred to as "upper". The side where "the other axial end" is located is also referred to as "lower". These terms "upper" and "lower" refer to the imaginary direction of the axis of the cylindrical shape, and the axial end in the direction in which ultrasonic waves are emitted is referred to as the "upper" end, and the opposite end is referred to as the "lower" end. The terms "upper" and "lower" do not explicitly refer to the mounting situation in a vehicle. The ultrasonic sensor and flat part with the decoupling element can be mounted in any direction in a vehicle.

[0023] An "arched shape" may be understood to mean a free form that is arched as a whole. Specifically, an "arched shape" may be understood to mean a shape formed by two edges that are spaced apart from each other on one side of the arched shape facing the lower axial end of the other and that converge on the side of the arched shape facing the upper axial end of the other. The edges may be straight, curved, or partly straight and partly curved. The radius of curvature need not be constant. The arched shape need not be mirror symmetric. Examples of arched shapes include an inverted "U" shape and an inverted "V" shape.

[0024] According to one embodiment, the arch shape slopes inwards in the radial direction.

[0025] In other words, in particular, the uppermost point of the arch shape in the axial direction is located further inward in a radial direction perpendicular to the axial direction than the midpoint of the distance between the two edges of the arch shape at the lower end of the arch shape. In particular, the radially inner edge of the arch shape may be shorter than the radially outer edge of the arch shape.

[0026] Therefore, the arched support ribs are better prevented from tilting outward under high pressure. Rather, the inwardly tilted arched support ribs are more advantageously encouraged to buckle inward even in the event of yielding. Therefore, empty spaces where water can accumulate are reliably prevented from occurring at the foot points where the outer surfaces of the ultrasonic transmitting / receiving elements, the upper surface of the sensor housing, and the lower surfaces of the inner edges of the arched support ribs meet.

[0027] According to a further embodiment, each of the two edges of the arch shape is at least twice as long as the inner distance between the edges on the open side of the arch shape.

[0028] Therefore, an arch shape with long, thin edges is proposed, which has a particularly advantageous force-displacement curve.

[0029] According to a further embodiment, one axial end of the radially inner edge of the arch shape, on the open side of the arch shape in the axial direction, is flush with the other axial end of the hollow cylindrical element and is connected to the hollow cylindrical element.

[0030] Preferably, the arched radially outer edge may have a free end that is not connected to any other element in particular.

[0031] Such an embodiment advantageously further encourages the support ribs to tilt inward and not outward when subjected to high pressures, thereby providing additional compression at the foot points where the cylindrical ultrasonic transmitting and receiving elements meet the cylindrical support ribs and the upper surface of the sensor housing.

[0032] "Connected" should be understood to mean, in particular, a one-piece connection. Particularly preferably, the connection can be integral. This means that the support rib and the hollow cylindrical element are formed as one piece, without being joined by a single molding. In this case, the radially inwardly facing outer surface of the arch-shaped radially inner edge can be directly connected to the radially outwardly facing outer surface of the hollow cylindrical element. However, a distance may be provided between the radially inwardly facing outer surface of the radially inner edge and the radially outwardly facing outer surface of the hollow cylindrical element. For example, a horizontally extending web on the underside of the decoupling element, at least between the radially inner edge and the hollow cylindrical element, fills this distance. It should be noted that the horizontally extending web can also extend radially outward up to, and possibly beyond, the radially outer edge of the arch-shaped radially outer edge.

[0033] According to a further embodiment, one of the support ribs extends in the circumferential direction of the hollow cylindrical element over an angular range of 30° to 60°, preferably over an angular range of 40° to 50°, particularly preferably over an angular range of 50°.

[0034] When the support rib extends over a predetermined angular range of the hollow cylindrical element, even if the arch shape is hollow or open on one side, the support rib can be sufficiently rigid to stably withstand the applied contact pressure, so that the support rib does not tilt outward but rather presses firmly against the foot point where the outer surface of the ultrasonic transmitting / receiving element, the upper surface of the sensor housing, and the underside of the inner edge of the arched support rib meet, preventing water from pooling and freezing at this point and pushing the ring upward.

