Radar device for a vehicle and method to assemble a radar device for a vehicle

Abstract

The invention relates to a radar device (2) for a vehicle (1). The radar device (2) comprises a housing (5) with a back part (6) and a front part (7) which in an assembled state of the radar device (2) form a receiving space (8) in which an antenna element (9) of the radar device (2) is located. The back part (6) comprises at least one pin (10) that protrudes into the receiving space (8) and to which the antenna element (9) is attached by means of a riveted joint. The invention also relates to a method to assemble the radar device (2) for the vehicle (1).

Description

[0001] Radar device for a vehicle and method to assemble a radar device for a vehicle

[0002] The invention relates to a radar device for a vehicle. Besides, the invention relates to a vehicle with such a radar device and a method to assemble a radar device for a vehicle.

[0003] A vehicle such as a motor vehicle may comprise at least one radar device. The radar device is configured to capture radar data that describe at least a part of an environment of the vehicle. The radar device typically comprises radar electronics, in particular at least one antenna element. Besides, the radar device comprises a housing comprising, for example, a back part for protection and heat dissipation and a front part that is transparent for radar echo. Assembling the radar device with the housing and the radar electronics may comprise multiple assembly steps. Therefore, it may be time-consuming and complex.

[0004] It is the object of the invention to simplify the assembly of a radar device for a vehicle.

[0005] The independent claims solve the object.

[0006] A first aspect of the invention relates to a radar device for a vehicle. The radar device comprises a housing with a back part and a front part. The back part may alternatively be referred to as back cover. The front part may alternatively be referred to as front cover. In an assembled state of the housing, the back part and the front part form a receiving space in which an antenna element of the radar device is located. The assembled state of the housing may alternatively be referred to as an assembled state of the radar device. The antenna element may alternatively be referred to as an antenna. The antenna element comprises, for example, at least one transmitting antenna and at least one receiving antenna.

[0007] The back part of the housing comprises at least one pin. The at least one pin protrudes into the receiving space. The antenna element is attached to the at least one pin by means of a riveted joint. This means that the back part comprises at least one protrusion, which is here the at least one pin, to fixate the antenna element to the back part. The fixation however is done by riveting meaning that the riveted joint locates the antenna element with respect to the back part of the housing. Preferably, the back part comprises multiple pins. A number and arrangement of the multiple pins may depend on a size and / or form of the antenna element. The larger the antenna element, the more pins may be comprised by the back part.

[0008] The at least one pin is, for example, shaped so that a length of the pin when viewed in a length direction is larger than a diameter of the pin when viewed in a transverse direction or a depth direction. The length direction is orientated perpendicular to a surface of the back part, wherein this surface of the back part is located at least partially opposite the front part of the housing. The at least one pin and the back part are typically manufactured as one piece. The back part may be made of plastic and / or metal. If the antenna element is placed on the at least one pin and if riveting techniques are applied, the antenna element is quickly and easily attached to the pin and hence to the housing. As a result, assembly of the radar device is simplified.

[0009] An embodiment comprises that the pin comprises a head that protrudes in radial direction of the pin. The head is a part of the pin that has a larger diameter (when viewed in transverse and depth direction) than the rest of the pin. The radial direction of the pin is perpendicular to the length direction of the pin. The head is located at an end of the pin that faces away from the surface of the back part. The head is formed by riveting the pin. In particular, it is formed by heat staking and / or ultrasonic riveting. The head at least contributes to attach the antenna element to the back part. However, the head is created during the assembly procedure of the radar device. This means that the pin is originally shaped, for example, as a rod or as a cylinder, but a part of the pin is reshaped as the head by riveting. In case of heat staking the pin may be made of plastic. The plastic material of the pin is deformed during the riveting process by applying heat and force for a predetermined process duration. The connection between the pin and the antenna element is made by partially deforming the plastic part to fix the antenna element. Alternatively or additionally to heat staking, ultrasonic riveting may be used to realize the riveted joint. In this case the pin may be made of plastic as well. During ultrasonic riveting, a melt deformation takes place and at least a part of the pin is plasticized. It is hence possible to join the pin to the antenna element, which may be another plastic part or a non-plastic component of the radar device. Because of the protruding head created during riveting, the antenna element cannot be moved away from the pin without destroying the pin and is hence attached to the back part.

