EP3625850B1

EP3625850B1 - Antenna device

Info

Publication number: EP3625850B1
Application number: EP19727736.1A
Authority: EP
Inventors: Massimo Calearo Ciman; Marco De Gregorio; Matteo FRANZAN; Roberto Mestriner; Luigi CORRA'; Oscar DINON; Reiko OKUYAMA
Original assignee: Calearo Antenne SpA
Current assignee: Calearo Antenne SpA
Priority date: 2018-06-15
Filing date: 2019-04-30
Publication date: 2023-06-07
Anticipated expiration: 2039-04-30
Also published as: EP3625850A1; WO2019239231A1

Description

TECHNICAL FIELD

The present invention relates to an antenna device.
Preferably, the present invention relates to an antenna device installable on a vehicle, preferably a motorized vehicle, such as, for example, a motor-vehicle or any similar vehicle, to which the ensuing description will make explicit reference, without, thereby, any loss of generality.

BACKGROUND ART

Antenna devices with a "shark-fin" shape for vehicles are known, which comprise: a support base, an electronic antenna board mounted on the support base, an inner casing coupled to the support base to form a closed space with the latter that contains the electronic antenna board, and an outer casing coupled to the inner casing so as cover it. There are many types of mechanisms for connecting the outer casing on the above-described antenna devices.
For example, patents US 7 580 002 B2 and US 7 429 958 B2 both describe an antenna device, in which the outer casing is fitted with a series of fastening clips which, in use, couple with respective coupling portions made in the inner casing to stably couple the outer casing to the inner casing.
Patent application US 2017/0104264 A1 describes a different structure from that described above, in which the outer casing is fitted with a series of lower internal fastening clips that engage through openings bore in the inner casing and have the lower ends coupled with respective coupling portions that extend inside the inner casing.
The above-described solutions are subject to the following technical problems.
The antenna casings, by being made of plastic materials, are subjected to dimensional variations due to environmental thermal stress. As time passes, the dimensional variations in the casings damage the sealing areas, i.e. the seals and/or clips, weakening the hermetic seal of the antenna device and triggering the risk of water infiltration that can cause damage to antenna electronics. This condition emerges in quite a significant manner when the antenna device is subjected to thermal shock. In fact, in this case, the thermal dilation, especially of the outer casing, can be significant, such as to provoke a dimensional variation in the clips sufficient to disengage them from the inner casing, thereby causing the accidental decoupling of the outer casing.
In addition, the mechanical fastening of the outer casing on the inner casing results in vibrations propagating from the inner casing to the outer one, which in certain conditions, can cause, for example, conditions of resonance, cause noise phenomena that can degrade the performance of the antenna device.
An antenna device is also described in WO 2017 / 141 635 A1 , WO 2018/105235 A1 and EP 3 093 920 A1 .

DISCLOSURE OF INVENTION

The applicant has carried out an in-depth study on antenna devices, with the objective of identifying a simple and inexpensive solution that enables overcoming the above-described technical problems.
The subject of the present invention is therefore that of providing a solution that enables achieving the aforesaid objective.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described with reference to the accompanying drawings, which illustrate a non-limitative embodiment, in which:

