Ultrasonic sensors for motor vehicles.

Abstract

The invention relates to an ultrasonic sensor system (1) for a motor vehicle, comprising a sensor housing (2) and a pan-shaped membrane (5) connected to the sensor housing (2), the membrane (5) having a membrane bottom (6) for transmitting and / or receiving ultrasonic signals and a membrane wall (7) connected to the membrane bottom (6) and partly extending into the sensor housing (2). In the housing interior space of the housing segment (9) facing the membrane bottom (6) of the sensor housing (2) a first encapsulation material (10) is arranged, which fills the housing interior space. According to the invention, the first encapsulation material (10) at least partly extends into the membrane interior space of the membrane (5) surrounded by the membrane wall (7), the membrane (5) being geometrically connected to the sensor housing (2) by the first encapsulation material (10).

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic sensor system for a motor vehicle, comprising a sensor housing and a pan-shaped membrane connected to the sensor housing, the membrane having a membrane bottom for transmitting and / or receiving ultrasonic signals and a membrane wall connected to the membrane bottom, a portion of the membrane wall extending into the sensor housing, and a first encapsulant disposed within the housing interior space of the housing segment facing the membrane bottom, the first encapsulant filling the housing interior space. [Background technology]

[0002] Modern motor vehicles typically include a number of ultrasonic sensors associated with driver assistance devices, such as parking assistance systems and / or braking assistance systems, that provide information about the surroundings of the motor vehicle, particularly obstacles and objects in the surroundings, and the distance of the motor vehicle from these. Such ultrasonic sensors are located around the motor vehicle, at least in the front and rear regions of the vehicle, and are usually integrated into fairing components, particularly the bumper.

[0003] In this regard, such ultrasonic sensors are typically positioned within an opening or cutout in a motor vehicle fairing component such that the leading or front membrane bottom of the ultrasonic sensor's pan-shaped membrane is essentially aligned with the surface of the fairing component, but such that ultrasonic waves can be transmitted from and received at the membrane bottom during operation.

[0004] An ultrasonic sensor of the aforementioned type is known, for example, from DE 10 2006 028 214 A1. The ultrasonic sensor comprises an essentially cylindrical sensor housing and a pan-shaped membrane with a disk-shaped membrane bottom supported on the sensor housing, with a piezo element arranged inside the membrane bottom to vibrate the membrane so that it generates an ultrasonic signal. The membrane is surrounded on its outer circumferential side by an annular isolating element that separates the membrane from the sensor housing in terms of vibration. The membrane is supported on its housing side by an annular housing segment of the sensor housing that surrounds the outer circumferential side of the isolating element facing the sensor housing, with the isolating element and the housing segment being connected to each other via a snap mechanism. Additionally, an encapsulant is arranged in the interior space of the sensor housing to protect the ultrasonic sensor and its electrical components from moisture and dirt.

[0005] Such a configuration has the drawback that the number of parts and assembly steps are large, which results in complicated manufacturing and an increase in overall manufacturing costs. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] DE102006028214A1 Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE INVENTION The problem to be solved by the present invention is therefore to disclose an improved configuration for an ultrasonic sensor that has a simplified structure and that has as few parts and as few assembly steps as possible in the manufacturing process. [Means for solving the problem]

[0008] This object is achieved by the teaching set forth in claim 1. Expedient embodiments and developments of the invention are set forth in the dependent claims as well as in the following description.

[0009] According to the document, the sensor is an ultrasonic sensor for a motor vehicle including a sensor housing and a pot-shaped membrane connected to the sensor housing, the membrane having a membrane bottom for transmitting and / or receiving ultrasonic signals and a membrane wall connected to the membrane bottom, a portion of the membrane wall extending into the sensor housing, and a first encapsulant material that fills the housing interior space is disposed within the housing segment on the side of the sensor housing facing the membrane bottom.

[0010] According to the present invention, the first encapsulating material at least partially penetrates into the inner space of the membrane surrounded by the membrane wall, and the membrane is shaped in a similar manner to the sensor housing by the first encapsulating material. join It has been done.

[0011] As a result, the membrane is adhered to the sensor housing by the first encapsulant and fixed relative to the sensor housing. That is, the first encapsulant has a corresponding shape in addition to the sealing function and the role of mechanically separating the membrane from the sensor housing. join It also plays a role in forming

[0012] Therefore, the configuration according to the present invention has an advantage in that it can provide an improved configuration of an ultrasonic sensor with a simplified structure and assembly.

[0013] To allow the membrane wall to extend into the sensor housing, the outer diameter of the membrane wall is smaller than the inner diameter of the sensor housing.

