Radar sensor system having a waveguide antenna that is snap-fit onto a radome

Abstract

The invention relates to a radar sensor system (1) comprising a waveguide antenna (2), a radome (3), a housing (4) and a receptacle for a printed circuit board (5), wherein the waveguide antenna (2) is attached to the radome (3) by means of a snap-fit ​​connection and the radome (3) is attached to the housing (4), wherein the housing (4) and the radome (3) together surround the waveguide antenna (2).

Description

Technical field

[0001] The invention relates to a radar sensor system, particularly for use in a vehicle, comprising a circuit board, a radome, a housing, and a waveguide antenna. The invention further relates to a method for manufacturing a radar sensor system. State of the art

[0002] Radar sensor systems typically use waveguide antennas to transmit radar waves generated by a microchip on a printed circuit board. These radar waves are coupled into the inputs of the waveguide antenna channels via so-called "ports" on the circuit board. It is known to attach the waveguide antenna to the circuit board with screws to establish contact between the inputs and the ports.

[0003] The invention is based on the objective of designing a radar sensor system and a method for manufacturing the radar sensor system in which the manufacturing of the radar sensor system can be simplified. Disclosure of the invention

[0004] A radar sensor system comprising a waveguide antenna, a radome, a housing, and a mounting for a printed circuit board is proposed. The waveguide antenna is attached to the radome by means of a snap-fit ​​connection. The radome is attached to the housing, with the housing and the radome together enclosing the waveguide antenna.

[0005] By attaching the waveguide antenna to the radome, pressure forces from the waveguide antenna to the circuit board could be prevented. This could extend the lifespan of the circuit board. Furthermore, attaching the waveguide antenna to the radome using the snap-fit ​​connection could simplify the installation of the radar sensor system. Instead of screwing the waveguide antenna to the circuit board, it could be positioned against the radome and secured by closing the snap-fit ​​connection. To close the snap-fit ​​connection, the waveguide antenna could simply be pressed against the radome until the connection clicks into place. The radome can then be attached to the housing, with the waveguide antenna being inserted into the housing.In particular, a coupling between the waveguide antenna and the circuit board can be established.

[0006] Firstly, attaching the waveguide antenna to the radome using the snap-fit ​​connection could be faster than screwing it to the circuit board or the radome. Secondly, closing the snap-fit ​​connection requires no additional tools, such as a screwdriver, or materials, such as screws. Compared to attaching the waveguide antenna to the radome using pins protruding from the radome, the ends of which are melted by heat treatment, the snap-fit ​​connection could also be used for faster attachment.

[0007] Furthermore, attaching the waveguide antenna to the radome could eliminate a step in the manufacturing process of the radar sensor on a production line where the housing is transported at a predetermined speed. Instead of first placing the waveguide antenna onto the circuit board and then attaching the radome to the housing in a second step, the radome, to which the waveguide antenna is attached, can be attached to the housing in a single step. The waveguide antenna can be attached to the radome outside the production line, thus eliminating a station in the production line where the waveguide antenna is inserted into the housing.Furthermore, if the back of the radar sensor is permeable to a laser for welding the radome and the welding is carried out with the laser on the production line, rotation of the housing with the circuit board could be avoided.

[0008] According to one variant, the snap-fit ​​connection comprises a first joining element and a second joining element. The first joining element extends perpendicularly from an inner wall of the radome, which covers the waveguide antenna, towards the waveguide antenna. Furthermore, the first joining element has an enlarged cross-section at its end, which is spaced apart from the inner wall, for snapping into the second joining element. The second joining element is located on the waveguide antenna and has at least one edge for snapping into the first joining element.

[0009] In most cases, the joining element of a snap-fit ​​connection that has an enlarged cross-section at its end—in this case, the first joining element—is more complex to manufacture than the one that has the edge—in this case, the second joining element. In a simple embodiment, the second joining element can simply have the edge, i.e., be shaped like the edge itself. Because the first joining element extends from the inner wall of the radome, it is located on the radome. Furthermore, since the first joining element has the end piece with the enlarged cross-section, it is the more complex of the two joining elements located on the radome. This could make it possible to manufacture the more complex joining element—i.e., the first joining element—together with the radome using a 3D printing process.

[0010] Manufacturing the radome together with the first joining element using 3D printing makes it possible, in particular, to produce the more complex of the two joining elements relatively easily. Specifically, the first joining element does not need to be screwed to the radome, which could simplify the assembly of the radar sensor system. Therefore, in a specific embodiment of the radar sensor system, the radome, and especially the radome and the first joining element, are manufactured using a 3D printing process.

[0011] When manufacturing the radome and the first joining element using 3D printing, the radome and the first joining element are built up layer by layer from a liquid or solid material. During this process, physical and / or chemical hardening and / or melting processes are carried out. The material used can be, for example, plastic, synthetic resin, or a metal in powder form. The radome and the first joining element are made of, for example, plastic or metal.

[0012] The first joining element has a principal axis that runs perpendicular to the inner wall of the radome. The first joining element is designed such that its length, measurable along the principal axis, is greater than its width, also measurable perpendicular to the principal axis. For example, the length is more than twice the width. The enlarged cross-section of the end piece means that the width of the first joining element at the end piece is greater than the width of the first joining element at a first part of the first joining element located between the inner wall and the end piece. The enlarged cross-section of the end piece could allow for the formation of a locking element for the locking connection at the end piece.

[0013] If the waveguide antenna is attached to the radome using the locking mechanism, the locking mechanism is closed. During the installation of the radar sensor system, the waveguide antenna and the radome are initially not connected, i.e., the locking mechanism is open.

[0014] To close the snap-fit ​​connection, the first joining element is brought close to the second joining element so that the first joining element touches the second joining element. For this purpose, the first joining element is moved relative to the second joining element, specifically in a joining direction. In most cases, the joining direction runs parallel to the main axis of the first joining element. Once the two joining elements are in contact, the first joining element can be moved relative to the second joining element in the joining direction to close the snap-fit ​​connection.

[0015] The first joining element, particularly in combination with the second joining element, is designed such that, when the first joining element moves relative to the second joining element in the joining direction, it can interact with the second joining element in such a way that at least an elastic part of the first joining element deforms in a deformation direction oriented transversely to the joining direction. Such deformation of the elastic part could, in particular, overcome a blockage of relative movement between the first and second joining elements in the joining direction. To effect deformation of the elastic part of the first joining element in the deformation direction, the end piece of the first joining element can have a butt edge or butt surface arranged at an acute angle to the principal axis.The acute angle can, for example, be in a range of about 5 to 30 degrees, especially in a range of about 10 to 20 degrees.

[0016] The deformation of the elastic component could, in particular, allow the first joining element to be shifted further in the joining direction relative to the second joining element such that the first joining element passes the second joining element. Furthermore, the first joining element, especially in combination with the second joining element, is designed such that the elastic component can deform in the opposite direction to the deformation direction once it has passed the second joining element and is located behind it in the joining direction. A deformation of the elastic component in the opposite direction to the deformation direction represents, in particular, a variant of the aforementioned snap-in engagement of the first joining element.

[0017] In a further embodiment, the first joining element comprises the first part described above, which extends away from the inner wall and to which the end piece is attached. In this embodiment, the end piece has a recess that divides it into at least two parts that move relative to each other when the connection is engaged. The edge is specifically designed as a circumferential edge surrounding the first part, completely enclosing it when the snap-fit ​​connection is engaged. The circumferential edge can, in particular, define an opening in the waveguide antenna through which the first joining element can be slid when the snap-fit ​​connection is engaged.

[0018] The two moving parts of the end piece, referred to below as locking elements, which move towards each other when snapping into place, could allow the width of the end piece to be reduced by moving these two locking elements relative to each other. This would allow the end piece to be pushed past the circumferential edge, particularly through the opening, in the direction of insertion. After the locking elements have passed the circumferential edge, particularly the opening, they could move away from each other. For this purpose, the waveguide antenna has a free space behind the circumferential edge in the direction of insertion.

