Waterproof electronic enclosure
The waterproof electronic antenna housing addresses sealing and integration issues by using a cap with an overmolded seal and retaining tabs, ensuring effective sealing and cost reduction in automotive applications.
Patent Information
- Application Number
- FR2023000628
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-01-24
- Publication Date
- 2025-01-10
- Estimated Expiration
- 2043-01-24
AI Technical Summary
Existing electronic antenna housings face challenges in ensuring effective sealing against liquids while minimizing production costs, assembly complexity, and maintaining integration efficiency, particularly in automotive applications where metal casings interfere with signal transmission and reception.
A waterproof electronic antenna housing design featuring a rigid chassis and cover with aligned openings, a cap with an overmolded seal, and retaining tabs to ensure sealing without additional assembly steps, allowing dismantling and recycling.
The design provides effective sealing, reduces production costs, simplifies assembly, and facilitates recycling by eliminating the need for separate antenna boards and additional sealing processes, while maintaining signal integrity and electromagnetic separation.
Smart Images
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Abstract
Description
Title of the invention: Waterproof electronic box Technical field
[0001] The present disclosure relates to the field of electronic antenna housing for transmitting and receiving signals and which can be used in applications implemented in an outdoor environment, in particular in the automotive field. Prior art
[0002] Electronic boxes with printed circuit boards are known which include antennas for receiving and communicating information remotely.
[0003] Such an electronic housing generally comprises a chassis fixed on a cover thus forming an envelope delimiting a housing space. A printed circuit board comprising the antenna region is received in the housing space. The antennas are traced near an edge of the printed circuit board. The cover, the chassis and the printed circuit board are then fixed together so as to hold the board in the electronic housing by fixing elements, such as screws.
[0004] The enclosures were primarily made of plastic, thus allowing the antennas located inside the enclosure to transmit and receive signals through the enclosure. However, with the increase in computing power and the required heat dissipation, the enclosures are now primarily made of metal which blocks the transmission and reception of signals. One solution is to arrange the antennas entirely outside the enclosure to avoid the Faraday cage phenomenon. Another solution is to provide an opening in the enclosure, thus allowing the antenna region to be put in direct contact with the environment outside the enclosure for the transmission and reception of signals.
[0005] However, these solutions must continue to ensure good protection of the electronic elements arranged in the electronic housing, and in particular to guarantee the sealing of the assembly against the penetration of a liquid or any other impurity. Furthermore, it is also desirable to limit production costs by limiting the number of assembly steps and storage costs by limiting the number of parts to be assembled.
[0006] Different solutions have been proposed to try to respond to these problems of lack of sealing.
[0007] In the configuration where the antennas are offset relative to the electronic card, that is to say the antenna region is no longer carried by the electronic card, The assembly therefore comprises two parts, a first part with the power printed circuit board and a second part with the antenna region produced on a second board. The two parts are generally interconnected by shielded cables. This solution results in a high production cost due to the greater number of parts required. In addition, the assembly formed by the two parts requires more space than in the case of a single box, and causes an integration problem. In addition, the additional parts lead to an increase in assembly time. Finally, the sealing problem is transferred to the connection between the two parts. This solution is therefore not satisfactory in terms of production cost optimization and in terms of sealing.
[0008] In order to overcome this drawback, it has been proposed to make an opening on the casing at the antenna region for the transmission and reception of signals. Thus, the housing is no longer split into two parts and comprises a single card on which the antennas are traced. However, since the antenna region is exposed to the external environment, it is necessary to implement a sealing solution to make the entire electronic housing waterproof, which consists of mounting a protective cap on the electronic card, covering the antenna region and the opening. A seal is then deposited at the interfaces between the edge of the opening and the cap to make the assembly waterproof. However, this solution is not entirely satisfactory, because it does not allow disassembly of the assembly, leading to an increase in the scrap rate and complicating recyclability.
[0009] There is therefore a need for a sealing solution compatible with all these problems. Summary
[0010] An aim of the present disclosure is to remedy the drawbacks of the prior art.
[0011] An aim of the present disclosure is to propose a solution which aims to ensure effective sealing, while limiting production costs and guaranteeing disassembly of the housing, in a restricted occupation volume so as not to disrupt its integration in applications, in particular applications in the automotive field.
