Housing for ultrasonic transducer having differently inclined bottom surface

Abstract

The invention relates to a housing (110, 200, 210, 220, 230) for an ultrasonic transducer (106) for detecting an object in an environment (102) of a vehicle (100); the housing includes: a peripheral sidewall (114) defining a main axis (118) of the housing (110); and a bottom wall (112) having a central housing (130) for supporting the transducer element and at least one modulator region (132); wherein the modulator region (132) extends radially from the receptacle (130) to a transition region (140) of the bottom wall (112) to the side wall (114) in a longitudinal cross-sectional plane (126) comprising the main axis (118); wherein the thickness (C) of the bottom wall (112) decreases radially outward across the modulator region (132); and wherein the inner side (120) of the bottom wall (112) in the modulator region (132) has at least two different inclination angles (E, D).

Description

Technical Field

[0001] The present invention relates to a housing of an ultrasonic transducer for detecting an object in the surroundings of a vehicle, and also to an ultrasonic transducer for detecting an object in the surroundings of a vehicle, and a vehicle. Background Art

[0002] Ultrasonic transducers for detecting objects in the vehicle's surroundings are used, for example, in parking systems and the like. Such ultrasonic transducers usually operate according to the pulse-echo principle, in which the same ultrasonic transducer is used as transmitter and receiver. It is therefore particularly difficult to design a close-range "blind zone" that is as small as possible, since no echo signal can be received or reliably detected from the blind zone. The size of this "blind zone" is characterized and determined by the reverberation time of the transducer after the pulse emission.

[0003] In order to achieve a high electroacoustic conversion efficiency and thus a wide detection range and / or a low signal-to-noise ratio, ultrasonic transducers are usually based on the bending transducer principle. A piezoelectric transducer disk is applied to a membrane and operated in resonant mode.

[0004] To facilitate this and avoid echoes from the road and / or very high objects (e.g. the roof of a parking lot and / or the top of a bridge), a pronounced directivity characteristic and a narrow aperture angle are usually employed. This can be achieved, for example, by a special film geometry.

[0005] An example of this is JP 2001 326987 A. This patent discloses a cup-shaped housing for an ultrasonic transducer, the bottom of which has a central disc-shaped thickening. This design sometimes exhibits a lower electroacoustic efficiency, which shortens the detection range of the resulting ultrasonic transducer. In addition, with this design, a longer reverberation time can be provided after the emission of the ultrasonic pulse, thereby expanding the close-range blind zone.

[0006] For example, JP 2006 174 003 teaches a design for improving reverberation time. The patent discloses a rotationally symmetrical cup-shaped housing for an ultrasonic transducer. The bottom portion of the housing has the shape of a truncated cone, the thickness of which increases inwardly from the side walls toward the central platform for a transducer element with a constant slope.

[0007] The production of sharp edges can be complicated in JP 2006 174 003. Furthermore, the change in radius can show a strong interaction with the resonance frequency.

[0008] DE 11 2009 003 590 T5 discloses an ultrasonic transducer with improved resonance frequency stability. The ultrasonic transducer described comprises a cylindrical housing provided with a lower side and a piezoelectric element, which is arranged substantially in the center of the lower side of the housing. The lower side of the housing has an inclined portion and a flat portion, the inclined portion gradually becoming thinner from the position where the piezoelectric element is arranged toward the inner wall surface of the housing, and the flat portion extends from the outer edge of the inclined portion to the inner wall surface of the housing while maintaining the thickness of the outer edge of the inclined portion.

[0009] In particular, in the design shown in FIG. 3 of DE 11 2009 003 590 T5, the reverberation time can be prolonged. The disclosed housing tends to have noticeable burrs on the outside of the vehicle body in the installed state. Compared with the design according to the above-mentioned JP 2001 326987A, the directivity characteristics can be degraded and the aperture angle can be widened. In addition, the electroacoustic efficiency can be reduced.