[0010] According to another embodiment, the radar device comprises at least one head that is positioned above the antenna element on the at least one pin. The head and the pin are riveted together. In other words, it is possible to add the head as an additional component. Here, the head is hence not create by riveting but riveting is used to attach two individual parts meaning the head and the pin so that the antenna element is fixated with respect to the back housing. The riveting joint may be realized by applying a predetermined force on the head and the pin. The head and / or the pin may be made of metal and / or plastic. It is thus possible to rely on various techniques in the field of riveting to attach the antenna element to the back part of the housing by means of the riveted joint.

[0011] A further embodiment comprises that the antenna element comprises at least one hole through which the at least one pin is passed. If the back part comprises more than one pin, the antenna element comprises more than one hole. A diameter of the hole is at least as big as a diameter of the pin so that the pin can be guided through the hole. Preferably, the diameter of the hole is at least partially smaller than the diameter of the head. The hole extends through the entire antenna element meaning, for example, from a top surface to an opposite bottom surface of the antenna element. This explains how the pin can connect the antenna element to the back part by the pin by means of the riveted joint, because the head protrudes in radial direction and cannot pass through the hole. Besides, the head is created after placing the antenna element on the pin by heat staking and / or ultrasonic riveting, or the head is added after passing the pin through the antenna element and then riveted to the pin. This shows more explicitly how to achieve the assembly of the radar device.

[0012] A preferred embodiment comprises that at an end of the hole a countersink is formed so that the head of the pin sits flush with the surface of the antenna element. The end is the end of the hole that faces away from the back part. The end may hence protrude the furthest into the receiving space compared to other subparts of the back part. The countersink is a part of the hole that has a larger diameter than other parts of the hole. Moreover, the countersink may have a conical shape. The countersink may be shaped in a way that it may take in the head of the pin entirely. At least the part of the hole that is adjacent to the countersink has a smaller diameter than the counter sink.

[0013] As described, the pin does not protrude from the surface of the antenna element towards, for example, the front part of the housing. A top of the head and the surface of the antenna element may thus be in one plane. Therefore, no part of the pin may shield any electromagnetic waves transmitted or received by the antenna element. It is particularly useful to use the countersink for the head to avoid any influence of the head and / or the pin on the measurement behavior of the radar device. Moreover, an embodiment comprises that the antenna element is a waveguide antenna. The antenna element used for the radar device is hence of a specific antenna type. The waveguide antenna may alternatively be referred to as a metalized plastic antenna. This means that the antenna element is at least partially made of plastic that is covered with a metal layer. This design of the antenna element is particularly cost-effective and offers high performance and / or a wide field of view of the radar device compared to other antenna types.

[0014] The waveguide antenna may require, for example, additional electronic components, such as a printed circuit board for energy and / or data connections and / or a wave generator to generate the electromagnetic wave to be transmitted by the antenna element.

[0015] Thus, another embodiment comprises that the radar device comprises a printed circuit board (PCB). The PCB is located between the back part and the antenna element. During the assembly procedure of the radar device, the PCB is, for example, positioned on the at least one pin before the antenna element is positioned on it. The PCB comprises at least one hole through which the at least one pin is passed. The PCB and the antenna element are placed on top of each other with their holes directly opposite each other when viewed in a height direction of the radar device which corresponds to the length direction of the pin. This means that the pin does not just pass through the at least one hole of the antenna element but also through the at least one hole of the PCB. The PCB is, for example, configured to provide energy, for example, for at least one electronic component of the radar device. The electronic component may be required for data processing and / or controlling of the radar device. It is hence useful to add the PCB to the radar device. However, the position of the PCB along the pin results in fixing it to the back part as well so that the radar device is robust during movement of the radar device.

[0016] A further embodiment comprises that the back part comprises at least one protrusion. The protrusion supports the PCB at least partially so that it is held at a predetermined height in the length direction of the pin. Thus, PCB is not placed anywhere with respect to the pin and the antenna element but at a specified position which is predetermined by the location and / or shape of the at least one protrusion. The protrusion provides a local surface of the back part that is located at a higher height when viewed in the length direction of the pin with respect to, for example, a height of a subpart of the back part that surrounds the pin. This allows to predetermine a position of the PCB in the receiving space without adding any additional parts to the radar device, in particular without an additional riveted joint. According to another embodiment, the radar device comprises a wave generator. The wave generator is in particular a radio frequency chip. The wave generator is configured to create an electromagnetic wave to be transmitted by the antenna element. The wave generator is connected to a wave entrance of the antenna element. This is based on the observation that a waveguide antenna typically comprises a wave entrance through which it may receive an electromagnetic wave, in particular a radio wave or a microwave. The waveguide antenna may transmit the received wave towards an environment of the radar device. Therefore, the received wave may first pass through tubes or pipes of the waveguide antenna towards a wave exit of the waveguide antenna.