[0012] To this end, a waterproof electronic antenna housing is proposed comprising: - a rigid chassis comprising a first opening positioned on one of the edges of the chassis; - a rigid hood comprising a second opening positioned on one of the edges of the hood; - an electronic card comprising an antenna region arranged near a edge of the electronic card, the card being mounted in the housing so that an upper face of the antenna region is oriented opposite the first opening of the chassis and a lower face of the antenna region is oriented opposite the second opening of the cover; - a cap configured to engage an edge of the electronic card to cover the antenna region and the first and second openings; - a seal overmolded on an external surface of the cap extending along the free edges of the cap so that when the cap and chassis are mounted on the electronic card, the seal is compressed against a surface of the chassis and the cap to seal the two openings.
[0013] According to one embodiment, the cap comprises an upper branch and a lower branch connected to each other by a transverse branch to form a U-shaped housing in which the antenna region is received, the upper branch covering a face of the antenna region oriented towards the chassis and the lower branch covering a face of the antenna region oriented towards the cover and the transverse branch covering a face of the edge of the electronic card.
[0014] The features set out in the following paragraphs may optionally be implemented. They may be implemented independently of one another or in combination with one another:
[0015] - the overmolded seal comprises a first seal strip which extends continuously along the free edge of the upper leg and a second sealing strip which extends continuously along the free edge of the lower leg and along the edge between the lower leg and the transverse leg.
[0016] - the cap comprises at least one projection formed on an internal face of the upper branch, and the electronic card comprises at least one associated hole intended to receive said at least one projection for holding the cap on the card.
[0017] - the cap comprises a centering rib formed on an internal face of the upper branch, and the electronic card includes an associated centering slot intended to receive the centering rib. The centering rib is not arranged in the plane of symmetry of the cap so as to provide orientation correction when positioning the cap on the electronic card.
[0018] - the cap comprises at least one stop element formed on an internal face of the upper branch, an edge of the electronic card coming to bear against the stop element when the cap is placed in position on the electronic card.
[0019] - the chassis comprises a first holding tab positioned in the first opening and the hood includes a second retaining tab positioned in the second opening, the retaining tabs extending from an edge of the opening perpendicular to the direction (F) of positioning the cap parallel to the direction of positioning (F) of the cap, and the cap comprises an associated groove configured so that when the cover and the chassis are mounted on the electronic card, the first and second holding tabs bear against a portion of the overmolded seal extending along the groove.
[0020] - the cap is made of rigid plastic material and the seal is made of thermoplastic elastomer. Brief description of the drawings
[0021] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which: Fig.l
[0022] [Fig.l] schematically illustrates an exploded perspective view of a sealed electronic antenna housing according to one embodiment; Fig. 2A
[0023] [Fig.2A] schematically illustrates a perspective view of the cap; Fig. 2B
[0024] [Fig.2B] schematically illustrates a profile view of the cap; Fig. 2C
[0025] [Fig.2C] schematically illustrates a top view of the cap; Fig. 2D
[0026] [Fig.2D] schematically illustrates a bottom view of the cap; Fig. 2E
[0027] [Fig.2E] schematically illustrates a view of an internal face of the cap; Fig. 3
[0028] [Fig.3] is an enlarged view of area A of [Fig.l]; Fig. 4
[0029] [Fig.4] schematically illustrates a sectional view of the sealed electronic antenna housing of [Fig.l]; Fig. 5A
[0030] [Fig.5A] schematically illustrates a step in the method of mounting the electronic housing of [Fig.l] in which the cap is in a position to engage on the electronic card; Fig. 5B
[0031] [Fig.5B] schematically illustrates a step in the method of mounting the electronic housing of [Fig.l] in which the cap is placed in position on the electronic card covering the antenna region; Fig. 5C
[0032] [Fig.5C] schematically illustrates a step in the method of mounting the electronic housing of [Fig.l] in which the cover and the chassis are fixed to the electronic board with the sealing gasket compressed against the cover and the chassis to seal the opening of the cover and the opening of the chassis; Fig. 6
[0033] [Fig.6] schematically illustrates a top view of an enlarged area (B) of the [Fig.5B] showing the cap mounted on the electronic board. Description of the embodiments
[0034] The drawings and the description below contain, for the most part, elements of a certain character. They may therefore not only serve to better understand the present disclosure, but also contribute to its definition, where appropriate.