[0010] Other housings for ultrasonic transducers known in the prior art:

[0011] JP 2005 039 689 A discloses a cup-shaped housing with a flat bottom for an ultrasonic transducer. On one side, the flat bottom is provided with one or more flat steps towards the outside of the bottom, thereby producing one or more thinner bottom sections. This one-sidedness causes the ultrasonic detection cone to be tilted relative to the longitudinal axis of the housing. As a result of this tilt, the ultrasonic detection cone is asymmetrical relative to the longitudinal axis. Therefore, the orientation of the sensor is to be observed during installation. This concept may not be suitable for embodiments that provide asymmetrical cable connections and / or require identical components on the left and right sides of the vehicle body. In other words, the housing of JP 2005 039 689 A is not suitable for embodiments that require a symmetrical overall sensor structure.

[0012] JP 2017 225 013 A discloses a housing in the form of a disk for an ultrasonic transducer having a central elliptical recess. The elliptical recess has a flat bottom with a kidney-shaped recess having a thinner flat bottom on the short side. The step-like change in the bottom thickness with a flat step results in a cross section along the longitudinal axis of the elliptical recess.

[0013] DE 10 2008 040905 A1 discloses a cup-shaped housing for an ultrasonic sensor, which has a bottom surface and side walls. An electromechanical transducer element, for example a piezoelectric element in the form of a cylindrical disk, is glued to the flat inner side of the bottom surface. Summary of the invention

[0014] Against this background, it is an object of the present invention to provide an improved ultrasonic transducer, in particular a housing for such a transducer. Here, a favourable compromise between directivity characteristics, electroacoustic efficiency and / or a short reverberation time is of primary importance.

[0015] Therefore, a housing for an ultrasonic transducer for detecting objects in the surroundings of a vehicle is proposed. The housing has a circumferential side wall and a bottom wall. The circumferential side wall defines the main axis of the housing. The bottom wall has a central housing for supporting a transducer element or an ultrasonic element and at least one modulator region. The modulator region extends radially from the housing to a transition zone of the bottom wall to the side wall in a longitudinal cross-sectional plane containing the main axis. The thickness of the bottom wall decreases radially outwards over the entire modulator region. The inner side of the bottom wall has at least two different inclination angles in the modulator region.

[0016] The housing achieves a compromise in the bottom wall. On the one hand, the housing is characterized by a directivity characteristic, which is achieved by a larger aperture in the longitudinal cross-sectional plane. On the other hand, the bottom wall is characterized by a higher electroacoustic efficiency, which is achieved by a suitable shaping of the modulator area. Furthermore, the proposed housing is suitable for desired shorter reverberation times and is ultimately also robust to variations in manufacturing tolerances. Due to the proposed bottom wall, the proposed housing can be manufactured very well.

[0017] In particular in the longitudinal cross-sectional plane, the thickness of the bottom wall decreases radially outwards over the entire modulator area.The inner side of the bottom wall has at least two different inclination angles in the modulator area, in particular in the longitudinal cross-sectional plane.

[0018] The side wall is preferably closed in the circumferential direction, however, variants are also conceivable with walls which are discontinuous and / or partially discontinuous in the circumferential direction.

[0019] The bottom wall has an outer side which preferably extends perpendicularly to the main axis. Various variants can also be envisaged in which the outer side is concavely curved and / or convexly curved and / or extends in the form of a truncated cone and / or extends to a point.

[0020] The inner side of the modulator region preferably extends in a convex rounding in the longitudinal cross-sectional plane. The tendency to reverberation is thereby reduced, i.e. improved. It is conceivable that the entire modulator region is implemented as a convex rounding, and it is also conceivable that a region of the modulator region is implemented as a convex rounding.