[0014] Advantageously, the membrane is integral with the membrane base and membrane wall, and is preferably made of aluminium.

[0015] In a preferred embodiment, the shape condition In this case, the force acts at least in the axial and circumferential directions. condition The case is performed at least in the axial and circumferential directions.

[0016] In a further preferred embodiment, a gap is formed in the housing interior space between the outside of the membrane wall extending into the sensor housing and the inside of the housing wall of the housing segment, and the first encapsulation material at least partially extends into this gap. In this case, the first encapsulation material is supported by the outside of the membrane wall and the inside of the housing wall. Preferably, the first encapsulation material completely extends into the gap, i.e., the first encapsulation material completely fills the gap. This allows a reliable shape in this region at least in the circumferential direction. Conclusion This contributes to achieving a consensus.

[0017] In a further preferred embodiment, the axial end of the membrane wall opposite the membrane bottom is provided with a ring-shaped protrusion extending outward in the circumferential direction around the axial end of the membrane wall, particularly preferably around the entire circumference. join The projections here preferably extend outward in the circumferential direction at right angles to the membrane wall.

[0018] In this regard, in a further preferred embodiment, protrusions of the membrane wall are provided in the first encapsulant. To the department A corresponding notch is provided, and the protrusion is disposed within the notch, thereby forming a shape at least axially and circumferentially. The bond In other words, the first encapsulant now has a notch that corresponds to and receives the surrounding protrusion, but in the assembled state the first filler material completely surrounds the protrusion.

[0019] In a further preferred embodiment, a ring-shaped flexible molding is arranged in the axial segment of the gap on the side facing the bottom side of the membrane, the protrusion resting on the molding and having a shape Conclusion In this case, the force acts in the axial direction. Conclusion In this case, the first encapsulating material acts via a flexible molding.

[0020] In a further preferred embodiment, the first encapsulant extends circumferentially within the housing interior space to the inside of the housing wall of the housing segment, while the first encapsulant extends circumferentially within the membrane interior space to the inside of the membrane wall.

[0021] In a further preferred embodiment, the first encapsulating material extends circumferentially within the membrane interior space to the inside of the membrane bottom. In this case, it is preferable that the first encapsulating material completely fills the membrane interior space. In this case, the first encapsulating material has a shape Conclusion They not only form a gap but also particularly preferably serve as a damper for the membrane bottom and / or membrane wall.

[0022] In a further preferred embodiment, the first encapsulant is integrally formed from a first material, which is advantageously made from an elastomer, a thermoplastic, a thermoset, or a silicone material.

[0023] In a further preferred embodiment, the first encapsulation material extends axially in the membrane interior space only along one segment of the membrane wall facing away from the membrane bottom, while a second encapsulation material is arranged in direct contact with the first encapsulation material and extends axially from the first encapsulation material to the inside of the membrane bottom and circumferentially to the inside of the membrane wall in the membrane interior space, advantageously made of a first material and the second encapsulation material made of a second material different from the first material, particularly preferably performing a vibration damping role in the membrane bottom and / or in the region of the membrane wall facing the membrane bottom. [Brief explanation of the drawings]

[0024] The present invention will now be described in more detail with reference to the accompanying drawings, in which: [Figure 1a] The ultrasonic sensor is shown in a three-dimensional exploded view. [Figure 1b] The ultrasonic sensor according to FIG. 1a is shown in cross section. [Figure 2a] 1 is an exploded view of an ultrasonic sensor according to an alternative embodiment; [Figure 2b] The ultrasonic sensor according to FIG. 2a is shown in cross section. [Figure 3a] An ultrasonic sensor according to a further alternative embodiment is shown in exploded view as follows: [Figure 3b] The ultrasonic sensor according to FIG. 3a is shown in cross section. [Figure 4a] An ultrasonic sensor according to a further alternative embodiment is shown in exploded view as follows: [Figure 4b] The ultrasonic sensor according to FIG. 4a is shown in cross section. [Figure 5a] Further alternative embodiments of ultrasonic sensors are shown in exploded views and [Figure 5b] 5a shows the ultrasonic sensor according to FIG. 5a in cross section. DETAILED DESCRIPTION OF THE INVENTION

[0025] Corresponding parts are always labeled with the same reference numerals in all figures.

[0026] 1a and 1b show an embodiment of an ultrasonic sensor 1 from different angles. In Fig. 1a, the ultrasonic sensor 1 is shown in an exploded view, and in Fig. 1b, it is shown in a cross-sectional view.

