A housing for an ultrasonic transducer, the housing having a variable sloped bottom surface

Abstract

(A housing for an ultrasonic transducer, the housing having a different sloped bottom surface) A housing (110, 200, 210, 220, 230) for an ultrasonic transducer (106) for detecting objects in the vicinity (102) of a vehicle (100), the housing (110) comprising a circumferential side wall (114) defining a major axis (118) of the housing (110), and a bottom wall (112) having a central receptacle (130) for supporting a transducer element and at least one modulator area (132), the modulator area (132) being oriented in a longitudinal plane (132) containing the major axis (118). A housing (110, 200, 210, 220, 230) for an ultrasonic transducer (106) is proposed, extending radially from a receptacle (130) to a transition (140) of the bottom wall (112) to the side wall (114) at 126, the thickness (C) of the bottom wall (112) decreasing radially outward throughout the modulator area (132), and the inner side (120) of the bottom wall (112) in the modulator area (132) has at least two different inclination angles (E, D).

Description

[Technical Field]

[0001] The present invention relates to a housing for an ultrasonic transducer for detecting objects in the vicinity of a vehicle, and also to an ultrasonic transducer for detecting objects in the vicinity of a vehicle, and to a vehicle. Summary of the Invention

[0002] Ultrasonic transducers for detecting objects in the vicinity of a vehicle are used, for example, in parking systems. Such ultrasonic transducers often function according to the pulse-echo principle, with the same ultrasonic transducer being used as both transmitter and receiver. Therefore, it is particularly difficult to design a "blind zone" that is as small as possible at close range, from which echo signals cannot be received or reliably detected. The size of this "blind zone" is characterized and determined by the reverberation time of the transducer after the emission of the pulse.

[0003] To obtain a high electroacoustic conversion efficiency and therefore a wide detection range and / or a low signal-to-noise ratio, ultrasonic transducers are generally based on the bending transducer principle: a piezoelectric transducer disk is applied to a membrane and operated in a resonant mode.

[0004] To aid in this, and to avoid echoes from very tall objects such as roofs and bridges on roadways and / or car parks, a strong directional characteristic and a narrow aperture angle are generally sought, which can be achieved, for example, by special membrane shapes.

[0005] One example is Japanese Patent Application Laid-Open No. 2001-326987, which discloses a cup-shaped housing for an ultrasonic transducer, the bottom of which has a central circular disk-shaped thick portion. This design may exhibit low electroacoustic efficiency, which shortens the detection range of the resulting ultrasonic transducer. Furthermore, this design may result in a long reverberation time after the emission of the ultrasonic pulse, thereby expanding the blind area at close range.

[0006] Japanese Patent Publication No. 2006-174003, for example, teaches a design for improving reverberation time. It discloses a rotationally symmetric cup-shaped housing for an ultrasonic transducer. The bottom section of the housing has a truncated cone shape, and its thickness increases inward from the sidewalls toward the center base, with respect to the transducer element having a constant slope.

[0007] In JP 2006-174003, sharp edges can complicate manufacturing. Furthermore, changes in radius can have a strong interaction with the resonant frequency.

[0008] DE 11 2009 003 590 T5 discloses an ultrasonic transducer with improved stability of the resonant frequency. The ultrasonic transducer described comprises a circular cylindrical housing with a lower side and a piezoelectric element disposed substantially in the center of the lower side of the housing. The lower side of the housing has a tapered section that gradually thins from the location of the piezoelectric element toward the inner wall surface of the housing, and a flat section that extends from the outer edge of the tapered section to the inner wall surface of the housing while maintaining the thickness of the outer edge of the tapered section.

[0009] In particular, the design shown in FIG. 3 of DE 11 2009 003 590 T5 can extend the reverberation time. However, the disclosed housing tends to show burrs on the outer side of the vehicle body when installed. Compared to the design of the aforementioned JP 2001-326987, the directional characteristics may be worsened and the aperture angle may be wider. Furthermore, the electro-acoustic efficiency may be reduced.