[0035] Here, there can preferably be four or five support ribs arranged at a distance from one another around the circumference of the hollow cylindrical element, in which case there is advantageously sufficient free space between the support ribs to allow any intruding water to drain.

[0036] According to a further embodiment, the decoupling element is integrally formed.

[0037] Integral formation is to be understood as meaning that it is formed in particular by one molding step.

[0038] Integrally formed decoupling elements can have particularly advantageous acoustic properties.

[0039] According to a further embodiment, at least the support ribs are made from a material having a hardness of 20 to 60 Shore A, preferably 30 to 50 Shore A, particularly preferably 40 Shore A.

[0040] The entire decoupling element of material may also be formed from a material having one of the hardnesses mentioned above.

[0041] The aforementioned hardnesses are suitable, on the one hand, to prevent the transmission of vibrations from the flat part to the ultrasonic transmitting / receiving element of the ultrasonic sensor, which may be introduced into the hollow cylindrical element of the decoupling element. On the other hand, these hardnesses are suitable for achieving an appropriate rigidity in the region of the support ribs, so that the support ribs have sufficient rigidity to stably withstand the applied contact pressure and do not tilt outward, but rather press firmly against the foot points where the outer surfaces of the ultrasonic transmitting / receiving element, the upper surface of the sensor housing, and the lower surface of the inner edge of the arch-shaped support ribs meet. This prevents water from accumulating in these areas and freezing, which could push the ring upward.

[0042] According to a further embodiment, the decoupling element is made from a flexible material, preferably a polymer, particularly preferably silicone.

[0043] Preferably the silicone is a liquid processed cross-linked silicone, which provides good resistance to temperatures between -40°C and +80°C that can be expected during vehicle operation.

[0044] According to a second aspect, an ultrasonic sensor is proposed, comprising a cylindrical ultrasonic transmitting and receiving element and the above-mentioned decoupling element, the hollow cylindrical element of the decoupling element surrounding the cylindrical ultrasonic transmitting and receiving element.

[0045] According to a third aspect, there is provided an arrangement including a flat part for a vehicle having a notch and an ultrasonic sensor according to the second aspect attached to the flat part, wherein the cylindrical ultrasonic transmitting / receiving element together with the hollow cylindrical element of the decoupling element surrounding it is introduced into the notch by the end portion at one of the axial ends, and the decoupling element is supported outside the notch in the region of an inner surface of the flat part.

[0046] According to one embodiment of the arrangement of the third aspect, the axial ends of the hollow cylindrical elements of the cylindrical ultrasound transmitting and receiving element and the surrounding decoupling element are flush with the outer surface of the flat part.

[0047] Therefore, a flush surface can be advantageously provided on the outer surface of the vehicle body, for example, which is not only aesthetically advantageous but also has the technical advantage that damage and dirt on the ultrasonic transmitting and receiving elements are avoided as much as possible.

[0048] According to a further embodiment, the flat part is an outer periphery of the vehicle, the outer surface of the flat part is an outer vehicle surface, and the inner surface of the flat part is an inner vehicle surface.

[0049] Thus, ultrasonic sensors can be used to record information about the vehicle's surroundings.

[0050] According to a further embodiment, the flat component is an interior trim panel of the vehicle, the exterior surface of the flat component is an interior vehicle surface, and the interior surface of the flat component is an exterior vehicle surface.

[0051] Thus, ultrasonic sensors can be installed in interior trim panels of a vehicle and can provide information about the interior of the vehicle, for example, information about the number of people in the passenger compartment.

[0052] According to a further embodiment, the ultrasonic sensor is pressed into the notch of the flat part together with the decoupling element under a predetermined contact pressure.

[0053] The contact pressure advantageously ensures a secure seating of the decoupling element on the surface of the sensor housing via a reaction force acting from the flat part on the support rib.