[0035] Reference is now made to [Fig.l] which illustrates a sealed electronic box 1 according to one embodiment. The electronic box 1 comprises a rigid chassis 2, a rigid cover 3, an electronic card 4 on which antennas 9 are traced near an edge of the electronic card and a cap 5 provided with a sealing gasket 6.
[0036] The waterproof electronic box 1 may be, for example, a radio reception box located under the fins of a vehicle or a telematics and / or emergency call box which must meet high waterproofing criteria to ensure the integrity of the electronic card.
[0037] The chassis 2 and the cover 3 are assembled together to form a housing in which the electronic card 4 is mounted. The cover 3 is configured to be fixed to the chassis 2 and to the electronic card 4 so as to hold the electronic card in the housing. Thus, the cover 3 and the electronic card 4 comprise a plurality of fixing holes 11, 12 intended to receive screws 13 making it possible to fix the electronic card 4 and the cover 3 to the chassis 2.
[0038] It can be seen in [Fig.l] that the electronic card 4 is provided with an antenna region 9 for transmitting and receiving signals. The antenna region is formed near the edge of the electronic card.
[0039] The chassis 2 and the cover 3 are both rigid in order to guarantee good integrity of the electronic card 4. The chassis 2 and the cover 3 are preferably made of metallic material in order to guarantee the electromagnetic shielding of the electronic card and the heat dissipation of the components carried by the card. In order to allow the antennas to transmit and receive signals through the metal walls of the housing, the chassis 2 has a first opening 7 made on an edge of the chassis and the cover 3 has a second opening 8 made on an edge of the cover. The card 4 is mounted in the housing so that an upper face of the region antenna region 9 is oriented opposite the first opening 7 of the chassis 2 and a lower face of the antenna region 9 is oriented opposite the second opening 8 of the cover 3. Thus, the signals can be transmitted and received by the antennas.
[0040] In order to ensure the sealing of the electronic housing, the electronic housing 1 comprises a cap 5 configured to engage on an edge of the card in the direction of the thickness of the electronic card to cover the antenna region 9, the first opening 7 and the second opening 8. The cap 5, unlike the prior art, is provided with an overmolded seal 6 on an external surface of the cap extending along the free edges of the cap so that when the cover 3 and the chassis 2 are mounted on the electronic card 4, the seal 6 is compressed against a surface of the chassis 2 and the cover 3 to seal the two openings 7, 8, as illustrated in [Fig. 4]. Thus, it is no longer necessary to deposit a seal before or after assembly.In addition, the fact of directly overmolding the sealing gasket directly onto the cap allows the cap to be dismantled in the event of a failure of the electronic box, allowing the defective electronic card or any other electronic element to be replaced, for example. This reduces manufacturing costs and the scrap rate. The dismantling of the cap also simplifies the recycling process for antenna electronic boxes.
[0041] The cap 5 is made of a material suitable for allowing the signals to pass through. Preferably, the cap 5 is made of a rigid plastic material and the seal 6 which is overmolded onto the cap 5 is made of a thermoplastic elastomer. The seal is for example made of a thermoplastic material having a hardness of between 30 and 80 Shores A, preferably equal to 50 Shores A.
[0042] According to another advantage, the cap 5 is outside the envelope formed by the chassis and the cover, it is not subject to the risk of fire starting. Finally, the cap 5 being made of a rigid plastic material, it allows repeatable handling, allowing the automation of the assembly of the electronic box.
[0043] Figures 2A-2E illustrate in more detail the configuration of the cap 5 according to different views.
[0044] According to one embodiment, the cap 5 comprises an upper branch 51 and a lower branch 52 connected to each other by a transverse branch 53 to form a U-shaped housing 56. When the cap is placed in position on the electronic card, the antenna region 9 is received in the housing 56. In other words, the upper branch 51 covers a face of the electronic card provided with the antenna region oriented towards the chassis 2 and the lower branch 52 covers a face of the electronic card oriented towards the cover 3. Finally, the transverse branch 53 covers a face of the edge of the electronic card 4.