[0019] Furthermore, combining the circumferential edge with the locking elements of the end piece could offer the advantage that the locking connection can be positioned at any point on the waveguide antenna located between its outer edges. For example, the circumferential edge, and in particular the opening, can be positioned in a region of the waveguide antenna through which no channels for transporting radar waves run. Specifically, this combination allows the locking connection to be realized in a central region encompassing at least one inner half of the waveguide antenna. This would enable a tensile force acting on the circumferential edge, and which can be caused in particular by a tensile stress within the first joining element, to be distributed more evenly across the waveguide antenna than would be the case if a tensile force were applied by a locking arm at an edge of the waveguide antenna.

[0020] It goes without saying that the end piece can also have two or more recesses, dividing it into more than two, for example three or four, locking sections that can move towards each other when locked in place. This could reduce stress on the waveguide antenna during locking.

[0021] Furthermore, the circumferential edge could have the advantage of providing centering for the end piece even when the snap-fit ​​connection is still open. This centering is particularly effective when the end piece touches the circumferential edge before it is pushed further through the opening in the direction of engagement.

[0022] In a further development, the end piece can have a conically shaped section, which is referred to below as the cone. An outer surface of the cone can, in particular, rest against the circumferential edge before snapping into place, thereby centering the waveguide antenna relative to the radome. Specifically, the interaction of the circumferential edge and the cone could enable precise centering of the waveguide antenna relative to the radome.

[0023] According to another possible variant, the first joining element has a locking arm to which the end piece is attached. In this variant, the end piece has a locking lug that engages with the edge of the second joining element. This variant could have the advantage that the locking lug is easier to manufacture than two or more of the aforementioned locking parts. In particular, the stiffness of the first joining element could be increased, thereby ensuring a more precise maintenance of the distance between the waveguide antenna and the radome over the radar sensor's lifetime.

[0024] The locking arm can, in principle, deform from a section adjacent to the inner wall of the radome in a deformation direction perpendicular to the joining direction, thus enabling movement of the locking lug in the deformation direction and subsequent engagement. Even with relatively high stiffness, deformation of the locking arm in its deformation direction, and therefore movement of the locking lug perpendicular to the joining direction, can be achieved along a certain length of the locking arm, allowing the locking lug to pass the edge of the second joining element. The aforementioned locking components can generally only deform in a specific area of ​​the end piece and would therefore, in most applications, exhibit lower stiffness than the locking arm. The deformation of the locking arm in the deformation direction integrates over its length, resulting in a deflection of the end piece in the deformation direction.The length of the locking arm is, in particular, at least three times the length of the end piece measured in a direction parallel to the main axis of the first joining element.

[0025] Furthermore, the locking arm could allow the locking connection to be located on an outer section of the waveguide antenna. This could save space in an inner section of the waveguide antenna, where the channels for transmitting the radar waves are typically located. Accordingly, in another possible embodiment, the edge is designed as an outer edge of the waveguide antenna.

[0026] In principle, if the first joining element has the locking arm, the edge of the second joining element can, in a further embodiment, be designed as an additional circumferential edge, defining a further opening in the waveguide antenna. In this embodiment, the end piece could be slid through the additional opening without deforming it. The locking lug can then be pushed through the additional opening and past the additional circumferential edge to cause the locking lug to deflect in the direction of deformation. This additional opening can be located in the central area of ​​the waveguide antenna. This would allow the tensile force exerted by the locking arm on the edge to be distributed more evenly across the waveguide antenna. Simultaneously, this embodiment would allow the advantage of the locking arm's increased stiffness to be utilized.

[0027] In general, the first joining element is elastic, i.e., the first joining element exhibits elastic behavior which allows the first joining element to snap into the second joining element.

[0028] According to one variant, the elastic behavior could allow the end piece to move in the direction of deformation perpendicular to the joining direction as it is slid past the second joining element. Furthermore, the elastic behavior could allow the end piece to move in the opposite direction to the deformation direction towards the main axis and spring back after the first joining element has passed the second joining element.

[0029] In another variant, the elastic behavior could allow the two locking elements to move towards each other when the buttress edge or surface is pushed past the edge. The end piece is designed to be elastic, particularly in a transition zone located between the two locking elements and adjacent to the recess. Furthermore, the elastic behavior could allow the two locking elements to move away from each other after the buttress edge or surface has passed the edge. In principle, the material of the transition zone can be more elastic than another material in a different area of ​​the first joining element.

[0030] In a further embodiment, the waveguide antenna includes a spacer, which is hereinafter referred to as the first spacer. The first spacer extends, in particular, from a side of the waveguide antenna facing away from the radome, hereinafter referred to as the rear side, in a direction away from the radome. Specifically, the first spacer is designed such that it blocks movement of the waveguide antenna in a direction perpendicular to the inner wall of the radome. This allows the first spacer to maintain a distance between the waveguide antenna and the circuit board. For this purpose, the first spacer can have a contact surface that provides a first distance to the rear side. In particular, the first spacer projects from the rear side by this first distance.In principle, the contact surface can rest against a counter-surface of the housing that runs perpendicular to the inner wall, in order to support the first spacer and thus block the movement of the waveguide antenna in a direction perpendicular away from the inner wall of the radome. It is also possible for the contact surface to rest against the circuit board.

[0031] According to a possible further development, the first spacer rests against the first joining element in the engaged state of the snap-fit ​​connection. Specifically, in this further development, the first spacer is arranged between the end piece of the first joining element and the inner wall of the radome when the snap-fit ​​connection is engaged. In particular, the end piece of the first joining element, especially a rear-facing side of the end piece (hereinafter referred to as the rear of the end piece), rests against the bearing surface. The bearing surface can have the aforementioned circumferential edge that defines the opening. This allows, in particular, one end of the first spacer to form the second joining element.

[0032] This could have the advantage that the first spacer and the second joining element could be realized with a single component. This could reduce both material and manufacturing time for the radar sensor. Furthermore, it could prevent support forces from the waveguide antenna from being exerted on the circuit board, or eliminate the need for a counter surface within the housing to support the first spacer. Integrating the second joining element into the first spacer allows for a gap between the first spacer and the circuit board. Therefore, in a further embodiment, the first spacer is designed to have a gap in a direction perpendicular to the inner wall of the radome and the circuit board.

[0033] In a further embodiment, the radome has a spacer, which is referred to below as the second spacer. In this embodiment, the waveguide antenna is pressed against the second spacer when the locking connection is engaged. The second spacer, in particular, prevents movement of the waveguide antenna towards the inner wall of the radome. For this purpose, when the locking connection is engaged, a contact surface of the waveguide antenna rests on a support surface of the second spacer. The support surface of the second spacer is located at a distance from a central plane of the radome, which is referred to below as the second distance. The central plane of the radome runs parallel to the circuit board. The second distance is, in particular, a multiple of half a wavelength of the radar waves. This could increase the transparency of the radome to the radar waves.

[0034] In particular, the position of the bearing surface of the first spacer can be adapted to the position of the bearing surface of the second spacer in such a way that a tensile stress can be generated inside the first joining element when the snap-fit ​​connection is closed. To achieve this, the contact surface of the waveguide antenna has a distance to the bearing surface of the first spacer in a direction perpendicular to the inner wall of the radome, which is slightly greater, for example in a range between 0.1 and 1 millimeter, than the distance between the rear of the end piece of the first joining element and the bearing surface of the second spacer in the direction perpendicular to the inner wall of the radome.

[0035] In a further embodiment, the snap-fit ​​connection comprises a first joining element and a second joining element. The first joining element extends perpendicularly from the waveguide antenna towards an inner wall of the radome that covers the waveguide antenna and has an enlarged cross-section at its end piece, which is spaced away from the waveguide antenna, for snapping into the second joining element. In this embodiment, the second joining element is arranged on the inner wall of the radome and has at least one edge for snapping the first joining element into place. This embodiment describes a situation where the first joining element is located on the waveguide antenna and the second joining element is located on the radome. This can be practical in certain circumstances, particularly if a different material is used for the waveguide antenna to be manufactured using a 3D printing process than for the radome to be manufactured using a different 3D printing process.In this case, it might be easier to manufacture the first mounting element together with the waveguide antenna rather than with the radome. However, since the radome, in most cases, completely covers the waveguide antenna with its inner wall, disassembling the waveguide antenna from the radome could be significantly easier if the first mounting element is located on the radome.