[0054] According to a further embodiment, the hollow cylindrical element of the decoupling element is mounted undersized to the cylindrical ultrasound transmitting and receiving element.

[0055] "Mounted undersized" should be understood to mean that the inner diameter of the hollow cylindrical element is smaller than the outer diameter of the cylindrical ultrasound transmitting and receiving element, especially in the relaxed state of the decoupling element before assembly.

[0056] Thus, the hollow cylindrical element of the decoupling element can be held to the cylindrical ultrasonic transmitting and receiving element by a clamping force acting radially inward, thereby preventing water from entering between the hollow cylindrical element and the cylindrical ultrasonic transmitting and receiving element.

[0057] According to a fourth embodiment, a motor vehicle is proposed comprising at least one component of the third embodiment or one of the embodiments of the third aspect.

[0058] Further possible implementations of the invention also include non-express combinations of the features or embodiments described above or below with respect to the exemplary embodiments, whereby a person skilled in the art may still add individual aspects as improvements or additions to the respective basic form of the invention.

[0059] Further advantageous configurations and aspects of the invention are the subject of the dependent claims and the exemplary aspects of the invention described below. The invention will be explained in more detail on the basis of preferred exemplary embodiments with reference to the attached drawings. [Brief explanation of the drawings]

[0060] [Figure 1] FIG. 1 shows a front view of a vehicle. [Figure 2] FIG. 2 shows a cross-sectional view of a known arrangement including a flat part and an ultrasonic sensor with a known decoupling element. [Figure 3] FIG. 3 shows a cross-sectional view of another known arrangement including a flat part and an ultrasonic sensor with a known decoupling element. [Figure 4] FIG. 4 shows a cross-sectional view of a construction including a flat part and an ultrasonic sensor with a decoupling element according to a first exemplary embodiment. [Figure 5] FIG. 5 shows a cross-sectional view of a construction including a flat part and an ultrasonic sensor with a decoupling element according to a first exemplary embodiment. [Figure 6] FIG. 6 shows a cross-sectional view of an arrangement including a further flat part and an ultrasonic sensor with a decoupling element according to a first exemplary embodiment. [Figure 7] FIG. 7 is a plan view to scale of a decoupling element according to a third exemplary embodiment. [Figure 8] FIG. 8 is a side view to scale of a decoupling element according to a third exemplary embodiment. [Figure 9] FIG. 9 shows a full-scale axial cross section BB through the decoupling element of the third exemplary embodiment of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0061] In the drawings, identical or functionally identical elements are designated by the same reference numbers unless otherwise noted.

[0062] 1 is a front view of a vehicle according to a first exemplary embodiment, which is a passenger car 50. The passenger car 50 has a front bumper, which is an example of a flat part 6. In the front bumper 6, an ultrasonic sensor 1 according to the first exemplary embodiment is mounted in a cutout 7. A construction 10, which is shown in FIG. 3 and will be described in more detail below, is used according to the first exemplary embodiment.

[0063] 2 and 3 show known arrangements 100, 200 for mounting an ultrasonic sensor 1 on a front bumper 6. These arrangements have already been described in the introduction.

[0064] 4 shows an axial cross-section of a component according to a first exemplary embodiment, comprising a front bumper 6 and an ultrasonic sensor 1. The ultrasonic sensor 1 is attached to the front bumper 6 and comprises a decoupling element 8 according to the first exemplary embodiment. The ultrasonic sensor 1 comprises a sensor housing 2 and a membrane pot 3 protruding therefrom, which is an example of an ultrasonic transmitter / receiver element. The membrane pot 3 comprises a cylindrical wall 4 supporting a membrane 5. The membrane 5 is used to transmit and receive ultrasonic pulses to and from the surrounding environment 9 of the vehicle (50 in FIG. 1). The membrane pot 3 is inserted by its upper axial end portion (the portion at the end along the axis A) into a notch 7 in a flat part 6 of the bumper 6 of the vehicle (50 in FIG. 1).