[0045] The cap is mounted on the electronic card by engaging it on the latter in the direction of the arrows F in figures 1 and 3. The width of the housing (L) is substantially greater than the thickness of the electronic card to facilitate mounting.
[0046] Advantageously and as illustrated in [Fig.l], the chassis 2 comprises a first holding tab 21 positioned in the first opening 7 and the cover 3 comprises a second holding tab 31 positioned in the second opening 8. The two holding tabs 21, 31 extend from an edge of the opening which is perpendicular to the direction (F) of positioning the cap parallel to the direction of positioning (F) of the cap. Thus, when the cover 3 and the chassis 2 are mounted on the electronic card 4, the first holding tab 21 bears against a face of the upper branch 51 of the cap 5 and the second holding tab 31 bears against a face of the lower branch 52 of the cap 5. Thus, the presence of these two tabs makes it possible to improve the holding in position of the cap on the electronic card and to limit the stress of this card during handling.In the case of a metal cover and chassis, the legs 21 and 31 allow electromagnetic separation of the antennas.
[0047] It can be seen in [Fig.l] that the first and second holding tabs 21, 31 are positioned substantially in the center of the first and second openings. The cap 5 also comprises an upper groove 57 in the upper branch 51 and a lower groove 57 in the lower branch 52. The two grooves have a U shape which extend parallel to the direction of positioning (F) of the cap. They are positioned substantially in the center of the two branches and positioned opposite each other. Thus, when the cap 5 is placed in position on the electronic card 4, and when the cover 3 and the chassis 2 are mounted on the electronic card 4, the first and second holding tabs 21, 31 bear against the free edges of the two grooves, covering the two grooves as illustrated in [Fig.5C].
[0048] It can be seen in [Fig.2C] that the overmolded seal 6 comprises a first seal strip 61 which extends continuously along the free edge of the upper branch.
[0049] It can be seen in [Fig.2D] that the overmolded seal 6 comprises a second seal strip 62 which extends continuously along the free edge of the lower branch. Advantageously, the second seal strip 62 extends continuously along the free edge of the lower branch and along the edge between the lower branch 52 and the transverse branch 53.
[0050] Thus, when the cover and the chassis are mounted on the electronic card, the first sealing strip 61 is compressed against the edge of the first opening 7 and the first holding tab 21, the second sealing strip 62 is compressed against the edge of the second opening 8 and the second holding tab 31. The presence of these sealing strips makes it possible to make the electronic housing watertight.
[0051] It will be noted that having a seal along the edge between the lower branch 52 and the transverse branch 53 makes it possible to prevent liquid from penetrating into the gap between the transverse branch and the inner face of the cover. In [Fig. 4], it can be seen that when the cover and the chassis are mounted on the electronic card, the seal strip 61 of the upper branch is compressed against the chassis and the first extension tab, the second seal strip 62 of the lower branch is compressed against the cover and the second extension tab. The seal strips thus form a protective barrier to prevent the penetration of liquid into the openings made on the cover and the chassis. In [Fig.4], we see that the water drops arriving on the housing naturally follow a flow path represented by an arrow along the external faces of the cap and are prevented from penetrating inside the U-shaped housing where the antenna region is located.
[0052] Advantageously and as illustrated in [Fig. 3], each sealing strip comprises two extensions 64, 65 which extend in the extension of the transverse arm 53, on either side of the transverse branch. The electronic card comprises two corresponding hollows 47, 48 in which the extensions 64, 65 are housed when the cap engages on the electronic card. The presence of these two extensions contributes to the sealing of the electronic housing.
[0053] Advantageously, the thermoplastic material selected to produce the overmolded seal is preferably chosen in a color that allows it to contrast with that of the rigid material chosen to produce the cap. This solution makes it easier to verify the integrity of the assembly by visual inspection.
[0054] Advantageously, the thermoplastic material is selected according to the following additional criteria: - having a chemical adhesion compatible with the cap material; - having a dielectric and wave absorption property compatible with the operating frequency range of the antennas of the electronic box, typically that of the Bluetooth, wifi, GPS functions but also the AM and FM bands; - having good temperature resistance, typically from -40 to 105°C.