Figure 1 is an exploded view of an antenna device made according to the principles of the present invention;
Figure 2 shows a lower part, with parts removed for clarity, of the antenna device shown in Figure 1;
Figure 3 is a section on a vertical plane III-III, with parts on an enlarged scale, of the antenna device shown in Figure 1;
Figure 4 is a section on a vertical plane IV-IV, with parts on an enlarged scale, of the antenna device shown in Figure 1, without the outer casing;
Figure 5 is a front elevation view, with parts in section and with parts on an enlarged scale, of the antenna device shown in Figure 1;
Figure 6 is an exploded view of the support base and the mechanical fastening connector of the antenna device shown in Figure 1;
Figures 7, 8 are two perspective views from above of the support base and the mechanical fastening connector of the antenna device shown in Figure 1;
Figure 9 is a perspective view from below of the support base and the mechanical fastening connector of the antenna device shown in Figure 1.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will now be described in detail, with reference to the accompanying figures, to allow an expert in the field to embody it and use it. Various modifications to the described embodiments will become immediately obvious to experts in the field, and the generic principles described herein can be applied to other embodiments and applications without, thereby, departing from the scope of the present invention, which is as defined in the appended claims. Therefore, the present invention should not be considered as limited to the embodiments described and shown herein, but is to be accorded the widest scope consistent with the appended claims.
Referring to Figure 1 and to the remaining accompanying figures, reference numeral 1 indicates, as a whole, an antenna device made according to the present invention. The antenna device 1 is structured so that it can be mounted on a vehicle (not shown), preferably a motor-vehicle or similar, preferably on the roof of the vehicle's passenger compartment.
As shown in the accompanying figures, the antenna device 1 comprises: a support base 2, an inner casing 3, an electronic antenna device 4, an anchorage ring 5, and an outer casing 6 that covers the inner casing 3 and is stably connected to the anchorage ring 5.
According to a preferred embodiment shown in Figure 1, the inner casing 3 and outer casing 6 are rigid and can be made of a material through which radio waves can pass, for example, based on polymeric materials, plastics or any similar material, such as synthetic resins, designed for the aforementioned purpose. The inner casing 3 and/or outer casing 6 can be conveniently shaped approximately like a shark fin. Nevertheless, it is understood that the present invention is not limited to an inner casing 3 and/or outer casing 6 shaped more or less like a shark fin, but can also be extended/applied to antenna devices 1 provided with casings of any shape, preferably, but not necessarily, shapes with aerodynamic profiles designed for motor-vehicles.
With regard to the electronic antenna device 4, this can be arranged in the internal housing space of the inner casing 3 and is configured so as to at least receive/provide an antenna signal. According to a preferred embodiment shown in Figure 1, the electronic antenna device 4 can comprise at least one printed circuit board (PCB) preferably arranged resting on the upper surface of the support base 2 and that, preferably, can be fixed to the latter by fastening means, for example, screws or similar systems. According to a preferred embodiment shown in Figure 1, the printed circuit board (PCB) of the electronic antenna device 4 can have a substantially rectangular shape and is formed by a series of circuits, preferably associated with respective, mutually different transmission/reception frequency bands, for example, a DAB band, an FM/AM band and/or similar.
The electronic antenna device 4 can be configured to perform analogue and/or digital processing of the antenna signal. To this end, the electronic antenna device 4 can comprise at least one amplifier circuit designed to amplify the antenna signal. However, the printed circuit board of the electronic antenna device 4 could additionally or alternatively comprise other antenna signal processing and treatment circuits, such as, for example, a filter circuit and/or an equalizer circuit and/or a modulation and demodulation circuit. The analogue/digital processing procedures performed on an antenna signal through the electronic circuits are known and, not being the main object of the present invention, will not be described any further.
Referring to Figure 1, the antenna device 1 also comprises a ground ring or frame 33 made of an electrically conductive material that is interposed between the lower surface of said printed circuit board of the electronic antenna device 4 and, at least partially, the upper surface 2a of the support base 2, and is structured to electrically connect a plurality of terminals, preferably ground terminals (not shown) of the electronic antenna device 4, to a common reference potential, preferably a ground potential. In the example shown, the frame 33 is shaped so as to have geometry approximately corresponding to the outer rectangular peripheral edge of the printed circuit board and is interposed between the latter and the support base 2. The frame 33 can be provided with through holes that house screws that fix the frame 33 to the support base 2. The frame 33 can also have a central transversal portion 33a that can be electrically coupled to the connector 15 so as to be, in use, electrically connected to the roof of the vehicle, i.e. to the ground potential. To this end, holes that receive the vertical connection pins on the connector 15 can be made in the central transversal portion 33a. To assemble the antenna device on the vehicle prior to the fixing operations, an upper plate (not shown) provided with lower anchorage clips that snap-fit into openings bore in the support base 2 can be used. The frame 33 conveniently forms a ground plane that allows positioning the ground contacts/terminals on the printed circuit board of the electronic antenna device 4 in an optimal and not geometrically binding manner.