[0027] The ultrasonic sensor 1 includes an integral sensor housing 2 with a plurality of connection pins 3 and a wiring board 4 disposed within the sensor housing 2 and connected to the connection pins 3. The ultrasonic sensor 1 also includes a pot-shaped membrane 5 connected to the sensor housing 2, the membrane 5 having a membrane bottom 6 for transmitting and / or receiving ultrasonic signals and a membrane wall 7 connected to the membrane bottom 6, with a portion of the membrane wall 7 extending into the sensor housing 2. A disk-shaped piezo ceramic is disposed inside the membrane bottom 6 and electrically connected to the wiring board 4. At the axial end of the sensor housing 4 opposite the membrane 5, the sensor housing 2 is closed by a cover 8.

[0028] A first encapsulant 10 is arranged in the housing interior space of the housing segment 9 on the side of the sensor housing 2 facing the membrane bottom 6, completely filling this housing interior space, and is formed integrally from a first material, particularly preferably an elastomer, thermoplastic, thermosetting or silicone material.

[0029] The first encapsulation material 10 extends in the circumferential direction R in the housing interior space of the sensor housing 2 up to the inside of the housing wall of the housing segment 9 of the sensor housing 2. In so doing, the first encapsulation material 10 completely fills the gap formed between the outside of the membrane wall 7 extending into the sensor housing 2 and the inside of the housing wall of the housing segment 9.

[0030] In addition, the first encapsulation material 10 extends into the membrane inner space of the membrane 5 surrounded by the membrane wall 7, and the first encapsulation material 10 extends to the inside of the membrane wall 7 in the circumferential direction R and to the inside of the membrane bottom 6 in the axial direction Z. That is, the first encapsulation material 10 completely fills the membrane inner space. to It serves as a damping agent for the membrane bottom 6 and the membrane wall 7 .

[0031] Furthermore, at the axial end of the membrane wall 7 opposite the membrane bottom 6, a ring-shaped protrusion 11 is provided, which is perpendicular to the membrane wall 7 and extends circumferentially outward, surrounding the entire periphery of the axial end of the membrane wall 7, and is located within the first encapsulating material 10 and engages with a notch corresponding to the protrusion 11, and the first encapsulating material 10 is configured to completely surround the protrusion 11.

[0032] The shape and arrangement of the first sealing material 10 as described above can provide a highly reliable shape acting in the axial direction Z and the circumferential direction R with the sensor housing 2, the inside of the membrane inner space of the membrane 5, and the membrane 5, particularly the protrusions 11 thereof. condition That is, the first encapsulation material 10 not only provides a sealing function, vibration damping between the membrane bottom 6 and the membrane wall 7, and mechanical isolation between the membrane 5 and the sensor housing 2, but also a suitable shape. condition It also plays a role in forming a bond and thus in a reliable fixation of the membrane 5 to the sensor housing 2 .

[0033] Figures 2a and 2b show different angles of an alternative embodiment of the ultrasonic sensor 1. In Figure 2a, the ultrasonic sensor 1 is shown in an exploded view, and in Figure 2b, it is shown in a cross-sectional view.

[0034] This ultrasonic sensor 1 is essentially similar to the ultrasonic sensor 1 shown in FIGS. 1 a to 1 b, but here the ultrasonic sensor 1 also comprises a second encapsulant 12 in addition to the first encapsulant 10 .

[0035] Here, the first encapsulation material 10 extends in the membrane interior space in the axial direction Z only along one segment of the membrane wall 7 opposite the membrane bottom 6, but a second encapsulation material 12 is arranged in direct contact with the first encapsulation material 10. The second encapsulation material 12 is 、 The second encapsulation material 12 extends in the membrane interior space from the first encapsulation material 10 in the axial direction Z to the inside of the membrane bottom 6 and in the circumferential direction R to the inside of the membrane wall 7. The second encapsulation material 12 is made of a second material different from the first material of the first encapsulation material 10. Here, the second encapsulation material 12 plays a role in particular of vibration damping in the region of the membrane bottom 6 and of the membrane wall 7 facing the membrane bottom 6. In this case, the second material can be a material that is particularly suitable for vibration damping purposes.

[0036] Figures 3a and 3b show a further alternative embodiment of the ultrasonic sensor 1 from different angles. In Figure 3a, the ultrasonic sensor 1 is shown in an exploded view, and in Figure 3b, it is shown in a cross-sectional view.

[0037] This ultrasonic sensor 1 is essentially similar to the ultrasonic sensor 1 shown in FIGS. 1a to 1b, but here, in addition to the first encapsulant 10, the ultrasonic sensor 1 also comprises a ring-shaped flexible molded body 13.