[0055] According to a particularly advantageous embodiment, the cap is provided with elements which make it easier to mount the cap on the electronic card and to improve the retention of the cap on the electronic card.
[0056] In the example illustrated in [Fig.2E] and [Fig.3], the cap 5 comprises two clipping projections 54, 55 formed on an internal face of the upper branch 5 and the card 4 comprises two associated holes 41, 42 formed near the antenna region 9. Each projection is intended to be inserted into a corresponding hole when the cap 5 is placed in position on the electronic card 4. This combination between the projection and the hole makes it possible to hold the cap on the electronic card during assembly. It will be noted that the use of the clip-on projections makes it easier to remove the cap compared to the use of screw fixing means.
[0057] According to the embodiment illustrated in [Fig.2E], the clipping projections 55, 54 are formed close to the free edge of the internal face of the upper branch, on the side opposite the transverse branch.
[0058] Advantageously, it will be noted that the projection has a truncated cone shape (visible in [Fig.2B]) whose edges form inclined ramp surfaces. Thus, when engaging the cap on the electronic card, the projections can be easily inserted into the associated holes without exerting pressure on the electronic card.
[0059] Advantageously, the cap 5 further comprises a centering rib 59 formed on an internal face of the upper branch 5 and the card 4 comprises an associated centering slot 43 formed on the edge of the antenna region 9. The centering slot 43 is intended to receive the centering rib 59 when the cap engages on the electronic card, thus helping to center the card relative to the antenna region.
[0060] According to the embodiment illustrated in [Fig.2E], the centering rib 59 and the slot 43 have an elongated shape oriented in the direction (F) of positioning the cap on the electronic card.
[0061] Advantageously, the centering rib 59 is not arranged in the plane of symmetry of the cap 5 so as to provide orientation correction when the cap is positioned on the electronic card.
[0062] As illustrated in [Fig. 3], it will be noted that the slot 43 has a slightly restricted opening 44 to locally manage the clearance with the centering rib 59, and it is flared outwards at its end, as indicated at 45, to allow easy insertion of the centering rib 59 into the slot 43.
[0063] As illustrated in [Fig.2E], the cap 5 further comprises two stop elements 60 formed on an internal face of the upper branch. These stop elements serve as a bearing surface when the cap is mounted on the electronic card. Thus, when the cap is placed in position on the card, an edge of the electronic card bears against the stop elements. The stop elements have the function of marking the stop of the engagement of the cap on the electronic card in order to avoid a risk of pressure being applied to the card during assembly.
[0064] With reference to Figures 5A-5C, the method of mounting the electronic box 1 is described below and comprises the following steps.
[0065] The chassis 2, the cover 3, the electronic card 4 provided with the antenna region 9 and the cap 5 with the overmolded seal 6 directly on the external surfaces of the cap are provided.
[0066] The cap 5 is centered relative to the antenna region 9 by virtue of the combination of the centering rib 59 and the centering slot 43. The cap 5 is then engaged on the electronic card 4 in the direction of the arrow F. In this movement, the arms of the cap 5 are slightly separated by the edge of the electronic card due to the slightly rounded shape of the ends of the arms and the projections 54, 55 are then inserted into the associated holes 41, 42 present on the electronic card 4 to hold the cap 5 on the electronic card 4.
[0067] The antenna region 9 is thus protected by the upper branch and the lower branch of the cap as illustrated in [Fig.5B].
[0068] The chassis 2 is placed against one face of the electronic card 4 and the cover 3 against an opposite face of the electronic card so that the antenna region 9 faces the opening 7 of the chassis and the opposite face of the antenna region faces the opening 8 of the cover.
[0069] The cover 3 is fixed to the electronic card 4 by fixing screws 13.
[0070] The cover 3 is fixed to the chassis 2 by fixing screws 13.
[0071] The various steps may be carried out in the order described here or, for some, in a different order. Similarly, the steps may be carried out sequentially or, for some, simultaneously.
[0072] According to another exemplary embodiment, the steps of fixing the cover on the electronic card and of fixing the cover on the chassis can be carried out simultaneously.
[0073] It will be noted that, since the sealing gasket 6 is directly overmolded onto the cap, the number of steps is reduced by eliminating the step of depositing the sealing gasket and therefore the costs associated with the production and assembly of the electronic housing.