According to a preferred embodiment shown in Figures 2, 3 and 4, the inner casing 3 has its lower peripheral edge 7 delimiting the lower opening, which is arranged resting on the upper surface 2a of the support base 2.
In the example shown in Figures 1 and 4, the inner casing 3 has preferably flat and horizontal lugs 8 protruding along the lower peripheral edge 7, each of which is arranged above an upper end of a preferably tubular and cylindrical support hub 9, which extends approximately vertically from the upper surface 2a of the support base 2.
Regarding the anchorage ring 5, this is removable, i.e. it is formed by an annular body independent of and separable from the support base 2. The anchorage ring 5 preferably has a shape substantially similar to that of the lower peripheral edge 7.
According to a preferred embodiment, the anchorage ring 5 is sized so that it can be fitted (from above) onto the inner casing 3, so as to be arranged resting on the protruding lugs 8 abutting on the lower peripheral edge 7. Preferably, the anchorage ring 5 can have a substantially rectangular cross-section and have, when fitted on the inner casing 3, its vertical inner side substantially in abutment against an outer surface portion of the inner casing 3 immediately above the lower peripheral edge 7. The anchorage ring 5 is arranged resting on the protruding lugs so as surround the outer surface of the inner casing 3 at the lower peripheral edge 7.
According to a preferred embodiment, the anchorage ring 5 is rigid. Preferably, the anchorage ring 5 can be conveniently made of a metal material. Nevertheless, it is understood that the present invention is not limited to having an anchorage ring made of a metal material; on the contrary, according to a different embodiment, the anchorage ring could be made of a rigid polymeric material.
According to a preferred embodiment, the anchorage ring 5 has a plurality of lateral fastening lugs 10 that are arranged above the protruding lugs 8 of the lower peripheral edge 7.
The antenna device 1 can also comprise fastening members 11 that connect the anchorage ring 5 and the inner casing 3 to the support base 2. According to a preferred embodiment shown in the accompanying figures, the fastening members 11 comprise screws, the shanks/threads of which are engaged in the through holes bore in the lugs 8 and 10 and have the ends centrally screwed/ fastened into the support hubs 9. The heads of the screws are arranged in abutment against the lugs 8 to fasten the anchorage ring 5 to the support base 2. The fastening of the anchorage ring 5 thus entraps the lugs 8 of the lower peripheral edge 7 and causes the inner casing 3 to be anchored within the support base 2.
Referring to accompanying figures, the outer casing 6 is fitted with a series of connection portions 12 that extend from the outer casing 6 towards the underlying support base 2, and are designed to connect to the anchorage ring 5 when the outer casing 6 is inserted/fitted on the inner casing 3.
According to a preferred embodiment shown in Figure 3, the connection portions 12 extend from the inner surface 6a of the outer casing 6 towards the support base 2 and have claw-like lower ends 13 that are anchored to the anchorage ring 5, preferably to the outer edge thereof. According to the implementation example shown in Figure 3, the connection portions 12 comprise clips shaped so that when the outer casing 6 is fitted on the inner casing 3, the clips create a snap-fit connection with the anchorage ring 5. Preferably, the connection portions 12 are spaced out from each other so as to connect to respective, preferably straight lengths of the anchorage ring 5 that join the protruding lugs 1C.
According to a preferred embodiment shown in Figure 3, the connection portions 12 are shaped so as have lower ends 13 that at least partially engage respective through openings 14 bore in the support base 2. The through openings 14 are conveniently designed to allow the clips to be decoupled from the anchorage ring 5, for example, by means of a tool, a screwdriver or similar.
Referring to Figures 1, 3 and 6, the antenna device 1 further comprises a mechanical connector 15 for fastening the support base 2 of the antenna device 1 to the vehicle. Preferably, the support base 2 comprises a rigid main plate-shaped body 19 made of a polymeric material, preferably a plastic material.
According to a possible embodiment shown in Figure 6, the mechanical connector 15 comprises a preferably flat, more or less horizontal plaque or plate 16, and an opportunely shaped mechanical connection element 18, for example, tubular with a circular section, which projects in a cantilever fashion from the lower surface of the flat plate 16, more or less perpendicularly to the latter, and is designed to engage, in use, a through opening (not shown) bore in the body of the vehicle, so that it can be stably connected to the latter and thus fix the antenna device 1 to the vehicle via internal fastening means (not shown).
Preferably, the flat plate 16 is made of a metal material, for example, an alloy with a zinc base metal and aluminium, magnesium and copper (ZAMA). Preferably, the plate 16 is at least partially embedded in the plastic material of the main plate-shaped body 19 so as to form a single body therewith. Conveniently, the rigid main plate-shaped body 19 is overmoulded on the plate 16 of the mechanical connector 15 so as to form a single body (monobloc) therewith. Conveniently, the rigid main plate-shaped body 19 is overmoulded on the plate 16 of the mechanical connector 15 so as trap just the peripheral edge of the latter and leave the remaining central portion of the plate 16 uncovered.