[0010] Further housings for ultrasonic transducers are known in the prior art: JP 2005-039689 A discloses a cup-shaped housing for an ultrasonic transducer having a flat bottom. On one side, the flat bottom is provided with one or more flat steps toward the outer side of the bottom, resulting in one or more further thinned bottom sections. This offset causes the ultrasonic sensing cone to tilt with respect to the longitudinal axis of the housing. This tilt results in the ultrasonic sensing cone being asymmetrical with respect to the longitudinal axis. Therefore, the orientation of the sensor must be monitored during installation. This concept may not be suitable for applications where asymmetric cable connections are provided and / or identical components are required on both the left and right sides of the vehicle body. In other words, the housing of JP 2005-039689 A is not suitable for applications requiring an overall symmetrical sensor structure.

[0011] JP 2017-225013 A discloses a circular disk-shaped housing for an ultrasonic transducer, which has an oval-shaped recess in the center with a flat bottom, which has a kidney-shaped recess with a thinner, flatter bottom on its shorter sides. A step course of the bottom thickness with a flat step results in a cross section along the longitudinal axis of the oval-shaped recess.

[0012] DE 10 2008 040905 A1 discloses a cup-shaped housing for an ultrasonic sensor having a bottom surface and a side wall, wherein an electromechanical transducer element, such as a cylindrical disk-shaped piezoelectric element, is adhesively bonded to the flat inner side of the bottom surface.

[0013] Against this background, one object of the present invention is to provide an improved ultrasound transducer, and in particular a housing for this transducer, in which an advantageous compromise between directional characteristics, electroacoustic efficiency and / or short reverberation time is in the foreground.

[0014] Therefore, a housing for an ultrasonic transducer for detecting objects around a vehicle is proposed. The housing has a circumferential side wall and a bottom wall. The circumferential side wall defines a major axis of the housing. The bottom wall has a central receptacle for supporting a transducer or ultrasonic element and at least one modulator area. The modulator area extends radially from the receptacle to a transition of the bottom wall to the side wall in a longitudinal cross-sectional plane containing the major axis. The thickness of the bottom wall decreases radially outward over the entire modulator area. The inner side of the bottom wall has at least two different inclination angles in the modulator area.

[0015] The housing implements a compromise in the bottom wall. On the one hand, the housing is distinguished by directional properties achieved by a large opening in the plane of the longitudinal section. On the other hand, the bottom wall is distinguished by a high electro-acoustic efficiency, which is achieved by an appropriate shape of the modulator area. Furthermore, the proposed housing is suitable for a desired short reverberation time and, finally, is robust with respect to variations in manufacturing tolerances. The proposed housing can be easily manufactured thanks to the proposed bottom wall.

[0016] The thickness of the bottom wall decreases radially outwardly over the entire modulator area, particularly in the plane of the longitudinal section.The inner side of the bottom wall has at least two different inclination angles in the modulator area, particularly in the plane of the longitudinal section.

[0017] The side walls are preferably circumferentially closed, although variations are contemplated having walls that are not circumferentially continuous and / or partially discontinuous.

[0018] The bottom wall has an outer side, which preferably extends perpendicular to the main axis. Variations are concave and / or convex curved and / or in the shape of a truncated cone and / or extending to a point.

[0019] The inner sides of the modulator area preferably extend convexly rounded in the plane of the longitudinal section, so that the tendency to reverberation is reduced, i.e. improved. It is conceivable that both the entire modulator area is embodied as convexly rounded, and that regions of the modulator area are embodied as convexly rounded.

[0020] In this specification, the terms "convex" and "concave" refer to an observer inside the housing. "Convex" means directed outward, especially rounded, when viewed from the inside side of the housing. Colloquially, "convex" can be seen as a bulge "outward." Functionally, the "convex" section of the inside side of the bottom wall corresponds to the larger interior volume of the housing. "Concave" means directed toward the inside side, especially rounded, when viewed from the inside of the housing. Colloquially, "concave" can be seen as a bulge "inward." Functionally, the "concave" section of the inside side of the bottom wall corresponds to the smaller interior volume of the housing.

[0021] According to one preferred option, a continuously differentiable course of the inner side in the plane of the longitudinal section is considered. Examples include a parabolic course and / or an exponential course. The frequency behavior can be improved in this way. It is conceivable that the inner side extends in a continuously differentiable manner over the entire modulator area. It is further conceivable that the inner side extends in a continuously differentiable manner over only a part of the modulator area.