[0021] In this specification, the terms "convex" and "concave" refer to the observation from the inside of the shell. "Convex" means facing outwards, especially rounding towards the outside, when observed from the inside of the shell. In layman's terms, "convex" can be regarded as bulging "outwards". Functionally, the "convex" part of the inner side of the bottom wall corresponds to the larger internal volume of the shell. "Concave" means facing inwards, especially rounding towards the inside, when observed from the inside of the shell. In layman's terms, "concave" can be regarded as bulging "inwards". Functionally, the "concave" part of the inner side of the bottom wall corresponds to the smaller internal volume of the shell.

[0022] According to a preferred embodiment, it is conceivable that in the longitudinal cross-sectional plane, the inner side has a continuously differentiable course. Examples include parabolic and / or exponential trajectories. In this way, the frequency characteristics can be improved. It is conceivable that the inner side extends in a continuously differentiable manner over the entire modulator area. Furthermore, it is conceivable that the inner side extends in a continuously differentiable manner only over a portion of the modulator area.

[0023] For reasons of electroacoustic efficiency, it is preferred that the rounded and / or parabolic outer edges tangentially adjoin an imaginary frustoconical angle.

[0024] If the modulator region comprises a plurality of truncated cone sections with at least two different inclination angles, the mold for the housing can be manufactured relatively easily. If two adjacent truncated cone sections, in particular radially adjacent truncated cone sections, are connected to one another by a convex rounding, the damping can be increased and the reverberation can be reduced. However, it is also conceivable that two adjacent truncated cone sections, in particular radially adjacent truncated cone sections, are connected to one another by an edge, so that the natural frequency characteristic becomes more pronounced. Both of these are preferred improvements, depending on the design.

[0025] For reasons of electroacoustic efficiency, it is also preferred that the closer to the radial outside a surface portion of the modulator region is arranged, the flatter the corresponding surface portion is. For example, if two frustoconical portions with different inclination angles are provided, it is electroacoustically more efficient to arrange the flatter frustoconical portion radially outside the steeper frustoconical portion. Specifications such as "flat" and "steep" preferably relate to an imaginary line perpendicular to the imaginary main axis.

[0026] If the or each modulator region extends symmetrically with respect to the main axis in a longitudinal cross-sectional plane, a directivity characteristic of the ultrasound transducer which is symmetrical with respect to the main axis can be achieved. For example, an ultrasound cone which is wider in the horizontal direction and narrower in the vertical direction can thus be provided.

[0027] If the side wall also extends to the accommodation portion in a second longitudinal cross-sectional plane containing the main axis and perpendicular to the longitudinal cross-sectional plane, a favorable directional characteristic can be achieved. Specifically, the effective aperture can be narrower in the direction of the second longitudinal cross-sectional plane than in the direction of the first longitudinal cross-sectional plane, so that the directional characteristic is wider in this direction of the second longitudinal cross-sectional plane. According to a preferred example, the side wall has a thickened portion parallel to and / or at least approximately parallel to and / or parallel to the longitudinal cross-sectional plane in some parts. The inner wall of the thickened portion can optionally extend concentrically to the accommodation portion.

[0028] Experiments have shown that in an electroacoustically effective housing, the inclination angle of the inside of the modulator region is at least 2°, preferably at least 2.5°, more preferably at least 3°. The "inside" of the modulator region means that the rounding in the connecting, preferably flat, receiving section and / or the rounding in the connecting, preferably steep side wall can have a smaller inclination angle. An inclination angle of 0° means perpendicular to the main axis, and an inclination angle of 90° means parallel to the main axis.

[0029] If the side wall is interrupted in the circumferential direction at least in some sections and / or projects by different amounts from the main axis when viewed in the circumferential direction, the housing may comprise a twist lock. In this way, a desired orientation of the directional feature relative to the vehicle may be safely set.

[0030] The inner side of the bottom wall preferably connects from the modulator region into the housing by a concave rounding.The housing can therefore withstand greater manufacturing deviations.

[0031] In order to be able to manufacture the housing more easily, the alternative is proposed that the inner side of the bottom wall is connected from the modulator area to the inner side of the side wall by a convex rounding.

[0032] If the receiving portion has a constant thickness, this is facilitated in attaching a disk-shaped transducer element.