[0036] In another variant, the waveguide antenna is attached to the circuit board using an additional snap-fit ​​connection. It goes without saying that in this variant, the radar sensor system incorporates the circuit board. The advantage of this variant could be that both the waveguide antenna and the circuit board can be attached to the radome before the radome is mounted to the housing. This could further simplify the assembly of the radar sensor system.

[0037] In a further development of this variant, the additional snap-fit ​​connection may be provided with a first joining element, hereinafter referred to as the further first joining element, and a second joining element, hereinafter referred to as the further second joining element. The further first joining element extends, in particular, perpendicularly from the waveguide antenna towards the printed circuit board and has, at its end piece spaced apart from the waveguide antenna, hereinafter referred to as the further end piece, an enlarged cross-section for snapping into the further second joining element. The further second joining element is, in particular, arranged on the printed circuit board and has at least one edge, hereinafter referred to as the further edge, for snapping the further first joining element of the additional snap-fit ​​connection.

[0038] In most cases, the connecting element of the secondary snap-fit ​​connection that has an enlarged cross-section at its end—in this case, the secondary first connecting element—is more complex to manufacture than the one that has the additional edge—in this case, the secondary second connecting element. In a simple embodiment, the secondary second connecting element can simply have the additional edge, i.e., be formed in the shape of the additional edge. Because the secondary first connecting element extends from the waveguide antenna, it is located on the waveguide antenna and not on the circuit board. Furthermore, since the secondary first connecting element has the additional end piece with the enlarged cross-section, the more complex of the two secondary connecting elements is located on the waveguide antenna. This could allow for the more complex connecting element, i.e.,The first connecting element, along with the waveguide antenna, is to be manufactured using a 3D printing process. The circuit board, however, cannot usually be manufactured solely using a 3D printing process.

[0039] Manufacturing the waveguide antenna together with the other first joining element using 3D printing makes it possible, in particular, to produce the more complex of the two additional joining elements relatively easily. Specifically, the other first joining element does not need to be screwed onto the waveguide antenna, which could simplify the assembly of the radar sensor system. Therefore, in a specific embodiment of the radar sensor system, the waveguide antenna, and especially the waveguide antenna and the other first joining element, are manufactured using a 3D printing process.

[0040] When manufacturing a waveguide antenna and its initial connecting element using 3D printing, the antenna and its component are built up layer by layer from a liquid or solid material. During this process, physical and / or chemical hardening and / or melting processes are carried out. Materials used include, for example, plastic, synthetic resin, or a metal in powder form. The waveguide antenna and its initial connecting element are, for instance, made of plastic. In a specific variant, the waveguide antenna is metallized.

[0041] The further first joining element extends, in particular, from the rear side of the waveguide antenna, which faces the printed circuit board, towards the printed circuit board. This further first joining element has a principal axis, which runs perpendicular to the rear side and is hereinafter referred to as the further principal axis. The further first joining element is designed such that its length, measurable along the further principal axis, is greater than its width, measurable perpendicular to the further principal axis. For example, the length is more than twice the width of the further first joining element.The enlarged cross-section of the additional end piece means that the width of the additional first joining element on the additional end piece is greater than the width of the additional first joining element on a first part of the additional first joining element, which is arranged between the back side and the additional end piece. The enlarged cross-section of the end piece could make it possible to form a locking element of the additional locking connection on the additional end piece.

[0042] If the waveguide antenna is attached to the circuit board using the additional locking connection, the additional locking connection is closed. During assembly of the radar sensor system, the waveguide antenna and the circuit board are initially not connected, i.e., the additional locking connection is open.

[0043] To close the next locking connection, the next first joining element is brought close to the next second joining element so that it touches. For this purpose, the next first joining element is moved relative to the next second joining element, particularly in a further joining direction. This further joining direction is, in most cases, parallel to the main axis of the next first joining element. Once the two next joining elements are in contact, the next first joining element can be moved relative to the next second joining element in this further joining direction to close the next locking connection.

[0044] The further first joining element, particularly in combination with the further second joining element, is designed such that, when the further first joining element moves relative to the further second joining element in the further joining direction, it can interact with the further second joining element in such a way that at least one further elastic part of the further first joining element deforms in a further deformation direction oriented transversely to the further joining direction. Such a deformation of the further elastic part could, in particular, overcome a blockage of relative movement between the further first and the further second joining element in the further joining direction.To cause the further elastic part of the further first joining element to deform in the further direction of deformation, the further end piece of the further first joining element can have a further butt edge or further butt surface arranged at a further acute angle to the further main axis. The further acute angle can, for example, be in a range of about 5 to 30 degrees, particularly in a range of about 10 to 20 degrees.

[0045] The deformation of the additional elastic part could, in particular, allow the additional first joining element to be pushed further in the further joining direction relative to the additional second joining element in such a way that the additional first joining element passes the additional second joining element. Furthermore, the additional first joining element, especially in combination with the additional second joining element, is designed such that the additional elastic part can deform in the opposite direction to the further deformation direction once it has passed the additional second joining element and is located behind it in the further joining direction. A deformation of the additional elastic part in the opposite direction to the further deformation direction represents, in particular, a variant of the aforementioned snap-in of the additional first joining element.

[0046] In a further embodiment, the waveguide antenna has at least one support element. This support element extends towards the circuit board to provide a defined distance between the waveguide antenna and the circuit board. The support element is specifically located on the rear side of the waveguide antenna. When the locking connection is closed, the support element contacts a side of the circuit board facing the waveguide antenna. The defined distance that the waveguide antenna maintains from the circuit board due to the support element could enable the inputs of the waveguide antenna, into which radar waves generated by components on the circuit board can be coupled via ports on the circuit board, to be correctly positioned in a direction perpendicular to the circuit board relative to the ports.This could increase the reliability of the transmission of radar waves from the ports to the waveguide antenna.

[0047] In a further development, the additional first joining element is adapted to the support element in such a way that, in the engaged state of the snap-fit ​​connection, the additional first joining element is under tensile stress. In this further development, the additional first joining element is placed under tensile stress, particularly in the engaged state, by blocking movement of the additional end piece against the direction of the further joining direction through a mechanical interaction between the further edge of the additional second joining element and the additional end piece. In this process, a compressive force can act from the further edge of the additional second joining element in the further joining direction onto the additional end piece, especially on its rear side. This could generate a frictional force between the further edge and the rear side of the additional end piece, which could prevent the additional snap-fit ​​connection from opening spontaneously.The tensile stress of the first connecting element could therefore reduce the risk of the subsequent snap-fit ​​connection opening on its own.

[0048] To adapt the second first joining element to the support element in such a way that, in the engaged state of the second locking connection, the second first joining element is under tensile stress, the distance between the back of the second end piece, against which the second edge rests in the engaged state, and the back of the waveguide antenna can be slightly smaller, for example in the range between 0.1 and 1 millimeter, than the sum of the extension of the support element in a direction perpendicular to the back of the waveguide antenna and the thickness of the circuit board. This would allow the support element to press the circuit board, and thus the second edge, in the direction of the second joining, while simultaneously pulling the second edge in the opposite direction to the second joining direction by means of the second end piece of the second first joining element.This could in particular reduce the frictional force described above and thus enable a stable holding of the locked state of the further locking connection.

[0049] In particular, the waveguide antenna features several support elements. This could allow for more precise positioning of the waveguide antenna relative to the circuit board before it snaps into place. This would ensure, in particular, that the waveguide antenna inputs are correctly positioned relative to the ports before the snap connection is closed. Specifically, at least three support elements could reduce the risk of the waveguide antenna tilting relative to the circuit board before the snap connection is closed. While tilting of the waveguide antenna could be prevented even more effectively with four support elements, this number places higher demands on the tolerances of the support elements than three.