[0022] For reasons of electroacoustic efficiency, it is preferred that the rounded and / or parabolic outer edge be tangentially adjacent to the imaginary frustum angle.

[0023] If the modulator area includes multiple 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, especially radially adjacent truncated cone sections, meet each other via a convex rounded portion, damping can be improved and reverberation can be reduced. However, if two adjacent truncated cone sections, especially radially adjacent truncated cone sections, meet each other via an edge, it is possible that the natural frequency behavior will be more pronounced. Depending on the design, both improvements are desirable.

[0024] For reasons of electroacoustic efficiency, it is also preferred that the surface sections of the modulator area be positioned radially outwardly the flatter the respective surface section is. For example, if two truncated conical sections with different inclination angles are provided, it is more electroacoustically efficient to position the flatter truncated conical section radially outward of the steeper truncated conical section. Specifications such as "flat" and "steep" preferably relate to an imaginary axis perpendicular to the imaginary major axis.

[0025] If the modulator area, or in each case one modulator area, extends symmetrically with respect to the main axis in the plane of the longitudinal section, a directional characteristic of the ultrasound transducer that is symmetric with respect to the main axis can be achieved. In this way, for example, an ultrasound cone that is wide in the horizontal direction and narrow in the vertical direction can be provided.

[0026] Advantageous directional characteristics can also be achieved if the side wall extends to the receptacle in a second plane of the longitudinal section, which second plane of the longitudinal section contains the main axis and is perpendicular to the plane of the longitudinal section. In particular, the effective opening can be narrower in the direction of the second plane of the longitudinal section than in the direction of the first plane of the longitudinal section, so that the directional characteristics are wider in this direction of the second plane of the longitudinal section. According to a preferred embodiment, the side wall has a thickened portion that is parallel and / or at least approximately parallel and / or partially parallel to the plane of the longitudinal section. The inner wall of the thickened portion can optionally extend concentrically with the receptacle.

[0027] Experiments have shown that for electroacoustically efficient housings, the angle of inward slope in the modulator area is at least 2°, preferably at least 2.5°, and more preferably at least 3°. "Inward" in the modulator area means that the rounded portion merging into the preferably flat receptacle and / or the rounded portion merging into the preferably steep sidewall may have a smaller slope angle. A slope angle of 0° thus means perpendicular to the major axis, and a slope angle of 90° therefore means parallel to the major axis.

[0028] If the side walls are interrupted in at least some places in the circumferential direction and / or project by different amounts from the main axis as viewed along the circumferential direction, the housing may include a twist lock, thus ensuring a desired orientation of the directional characteristic relative to the vehicle.

[0029] The inner side of the bottom wall preferably meets with a rounded portion that is concave from the modulator area into the receptacle, making the housing more tolerant of manufacturing variations.

[0030] To make the housing easier to manufacture, it is proposed that the inner side of the bottom wall optionally merges from the modulator area into the inner side of the side wall with a convex rounded portion.

[0031] If the receptacle has a constant thickness, it is advantageous for mounting the disc-shaped transducer element.

[0032] According to a further aspect of the invention, an ultrasonic transducer is proposed, which comprises a housing according to one of the above options and a transducer element, which is supported in and / or on a receptacle, for example by adhesive, welding and / or chemical and / or mechanical fastening methods.

[0033] According to yet another aspect, a vehicle is proposed that includes at least one such ultrasonic transducer.

[0034] The vehicle may be, for example, a car or a truck.

[0035] Further possible implementations of the invention also include not explicitly mentioned combinations of features or embodiments described above or below with respect to the exemplary embodiments, and those skilled in the art will in such cases also add individual aspects as improvements or additions to the respective basic forms of the invention.