The applicant has found that the overmoulding of the main plate-shaped body 19 on the plate 16 of the mechanical connector 15 can be carried out through a moulding process with over-injection of the polymeric material on the plate. The process can include, for example, positioning the plate 16 in the closed moulding hob of a mould (not shown), modelled according to the shape of the main plate-shaped body 19, and injecting the polymeric material in the liquid state into the hob so as to at least partially embed the peripheral edge of the plate 16 in the polymeric material of the main plate-shaped body 19.
According to a preferred embodiment shown in Figures 6-9, the support base 2 is at least partially covered by a sealing layer 20 made of an elastomeric material, for example, a rubber-based one.
Referring to Figure 6, there can be a vertical inner border or frame 21 on the upper surface 2a of the support base, more or less rectangular and made of a rigid polymer material, and on the top of which the printed circuit board of the electronic antenna device 4 can be laid. Preferably, the sealing layer 20 can extend over a portion of the area of the upper surface 2a external to the inner frame 21. Preferably, referring to Figures 3 and 4, the lower peripheral edge 7 of the inner casing 3 is conveniently arranged in abutment against the sealing layer 20 so as to create a hermetically sealed closure between the inner casing 3 and the upper surface 2a of the support base 2. Preferably the sealing layer 20 has openings 28 made in correspondence to the underlying openings 14 designed to receive the connection portions 12.
Preferably, the sealing layer 20 made of an elastomeric material is overmoulded on the upper surface 2a of the main plate-shaped body 19 so as to form a single body therewith. The applicant has found that the overmoulding of the sealing layer 20 on the rigid main plate-shaped body 19 can be carried out through a moulding process with over-injection of the elastomeric material. The process can include positioning the main plate-shaped body 19 in the closed moulding hob of a mould, modelled according to the shape of the sealing layer 20, and injecting the elastomeric material in the liquid state into the hob so as to deposit it on the upper surface 2a of the main plate-shaped body 19 to be covered.
Preferably, the antenna device 1 also comprises a lower annular portion 22 made of an elastomeric material that is conveniently overmoulded on the lower surface 2b of the rigid main plate-shaped body 19 and is designed to be arranged, in use, between the latter and the surface of the vehicle body. Preferably, the lower annular portion 22 is arranged at and surrounding the outer peripheral edge of the main plate-shaped body 19.
In the example shown in Figures 3, 4 and 9, the lower annular portion 22 made of an elastomeric material is part of the sealing layer 20, i.e. it forms a single body with the latter. The applicant has found that the overmoulding of the sealing layer 20 and the annular portion 22 on the rigid main plate-shaped body 19 can actually be carried out through a single moulding process with over-injection of the elastomeric material. The process can include positioning the main plate-shaped body 19 in the closed moulding hob of a mould, modelled according to the shape of the sealing layer 20 and the annular portion 22, and injecting the elastomeric material in the liquid state into the hob so as to deposit it on the upper surface 2a of the main plate-shaped body 19 to be covered and partly on the lower surface 2b so as to create the annular portion 22.
The above-described antenna device has the following advantages.
The metal anchorage ring reduces dimensional variations of the two casings due to thermal expansion, thereby reducing wear on the underlying elastomeric sealing layer, consequently ensuring a more effective and longer-lasting hermetically sealed closure.
The anchorage ring, if made of metal, considerably dampens the propagation of vibrations between the outer casing, the inner casing and the support base, and consequently enables achieving a reduction in noise phenomena.
Furthermore, laboratory tests carried out by the applicant have demonstrated that the anchorage ring made of metal tends to remain dimensionally stable, even when subjected to thermal shocks, and is therefore able to ensure effective anchorage of the outer casing.
The connection of the support base and the metal plate of the connector obtained via the overmoulding processes of the polymeric material and elastomeric material enables, on one hand, to lighten the antenna device and, on the other, to reduce the effects of galvanic corrosion between parts due to atmospheric agents. Moreover, this solution effectively increases the manufacturing versatility of the antenna device, as it makes it possible to easily adapt the support base to any type of mechanical fastening connector, for example fast lock or nut lock.
The overmoulded elastomeric layer is particularly advantageous as it creates an annular waterproof seal. Instead, with regard to the lower elastomeric annular portion, this acts both as an aesthetically appreciable sealing, and as a dust guard between the roof of the vehicle and the support base of the antenna. The excess rubber of the annular portion in the areas further away from the point of mechanical connection with the roof makes the antenna device better match the curvature of the roof, completely adhering to it.
Finally, it is clear that modifications and variants can be made regarding the antenna device described and shown herein without, thereby, departing from the scope of the present invention defined by the appended claims.