[0033] According to another aspect of the present invention, an ultrasonic transducer is provided. The ultrasonic transducer has a housing according to one of the above-mentioned optional solutions and a transducer element. The transducer element is supported in and / or on the receiving portion, for example, by bonding, welding and / or chemical and / or mechanical fastening methods.

[0034] According to a further aspect, a vehicle comprising at least one such ultrasonic transducer is proposed.

[0035] The vehicle is, for example, a passenger car or even a truck.

[0036] Other possible implementations of the present invention also include the combination of features or embodiments not explicitly mentioned above or below in relation to exemplary embodiment description. In this case, those skilled in the art will also add separate aspects as improvements or additions to the corresponding basic forms of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Further advantageous configurations and aspects of the invention are the subject matter of the dependent claims and of the exemplary embodiments of the invention described below.The invention is explained in more detail below based on preferred embodiments with reference to the drawings.

[0038] FIG1 shows a schematic top view of a vehicle including a plurality of ultrasonic transducers;

[0039] FIG2 shows a schematic perspective cross-sectional view of a housing for an ultrasonic transducer according to a first embodiment of the present invention;

[0040] 3 is a schematic longitudinal cross-sectional view showing a portion of a bottom wall and a portion of a side wall of a housing for an ultrasonic transducer according to a first embodiment of the present invention;

[0041] 4 shows a schematic longitudinal cross-sectional view of a portion of a bottom wall and a portion of a side wall of a housing for an ultrasonic transducer according to a second embodiment of the present invention;

[0042] 5 is a schematic longitudinal cross-sectional view showing a portion of a bottom wall and a portion of a side wall of a housing for an ultrasonic transducer according to a third embodiment of the present invention;

[0043] 6 is a schematic longitudinal cross-sectional view showing a portion of a bottom wall and a portion of a side wall of a housing for an ultrasonic transducer according to a fourth embodiment of the present invention; and

[0044] 7 is a schematic longitudinal cross-sectional view showing a portion of a bottom wall and a portion of a side wall of a housing for an ultrasonic transducer according to a fifth embodiment of the present invention.

[0045] Unless stated otherwise, identical or functionally identical elements in the figures are provided with the same reference symbols. DETAILED DESCRIPTION

[0046] FIG1 shows a schematic diagram of a vehicle 100 from a bird's eye view. The vehicle 100 is, for example, a car arranged in an environment 102. The car 100 has a control unit 104. In addition, a plurality of ultrasonic transducers 106 are provided on the car 100. The ultrasonic transducers 106 are configured to detect the distance to an object arranged in the environment 102 and output corresponding sensor signals. The ultrasonic transducers 106 are connected to the control unit 104.

[0047] 2 and 3 show a housing 110 for an ultrasound transducer 106 according to a first embodiment of the housing 110 .

[0048] 2 shows a longitudinal sectional perspective view of the structure of the housing 110. The housing 110 has a bottom wall 112 and a side wall 114.

[0049] The side wall 114 is circumferentially closed, thereby forming an irregularly shaped tube internally. The side wall 114 defines a major axis 118 at its center.

[0050] At one axial end of the side wall 114, the housing is closed like a cup by an approximately disk-shaped bottom wall 112. The inner side 120 of the bottom wall 112 and the inner side 122 of the side wall 114 define an interior 124 of the housing 110.

[0051] In the illustration of FIG. 2 , the housing 110 is cut through in a longitudinal section plane 126 which contains the main axis 118 .

[0052] Figure 3 shows a portion of the longitudinal section from Figure 2 in a top view of the section surface. Figure 3 thus shows a section of the housing 110 with the longitudinal section plane 126. A portion of the side wall 114 is shown on the left side of the figure and the main axis 118 is shown on the right side of the figure.

[0053] The bottom wall 112 has a receiving portion 130 and a modulator region 132 radially outward from the main axis 118. The side wall 114 adjoins the modulator region 132 radially outward.