[0036] 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 will be explained in more detail below on the basis of preferred embodiments with reference to the attached drawings. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 shows a schematic top view of a vehicle including multiple ultrasonic transducers. [Figure 2] FIG. 2 shows a schematic perspective cross-sectional view of an ultrasonic transducer housing according to a first embodiment of the invention. [Figure 3] FIG. 3 shows a schematic view in vertical section of a part of the bottom wall and a part of the side wall of an ultrasonic transducer housing according to a first embodiment of the invention. [Figure 4] FIG. 4 shows a schematic view in longitudinal section of a portion of the bottom wall and a portion of the side wall of a housing for an ultrasonic transducer according to a second embodiment of the invention. [Figure 5] FIG. 5 shows a schematic view in longitudinal section of a portion of the bottom wall and a portion of the side wall of a housing for an ultrasonic transducer according to a third embodiment of the invention. [Figure 6] FIG. 6 shows a schematic view in longitudinal section of a portion of the bottom wall and a portion of the side wall of a housing for an ultrasonic transducer according to a fourth embodiment of the invention. [Figure 7] FIG. 7 shows a schematic view in longitudinal section of a portion of the bottom wall and a portion of the side wall of a housing for an ultrasonic transducer according to a fifth embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0038] In the drawings, identical or functionally identical elements are designated by the same reference numbers unless otherwise noted.

[0039] 1 shows a schematic bird's-eye view of a vehicle 100. The vehicle 100 is, for example, an automobile disposed in a surrounding environment 102. The automobile 100 includes a control unit 104. The automobile 100 is further provided with a plurality of ultrasonic transducers 106. The ultrasonic transducers 106 are configured to detect a distance from an object disposed in the surrounding environment 102 and output a corresponding sensor signal. The ultrasonic transducers 106 are connected to the control unit 104.

[0040] 2 and 3 show a housing 110 for an ultrasonic transducer 106 according to a first embodiment of the housing 110. FIG.

[0041] 2 is a vertical cross-sectional view showing the configuration of the housing 110. The housing 110 has a bottom wall 112 and a side wall 114.

[0042] The sidewall 114 is circumferentially closed, thereby forming an irregular tubular shape on the inside. The sidewall 114 defines a major axis 118 at its center.

[0043] At one axial end of the side wall 114, the housing is closed in a cup-like manner by a generally disc-shaped bottom wall 112. An inner side 120 of the bottom wall 112 and an inner side 122 of the side wall 114 define an interior 124 of the housing 110.

[0044] In the view of FIG. 2, the housing 110 is in cross section at a longitudinal cross-sectional plane 126 that includes the main axis 118 .

[0045] Figure 3 shows in cross-sectional top view a portion of the longitudinal section of Figure 2. Thus, Figure 3 shows a cross section through longitudinal section plane 126 of housing 110. A portion of side wall 114 is shown on the left side of the image, and main axis 118 is shown on the right side of the image.

[0046] The bottom wall 112 has a receptacle 130 and a modulator area 132 radially outward from the major axis 118. The side wall 114 is radially outwardly adjacent the modulator area 132.

[0047] The receptacle 130 is an area of the bottom wall 112 provided to support a transducer element (not shown), preferably a piezoelectric element for transduction between mechanical and electrical vibrations in the ultrasonic range.

[0048] An outer side 136 of the bottom wall 112 preferably extends perpendicular to the major axis 118 .

[0049] The transducer element is preferably connected to the receptacle 130, for example by adhesive bonding. For this purpose, the inner side 120 preferably extends perpendicular to the main axis 118 in the area of the receptacle 130. The receptacle 130 therefore has a thickness A.

[0050] In the longitudinal cross-sectional plane 126, the modulator area 132 is located between the receptacle 130 and the sidewall 114. In the first embodiment, the modulator area 132 is adjacent to the receptacle 130 by an inner transition portion 138. Furthermore, in the first embodiment, the modulator area 132 is adjacent to the sidewall 114 by an outer transition portion 140.

[0051] The bottom wall 112 has a minimum thickness B at the outer transition portion 140. This radially outer minimum thickness B is less than the radially inner thickness A of the receptacle 130.

[0052] The thickness C at any point in the modulator area 132 gradually decreases from the receptacle 130 toward the transition portion 140. More precisely, in the first embodiment, the thickness C of the bottom wall 112 gradually decreases from the inner transition portion 138 toward the outer transition portion 140. In other words, the thickness C at each inner point in the modulator area 132 is smaller than the thickness A and larger than the thickness B.