[0065] It should be noted that the arrows labeled "a" in the drawings point upward in the axial direction defined by axis A. Here, "upper / above / upper side" refers to the image plane in FIG. 4 and should not be understood as a limitation on the mounting position of arrangement 10. The arrows labeled "r" point outward in the radial direction perpendicular to the axial direction.

[0066] A decoupling ring 8, which is an example of a decoupling element 8, is provided to prevent vibrations from being transmitted from the vehicle body to the membrane 5 of the membrane pot 3 via the front bumper 6. The decoupling ring 8 has a hollow cylindrical element 15 and a plurality of support ribs 13 arranged radially outward of the hollow cylindrical element 15. Although not shown in FIG. 4, the plurality of support ribs 13 are arranged at intervals from one another in the circumferential direction of the hollow cylindrical element 15.

[0067] The uppermost point 14 of the support rib 13 forms a support plateau for the front bumper 6. In particular, the ultrasonic sensor 1 is introduced or pressed into the recess 7 of the front bumper 6 under a predetermined contact pressure on part of its axial upper end, so that the membrane 5 is flush with the outer surface of the front bumper 6, as shown in FIG. 4 . In this state, the decoupling ring 8 is supported by the support rib 13 outside the recess 7 in the area of ​​the lower outer surface of the front bumper 6 in FIG. 4 . This means that the lower surface of the front bumper 6 exerts a holding force axially downwards on the uppermost point 14 of the support rib 13, which presses the decoupling ring 8 axially against the sensor housing 2 of the ultrasonic sensor 1. This holding force advantageously prevents water that may get between the bumper and the hollow cylindrical element 15 or between the hollow cylindrical element 15 and the membrane pot 3 during cleaning with a high-pressure washer from pushing the decoupling ring 8 axially upwards and out of the recess 7. This prevents water from collecting and possibly freezing below the decoupling ring 8, especially at the leg points 12 where the decoupling ring 8, the membrane pot 3 and the sensor housing 2 meet.

[0068] In this case, the support rib 13 has an arched shape in axial cross section as shown in Figure 4. The arched shape is formed in this example by a bent inner edge 16 and a bent outer edge 17. The arched edges 16 and 17 are axially open towards a lower axial end and converge towards an upper axial end at the top point 14. The arched shape of the support rib 13 therefore spans (extends) into the cavity 18.

[0069] The arch-shaped support rib 13 has particularly high structural stability, and therefore can withstand the holding force exerted by the front bumper 6, and the decoupling ring 8 is stably pressed and held against the sensor housing 2 in the axial direction.

[0070] If an axially thick, flat part 6 is used instead of the front bumper 6, a larger force acts from the flat part 6 on the arched support rib 13 when attaching the ultrasonic sensor 2 to the flat part. However, the arched support rib 13 with its narrow edges 16 and 17 can absorb and mitigate this large force without excessively increasing the contact pressure. The arched shape of the support rib 13 further promotes the effect that the support rib 13 in this example is compressed axially downward and does not tilt radially outward to the side.

[0071] In particular, the radially inner edge 16 on the axially open side of the arch shape is flush with the lower axial end of the hollow cylindrical element 15 and is connected to the hollow cylindrical element 15. In contrast, the axial end of the radially outer edge 17 is a free end. This configuration further promotes the effect that the support ribs are crushed with high contact pressure and are crushed and compressed radially inward, preventing them from tilting outward.

[0072] 5 and 6 show cross-sectional views of an arrangement 10 including a flat part 6 and an ultrasonic sensor 2 with a decoupling element 8 according to a second exemplary embodiment. Identical or functionally identical elements are given the same reference numerals as in the first exemplary embodiment and only the differences will be described.

[0073] 5 and 6 show, in addition to the elements already described, a portion of a holder 19 that holds the sensor housing 2 in place. The holder 19 may be positioned to limit radial outward movement of the arched second edge 17 of the support rib 13.