[0017] Besides, the wave generator is connected to the PCB. The PCB provides, for example, energy and / or control commands for the wave generator. The wave generator may be directly connected to the wave entrance and / or may be indirectly connected to it through the PCB, for example, via a connecting element. The connecting element may be part of the PCB. Hence, the radar device comprises all components required for the antenna element to be reliably functional.

[0018] Moreover, an embodiment comprises that a side of the wave generator faces at least a section of the back part. On that side a thermally conductive element is positioned to dissipate heat from the wave generator to the back part. The reason for this is that the wave generator is typically a part or a component of the radar device that may produce heat during its operation. It is therefore useful to add the thermally conductive element to pass on the generated heat, for example, so that the heat is guided away from other parts of the radar device by the back part. The thermally conductive element is in particular a thermally conductive paste that is positioned, for example, in a gap between the back part and the wave generator. The back part may comprise a further protrusion so that the gap for the thermally conductive element is particularly small compared to a back part without the further protrusion. Preferably, the further protrusion of the back part and the at least one pin of the back part are located spatially apart from each other. Adding the thermally conductive element is particularly useful if the back part is made of a thermally conductive material, such as metal, to achieve heat dissipation.

[0019] Another embodiment comprises that a side of the wave generator faces at least a section of the back part. On that side an air gap is located to thermally isolate the wave generator from the back part. In case of a back part that is, for example, made of plastics or a material with lower thermal conductivity than metal, it may be useful to avoid heat dissipation from the wave generator to the back part. Instead, the back part is at least partially thermally isolated from the wave generator by the air gap. Therefore, the gap between the back part, in particular the protrusion of the back part, and the wave generator remains empty of an additional component such as the thermally conductive element. The air gap is, for example, part of the receiving space of the housing.

[0020] Whether the air gap or the thermally conductive element is part of the radar device may depend on a material choice of the back part of the housing and hence on a need for heat dissipation or thermal isolation, respectively.

[0021] Another embodiment comprises, that the front part is formed as a radome. The front part is hence made of a material through which electromagnetic waves can pass. The electromagnetic waves are at least radio waves and / or microwaves. The front part is, for example, made of a specific plastic that is designed for front covers of radar devices. The front part and the back part are fixated to each other is the assembled state of the radar device. They may be fixated by an adhesive, ultrasonic welding, laser welding and / or by at least one screw. Alternatively or additionally, the connection between the front part and the back part may be based on a riveted joint as well. Other fixation techniques may be possible if suitable for a radar device.

[0022] Another aspect of the invention relates to a vehicle with a radar device as described above. The vehicle may comprise at least one radar device in a front area, a rear area and / or a side area of the vehicle. The vehicle is, for example, a motor vehicle, such as a passenger car, a truck, a bus, a motorcycle, and / or a moped.

[0023] Another aspect of the invention relates to a method to assemble a radar device for a vehicle. The radar device comprises a housing with a back part and a front part. The method comprises positioning at least one antenna element on the back part so that at least one pin that protrudes from the back part passes through the antenna element. Therefore, the antenna element may comprise at least one hole so that the pin passes through it. The method comprises attaching the antenna element to the at least one pin by means of a riveted joint. This is in particular done by heat staking and / or ultrasonic riveting. Besides, the method comprises attaching the front part to the back part so that the housing forms a receiving space in which the antenna element is located. After attaching the antenna element to the pin by means of the riveted joint it is hence possible to close the housing by, for example, fixating an edge of the front part to an edge of the back part. An embodiment of the inventive method comprises positioning a printed circuit board (PCB) between the back part and the antenna element so that the at least one pin also passes through the PCB. Therefore, the PCB may comprise as well at least one hole that the pin passes through.

[0024] In summary, if watched from bottom to top of the radar device when viewed in a height direction of the radar device, the radar device first comprises the back part with the at least one pin, on top of which the PCB may be located. On top pf the PCB the antenna element is located. The antenna element is then hold in its position by, for example, a head of the pin and hence by the riveted joint. On top of the antenna element the front part of the housing is positioned, wherein the front part of the housing may only be directly connected to the back part and not to the antenna element.

[0025] The embodiments described in connection with the inventive radar device, in each case individually as well as in combination with each other, apply accordingly, as far as applicable, to the inventive vehicle and the inventive method. The invention includes combinations of the described embodiments.