[0053] In the first embodiment, the transitions 138, 140 are formed continuously, so that the thickness C of the modulator area 132 at the inner edge of the modulator area 132 is equal to the thickness A, and the thickness C of the modulator area 132 at the outer edge is equal to the thickness B.

[0054] In the first embodiment, the modulator area 132 has two frusto-conical sections 150 and 152. The frusto-conical section 150 located radially inward of the modulator area 132 has a proportionally larger tilt angle D. The frusto-conical section 152 located radially outward of the modulator area 132 has a proportionally smaller tilt angle E.

[0055] A favorable compromise between directional characteristics and electro-acoustic efficiency is achieved by the different tilt angles D and E of the modulator area 132 .

[0056] The inclination angle D, E of the truncated cone 150, 152 or cone in this case is the cone angle between the base and the side of the cone or truncated cone.

[0057] The inner side 120 has a flat section 134 in the area of each of the frustoconical sections 150, 152.

[0058] The frusto-conical sections 150 and 152 join one another in the first embodiment by an intermediate radial transition 154 .

[0059] The inner transition 138 from the receptacle 130 to the inner frusto-conical section 150 is a concave transition 156 and therefore an inwardly curved transition when viewed from the interior 124 .

[0060] The intermediate transition 154 from the inner frusto-conical section 150 to the outer frusto-conical section 152 and the outer transition 140 from the outer frusto-conical section 152 to the side wall 114 are each convex transitions 158, and therefore are transitions that curve outward when viewed from the interior 124.

[0061] While FIG. 3 shows only half of the cross section in the longitudinal section plane 126 with the bottom wall 112, FIG. 2 shows that there are two modulator areas 132 in the longitudinal section plane 126, which are symmetrically arranged with respect to the major axis 118.

[0062] The side wall 114 has a section, in this case, designed as a collar 160, which is arranged, for example, at the end of the side wall 114 remote from the bottom wall 112. The collar 160 protrudes radially outward but has a variable width in the circumferential direction. Thus, FIG. 2 shows a narrow collar section 162 and a wide collar section 164. Due to the alternation of the narrow and wide collar sections 162, 164, a twist lock is achieved after the housing 110 is inserted, for example, into diametrically opposed recesses in the bumper of the vehicle 100. Thus, the orientation of the directional characteristics of the ultrasonic transducer 104 in the vehicle 100 can be monitored and set.

[0063] The design advantages of the first embodiment will be described below. It is clear that these preferred dimensions and ratios are each advantageous in their own right.

[0064] The distance from major axis 118 to transition portion 138 is designated in FIG. 3 as radius F. The distance from major axis 118 to inner side 122 of sidewall 114 is designated as radius G or as distance G. The difference between thickness A and thickness B is designated as depth H. Depth H is the depth of the recess formed by modulator area 132 with respect to receptacle 130, see FIG. 2. Finally, the outer radius of sidewall 114 is designated by J.

[0065] The ratio of radius G to radius J has a significant effect on the directional properties. Thus, the thinnest possible sidewall 114 is sought in the cross-sectional plane 126. An advantageous ratio G / J is in the range greater than 0.9, preferably greater than 0.92.

[0066] For example, the receptacle radius F may be 4.1 mm, the distance G may be 7.1 mm, and / or the sidewall 114 may be 0.6 mm thick at the cross-sectional plane 126.

[0067] The directional characteristics are also significantly affected by the outer radius F of the receptacle 130. FIG. 2 shows, by way of example, that the side wall 114 has a thickened portion 170 in the area adjacent to the bottom wall. The thickened portion 170 is designed so that it extends substantially parallel to and is spaced from the plane 126 of the longitudinal cross section by approximately the radius F of the receptacle 130. "Approximately" in this particular context particularly means a range of +30% to -30%, and preferably a range of +5% to -15%. The outer radius F of the receptacle 130 is primarily affected 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.