[0038] The flexible molding 13 is arranged in the gap between the outside of the membrane wall 7, which is recessed into the sensor housing 2, and the inside of the housing wall of the housing segment 9 of the sensor housing 2, in the axial region on the side facing the membrane bottom 6. In this case, the protrusions 11 formed on the membrane wall 7 come into contact with the molding 13 and are deformed in the axial direction Z. Conclusion In short, here, the shape Conclusion In this case, the first encapsulating material 10 and the flexible molding 13 are interposed therebetween.

[0039] Figures 4a and 4b show a further alternative embodiment of the ultrasonic sensor 1 from different angles. In Figure 4a, the ultrasonic sensor 1 is shown in an exploded view, and in Figure 4b, it is shown in a cross-sectional view.

[0040] This ultrasonic sensor 1 is essentially similar to the ultrasonic sensor 1 shown in FIGS. 2a to 2b, but here, in addition to the first encapsulant 10, the ultrasonic sensor 1 also comprises a ring-shaped flexible molded body 13.

[0041] The flexible molded body 13 itself is then arranged in the axial region facing the membrane bottom 6 between the outside of the membrane wall 7 that is recessed into the sensor housing 2 and the inside of the housing wall of the housing segment 9 of the sensor housing 2, while the protrusions 11 formed on the membrane wall 7 rest on the molded body 13, so that the shape condition In this case, it acts in the axial direction Z. condition In this case, the first encapsulating material 10 and the flexible molding 13 are interposed therebetween.

[0042] Figures 5a and 5b show a further alternative embodiment of the ultrasonic sensor 1 from different angles. In Figure 5a, the ultrasonic sensor 1 is shown in an exploded view, and in Figure 5b, it is shown in a cross-sectional view.

[0043] The ultrasonic sensor 1 is essentially similar to the ultrasonic sensor 1 shown in Figures 1a to 1b, but here the sensor housing 2 is formed as a hollow cylinder in the axial end region facing the membrane bottom 6, and in this axial end region a front cap 14 is connected to the sensor housing 2 by means of a snap connection.

[0044] It will be apparent to those skilled in the art that such an arrangement with a similar sensor housing 2 and a similar front cap 14 can also be used for the embodiments of Figures 2a to 4b. The present application relates to the invention described in the claims, but also includes the following as other aspects. 1. Sensor housing (2) And, Connected to the sensor housing (2) An ultrasonic sensor for a motor vehicle, comprising a pan-shaped membrane (5) , Membrane (5) is A membrane bottom (6) for transmitting and / or receiving ultrasonic signals. And, Membrane wall (7) connected to membrane bottom (6) and With death, Applicable A part of the membrane wall (7) is embedded in the sensor housing (2). hand, S Sensor housing (2) 、 A housing for a motor vehicle, in which a first filling material (10) is arranged in the housing interior space of the housing segment (9) on the side facing the membrane bottom (6), filling the housing interior space. super An ultrasonic sensor, The first encapsulant (10) at least partially penetrates into the inter-membrane space of the membrane (5) surrounded by the membrane wall (7). , applicable The membrane (5) is shaped to fit the sensor housing (2) by the first encapsulant (10). join An ultrasonic sensor (1) characterized by: 2. shape Conclusion The ultrasonic sensor (1) according to claim 1, characterized in that the force acts in at least one axial direction (Z) and at least one circumferential direction (R). 3. 3. The ultrasonic sensor (1) according to claim 1 or 2, characterized in that a gap is formed in the interior space of the housing between the outside of the membrane wall (7) extending into the sensor housing (2) and the inside of the housing wall of the housing segment (9), and the first encapsulant (10) at least partially extends into the gap. 4. Any one of the ultrasonic sensors (1) described above, characterized in that a ring-band-shaped protrusion (11) extending outward in the circumferential direction is provided at the axial end of the membrane wall (7) opposite the membrane bottom (6), surrounding the axial end of the membrane wall (7). 5. The first encapsulant (10) has a notch therein corresponding to the protrusion (11) of the membrane wall (7). , applicable A protrusion (11) is disposed within the notch, thereby securing at least the shaft Direction (Z) and circumferential direction (R ) to shape join 5. The ultrasonic sensor (1) according to claim 4, characterized in that: 6. A ring-shaped flexible molding (13) is arranged in the axial segment of the gap on the side facing the membrane bottom (6), and the protrusion (11) rests on the molding (13). ,shape Condition Conclusion If axis Acts in the direction (Z) Let 5. The ultrasonic sensor (1) according to any one of 2 to 4 above, 7. The first encapsulant (10) is disposed within the housing interior space. 、 Circumferential direction (R) to , Ha Any one of the above ultrasonic sensors (1), characterized in that the first encapsulating material (10) extends to the inside of the housing wall of the housing segment (9), and the first encapsulating material (10) extends to the inside of the membrane wall (7) in the circumferential direction (R) within the membrane internal space. 8. Any one of the above ultrasonic sensors (1), characterized in that the first encapsulating material (10) extends in the axial direction (Z) within the membrane inner space to the inside of the membrane bottom (6). 9. Any one of the above ultrasonic sensor devices (1), wherein the first encapsulant (10) is integrally formed from a first material. 10. 9. The ultrasonic sensor (1) according to any one of 1 to 8 above, characterized in that the first encapsulating material (10) extends in the axial direction (Z) within the membrane internal space only along one segment of the membrane wall (7) facing away from the membrane bottom (6), but a second encapsulating material (12) is arranged in direct contact with the first encapsulating material (10) within the membrane internal space, extending from the first encapsulating material (10) in the axial direction (Z) to the inside of the membrane bottom (6) and in the circumferential direction (R) to the inside of the membrane wall (7). [Explanation of symbols]