[0026] The figures show:

[0027] Fig. 1 a schematic representation of a vehicle with multiple radar devices,

[0028] Fig. 2 a schematic cross section of a radar device for a vehicle, and

[0029] Fig. 3 a schematic top view of an antenna element for a radar device.

[0030] In the figures, elements with identical functions are given the same reference signs.

[0031] Fig. 1 shows a vehicle 1 that comprises multiple radar devices 2. Here it comprises three radar devices 2 in its front, three radar devices 2 in its rear and at least one radar device 2 on each side of the vehicle 1 . The respective radar device 2 is configured to describe at least a part of an environment 3 of the vehicle 1 . Besides, the vehicle 1 may comprise a control device 4 to provide control commands for the respective radar device 2. The control device 4 is, for example, an on-board computer of the vehicle 1 . The vehicle 1 is preferably a motor vehicle. Additional or alternative positions of the radar devices 2 in the vehicle 1 are possible. Fig. 2 shows a cross section of the radar device 2 for the vehicle 1 . The radar device 2 comprises a housing 5 with a back part 6 and a front part 7. In an assembled state such as the state shown here, the housing 5 forms a receiving space 8 in which an antenna element 9 of the radar device 2 is located. The receiving space 8 may comprise other components of the radar device 2 besides the antenna element 9. The antenna element 9 is here a waveguide antenna which may alternatively be referred to as a metalized plastic antenna.

[0032] The back part 6 comprises at least one pin 10 that protrudes into the receiving space 8. Here it comprises two pins 10. A number and arrangement of the pins 10 may depend on a size and / or form of the antenna element 9. The larger the antenna element 9 the more pins 10 may be comprised by the back part 6. The antenna element 9 is attached to the pin 10 by means of a riveted joint. In more detail, the pin 10 may comprise a head 11 . The head 11 protrudes in radial direction from the pin 10. The radial direction is here the x- direction and the y-direction. The radial direction is thus perpendicular to a height direction of the radar device 2 and a length direction of the pin 10 (z-direction). The head 11 may be formed by riveting the pin 10. In particular it may be created by heat staking and / or ultrasonic riveting. Alternatively, the radar device 2 comprises at least one head 11 which is formed as an individual component. The head 11 is positioned above the antenna element 9 on the at least one pin 10 and the head 11 and the pin 10 are then riveted together. There are hence two ways to create the riveted joint.

[0033] A further component of the radar device 2 may be a printed circuit board (PCB) 12 that is located between the back part 6 and the antenna element 9. Besides, the radar device 2 may comprise at least one protrusion 13 which supports the PCB 12 at least partially so that it is held at a predetermined position in the length direction of the pin 10 (here the z- direction).

[0034] The radar device 2 may comprise a wave generator 14. The wave generator 14 is in particular a radio frequency chip. The wave generator 14 is configured to create an electromagnetic wave to be transmitted by the antenna element 9 towards the environment 3 of the radar device 2. The created wave may be a radio wave or a microwave. The wave generator 14 is here connected to a wave entrance 15 of the antenna element 9 and to the PCB 12. The PCB 12 may provide energy and / or control commands for the wave generator 14. The radar device 2 may comprise a thermally conductive element 16. It is located at a side of the wave generator 14 that faces at least a section of the back part 6. It is positioned between the wave generator 14 and, for example, a further protrusion 13 of the back part 6. The thermally conductive element 16 is configured to dissipate heat from the wave generator 14 to the back part 6. The thermally conductive element 16 may be a thermally conductive paste. Alternatively to the thermally conductive element 16 there may be an air gap between the wave generator 14 and the back part 6 to thermally isolate the wave generator 14 from the back part 6.

[0035] The front part 7 is formed as a radome. The front part 7 and the back part 6 may be fixated to each other to form the housing 5. The back part 6 and the front part 7 may therefore be connected by glue, at least one screw and / or welding.

[0036] Fig. 3 shows a top view on the antenna element 9 to illustrate how the pin 10 can pass through the antenna element 9. The antenna element 9 may comprise at least one hole 17. Here it comprises two holes 17, one for each of the two pins 10. The at least one pin 10 is passed through the at least one hole 17. At an end of the hole 17 that faces away from the back part 6 a countersink 18 may be formed so that the head 11 of the pin 10 sits flush with a surface 19 of the antenna element 9. The PCB 12 may also comprise at least one hole 17 through which the at least one pin 10 is passed. This explains how the assembly of Fig. 2 can be achieved.