[0068] The directional characteristics are furthermore decisively influenced by the ratio of the depth H to the outer thickness B. This also applies to the electro-acoustic efficiency. Preferably, the depth H has an absolute value greater than the outer thickness B. Experiments have shown that an H / B ratio range of 1 to 2 is preferred, and in particular an H / B ratio range of 1.2 to 1.5 is preferred.

[0069] Experiments have shown that for robust behavior against manufacturing variations, the minimum tilt angle E is at least 2°. Preferably, the minimum tilt angle E is at least 2.5°, and particularly preferably at least 3°. The tilt angle is preferably measured or compared with respect to a perpendicular to the main axis 118.

[0070] Experiments have also shown that the steepest inclination angle D is at least 25°, preferably at least 30°. In preferred variants with two truncated cone sections, the steeper inclination angle D is in some cases 40° and in other cases 30°.

[0071] The radial extension of the modulator area 132 has the difference GF. The preferred ratio of the depth H to the radial extension of the modulator area 132, hence the ratio H / (GF), is in the range of 0.1 to 0.4, preferably in the range of 0.15 to 0.25. In other words, the wider the modulator area 132 is in the radial direction, the more favorable the transmission behavior of the housing 110.

[0072] For high electroacoustic efficiency, the aforementioned ratio H / B is important. On the other hand, in the area of the transition 140 to the side wall, a transition as smooth as possible from the thickness A of the receptacle 130 to the thickness B of the bottom wall 112 is sought. For this purpose, the ratio of the inclination angles D and E and the largest possible radius of the convex intermediate transitions 154, 158 are advantageous. In this case, the intermediate transition 154 is embodied with an exemplary radius of 0.75 mm with a thickness B of 0.4 mm or a thickness A of 0.94 mm. With these dimensions, the radial mode or radial oscillation form of the preferred piezoelectric-based transducer element can be advantageously efficiently converted into the bending mode or bending oscillation form of the ultrasonic transducer 106. The smooth shape of the modulator section 132 ensures an equalization of the impedance of the transducer element here.

[0073] Two strategies have been proposed to shorten the reverberation time after the ultrasonic pulse is emitted. First, after the transducer elements are installed, the interior 124 can be potted or filled with a damping material. Silicone is preferred for this purpose. Second, linear surfaces between the transducer elements or receptacles 130 and the side walls 114 are avoided. By using curved surfaces whenever possible, the energy can be better introduced into the damping material and distributed more evenly than before.

[0074] Finally, it is noted that the smoothest possible course of the modulator area 132 prevents burrs, impressions, and / or marks from appearing on the outer side 136 of the bottom wall 112 during manufacturing, thereby improving customer acceptability.

[0075] A housing 200 according to a second embodiment of the invention will be proposed below. Differences from the first embodiment will be mainly described here.

[0076] The second embodiment shows an ideal form of the invention. The housing 200 of the second embodiment has a modulator area 132, which has a continuous curvature 202 on the inner side 120 between the receptacle 130 and the side wall 114. The side wall side inclination angle or outer side inclination angle E is at least 2°, preferably at least 2.5°, and in particular at least 3°. The receptacle side inclination angle D or inner side inclination angle D is, for example, 60° in this case.

[0077] Transition 138 is embodied as a sharp edge 204. Transition 140 is embodied as a sharp edge 206.

[0078] The continuous curvature 202 follows, for example, a parabola that opens towards the side wall 114, whereby the thickness C of the modulator area decreases more strongly near the receptacle 130 than near the side wall 114. The design of the continuous curvature 202, insofar as it is based on a recumbent parabola, corresponds to the proposal that of two truncated conical sections, the flatter one is preferably positioned radially outward. Instead of a parabolic shape, a course that follows an exponential function is also preferred. More generally: experiments have shown that a continuously differentiable course of the inner side 120 of the bottom wall 114 has the smoothest course and therefore the highest electro-acoustic efficiency. A continuously differentiable course can also be interpreted as an extreme shape of "at least two different inclination angles."

[0079] Further, reference is made to the description of the first embodiment, in particular the description of preferred dimensions and ratios.

[0080] The housing 210 according to the third embodiment shown in Figure 5 differs from the housing 200 according to the second embodiment in the transition section 138. Instead of the sharp edge 204, a concave rounded section 156 is provided. Further reference is made to the previous description, in particular to the second embodiment.