[0050] In a further embodiment, the further first joining element comprises the further first part described above, which extends away from the waveguide antenna and to which the further end piece is arranged. In this embodiment, the further end piece has a recess that divides the further end piece into at least two further parts that move relative to each other when snapped into place. The further edge is specifically designed as a further edge surrounding the further first part, which completely encircles the further first part when the further snap connection is engaged.

[0051] The additional circumferential edge could have the advantage of providing centering for the additional end piece while the additional locking connection is still open. Centering is particularly effective when the additional end piece contacts the additional circumferential edge before it is pushed further into the assembly direction to engage. The additional end piece has, in particular, a conical section, which is referred to below as the additional cone. An outer surface of the additional cone can, in particular, rest against the additional circumferential edge before engagement, thereby centering the waveguide antenna relative to the circuit board.The two additional parts of the end piece, which move towards each other when snapping into place and are referred to below as additional locking elements, could allow the width of the end piece to be reduced by moving these two additional locking elements relative to each other. This would allow the end piece to be slid past the additional circumferential edge in the further assembly direction. After the additional locking elements have passed the additional circumferential edge, they could move away from each other. For this purpose, the circuit board has, in particular, an additional free space behind the additional circumferential edge in the further assembly direction.

[0052] Furthermore, combining the additional circumferential edge with the additional locking elements of the additional end piece could offer the advantage that the additional locking connection can be positioned at any point on the printed circuit board (PCB) located between the PCB's outer edges. In particular, this combination allows the additional locking connection to be implemented in a central area encompassing at least one inner half of the PCB. This would enable a tensile force acting on the additional circumferential edge, and especially one caused by the tensile stress within the additional first joining element, to be distributed more evenly across the PCB than would be the case if the tensile force acted on an edge of the PCB.

[0053] It goes without saying that the additional end piece can also have two or more recesses, dividing it into more than two, for example three or four, further locking sections that can move towards each other when snapping into place. This could reduce stress on the circuit board during snapping.

[0054] According to a further possible variant, the first joining element has a locking arm to which the further end piece is attached and which is hereinafter referred to as the further locking arm. In this variant, the further end piece has a locking lug that engages with the further edge of the second joining element and is hereinafter referred to as the further locking lug. This variant could have the advantage that the further locking lug can be manufactured more easily than two or more of the aforementioned further locking parts. In particular, the stiffness of the first joining element could be increased, which would allow the defined distance between the waveguide antenna and the circuit board to be maintained more accurately over the radar sensor's lifetime.

[0055] The secondary locking arm can, in principle, deform from a section adjacent to the rear of the waveguide antenna in a deformation direction, hereinafter referred to as the secondary deformation direction, which runs perpendicular to the secondary joining direction, in order to allow movement of the secondary locking lug in the secondary deformation direction and subsequent engagement of the secondary locking lug. Even with comparatively high stiffness, deformation of the secondary locking arm in the secondary deformation direction, and thus movement of the secondary locking lug perpendicular to the secondary joining direction, can be achieved over a certain length of the secondary locking arm, allowing the secondary locking lug to pass the secondary edge of the secondary joining element.The aforementioned additional locking elements can generally only deform in a specific area of ​​the additional end piece and would therefore, in most applications, exhibit lower stiffness than the additional locking arm. The deformation of the additional locking arm in the direction of deformation integrates over its length, resulting in a deflection of the additional end piece in the same direction of deformation. The length of the additional locking arm is, in particular, at least three times the length of the additional end piece measured in a direction parallel to the main axis of the additional first joining element.

[0056] Furthermore, the additional locking arm could allow the further locking connection to be located on an outer area of ​​the circuit board. This could save space in an inner area of ​​the circuit board, where electronic components and wires are typically located. Accordingly, in another possible embodiment, the additional edge is designed as an outer edge of the circuit board.

[0057] In general, the further first joining element is elastic, i.e., the further first joining element exhibits elastic behavior, which can enable the further first joining element to snap into the further second joining element.

[0058] According to one variant, the elastic behavior of the additional first joining element could allow the additional end piece to move in the further deformation direction transversely to the further joining direction when the additional end piece is slid past the additional second joining element. Furthermore, the elastic behavior of the additional first joining element could allow the additional end piece to move in the opposite direction to the further deformation direction towards the further principal axis and spring back after the additional first joining element has passed the additional second joining element.

[0059] In another variant, the elastic behavior of the first joining element could allow the two additional locking parts to move towards each other when the additional butt edge or surface is slid past the first edge. The additional end piece is elastically designed, particularly in a further transition zone located between the two additional locking parts and adjacent to the recess of the additional end piece. Furthermore, the elastic behavior of the first joining element could allow the two additional locking parts to move away from each other after the additional butt edge or surface has passed the first edge. In principle, a material in the additional transition zone can be more elastic than another material in a different area of ​​the first joining element.

[0060] Furthermore, a method for manufacturing a radar sensor system comprising a waveguide antenna, a radome, a housing, and a printed circuit board is proposed. The method includes assembling the radar sensor system in the following steps. In a first step, the waveguide antenna is brought close to the radome. This can be done by a person or, alternatively, with the aid of robotic arms. In a second step, the waveguide antenna is pressed against the radome to close a snap-fit ​​connection between the waveguide antenna and the radome. In particular, the waveguide antenna is pressed in the aforementioned joining direction relative to the radome. In a third step, the printed circuit board is inserted into the housing. In a fourth step, the radome is placed onto the housing, whereby the waveguide antenna, attached to the radome by means of the snap-fit ​​connection, is inserted into the housing.In a fourth step, the housing is closed by attaching the radome to the housing. The radome can, for example, be welded to the housing.

[0061] In one possible embodiment of the process, the method comprises the production of the radome and a first joining element of the snap-fit ​​connection using a 3D printing process. The 3D printing process is carried out in such a way that at least part of the first joining element is produced as an integral component of the radome. In this 3D printing process, a material is applied layer by layer and / or hardened layer by layer. As an integral component of the radome, the first joining element shares a common layer of the same material with the radome or at least has a first boundary layer that adjoins a second boundary layer of the radome. In particular, the first boundary layer is fused with the second boundary layer. Specifically, the first boundary layer and the second boundary layer are produced sequentially in a single 3D printing process.The 3D printing process involves the layer-by-layer application of material, in particular the first and second boundary layers or the common layer, wherein during the application a position of the radome, in particular a first layer of the radome, relative to a stationary support of a robot arm from which the material for layer-by-layer application emerges, remains unchanged. Brief description of the drawings

[0062] Further advantages, features, and details of the invention will become apparent from the following description, in which exemplary embodiments of the invention are explained in more detail with reference to the drawings. The drawings schematically depict... Figure 1: A vehicle with a radar sensor; Figure 2: A sectional view of a variant of the [in Figure 2] Figure 1 The radar sensor shown comprises a circuit board, a radome, and a waveguide antenna, and a variant of a locking connection between the waveguide antenna and the radome in a closed state; Figure 3 in Figure 2 The variant of the locking connection shown is in an open state; Figure 4 shows an upper edge of the... Figure 3 shown locking connection on a front face of the waveguide antenna; Figure 5 a lower edge of the in Figure 3 shown locking connection on a rear side of the waveguide antenna; Figure 6 a sectional view of another variant of a locking connection between the waveguide antenna and the radome in a closed state; Figure 7 a top view of the Figure 6 waveguide antenna shown; Figure 8 another sectional view of the in Figure 1 radar sensor shown with circuit board, radome and waveguide antenna; Figure 9 in Figure 6 Another variant of the locking connection shown in an open state; Figure 10 a perspective view of the radome with a first joining element of the in Figure 2 shown rest connection; Figure 11 the in Figure 10 The radome shown, which uses the in Figure 2shown with locking connection, attached waveguide antenna; Figure 12 a sectional view of a variant of the in Figure 1 radar sensor shown with the in Figure 2 shown locking connection between the waveguide antenna and the radome and another locking connection between the waveguide antenna and the circuit board in a closed state; Figure 13 shown in Figure 12 The variant of the further locking connection shown in an open state; Figure 14 shows an upper edge of the in Figure 13 further locking connection shown on a front side of the circuit board; Figure 15 a lower edge of the in Figure 13 Figure 16 shows a further locking connection on the back side of the circuit board; Figure 16 shows a sectional view of another variant of the further locking connection between the waveguide antenna and the circuit board in a closed state; Figure 17 shows a top view of the Figure 12 shown waveguide antenna and a sectional view of the in Figure 12shown radome; Figure 18 another sectional view of the in Figure 12 radar sensor shown; Figure 19 in Figure 16 Figure 20 shows a further variant of the additional locking connection in an open state; Figure 20 shows a perspective view of the circuit board and the waveguide antenna with a locking arm engaged at an edge of the circuit board; Figure 21 shows another perspective view of the in Figure 10 shown circuit board and waveguide antenna with the in Fig. 12 shown variant of the further rest area connection and the one in Figure 16 shown further variant of the further rest area connection.