[0054] The accommodation portion 130 is a region of the bottom wall 112 which is prepared to support a transducer element (not shown). In this case, a piezoelectric element for converting between mechanical oscillations and electrical oscillations in the ultrasonic range is preferably used as the transducer element.

[0055] The outer side 136 of the bottom wall 112 preferably extends perpendicular to the main axis 118 .

[0056] The transducer element is preferably connected, for example adhesively bonded, to the receptacle 130. For this purpose, the inner side 120 preferably extends perpendicularly to the main axis 118 in the region of the receptacle 130. The receptacle 130 therefore has a thickness A.

[0057] In the longitudinal cross-sectional plane 126, the modulator region 132 is located between the receiving portion 130 and the side wall 114. In the first embodiment, the modulator region 132 adjoins the receiving portion 130 via an inner transition region 138. Furthermore, in the first embodiment, the modulator region 132 adjoins the side wall 114 via an outer transition region 140.

[0058] The bottom wall 112 has a minimum thickness B at the outer transition zone 140 . This radially outer minimum thickness B is smaller than the radially inner thickness A of the receiving portion 130 .

[0059] The thickness C at any point of the modulator region 132 gradually decreases from the receiving portion 130 to the transition region 140. More specifically, in the first embodiment, the thickness C of the bottom wall 112 gradually decreases from the inner transition region 138 to the outer transition region 140. In other words, each thickness C of a point on the inner side of the modulator region 132 is less than the thickness A and greater than the thickness B.

[0060] Since the transition regions 138, 140 are continuously formed in the first embodiment, the thickness C of the modulator region 132 is equal to the thickness A at its inner edge, and the thickness C is equal to the thickness B at its outer edge.

[0061] In the first embodiment, the modulator region 132 has two truncated cone portions 150 and 152. The truncated cone portion 150 disposed radially inside the modulator region 132 has a proportionally larger tilt angle D. The truncated cone portion 152 disposed radially outside the modulator region 132 has a proportionally smaller tilt angle E.

[0062] By means of the modulator region 132 , a favourable compromise between directivity characteristics and electroacoustic efficiency is achieved by means of different tilt angles D and E.

[0063] The inclination angle D, E of the frustoconical portion 150 , 152 or of the cone is in this case the cone angle between the base and the side of the cone or frustoconical portion.

[0064] The inner side 120 has a planar section 134 in the region of each frustoconical portion 150 , 152 .

[0065] In the first embodiment, the frustoconical portions 150 and 152 are interconnected by a radial intermediate transition zone 154 .

[0066] The inner transition 138 from the receptacle 130 to the inner frustoconical portion 150 is a concave transition 156 and thus is an inwardly curved transition when viewed from the interior 124 .

[0067] The intermediate transition region 154 from the inner frustoconical portion 150 to the outer frustoconical portion 152 and the outer transition region 140 from the outer frustoconical portion 152 to the sidewall 114 are both convex transition regions 158 and thus are outwardly curved transition regions when viewed from the interior 124 .

[0068] Although FIG. 3 shows only half of the cross-sectional surface of the longitudinal cross-sectional plane 126 with the bottom wall 112 , FIG. 2 shows that there are two modulator regions 132 in the longitudinal cross-sectional plane 126 , which are arranged symmetrically about the main axis 118 .

[0069] In the present case, the side wall 114 has a section designed as a flange 160, which is arranged, for example, at the end of the side wall 114 remote from the bottom wall 112. The flange 160 protrudes radially outwards, but has different widths when viewed in the circumferential direction. Therefore, FIG. 2 shows a narrow flange section 162 and a wide flange section 164. After the housing 110 is inserted into a groove formed diametrically opposite, for example in the bumper of the vehicle 100, the alternation of narrow flange sections 162 and wide flange sections 164 realizes a twist-lock function. Thus, the orientation of the directional characteristics of the ultrasonic transducer 104 in the vehicle 100 can be monitored and set.