[0037] It is possible to assemble the radar device 2 in a particularly fast and easy way. Therefore, the PCB 12 may be first positioned on top of the back part 6 with the at least one pin 10 so that the at least one pin 10 passes through the hole 17 in the PCB 12. The PCB 12 is then held at its position by means of the protrusion 13 of the back part 6. Afterwards, the antenna element 9 is positioned on the back part 6 so that the at least one pin 10 passes through the hole 17 in the antenna element 9. Then, the antenna element 9 is attached to the respective pin 10 by means of the riveted joint. Finally, the front part 7 is attached to the back part 6 so that the receiving space 8 is formed and sealed.

[0038] In summary, an assembly and stack of the radar device 2 using the housing 5 to fix a waveguide antenna as antenna element 9 and a PCB 12 by heat staking has been described. The idea here is to simplify the assembly and the stack of the radar device 2 by using pins 10 from the back part 6 which fix the PCB 12 and the antenna element 9 by heat staking those pins 10. The invention describes the simplification of the assembly process and the stack up of the radar device 2. The PCB 12 and the antenna element 9 will be placed over the pins 10 on the back part 6 of the housing 5. The back part 6 supports the PCB 12. Finally, the pins 10 are heat staked.

Claims

Claims1 . Radar device (2) for a vehicle (1 ) comprising a housing (5) with a back part (6) and a front part (7) which in an assembled state of the radar device (2) form a receiving space (8) in which an antenna element (9) of the radar device (2) is located, characterized in that the back part (6) comprises at least one pin (10) that protrudes into the receiving space (8) and to which the antenna element (9) is attached by means of a riveted joint.

2. Radar device (2) according to claim 1 , characterized in that the at least one pin (10) comprises a head (11) protruding in radial direction of the pin (10), wherein the head (11 ) is formed by riveting the pin (10), in particular by heat staking and / or ultrasonic riveting.

3. Radar device (2) according to any one of the preceding claims, characterized in that the radar device (2) comprises at least one head (11) that is positioned above the antenna element (9) on the at least one pin (10), wherein the head (11) and the pin (10) are riveted together.

4. Radar device (2) according to any one of the preceding claims, characterized in that the antenna element (9) comprises at least one hole (17) through which the at least one pin (10) is passed.

5. Radar device (2) according to claim 4 and one of the claims 2 or 3, characterized in that at an end of the at least one hole (17) that faces away from the back part (6) a countersink (18) is formed so that the head (11) of the at least one pin (10) sits flush with a surface of the antenna element (9).

6. Radar device (2) according to any one of the preceding claims, characterized in that the antenna element (9) is a waveguide antenna.

7. Radar device (2) according to claim 6, characterized in that the radar device (2) comprises a printed circuit board (12) that is located between the back part (6) and the antenna element (9) and that comprises at least one hole (17) through which the at least one pin (10) is passed.

8. Radar device (2) according to claim 7, characterized in that the back part (6) comprises at least one protrusion (13) which supports the printed circuit board (12) at least partially so that it is held at a predetermined height in a length direction of the pin (10).

9. Radar device (2) according to claim 7 or 8, characterized in that the radar device (2) comprises a wave generator (14), in particular a radio frequency chip, configured to create an electromagnetic wave to be emitted by the antenna element (9), wherein the wave generator (14) is connected to a wave entrance (15) of the antenna element (9) and to the printed circuit board (12).

10. Radar device (2) according to claim 9, characterized in that a side of the wave generator (14) faces at least a section of the back part (6) and on that side a thermally conductive element (16), in particular a thermally conductive paste, is positioned to dissipate heat from the wave generator (14) to the back part (6).11 . Radar device (2) according to claim 9, characterized in that a side of the wave generator (14) faces at least a section of the back part (6) and on that side an air gap is located to thermally isolate the wave generator (14) from the back part (6).

12. Radar device (2) according to any one of the preceding claims, characterized in that the front part (7) is formed as a radome.

13. Vehicle (1) with a radar device (2) according to any one of the preceding claims.

14. Method to assemble a radar device (2) for a vehicle (1 ), wherein the radar device (2) comprises a housing (5) with a back part (6) and a front part (7), characterized in that the method comprises:- positioning an antenna element (9) on the back part (6) so that at least one pin (10) that protrudes from the back part (6) passes through the antenna element (9);- attaching the antenna element (9) to the pin (10) by means of a riveted joint;- attaching the front part (7) to the back part (6) so that the housing (5) forms a receiving space (8) in which the antenna element (9) is located.

15. Method according to claim 14, characterized in positioning a printed circuit board(12) between the back part (6) and the antenna element (9) so that the at least one pin (10) also passes through the printed circuit board (12).

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