[0074] In the case of the decoupling ring (decoupling element) 8 of the second exemplary embodiment, the support rib 13 has an arched shape that is inclined radially inward, i.e., the uppermost point 14 of the arched shape is located further inward in the radial direction r than the central position 21 between the radially outer edge 17 and the radially inner edge 18 on the axially lower, open side of the arched shape.

[0075] 5, the support rib 14 has a stable arch shape, which allows a force to be applied by the front bumper 6 through its two edges 16 and 17 to the top point 14, thus pressing the decoupling ring 8 axially against the sensor housing 2 and ensuring that there are no gaps at the foot points 12 that could become attack points for pressurized water.

[0076] If the front bumper 6 is replaced with a flat part 66 thicker in the axial direction a in the mounting configuration shown in FIG. 5 but otherwise unchanged, the mounting configuration shown in FIG. 6 results. Due to the thicker flat part 66, the contact pressure increases, causing the radially inner edge 16 to collapse. However, the support rib 13 does not tilt outward, but rather collapses in the space defined by the flat part 66, the sensor housing 2, the membrane pot 3, and the holder 19. Therefore, even in this situation, the decoupling ring 8 is pressed into the corner formed by the membrane pot 3 and the sensor housing 2 at the foot point 12. This effectively prevents a water jet from a high-pressure washer or the like entering from the outside 9 from pushing the decoupling ring 9 upward in the axial direction through the notch 7.

[0077] It should be noted that the above-described effect is facilitated by the holder 19, which defines a space in which the support rib 13 can collapse. However, the above-described effect occurs even if the holder 19 is not provided or is not provided in the position shown.

[0078] An example of a decoupling ring 8 according to the solution proposed as a third exemplary embodiment will now be described on the basis of FIGS.

[0079] Figure 7 is a top view of the decoupling ring 8 of the third exemplary embodiment, in the direction designated "up" in Figures 4 to 6. That is, the axis A of the hollow cylindrical element 15 extends outward from the image plane in Figure 7.

[0080] The decoupling ring 8 has four support ribs 13. The support ribs 13 are arranged concentrically around the hollow cylindrical element 15 in the radial direction and are uniformly spaced apart at a distance of α=40° from each other along the circumference of the hollow cylindrical element 15. Thus, the support ribs 13 extend over an angular range of 50° in the circumferential direction. Therefore, on the one hand, the support ribs 13 are sufficiently rigid to achieve the effects described herein. On the other hand, a sufficiently large angular area remains between the support ribs 13, through which any intruding water can escape.

[0081] Figure 8 shows a side view of the decoupling ring from Figure 8. As shown in Figure 8, the support ribs 13 each have an arch shape that opens towards their lower ends in the axial direction.

[0082] Figure 9 shows cross section BB of Figure 7. The arched shape of the support rib 13 of the decoupling ring 8 of the third exemplary embodiment also slopes inward, with the uppermost point 14 of the arched shape located further inward in the radial direction r than the central position 21 between the two edges 16, 17 at the axially lower open end of the arched shape.

[0083] The hollow cylindrical element 15 has on its inner circumferential surface a manufacturing-related recess 22. It should be noted that the membrane pot at the axial height of the recess 22 may have a burr corresponding to the recess 22.

[0084] For example, the hollow cylindrical element 15 of the decoupling ring 8 has an inner diameter of 15 mm and an outer diameter of 17.32 mm. The decoupling ring 8 including the support ribs 14 has an outer diameter of 21.7 mm. For example, the inner height h1 of the arched shape of the support ribs 13 is 2.42 mm. For example, the height h2 of the hollow cylindrical element 15 is 5 mm. The inner distance between the radially inner edge 16 and the radially outer edge 17 at the lower open end of the arched shape of the support ribs 13 is, for example, 0.91 mm. The width of the radially outer edge is, for example, 0.36 mm.

[0085] The decoupling ring 8 in FIGS. 7 to 9 is integrally molded in one step by a cross-linking silicone liquid treatment, and has a hardness of 40 Shore A.