[0070] The design advantages of the first embodiment will be discussed below. It goes without saying that these preferred dimensions and ratios are also individually advantageous.

[0071] In FIG3 , the distance from the main axis 118 to the transition region 138 is designated as radius F. The distance from the main axis 118 to the inner side 122 of the sidewall 114 is designated as radius G or distance G. The difference between thickness A and B is designated as depth H. Depth H is the depth of the recess formed by the modulator region 132 relative to the receiving portion 130, see FIG2 . Finally, the outer radius of the sidewall 114 is denoted by J.

[0072] The ratio of radius G to radius J influences the directional characteristics to a great extent. Therefore, it is desirable to have as thin a side wall 114 as possible in the longitudinal cross-sectional plane 126. An advantageous ratio G / J is in the range of greater than 0.9, preferably greater than 0.92.

[0073] For example, the radius F of the receptacle may be 4.1 mm, the distance G may be 7.1 mm, and / or the thickness of the sidewall 114 in the longitudinal cross-sectional plane 126 may be 0.6 mm.

[0074] The directional characteristics are also greatly influenced by the outer radius F of the housing 130. FIG. 2 shows by way of example that the side wall 114 has a thickened portion 170 in the region adjacent to the bottom wall. The thickened portion 170 is designed so that it is spaced apart from the longitudinal cross-sectional plane 126 by approximately the radius F of the housing 130 and extends substantially parallel. In this particular context, "approximately" means in particular a range of +30% to -30%, and preferably a range of +5% to -15%. The outer radius F of the housing 130 is primarily influenced by the transducer element to be mounted. For example, a transducer element with a radius of 4 mm and a matching outer radius F of 4.1 mm is proposed.

[0075] Furthermore, the directivity characteristics are also decisively influenced by the ratio of the depth H to the outer thickness B. This also applies to the electroacoustic efficiency. Preferably, the absolute value of the depth H is greater than the outer thickness B. According to experiments, the ratio H / B is preferably in the range of 1 to 2, in particular 1.2 to 1.5.

[0076] Experiments have shown that the minimum tilt angle E is at least 2° to demonstrate robustness against manufacturing deviations. Preferably, the minimum tilt angle E is at least 2.5°, particularly preferably at least 3°. The tilt angle is preferably measured or compared relative to a perpendicular to the main axis 118 .

[0077] Experiments have also shown that the steepest angle of inclination D is at least 25°, preferably at least 30°. In a preferred variant with two frustoconical sections, the steeper angle of inclination D is once 40° and once 30°.

[0078] The radial extension of the modulator region 132 is the difference GF. A preferred ratio of the depth H to the radial extension of the modulator region 132, i.e. the ratio H / (GF), is in the range of 0.1 to 0.4, and preferably in the range of 0.15 to 0.25. In other words, the wider the modulator region 132 is radially, the more advantageous the transmission performance of the housing 110 is.

[0079] On the one hand, the above ratio H / B is important for high electroacoustic efficiency. On the other hand, in the region of the transition zone 140 leading to the side wall, it is desired to have a transition as smooth as possible from the thickness A of the receptacle 130 to the thickness B of the bottom wall 112. The ratio between the inclination angles D, E and the maximum possible radius of the convex intermediate transition zones 154, 158 is advantageous for this. In the present case, the intermediate transition zone 154 is implemented with an exemplary radius of 0.75 mm at a thickness B of 0.4 mm or a thickness A of 0.94 mm. With the aid of these measures, the radial mode or radial oscillation form of the transducer element, which is preferably based on piezoelectricity, can be advantageously effectively converted into a bending mode or bending oscillation mode of the ultrasonic transducer 106. The smooth form of the modulator region 132 ensures a balance with the impedance of the transducer element.

[0080] In order to shorten the reverberation after the emission of the ultrasonic pulse, two measures are proposed. First, after the transducer element is installed, the interior 124 can be poured or filled with a damping material. Silicone is preferred for this purpose. Second, linear surfaces between the transducer element or the housing 130 and the side wall 114 are avoided. Because the most curved surface is used, the introduction of energy into the damping material can be improved and the energy can be distributed more evenly than before.