[0074] The solution of the present disclosure makes it possible to address problems of sealing electronic boxes whose chassis and cover are made of metallic material and which include antennas.
[0075] The electronic box of the present invention has the following technical advantages: - The electronic box can be dismantled thanks to the presence of the overmolded seal on the cap, thus allowing the box to be repaired and the box elements to be recycled. - the antennas remain on the main electronic board, there is no need to move the antennas outside the main electronic board. The solution of the present invention thus makes it possible to reduce production costs. - it is no longer necessary to implement sealant deposition processes, thus reducing machine cost and production time. - thanks to the architecture of the cap, it is possible to implement a shielding partition 16 to the chassis and the cover by surrounding the antenna region as illustrated in [Fig.6], thus making it possible to separate the antennas from the rest of the electronic card. The antennas are therefore no longer disturbed by other sources of electromagnetic radiation on the electronic card. Industrial application
[0076] The electronic box according to the invention is particularly suitable for equipping the connected devices of a motor vehicle. It can also equip all connected products which are equipped with internal antennas housed in a box whose casing is metallic.
Claims
Claims
1. Waterproof electronic antenna housing (1) comprising: - a rigid chassis (2) having a first opening (7) positioned on one of the edges of the chassis; - a rigid cover (3) having a second opening (8) positioned on one of the edges of the cover; - an electronic card (4) having an antenna region (9) arranged close to an edge of the electronic card, the card being mounted in the housing so that an upper face of the antenna region is oriented opposite the first opening (7) of the chassis and a lower face of the antenna region (9) is oriented opposite the second opening (8) of the cover; - a cap (5) configured to engage on an edge of the electronic card (4) in order to cover the antenna region and the first and second openings;- a seal (6) overmolded on an external surface of the cap extending along the free edges of the cap (5) so that when the cover (3) and the chassis (2) are mounted on the electronic card (4), the seal (6) is compressed against a surface of the chassis and the cover to seal the two openings.;
2. Housing according to claim 1, in which the cap (5) comprises an upper branch (51) and a lower branch (52) connected to each other by a transverse branch (53) to form a U-shaped housing (56) in which the antenna region (9) is received, the upper branch covering a face of the antenna region oriented towards the chassis (2) and the lower branch covering a face of the antenna region oriented towards the cover (3) and the transverse branch covering a face of the edge of the electronic card (4).
3. A housing according to claim 2, wherein the overmolded seal (6) comprises a first seal strip (61) which extends continuously along the free edge of the upper leg and a second seal strip (62) which extends continuously along the free edge of the lower leg and along the edge between the lower leg (52) and the transverse leg (53).
4. Housing according to one of claims 2 to 3, in which the cap (5) comprises at least one projection (54, 55) formed on an internal face of the upper branch, and the electronic card (4) comprises at least one associated hole (41, 42) intended to receive said at least one projection for holding the cap on the card.
5. Housing according to one of claims 2 to 4, in which the cap (5) comprises a centering rib (59) formed on an internal face of the upper branch, and the electronic card (4) comprises an associated centering slot (43) intended to receive the centering rib.
6. Housing according to claim 5, in which the centering rib (59) is not arranged in the plane of symmetry of the cap (5) so as to provide orientation correction when positioning the cap on the electronic card.
7. Housing according to one of claims 2 to 6, in which the cap (5) comprises at least one stop element (60, 61) formed on an internal face of the upper branch, an edge of the electronic card coming to bear against the stop element when the cap is placed in position on the electronic card.
8. Housing according to one of the preceding claims, wherein the chassis (2) comprises a first holding tab (21) positioned in the first opening (7) and the cover (3) comprises a second holding tab (31) positioned in the second opening (8), the holding tabs extending from an edge of the opening perpendicular to the direction (F) of positioning the cap parallel to the direction of positioning (F) of the cap, and the cap comprises an associated groove (57) configured so that when the cover (3) and the chassis (2) are mounted on the electronic card (4), the first and second holding tabs bear against a portion of the overmolded seal extending along the groove (57).
9. Housing according to one of the preceding claims, in which the cap (5) is made of rigid plastic material and the sealing gasket (6) is made of thermoplastic elastomer.