[0063] In the figures, identical components are labelled with the same reference symbols. embodiment(s) of the invention

[0064] Fig. 1Figure 1 shows a vehicle 10 equipped with a radar sensor system 1 for detecting an object 8 in the vicinity of the vehicle 10. The object 8 may be another vehicle. The radar sensor system 1 is specifically configured to emit and / or receive radar waves. Conveniently, the radar sensor system 1 is controlled by a control unit 9. The control unit 9 may be configured to process received signals from the radar sensor system 1 based on the received radar waves, which were, for example, reflected by the object 8.

[0065] Fig. 2Figure 1 schematically shows a possible variant of the radar sensor system 1 in a sectional view. The radar sensor system 1 comprises a waveguide antenna 2, a radome 3, a housing 4, and a circuit board 5. The radome 3 is attached to the housing 4. The housing 4 and the radome 3 together surround the circuit board 5 and the waveguide antenna 2. In principle, the radome 3 can also be considered part of the housing 4. Furthermore, the waveguide antenna 2 is attached to the radome 3 by means of a snap-fit ​​connection. For mounting the radar sensor system 1, the circuit board 5 can be placed in a space enclosed by the housing 4. Subsequently, the radome 3, together with the waveguide antenna 2 attached to the radome 3, can be attached to a top surface of the housing 4, for example, by welding.

[0066] The radar waves can be generated, in particular, with the aid of the circuit board 5, and especially with the aid of a radar wave generator 6. The radar waves generated with the aid of the radar wave generator 6 can be transmitted with the aid of the waveguide antenna 2. For this purpose, the radar waves can be in Fig. 2 For clarity, the channels of the waveguide antenna 2, not shown, are coupled in. The inputs of the channels can be connected to... Fig. 2 The radar wave generator 6 can be configured, in particular, as a high-frequency microchip. Furthermore, the radar wave generator 6 can be equipped with additional components located in the circuit board 5. Fig. 2 The components of the circuit board 5, which are not shown, can be controlled.

[0067] Fig. 2 This shows one variant of how the waveguide antenna 2 can be attached to the radome 3 using a first snap-fit ​​connection. Here, it shows Fig. 2The first snap-fit ​​connection is in a locked, i.e., closed, state. The first snap-fit ​​connection has a first joining element 11 and a second joining element 12, which is in Fig. 3 The first joining element 11 of the first snap connection, hereinafter referred to as the first joining element 11, extends in particular vertically from an inner wall 7 of the radome 3 covering the waveguide antenna 2 in the direction of the waveguide antenna 2.

[0068] Furthermore, the first joining element 11 can have an enlarged cross-section at its end piece 11.2, which is spaced apart from the inner wall 7, for snapping into the second joining element 12 of the first snap-fit ​​connection, hereinafter referred to as the second joining element 12. The second joining element 12 can be arranged on the waveguide antenna 2 and have at least one edge, such as a second edge 12.2, for snapping the first joining element 11 into it.

[0069] The second joining element 12 is located in the Fig. 2, 3, 4, 5 The illustrated embodiment of the radar sensor system 1 is designed in the form of a bore. The bore is enclosed by a Fig. 4 The first circumferential edge 12.1, shown, is located on a side of the waveguide antenna 2 facing the radome 3, hereinafter referred to as the front of the waveguide antenna 2, and defines a second circumferential edge 12.2. The second circumferential edge 12.2 is located on a side of the waveguide antenna 2 facing away from the radome 3, hereinafter referred to as the rear of the waveguide antenna 2, and is in Fig. 5 The first edge 12.1 therefore limits the bore on the front side of the waveguide antenna 2 and the second circumferential edge 12.2 limits the bore on the back side of the waveguide antenna 2.

[0070] Fig. 3Figure 1 shows an optional division of the first joining element 11 into a first part 11.1, which extends away from the radome 3 along a principal axis 100 of the first joining element 11 and on which the end piece 11.2 is arranged, and an end piece 11.2, which forms a second part of the first joining element 11. The end piece 11.2 can, in particular, be conical. Furthermore, the end piece 11.2 can be divided into at least two parts that move towards each other when snapping into place, namely a first snapping part 14.1 and a second snapping part 14.2.

[0071] Out of Fig. 3It is evident that the width of the end piece 11.2 is greater than the width of the first part 11.1, at least in one region of the end piece 11.2. The width is measured in a direction 102 that runs perpendicular to the main axis 100. In particular, the greatest width of the end piece 11.2 is greater than the diameter of the bore 12. This causes the two locking parts 14.1 and 14.2 to be pressed together when the first joining element 11 is pushed through the bore 12 in a joining direction 101. To facilitate the movement of the two locking parts 14.1 and 14.2 towards each other, the end piece 11.2 can have at least one recess 13. As the two locking parts 14.1 and 14.2 move towards each other, the greatest width of the end piece 11.2 is reduced, allowing the end piece 11.2 to be pushed through the bore 12. After the end piece 11.Once the end piece 11.2 has passed through the bore 12, that is, when viewed in the assembly direction 101, is positioned behind the bore 12, in particular behind the second circumferential edge 12.2, the two locking elements 14.1 and 14.2 can move apart again. The waveguide antenna 2 has a free space on its rear side for this purpose, which is located immediately behind the second circumferential edge 12.2 in the assembly direction 101. The two locking elements 14.1, 14.2 can spring back into this free space, particularly due to their elastic properties, after the end piece 11.2 has passed the second circumferential edge 12.2. In principle, the two locking elements 14.1, 14.2 can also be pressed together without the recess 13 due to their elastic properties. In this case, the two locking elements 14.1, 14.2 are not separated from each other, but form a dome-shaped end piece. However, recess 13 could allow for easier engagement and opening of the first locking connection.

[0072] Fig. 6 shows another variant of the radar sensor system 1. In the Fig. 6 In the variant shown, the waveguide antenna 2 is attached to the radome 3 using a second snap connection. Fig. 6 The second snap-fit ​​connection is shown in a locked, i.e., closed, state. The second snap-fit ​​connection has a first joining element 21 and a second joining element 22, which is in Fig. 9 The first joining element 21 of the second snap-fit ​​connection, hereinafter referred to as the first joining element 21, can extend from the radome 3 towards the waveguide antenna 2 and have an enlarged cross-section at its end piece 21.3, which is spaced from the inner wall 7, for snapping into the second joining element 22 of the second snap-fit ​​connection, hereinafter referred to as the second joining element 22. The second joining element 22 is shown in the Fig. 6, 7 , 8 and 9The depicted variant of the radar sensor system 1 is formed in the form of an edge of the waveguide antenna 2. The edge is bounded by a first upper edge 22.1 of the waveguide antenna 2, which is located on the front of the waveguide antenna 2, and a second lower edge 22.2, which is located on the rear of the waveguide antenna 2. The end piece 21.3, in particular a locking lug 21.4 of the end piece 21.3, can engage on the second edge 22.2.