[0081] Finally, it is noted that the smoothest possible course of the modulator region 132 prevents burrs, indentations and / or marks on the outer side 136 of the bottom wall 112 from being produced during the manufacturing process, thereby improving customer acceptance.

[0082] A housing 200 according to a second embodiment of the present invention is presented below. The differences from the first embodiment are mainly discussed here.

[0083] It can be said that the second embodiment shows an ideal form of the present invention. The housing 200 of the second embodiment has an adjuster area 132, which has a continuous curvature 202 on the inner side 120 between the receiving portion 130 and the side wall 114. The side wall-side inclination angle or outer inclination angle E is at least 2°, preferably at least 2.5°, and in particular at least 3°. In this case, the receiving portion-side inclination angle or inner inclination angle D is, for example, 60°.

[0084] Transition region 138 is implemented as a sharp edge 204 . Transition region 140 is implemented as a sharp edge 206 .

[0085] The continuous curvature 202 follows, for example, a parabola opening towards the side wall 114, so that the thickness C of the modulator area decreases more strongly near the housing 130 than near the side wall 114. The design of the continuous curvature 202 based on an inverted parabola corresponds to a certain extent to a solution with two truncated cone parts, the flatter of which is preferably arranged radially on the outside. Instead of a parabolic shape, a trend according to an exponential function is also preferred. More generally: experiments have shown that a continuously differentiable trend of the inner side 120 of the bottom wall 114 has the smoothest trend and therefore has the highest electroacoustic efficiency. A continuously differentiable trend can also be interpreted as an extreme shape of "at least two different inclination angles".

[0086] Furthermore, reference is made to the description of the first embodiment, particularly the description of preferred dimensions and ratios.

[0087] 5, a housing 210 according to the third embodiment differs from the housing 200 according to the second embodiment in the transition region 138. Instead of the sharp edge 204, a concave rounding 156 is provided. In addition, reference is made to the previous description, in particular to the description of the second embodiment.

[0088] 6, the housing 220 according to the fourth embodiment differs from the housing 210 according to the third embodiment in the transition zone 140. Instead of the sharp edge 206, a convex rounding 158 is provided. In addition, reference is made to the previous description, in particular to the description of the second and third embodiments.

[0089] Finally, Figure 7 shows a housing 230 according to a fifth embodiment. The difference with respect to the first embodiment lies essentially in that, instead of the intermediate transition zone 154 between the frustoconical portions 150 and 152, a sharp edge 232 is provided.

[0090] As a precaution, it should be noted with regard to the drawings that the flattest tilt angle in each figure is at least 2°, even though this fineness is difficult to show in the drawings.

[0091] Each dimension shown describes a preferred embodiment. These dimensions may take other values ​​individually or collectively.

[0092] Although the present invention has been described based on exemplary embodiments, it can be modified in many ways.