[0086] Tests by the inventors have shown that the decoupling ring 8 manufactured in this way can be used with flat components 6 having a thickness in the axial direction a ranging from 2.5 mm to 4 mm, in a mounting situation in which the membrane 5 of the cylindrical membrane pot 3 is positioned substantially flush with the outer surface of the flat component 6, as shown in Figures 4 to 6, under practically permissible contact pressures, without impairing the sealing function of the decoupling ring 8, especially at the foot points 12. In contrast, a decoupling ring 208 (if applicable) of the same dimensions, designed as in the example of Figure 3 from the prior art, can only accommodate a thickness in the range from 2.7 mm to 3.3 mm without excessively high contact pressures or impairing the sealing function. The proposed decoupling ring 8 from Figures 7 to 9 therefore has a more favorable force-displacement curve than the decoupling ring 208 from the prior art.

[0087] While the present invention has been described with reference to exemplary embodiments, various modifications are possible.

[0088] The decoupling ring does not have to be made from silicone, but can be made from another rubber-like material, such as TPE.

[0089] The specific dimensions given in the third exemplary embodiment and the freeform shapes shown in the drawings should be considered purely as examples and not as limitations.

[0090] In all exemplary embodiments, in the relaxed state of the decoupling ring 8, e.g. before mounting on the ultrasonic sensor 1, the inner diameter of the hollow cylindrical element 15 of the decoupling ring may preferably be smaller than the outer diameter of the membrane pot 3 of the ultrasonic sensor 1. Thus, the decoupling ring 8 fits undersized on the membrane pot 3.

[0091] In the exemplary embodiment, a front bumper 6 is used as an example of the flat component 6. However, the flat component 6 may also be a rear bumper, a side bar, or other outer peripheral surface of the vehicle 50. In the above case, the inner surface of the flat component is the vehicle interior surface, and the ultrasonic sensor 1 records information about the surrounding environment 9 of the vehicle 50. However, as an alternative to this, the ultrasonic sensor 1 may record information about the interior of the vehicle. In this case, the outer surface of the flat component 6 is the vehicle interior surface, and the flat component 6 is any element of an interior trim panel of the vehicle 50.

[0092] A passenger car is shown purely by way of example as an example of a vehicle 50. However, the proposed ultrasonic sensors, the proposed arrangements and the proposed decoupling elements may also be used in other moving or mobile objects, such as trucks, forklifts, robots, etc., having driving assistance systems, parking assistance systems and / or systems for partial or full autonomous driving.

[0093] 1 ultrasonic sensor 2 Sensor Housing 3 ultrasonic transmitting and receiving elements, membrane pot 4 Wall, side 5 membrane 6 Flat parts, front bumper 7 Notch 8 Decoupling Elements 9 Vehicle Surroundings 10. Construction including a flat part and an ultrasonic sensor with a decoupling element 11 contact points 12 leg points 13 Arched support rib 14. The highest point of the arch 15 Hollow cylindrical element 16. Arched radially inner edge 17 Arched radially outer edge 18 cavities 19 Holder 21 center position 22 recess 50 vehicles, passenger cars 66 Thick flat parts 100 Known construction including a flat part and an ultrasonic sensor with a decoupling element 101 known ultrasonic sensors 108 Known Decoupling Elements 200 Known structure including a flat part and an ultrasonic wave with a decoupling element 201 known ultrasonic sensors 208 Known Decoupling Elements 213 known spacer elements 214 Upper surface of known spacer element 215 Known hollow cylindrical elements A axis of hollow cylindrical element a Axial direction, especially upward axial direction h1 Inner height of arch shape h2 Height of hollow cylindrical element r Radial direction, especially outward radial direction α Circumferential distance between support ribs s The inner distance between the edges at the open end of the arch b Width of the radial outer edge