[0073] Fig. 7 shows the waveguide antenna 2 in a top view and the radome 3 and the first joining element 21 in a section view. Fig. 6 shows the housing 4 and the radome 3 in a cross-section in the Fig. 7 Section plane CC shown. To provide space for the first joining element 21, a recess 70 can be provided in the housing 4, which is in Fig. 6 and Fig. 7 The recess 70 can extend particularly through the radome 3. Fig. 8The radar sensor system 1 is shown in a cross-section along the in Fig. 7 shown section plane DD.

[0074] In Fig. 9 It can be seen that the first joining element 21 has a locking arm 21.1 on which the end piece 21.3 is arranged. In the closed state of the second locking connection, the locking lug 21.4 is engaged on the second edge 22.2 of the second joining element 22. Fig. 9 shows the second locking connection in an open state.

[0075] To close the second locking connection, the first joining element 21 is moved in the joining direction 101, thereby approaching the second joining element 22. The first joining element 21 is moved in the joining direction 101 until a contact surface 90 of the end piece 21.3 touches the first edge 22.1 of the second joining element 22. If the first joining element 21 is moved further in the joining direction 101 after the contact surface 90 has touched the first edge 22.1, the end piece 21.3 moves in a displacement direction 201 perpendicular to the joining direction 101, bending the locking arm 21.1 in the direction 201.

[0076] A displacement of the end piece 21.3 in direction 201 allows the locking lug 21.4 to slide past the edge of the waveguide antenna 2, i.e., the second joining element 22, in the direction of the second edge 22.2. After the locking lug 21.4 has passed the second edge 22.2, the end piece 21.3 can spring back in a direction opposite to the displacement direction 201. To enable the end piece 21.3 to spring back, a free space is provided behind the second edge 22.2 when viewed in the joining direction 101.

[0077] The butt surface 90 is oriented obliquely to a principal extension direction 200 of the first joining element. In particular, the butt surface 90 can have an angle to the principal extension direction 200 of approximately 5 to 20 degrees.

[0078] Out of Fig. 9It is further evident that the end piece 21.3 has a greater width than the locking arm 21.1, the width being measurable in a direction transverse to the main extension direction 200.

[0079] A second part 21.2 of the first joining element 21 can extend along the main direction 200 of the waveguide antenna 2. The second part 21.2 is, in particular, integrated into the radome 3. Such integration of the second part 21.2 into the radome 3 can, for example, be achieved by manufacturing the first joining element 21 together with the waveguide antenna 2 using a 3D printing process.

[0080] Fig. 10 Figure 1 shows a perspective view of an exemplary further embodiment of the radome 3. The radome 3 includes, in particular, the first joining element 11 and at least one first side wall 91. When the waveguide antenna 2 is attached to the radome 3 using the first snap-fit ​​connection, as shown in Figure 2, the radome 3 is connected to the first side wall 91. Fig. 11As shown, the waveguide antenna 2 can abut the side wall 91. In particular, a first edge 81 of the waveguide antenna 2 can run along the side wall 91 and abut the side wall 91. This could prevent the waveguide antenna 2 from twisting relative to the radome 3.

[0081] Fig. 11Figure 1 further shows an optional spacer 31 of the waveguide antenna 2, which is hereinafter referred to as the first spacer 31. The first spacer 31 has, in particular, the functionality of the first spacer described above. Specifically, the first spacer 31 extends from the rear of the waveguide antenna 2 in a direction away from the radome 3. Furthermore, a contact surface 82 of the first spacer 31 can have a first distance 71 to the rear of the waveguide antenna 2. In particular, the first spacer 31 projects from the rear of the waveguide antenna 2 by the first distance 71. Specifically, the first spacer 31 is designed such that it blocks movement of the waveguide antenna 2 in a direction perpendicular away from the inner wall 7 of the radome 3.

[0082] Furthermore, it shows Fig. 11 a variant in which the first spacer 31 is in Fig. 3 shown second joining element 12. As in Fig. 11 As shown, in this variant, the back side of the end piece 11.2 can rest against the support surface 82. In the Fig. 11 In the illustrated variant, the first spacer 31 has the two circumferential edges 12.1 and 12.2 and thus the bore which is in Fig. 11 not shown.

[0083] Fig. 10Figure 1 shows an optional spacer 32 of the radome 3, which is referred to below as the second spacer 32. The second spacer 32 can extend from the inner wall 7 towards the waveguide antenna 2. In a locked state of the first locking connection, the waveguide antenna 2 is pressed against the second spacer 32. In particular, in the locked state of the first locking connection, a contact surface of the front of the waveguide antenna 2, which is not shown in the figures, is pressed against a bearing surface 32.1 of the second spacer 32.

[0084] The first joining element 11 is adapted to the second spacer 32 such that, in a locked state of the first locking connection, the first joining element 11 is under tensile stress. To achieve this, the contact surface of the waveguide antenna 2 has, in particular, a first design distance to the bearing surface 82 of the first spacer 31 in a direction perpendicular to the inner wall 7 of the radome 3, which is slightly larger, for example in a range between 0.1 and 1 millimeter, than a second design distance between the rear side of the end piece 11.2 of the first joining element 11 and the bearing surface 32.1 of the second spacer 32 in the direction perpendicular to the inner wall 7 of the radome 3. The first design distance can be measured in a state of the waveguide antenna 2 in which the waveguide antenna 2 is not attached to the radome 3, i.e., the first locking connection is open.Similarly, the second constructive distance can be measured if the waveguide antenna 2 is not connected to the radome 3 using the first snap connection, as shown in . Fig. 10 shown.

[0085] Optionally, the waveguide antenna 2 can be configured in Fig. 2 The third spacer 33 shown is located at the front of the waveguide antenna 2 and extends towards the radome 3. When the first locking connection is closed, the waveguide antenna 2 can press the third spacer 33 against the inner wall 7.

[0086] It goes without saying that the waveguide antenna 2 can also be attached to the radome 3 using the first and second locking connections. A combination of two or more of the first and / or second locking connections for attaching the waveguide antenna 2 to the radome 3 is also possible.

[0087] For mounting the radar sensor system 1, it can be particularly advantageous if not only the waveguide antenna 2, but also the circuit board 5 is attached to the radome 3 using a snap-fit ​​connection. Therefore, a variant of the one described in the following is presented. Figures 1 to 11The possible embodiments of the radar sensor system 1 shown are described, in which the circuit board 5 is attached to the waveguide antenna 2 by means of an additional snap-fit ​​connection. For the assembly of the radar sensor system 1, the circuit board 5 can first be attached to the waveguide antenna 2 using the additional snap-fit ​​connection. In a second step, the waveguide antenna 2, together with the circuit board 5, can be attached to the radome 3 using the snap-fit ​​connection described above, which may include the first and / or second snap-fit ​​connection. It is also possible that the waveguide antenna 2 is first attached to the radome 3 using the snap-fit ​​connection described above, and then the circuit board 5 is attached to the waveguide antenna 2 using the additional snap-fit ​​connection. The additional snap-fit ​​connection can be designed similarly to the first or second snap-fit ​​connection described above.The following describes two possible variants of the further rest connection, which can also be combined with each other.

[0088] Fig. 12 Figure 1 shows a possible variant of the radar sensor system 1 with the snap-fit ​​connection and the additional snap-fit ​​connection in a sectional view. The waveguide antenna 2 is attached to the circuit board 5 using the additional snap-fit ​​connection. For mounting the radar sensor system 1, the circuit board 5 and the waveguide antenna 2 can be inserted together as a unit into a space enclosed by the housing 4 by placing the radome 3 onto the housing 4. Subsequently, the radome 3 can be welded to a top surface of the housing 4.

[0089] Fig. 12 Figure 1 shows one variant of how the waveguide antenna 2 can be attached to the circuit board 5 using a further first snap-fit ​​connection. Figure 2 shows Fig. 12The further first snap-fit ​​connection is in a snapped, i.e., closed, state. The further first snap-fit ​​connection has a first joining element 111 and a second joining element 112, which is in Fig. 13 The first joining element 11 of the further first snap connection, hereinafter referred to as the first joining element 111, extends in particular perpendicularly from the waveguide antenna 2 in the direction of the circuit board 5.