[0093] Reference Symbols List

[0094] 100 vehicles

[0095] 102 Surrounding Environment

[0096] 104 control unit

[0097] 106 Ultrasonic transducer

[0098] 110 Shell

[0099] 112 bottom wall

[0100] 114 side wall

[0101] 118 Main Axis

[0102] 120Inner side of bottom wall

[0103] 122Inside of the side wall

[0104] 124 Internal

[0105] 126 Longitudinal Section Plane

[0106] 130 accommodating part

[0107] 132 Modulator Area

[0108] 134 plane part

[0109] 136 outside

[0110] 138 Internal Transition Zone

[0111] 140 External transition zone

[0112] 150 frustoconical section

[0113] 152 frustoconical section

[0114] 154 Intermediate Transition Zone

[0115] 156 Concave transition zone

[0116] 158 Convex transition zone

[0117] 160 flange

[0118] 162 flange part

[0119] 164 flange part

[0120] 170 thickened part

[0121] 200 Shell

[0122] 202 Continuous curvature

[0123] 204 Sharp Edges

[0124] 206 Sharp Edges

[0125] 210 housing

[0126] 220 Shell

[0127] 230 Shell

[0128] 232 Sharp Edges

[0129] AInner thickness

[0130] B External thickness

[0131] The thickness of the C modulator region

[0132] D inner tilt angle

[0133] E outer tilt angle

[0134] F Radius

[0135] G Radius

[0136] H Depth

[0137] J Radius

Claims

1. A housing (110, 200, 210, 220, 230) for an ultrasonic transducer (106) for detecting an object in an environment (102) surrounding a vehicle (100), the housing comprising: a circumferential side wall (114) defining a major axis (118) of the housing (110), and a bottom wall (112) having a central housing (130) for supporting a transducer element and at least one modulator region (132), wherein the modulator region (132) extends radially from the receiving portion (130) in a longitudinal cross-sectional plane (126) containing the main axis (118) to a transition region (140) of the bottom wall (112) to the side wall (114), wherein the thickness (C) of the bottom wall (112) decreases radially outwardly across the modulator region (132), and Wherein, the inner side (120) of the bottom wall (112) in the modulator region (132) has at least two different inclination angles (E, D).

2. The housing (200, 210, 220) according to claim 1, characterized in that: The inner side (120) of the modulator region (132) extends in a longitudinal cross-sectional plane (126) with a convex rounding (202).

3. The housing (200, 210, 220) according to claim 1 or 2, characterized in that: The inner side (120) extends continuously and microscopically at least once in the longitudinal cross-sectional plane (126).

4. The housing (110, 230) according to any one of the preceding claims, characterized in that The modulator region (132) includes a plurality of frustoconical portions (150, 152) having different tilt angles (D, E).

5. The housing (110, 230) according to claim 5, characterized in that: At least two radially adjacent frustoconical sections (150, 152) are interconnected by a convex rounding (158).

6. The housing (110, 230) according to any one of the preceding claims, characterized in that The plane portion (134) of the modulator region (132) is arranged such that the closer to the radial outside, the flatter the corresponding plane portion (134) is.

7. The housing (110, 200, 210, 220, 230) according to any one of the preceding claims, characterized in that The modulator region (132) or in each case the modulator region (132) extends symmetrically with respect to the main axis (118) in a longitudinal section plane (126).

8. The housing (110, 200, 210, 220, 230) according to any one of the preceding claims, characterized in that The side wall (114) has a thickened portion (170) parallel to the longitudinal cross-sectional plane (126).

9. The housing (110, 200, 210, 220, 230) according to any one of the preceding claims, characterized in that The tilt angle (D, E) inside the modulator region (132) is at least 2°, preferably at least 2.5°, and more preferably at least 3°.

10. The housing (110, 200, 210, 220, 230) according to any one of the preceding claims, characterized in that The side wall (114) is interrupted in the circumferential direction at least in sections and / or projects at different distances from the main axis when viewed in the circumferential direction.

11. The housing (110, 210, 220, 230) according to any one of the preceding claims, characterized in that The inner side (120) of the bottom wall (112) is connected from the modulator region (132) into the receiving portion (130) by a concave rounding (156).

12. The housing (110, 200, 210, 220, 230) according to any one of the preceding claims, characterized in that The inner side (120) of the bottom wall (112) is connected from the modulator region (132) to the inner side (122) of the side wall (114) by a convex rounding (158).

13. The housing (110, 200, 210, 220, 230) according to any one of the preceding claims, characterized in that The receiving portion (130) has a constant thickness (A).

14. An ultrasonic transducer (106) for detecting objects in the surroundings (102) of a vehicle (100), comprising a housing (110, 200, 210, 220, 230) according to any of the preceding claims and a transducer element supported on and / or in the receiving portion (130).

15. A vehicle (100) having an ultrasonic transducer (106) according to claim 14.

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