[0081] The housing 220 according to the fourth embodiment shown in Figure 6 differs from the housing 210 according to the third embodiment in the transition section 140. Instead of the sharp edge 206, a convex rounded section 158 is provided. Further reference is made to the previous description, in particular to the second and third embodiments.

[0082] Finally, Figure 7 shows a housing 230 according to a fifth embodiment, which differs from the first embodiment mainly in that a sharp edge 232 is provided instead of the intermediate transition 154 between the truncated conical section 150 and the truncated conical section 152.

[0083] As a note, with respect to the accompanying drawings, it is noted that the flattest tilt angle in each drawing is at least 2°, even though this flatness may be difficult to show in the drawing.

[0084] The dimensions shown are representative of a preferred embodiment. They may assume other values, either individually or collectively.

[0085] Although the present invention has been described with reference to exemplary embodiments, it can be varied in many ways.

[0086] List of Reference Numbers 100 vehicles 102 Surroundings 104 Control Unit 106 Ultrasonic Transducer 110 Housing 112 Bottom wall 114 Side wall 118 Main axis 120 Inside side of bottom wall 122 Inner side of side wall 124 Internal 126 Plane of longitudinal section 130 receptacle 132 Modulator Area 134 Plane Section 136 Outer Side 138 Medial transition 140 Outer transition section 150 truncated cone section 152 Conical Section 154 Intermediate Transition Section 156 Concave transition 158 Convex transition 160 colors 162 Color Section 164 Color Section 170 Thick wall part 200 Housing 202 Continuous curvature 204 Sharp Edge 206 Sharp Edge 210 Housing 220 Housing 230 Housing 232 Sharp Edge A Inner thickness B. Outer thickness C Thickness of the modulator area D Inner slope angle E Outer slope angle F radius G radius H Depth J radius

Claims

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

2. 2. The housing (200, 210, 220) according to claim 1, characterized in that the inner side (120) of the modulator area (132) extends in a convex rounded portion (202) in the plane (126) of the longitudinal section.

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

4. A housing (110, 230) according to any one of claims 1 to 3, characterized in that the modulator area (132) comprises a plurality of frusto-conical sections (150, 152) with different inclination angles (D, E).

5. 6. The housing (110, 230) of claim 5, wherein at least two radially adjacent frusto-conical sections (150, 152) merge with one another via a convex rounded portion (158).

6. A housing (110, 230) according to any one of claims 1 to 5, characterized in that the planar sections (134) of the modulator area (132) are arranged further radially outward the flatter the respective planar section (134) is.

7. A housing (110, 200, 210, 220, 230) according to any one of claims 1 to 6, characterized in that the or in each case the modulator area (132) extends symmetrically with respect to the main axis (118) in the plane (126) of the longitudinal section.

8. A housing (110, 200, 210, 220, 230) according to any one of claims 1 to 7, characterized in that the side wall (114) has a thickened portion (170) parallel to the plane (126) of the longitudinal section.

9. A housing (110, 200, 210, 220, 230) according to any one of claims 1 to 8, characterized in that the inner tilt angle (D, E) in the modulator area (132) is at least 2°, preferably at least 2.5°, more preferably at least 3°.

10. The housing (110, 200, 210, 220, 230) according to any one of claims 1 to 9, characterized in that the side wall (114) is interrupted at least at some points in the circumferential direction and / or projects at different distances from the main axis as viewed along the circumferential direction.

11. The housing (110, 210, 220, 230) according to any one of claims 1 to 10, characterized in that the inner side (120) of the bottom wall (112) merges from the modulator area (132) into the receptacle (130) by a concave rounded portion (156).

12. The housing (110, 200, 210, 220, 230) according to any one of claims 1 to 11, characterized in that the inner side (120) of the bottom wall (112) merges from the modulator area (132) into the inner side (122) of the side wall (114) by a convex rounded portion (158).

13. The housing (110, 200, 210, 220, 230) according to any one of claims 1 to 12, characterized in that the receptacle (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 one of claims 1 to 13 and a transducer element supported on and / or within the receptacle (130).

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

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