[0090] Furthermore, the first joining element 111 can have an enlarged cross-section at its end piece 111.2, which is spaced apart from the waveguide antenna 2, for snapping into the second joining element 112 of the further first snap-fit ​​connection, hereinafter referred to as the second joining element 112. The second joining element 112 can be arranged on the printed circuit board 5 and has at least one further edge, such as a further second edge 112.2, for snapping the first joining element 111 into it.

[0091] The second joining element 112 is located in the Figs. 12, 13, 14, 15 The illustrated embodiment of the radar sensor system 1 is designed in the form of an additional bore. The additional bore is connected by a Fig. 14 The further first circumferential edge 112.1 shown is located on the front side of the circuit board 5 and defines a further second circumferential edge 112.2. The further second circumferential edge 112.2 is located on the back side of the circuit board 5 and is in Fig. 15 The further first edge 112.1 therefore limits the further hole on the front of the circuit board 5 and the further second circumferential edge 112.2 the further hole on the back of the circuit board 5.

[0092] Fig. 13Figure 1 shows an optional division of the first joining element 111 into a first part 111.1, which extends away from the waveguide antenna 2 along a principal axis 1100 of the first joining element 111 and on which the end piece 111.2 is arranged, and the end piece 111.2, which forms a second part of the first joining element 111. The end piece 111.2 can, in particular, be conical. Furthermore, the end piece 111.2 can be divided into at least two parts that move towards each other when snapping into place, namely a further first snapping part 114.1 and a further second snapping part 114.2.

[0093] Out of Fig. 13It is evident that the width of the end piece 111.2 is greater than the width of the first part 111.1, at least in one area of ​​the end piece 111.2. The width is measured in a direction 1102 that runs perpendicular to the main axis 1100. In particular, the greatest width of the end piece 111.2 is greater than the diameter of the further bore 112. This causes the two further locking parts 114.1 and 114.2 to be pressed together when the first joining element 111 is pushed through the bore 112 in a further joining direction 1101. To facilitate the movement of the two further locking parts 114.1 and 114.2 towards each other, the end piece 111.2 can have at least one further recess 113. If the two further locking parts 114.1 and 114.2 move towards each other, the greatest width of the end piece 111.2 is reduced, so that the end piece 111.2 can be pushed through the further bore 112.

[0094] After the end piece 111.2 has passed the further bore 112, that is, after it has been positioned behind the further bore 112, in particular behind the further second circumferential edge 112.2, as seen in the further assembly direction 1101, the two further locking elements 114.1 and 114.2 can move apart again. The circuit board 5 has a further free space on its back side for this purpose, which is located immediately behind the further second circumferential edge 112.2 in the further assembly direction 1101. The two further locking elements 114.1, 114.2 can spring back into this further free space, particularly due to their elastic properties, after the end piece 111.2 has passed the further second circumferential edge 112.2. In principle, the two further locking elements 114.1, 114.2 can also be pressed together without the further recess 113 due to their elastic properties. In this case, the two other locking parts are 114.1, 114.The two parts are not separate but form a dome-shaped end piece. However, the additional recess 113 could facilitate easier engagement and opening of the first locking connection.

[0095] According to one possible embodiment, the waveguide antenna 2 can have a support element 19 which extends from a surface 20 of the waveguide antenna 2 facing the circuit board 5 towards the circuit board 5. The support element 19 may be formed by the walls of the channels of the waveguide antenna 2. Alternatively, the support element 19 may be arranged separately from the walls of the channels.

[0096] The first joining element 111 is adapted to the support element 19 in such a way that, in a locked state of the further first locking connection, the first joining element 111 is under tensile stress. This can be achieved in particular by making the length 18 of the first part 111.1 of the first joining element 111, which is measurable in the direction of the main axis 1100, slightly smaller, i.e., for example, 0.1 to 1 mm smaller, than the sum of the thicknesses of the printed circuit board 5, in particular the distance between the further first circumferential edge 112.1 and the further second circumferential edge 112.2 in the direction of the main axis 1100, and by extending the support element 19 in a direction parallel to the main axis 1100.

[0097] Fig. 16 shows another variant of the further rest area connection. In the Fig. 6In the variant of radar sensor system 1 shown, the waveguide antenna 2 is attached to the circuit board 5 by means of a further second snap connection. Fig. 16 Figure 1 shows the second snap-fit ​​connection in a locked, i.e., closed, state. This second snap-fit ​​connection has a first joining element 121 and a second joining element 122, which is located in Fig. 19 The first joining element 121 of the second snap-fit ​​connection, hereinafter referred to as the first joining element 121, can extend from the waveguide antenna 2 towards the circuit board 5 and have an enlarged cross-section at its end piece 121.3, which is spaced apart from the waveguide antenna 2, for snapping into the second joining element 122 of the second snap-fit ​​connection, hereinafter referred to as the second joining element 122. The second joining element 122 is shown in the Figs. 16, 17 , 18 and 19The illustrated variant of the radar sensor system 1 is formed in the form of an edge of the printed circuit board 5. The edge is bounded by a first upper edge 122.1 of the printed circuit board 5, which is located on the front side of the printed circuit board 5, and a second lower edge 122.2 of the printed circuit board 5, which is located on the back side of the printed circuit board 5. The end piece 121.3, in particular a locking lug 121.4 of the end piece 121.3, can engage with the second lower edge 122.2.

[0098] Fig. 17 The figure shows the waveguide antenna 2 according to the variant with the second locking connection and the further first locking connection in a top view and the radome 3 in a section view. Fig. 16 shows the housing 4 and the radome 3 in a cross-section in the Fig. 17 Section plane CC shown. To provide space for the first joining element 121, the aforementioned recess 70 or another recess can be provided in the housing, which is shown in Fig. 16 and Fig. 17not shown. The further recess can extend in particular through the radome 3 and is in particular larger than the recess 70. Fig. 18 The radar sensor system 1 is shown in a cross-section along the in Fig. 17 shown section plane DD.

[0099] In Fig. 19 It can be seen that the first joining element 121 has a locking arm 121.1 on which the end piece 121.3 is arranged. In the closed state of the second locking connection, the locking lug 121.4 is engaged on the second edge 122.2 of the second joining element 122. Fig. 19 shows the second locking connection in an open state.

[0100] To close the second locking connection, the first joining element 121 is moved in the further joining direction 1101, thereby approaching the second joining element 122. The first joining element 121 is moved in the joining direction 1101 until a butt surface 190 of the end piece 121.3 contacts the first upper edge 122.1 of the second joining element 122. If the first joining element 121 is moved further in the further joining direction 1101 after the butt surface 190 has contacted the first upper edge 122.1, the end piece 121.3 moves in a further displacement direction 1201, which is perpendicular to the further joining direction 1101, whereby the locking arm 121.1 is bent in the further displacement direction 1201.

[0101] A displacement of the end piece 121.3 in the further displacement direction 1201 allows the locking lug 121.4 to slide past the edge of the circuit board 5, i.e., the second joining element 122, in the direction of the second lower edge 122.2. After the locking lug 121.4 has passed the second lower edge 122.2, the end piece 121.3 can spring back in a direction opposite to the displacement direction 1201. To enable the end piece 121.3 to spring back, a further free space is provided behind the second lower edge 122.2 in the further joining direction 1101.

[0102] The butt surface 190 is oriented obliquely to a principal extension direction 1200 of the first joining element 121. In particular, the butt surface 190 can have an angle to the principal extension direction 1200 of approximately 5 to 20 degrees.

[0103] Out of Fig. 19It is further evident that the end piece 121.3 has a greater width than the locking arm 121.1, the width being measurable in a direction transverse to the main extension direction 1200.

[0104] A second part 121.2 of the first joining element 121 can extend along the main direction 1200 of the waveguide antenna 2. The second part 121.2 is, in particular, integrated into the waveguide antenna 2. Such integration of the second part 121.2 into the waveguide antenna 2 can, for example, be achieved by manufacturing the first joining element 121 together with the waveguide antenna 2 using a 3D printing process.