Claims

1. A decoupling element (8) for an ultrasonic sensor (1) that can be mounted on a flat part (6) for a vehicle (5), the flat part (6) having a notch (7), the decoupling element (8) for the ultrasonic sensor (1) having a cylindrical ultrasonic transmitting / receiving element (3) that can be introduced into the notch (7), a hollow cylindrical element (15) for surrounding the cylindrical ultrasonic transmitting / receiving element (3) of the ultrasonic sensor (1); a plurality of support ribs (13) arranged on the outside in the radial direction (r) of the hollow cylindrical element (15) and spaced apart from one another in the circumferential direction of the hollow cylindrical element (15), for supporting the decoupling element (8) outside the notch (7) in the area of ​​the flat part (6) when the cylindrical ultrasonic transmitting / receiving element (3) together with the hollow cylindrical element (15) surrounding it is introduced into the notch (7) by its end portion at the axial end, In an axial cross section of the decoupling element (8), each support rib (13) has an arch shape that opens in the axial direction (a) towards the other axial end of the hollow cylindrical element (15), The decoupling element (8), wherein the arch shape slopes inwardly in the radial direction (r).

2. 2. A decoupling element according to claim 1, wherein the inner height (h1) of the arch shape is at least twice as long as the inner distance (s) between the two edges (16, 17) at the open side of the arch shape.

3. 2. The decoupling element according to claim 1, wherein one end in the axial direction (a) of the radially inner edge (16) of the arch shape on the open side of the arch shape in the axial direction (a) is flush with the other axial end of the hollow cylindrical element (15) and is connected to the hollow cylindrical element (15).

4. 2. The decoupling element according to claim 1, wherein an angle between two circumferential ends of the support rib (13) relative to a circle center of the hollow cylindrical element (15) is in the range of 30° to 60°.

5. The decoupling element (8) according to claim 1, wherein the decoupling element (8) is integrally formed.

6. A decoupling element according to claim 1, wherein at least the support ribs (13) are made from a material having a hardness of 20 to 60 Shore A.

7. The decoupling element (8) according to claim 1, wherein the decoupling element (8) is made from a flexible material.

8. An ultrasonic sensor (1) having a cylindrical ultrasonic transmitting / receiving element (3) and a decoupling element (8) according to claim 1, The hollow cylindrical element (15) of the decoupling element (8) surrounds the cylindrical ultrasonic transmitting and receiving element (3).

9. 10. A construction (10) comprising a flat part (6) for a vehicle (50), the flat part (6) having a notch (7), and an ultrasonic sensor (1) according to claim 8 attached to the flat part (6), the cylindrical ultrasonic transmitting and receiving element (3) together with the hollow cylindrical element (15) of the decoupling element (8) surrounding it is introduced into the notch (7) by the end portion at one of the axial ends, The decoupling element (8) is supported outside the notch (7) in the area of ​​the inner surface of the flat part (6).

10. 10. The arrangement according to claim 9, wherein the axial ends of the hollow cylindrical element (15) of the cylindrical ultrasonic transmitting and receiving element (3) and the surrounding decoupling element (8) are flush with the outer surface of the flat part (6).

11. The flat part (6) is an outer peripheral surface of the vehicle (50), the outer surface of the flat part (6) is an outer vehicle surface, and the inner surface of the flat part (6) is an inner vehicle surface, or 10. The structure of claim 9, wherein the flat component (6) is an interior trim panel of the vehicle (50), the outer surface of the flat component (6) is an inner vehicle surface, and the inner surface of the flat component (6) is an outer vehicle surface.

12. 10. The arrangement according to claim 9, wherein the ultrasonic sensor (1) is pressed into the notch (7) of the flat part (6) together with the decoupling element (8) under a predetermined contact pressure.

13. 13. The arrangement according to any one of claims 9 to 12, wherein the hollow cylindrical element (15) of the decoupling element (8) is mounted undersized to the cylindrical ultrasonic transmitting and receiving element (3).

14. A motor vehicle comprising at least one component according to any one of claims 9 to 12.

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