Claims

An antenna device (1) for a vehicle, comprising:
a support base (2) designed to be arranged resting on the vehicle body,

an inner casing (3) arranged on said support base (2), electronic antenna means (4) arranged within said inner casing (3),

an anchorage ring (5) made of a rigid material, which is arranged resting on the upper surface of the support base (2), extends outside of the inner casing (3), and is connected to the support base (2) via mechanical fastening members (11), and

an outer casing (6) that is provided with connection portions (12) that extend from said outer casing (6) towards said support base (2), and are configured to connect to said anchorage ring (5) when the outer casing (6) is inserted on said inner casing (3) to cover it.
The antenna device according to claim 1, wherein the inner casing (3) has lateral lugs (8) protruding from the outer surface of its lower peripheral edge (7) that are trapped between the anchorage ring (5) and said support base (2).
The antenna device according to claim 2, wherein the anchorage ring (5) is provided with a series of lateral lugs (10), which are arranged resting on the respective underlying lateral lugs (8) of the inner casing (3) and are fixed to the latter via said mechanical fastening members (11); connection portions (12) of said outer casing (6) are coupled to respective straight lengths of the anchorage ring (5) comprised between said lateral lugs (10).
The antenna device according to any one of the preceding claims, wherein said support base (2) further comprises through openings (14), said openings being partially engaged by said connection portions (12) and are designed to allow, in use, the disengagement of the connection portions (12) from the anchorage ring (5).
The antenna device according to any one of the preceding claims, comprising a mechanical fastening connector (15) designed to fix the antenna device to said vehicle; the mechanical fastening connector (15) comprising a flat plate (16) made of metal material; said support base (2) comprising a rigid plate-shaped body (19) made of polymeric material; said flat plate (16) being at least partially embedded in the plastic material of said plate-shaped body (19) so as to form a single body with said plate-shaped body.
The antenna device according to claim 5, wherein said rigid plate-shaped body (19) is overmoulded on said flat plate (16) of said mechanical fastening connector (15), thus forming a single body with said flat plate of said mechanical fastening connector.
The antenna device according to claim 5 or 6, wherein said support base (2) is at least partially coated with a sealing layer (20) made of elastomeric material; the lower peripheral edge (7) of said inner casing (3) being arranged in abutment on said sealing layer (20) so as to achieve a hermetically sealed closure with said support base (2).
The antenna device according to claim 7, wherein said sealing layer (20) made of elastomeric material is overmoulded on at least the upper surface of said plate-shaped body (19) so as to form a single body with said plate-shaped body.
The antenna device according to any one of claims 5 to 8, comprising an annular portion (22) made of elastomeric material that is overmoulded on the lower surface of the rigid plate-shaped body (19) and is designed to be arranged between said plate-shaped body and the surface of the vehicle.
The antenna device according to claims 8 and 9, wherein said annular portion (22) made of elastomeric material is included in said sealing layer (20).
The antenna device according to any one of claims 5 to 10, wherein said electronic antenna means (4) comprise an electronic board; said antenna device further comprising a ground frame (33) made of electrically conductive material that is interposed between said electronic board and said support base (2) so as to connect one or more ground terminals of said electronic board to said mechanical fastening connector (15).
The antenna device according to any one of the preceding claims, wherein said anchorage ring (5) is made of a metal material or rigid polymeric material.
The antenna device according to any one of the preceding claims, wherein said anchorage ring (5) has a substantially rectangular cross-section and has, when fitted on the inner casing (3), its vertical inner side substantially in abutment against an outer surface portion of the inner casing (3).
The antenna device according to any one of the preceding claims, wherein said connection portions (12) comprise clips shaped so that when the outer casing (6) is fitted on the inner casing (3), the clips create a snap-fit connection with said anchorage ring (5).