[0105] Fig. 20 shows a perspective view of the waveguide antenna 2, the first joining element 121, the circuit board 5 and the second joining element 122 with the upper first edge 122.1 and the lower second edge 122.2.

[0106] Fig. 21Figure 1 shows a variant of the radar sensor system 1 in which the waveguide antenna 2 is attached to the circuit board 5 by means of the additional first locking connection and the additional second locking connection. In this variant, the additional second locking connection is arranged opposite the additional first locking connection. Accordingly, in the Fig. 21 The variant of radar sensor system 1 shown, the circuit board 5, both of which are in Figs. 12 and 13 The illustrated bore 112 is for snapping the first joining element 111, and the second joining element 122 is for snapping the first joining element 121. According to one possible embodiment, the waveguide antenna 2 can be attached to the circuit board 5 by means of additional snap connections. The additional snap connections can each be designed analogously to the first or the second snap connection.

[0107] Furthermore, another radar sensor system is proposed. This additional radar sensor system comprises a waveguide antenna, a radome, a housing, and a printed circuit board, wherein the radome is attached to the housing, and the housing and the radome together surround the printed circuit board and the waveguide antenna, and radar signals generated by the printed circuit board can be emitted by means of the waveguide antenna, wherein the waveguide antenna is attached to the printed circuit board by means of a snap-fit ​​connection.

[0108] The waveguide antenna of the additional radar sensor system can be manufactured using a 3D printing process.

[0109] In the further radar sensor system, the snap-fit ​​connection can have a first joining element and a second joining element, and the first joining element can extend perpendicularly from the waveguide antenna towards the circuit board and have an enlarged cross-section at its end piece spaced away from the waveguide antenna for snapping onto the second joining element, and the second joining element can be arranged on the circuit board and have at least one edge for snapping the first joining element into place.

[0110] Furthermore, in the additional radar sensor system, the waveguide antenna can have at least one support element that extends towards the circuit board in order to provide a defined distance between the waveguide antenna and the circuit board.

[0111] Furthermore, in the additional radar sensor system, the first joining element can be adapted to the support element in such a way that, in a locked state of the locking connection, the first joining element is under tensile stress.

[0112] Furthermore, in the additional radar sensor system, the first joining element can have a first part that extends away from the waveguide antenna and on which the end piece is arranged, and the end piece can have a recess that divides the end piece into at least two parts that move towards each other when snapping into place, and the edge can be designed as an edge circumferential to the first part that completely surrounds the first part in the snapped state of the connection.

[0113] Furthermore, in the additional radar sensor system, the first joining element can have a locking arm on which the end piece is arranged, wherein the end piece has a locking lug that is engaged on the edge of the second joining element.

[0114] Furthermore, in the additional radar sensor system, the edge can be designed in the form of an outer edge of the circuit board.

[0115] Furthermore, a method for manufacturing another radar sensor system is proposed, comprising a waveguide antenna, a radome, a housing and a printed circuit board, the method comprising an assembly of the radar sensor system with the following steps: Bring the waveguide antenna closer to the circuit board; press the waveguide antenna against the circuit board to close a snap connection between the waveguide antenna and the circuit board; insert the waveguide antenna and the circuit board, which is attached to the waveguide antenna using the snap connection, into the housing; close the housing by attaching the radome to the housing.

[0116] The method for manufacturing a further radar sensor system can include manufacturing the waveguide antenna and a first joining element of the snap connection using a 3D printing process, wherein the 3D printing process is carried out in such a way that at least a part of the first joining element is manufactured as an integral part of the waveguide antenna.

Claims

1. Radar sensor system (1) comprising a waveguide antenna (2), a radome (3), a housing (4) and a receptacle for a printed circuit board (5), wherein the waveguide antenna (2) is attached to the radome (3) by means of a snap-fit ​​connection and the radome (3) is attached to the housing (4), wherein the housing (4) and the radome (3) together surround the waveguide antenna (2).

2. Radar sensor system (1) according to claim 1, wherein the radome (3) is manufactured using a 3D printing process.

3. Radar sensor system (1) according to claim 1 or 2, wherein the snap-fit ​​connection has a first joining element (11; 21) and a second joining element (12; 22) and the first joining element (11; 21) extends perpendicularly from an inner wall (7) of the radome (3) covering the waveguide antenna (2) in the direction of the waveguide antenna (2) and has an enlarged cross-section at its end piece (11.2; 21.3) spaced apart from the inner wall (7) for snapping onto the second joining element (12; 22) and the second joining element (12; 22) is arranged on the waveguide antenna (2) and has at least one edge (12.2; 22.2) for snapping the first joining element (11; 21).

4. Radar sensor system (1) according to claim 3, wherein the first joining element (11) has a first part (11.1) extending away from the inner wall (7) and on which the end piece (11.2) is arranged, and the end piece (11.2) has a recess (13) which divides the end piece (11.2) into at least two parts (14.1, 14.2) which move towards each other when snapping into place, and the edge (12.2) is designed as an edge circumferential to the first part which completely surrounds the first part (11.1) in the snapped state of the snap connection.

5. Radar sensor system (1) according to claim 3, wherein the first joining element (21) has a locking arm (21.1) on which the end piece (21.3) is arranged, wherein the end piece (21.3) has a locking lug (21.4) which is engaged on the edge (22.2) of the second joining element (22).

6. Radar sensor system (1) according to one of the preceding claims, wherein the waveguide antenna (2) has a spacer (31) extending from a side of the waveguide antenna (2) facing away from the radome (3) in a direction away from the radome (3).

7. Radar sensor system (1) according to one of the preceding claims, wherein the radome (3) has a spacer (32) and the waveguide antenna (2) is pressed against the spacer (32) in a locked position of the locking connection.

8. Radar sensor system (1) according to claim 1, wherein the snap-fit ​​connection comprises a first joining element and a second joining element, and the first joining element extends perpendicularly from the waveguide antenna (2) in the direction of an inner wall of the radome (3) covering the waveguide antenna (2) and has an enlarged cross-section at its end piece spaced apart from the waveguide antenna (2) for snapping onto the second joining element, and the second joining element is arranged on the inner wall of the radome (3) and has at least one edge for snapping the first joining element.

9. Radar sensor system (1) according to one of the preceding claims, wherein the radar sensor system (1) comprises the circuit board (5) and the waveguide antenna (2) is attached to the circuit board (5) by means of a further snap-fit ​​connection.

10. Radar sensor system (1) according to claim 9, wherein the further snap-fit ​​connection has a first joining element (111; 121) and a second joining element (112; 122) and the first joining element (111; 121) of the further snap-fit ​​connection extends perpendicularly from the waveguide antenna (2) in the direction of the circuit board (5) and has an enlarged cross-section at its end piece (111.2; 121.3) spaced apart from the waveguide antenna (2) for snapping onto the second joining element (112; 122) of the further snap-fit ​​connection and the second joining element (112; 122) of the further snap-fit ​​connection is arranged on the circuit board (5) and has at least one edge (112.2; 122.2) for snapping the first joining element (111; 121) of the further snap-fit ​​connection.

11. Method for manufacturing a radar sensor system (1) comprising a waveguide antenna (2), a radome (3), a housing (4) and a printed circuit board (5), the method comprising assembling the radar sensor system (1) by the following steps: - bringing the waveguide antenna (2) close to the radome (3); - pressing the waveguide antenna (2) against the radome (3) to close a snap-fit ​​connection between the waveguide antenna (2) and the radome (3); - inserting the printed circuit board (5) into the housing (4); - placing the radome (3) onto the housing (4), whereby the waveguide antenna (2) attached to the radome (3) by means of the snap-fit ​​connection is inserted into the housing (4); - closing the housing (4) by attaching the radome (3) to the housing (4).

12. Method according to claim 11, wherein the method comprises manufacturing the radome (3) and a first joining element (11; 21) of the snap connection using a 3D printing method, wherein the 3D printing method is carried out in such a way that at least a part of the first joining element (11; 21) is manufactured as an integral part of the radome (3).

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