[0045] 1 ultrasonic sensor 2 Sensor Housing 3 connecting pins 4. Wiring board 5. Membrane 6 membrane bottom 7. Membrane Wall 8 Cover 9 Housing segments of the sensor housing 10 First Enclosure 11 Protrusion 12 Secondary Encapsulating Material 13 Molded body 14 Front cap R circumferential direction Z axis direction

Claims

1. The sensor comprises a sensor housing (2) and a pot-shaped membrane (5) connected to the sensor housing (2); The membrane (5) has a membrane bottom (6) for transmitting and / or receiving ultrasonic signals and a membrane wall (7) connected to the membrane bottom (6); A portion of the membrane wall (7) extends into the sensor housing (2), 1. An ultrasonic sensor for a motor vehicle, comprising: a housing segment (9) on a side of a sensor housing (2) facing a membrane bottom (6) and a first encapsulating material (10) arranged in the housing interior space, the first encapsulating material filling the housing interior space; The ultrasonic sensor (1) is characterized in that the first encapsulating material (10) at least partially penetrates into the internal space of the membrane (5) surrounded by the membrane wall (7), and the membrane (5) is form-fitted to the sensor housing (2) by the first encapsulating material (10), and the form-fitting acts in the axial direction (Z) and the circumferential direction (R).

2. 2. The ultrasonic sensor (1) according to claim 1, characterized in that a gap is formed in the interior space of the housing between the outside of the membrane wall (7) extending into the sensor housing (2) and the inside of the housing wall of the housing segment (9), and the first encapsulant (10) at least partially extends into this gap.

3. 3. The ultrasonic sensor (1) according to claim 1 or 2, characterized in that the axial end of the membrane wall (7) opposite the membrane bottom (6) is provided with a ring-band-shaped protrusion (11) extending outward in the circumferential direction and surrounding the axial end of the membrane wall (7).

4. 4. The ultrasonic sensor (1) according to claim 3, characterized in that the first encapsulation material (10) has a notch corresponding to the protrusion (11) of the membrane wall (7), the protrusion (11) being arranged in the notch, thereby providing a positive connection at least in the axial direction (Z) and the circumferential direction (R).

5. 4. The ultrasonic sensor (1) according to claim 3, characterized in that a ring-shaped flexible molding (13) is arranged in the axial segment of the gap on the side facing the membrane bottom (6), and the protrusion (11) rests on the molding (13) and exerts a form-lock in the axial direction (Z).

6. 3. The ultrasonic sensor (1) according to claim 1 or 2, characterized in that the first encapsulating material (10) extends in the circumferential direction (R) within the housing interior space to the inside of the housing wall of the housing segment (9), and the first encapsulating material (10) extends in the circumferential direction (R) within the membrane interior space to the inside of the membrane wall (7).

7. 3. The ultrasonic sensor (1) according to claim 1 or 2, characterized in that the first encapsulation material (10) extends in the axial direction (Z) within the membrane interior space up to the inside of the membrane bottom (6).

8. 3. Ultrasonic sensor (1) according to claim 1 or 2, characterized in that the first encapsulant (10) is formed in one piece.

9. The first encapsulation material (10) extends in the membrane interior space in the axial direction (Z) only along one segment of the membrane wall (7) facing away from the membrane bottom (6), 3. The ultrasonic sensor (1) according to claim 1 or 2, characterized in that a second encapsulation material (12) is arranged in direct contact with the first encapsulation material (10) and extends in the membrane interior space from the first encapsulation material (10) in the axial direction (Z) to the inside of the membrane bottom (6) and in the circumferential direction (R) to the inside of the membrane wall (7).

Images