JP6139295B2 - Automotive antenna - Google Patents

Description

  The present invention relates to a waterproof structure for an in-vehicle antenna used for transmitting / receiving radio waves in a cellular phone band, for example.

  In recent years, antennas for transmitting and receiving radio waves in the cellular phone band have been installed inside the bumpers before and after the vehicle. The vehicle-mounted antenna provided inside the bumper is required to have a waterproof structure because it is affected by wind and rain.

  For this reason, conventionally, as described in Patent Documents 1 and 2 below, it has been proposed to resin mold so as to cover the antenna element, the circuit board, the electronic components mounted thereon, and the connection end of the cable. Yes.

JP 2010-41625 A JP-A-9-148833

  The conventional structure in which the entire antenna element is covered with a resin mold together with a circuit board or the like requires an outer shape and a mold for insert molding.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a vehicle-mounted antenna that achieves waterproofing with a simple and inexpensive structure.

  One embodiment of the present invention is a vehicle-mounted antenna. The vehicle-mounted antenna is surrounded by an antenna element, a bracket, a first insulator part and a second insulator part that sandwich the antenna element and the bracket, and the first and second insulator parts. A printed circuit board disposed in the internal space, an external output portion partially disposed in the internal space, and a sealing material filled in the internal space.

  In the above aspect, the antenna element and the bracket arranged on one side of the first insulator component are insulated from each other by a step portion of the first insulator component and positioned at a predetermined interval, and the first It is preferable that the contact surface in contact with the second insulator component formed by the insulator component, the antenna element, and the bracket is flat.

  In the above aspect, the width of the mounting portion of the antenna element and the bracket to the first insulator component may be equal to the width of the first insulator component.

  In the aspect, it is preferable that the printed circuit board is provided with an interval with respect to the first insulator component.

  In the above aspect, the external output unit may be a connector attached to the printed circuit board, and an external connection portion of the connector may be exposed to the opening side of the internal space.

  In the above aspect, the first insulator component is a base in contact with the antenna element and the back side of the bracket, and the second insulator component is in contact with the antenna element and the bracket in front of the base. The base and the case may cover only a part of the antenna element and the bracket.

  It should be noted that any combination of the above-described constituent elements, and those obtained by converting the expression of the present invention between methods and systems are also effective as aspects of the present invention.

  According to the vehicle-mounted antenna according to the present invention, the internal space in which the antenna element and the bracket are sandwiched between the first and second insulator parts, surrounded by the first and second insulator parts, and the printed circuit board is disposed. It is only necessary to fill the sealing material with water, and since the waterproofing is performed by filling the sealing material once, the waterproofing can be realized with a simple and inexpensive structure.

1 is an exploded perspective view of a vehicle-mounted antenna according to the present invention as seen from the front. The perspective view similarly seen from the front. The perspective view similarly seen from the back. The front view of embodiment. The rear view. The left side view. The right side view. FIG. The bottom view. AA sectional drawing of FIG. BB sectional drawing. CC sectional drawing. DD sectional drawing. EE sectional drawing. FIG. 3 is an exploded perspective view showing the assembly procedure of the embodiment; FIG. 3 is an exploded perspective view showing the assembly procedure of the embodiment, part 2; FIG. 6 is an exploded perspective view showing the assembly procedure of the embodiment, part 3;

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or equivalent component, member, process, etc. which are shown by each drawing, and the overlapping description is abbreviate | omitted suitably. In addition, the embodiments do not limit the invention but are exemplifications, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

  As shown in FIGS. 1 to 17, the on-vehicle antenna includes an antenna element 1 made of a conductive metal plate, a bracket 10 made of a conductive metal plate, and a first insulator part that sandwiches the antenna element 1 and the bracket 10. Base 20 and case 30 as the second insulator component, printed circuit board 40 disposed in internal space P surrounded by base 20 and case 30, and external output portion partially disposed in internal space P As a coaxial connector 50.

  The base 20 is made of resin, and the boss 21 for positioning the antenna element and the screw hole 22 for mounting on the surface S1 in contact with the back surface of the antenna element 1 are aligned with the surface S2 in contact with the mounting portion 31 of the case 30. A boss 24 for bracket alignment and a screw hole 25 for attachment are formed on a surface S3 where the boss 23 for contact is in contact with the bent portion 11 of the bracket 10. Further, step portions 26 a and 26 b that are in contact with one side of the antenna element 1 are formed on the base 20. Similarly, step portions 27 a and 27 b that are in contact with one side of the bent portion 11 of the bracket 10 are formed. These step portions 26 a and 27 a are provided for electrical insulation between the antenna element 1 and the bracket 10. The heights (steps) of the step portions 26 a and 26 b are set equal to the plate thickness of the antenna element 1, and the heights (steps) of the step portions 27 a and 27 b are set equal to the plate thickness of the bracket 10.

  The antenna element 1 is formed with an alignment hole 2 that fits into the boss 21 of the base 20 and a mounting hole 3 corresponding to the screw hole 22. Further, a tongue piece portion 4 for attaching a printed circuit board extends from one side (lower side) of the antenna element 1. The base of the tongue piece 4 is bent in an L shape so that a gap is generated between the tongue piece 4 and the base 20 when the vehicle-mounted antenna is assembled. A screw hole 5 for attaching the printed circuit board 40 is formed in the tongue piece 4. The width of the mounting portion of the antenna element 1 to the base 20 is set to be equal to the width of the base 20 from the viewpoint of miniaturization.

  The bracket 10 has a bent portion 11 that rises vertically from a wide mounting portion 12. The mounting portion 12 is formed with a mounting hole 13 for mounting to a metal frame inside the bumper of the vehicle, for example. The bent portion 11 is formed with a mounting hole 15 corresponding to the positioning hole 14 and the screw hole 25 which are fitted to the boss 24 on the base 20 side. Further, tongue pieces 16a and 16b for attaching the printed circuit board extend from one side (upper side) of the bent portion 11. The base portions of the tongue pieces 16a and 16b are bent in an L shape so that a gap is generated between the tongue pieces 16a and 16b and the base 20 when the vehicle-mounted antenna is assembled. Screw holes 17a and 17b for attaching the printed circuit board 40 are formed in the tongue pieces 16a and 16b. The lateral width of the mounting portion of the bracket 10 to the base 20 (that is, the bent portion 11) is equal to the lateral width of the base 20 from the viewpoint of miniaturization.

  Mounting holes 41 corresponding to the screw holes 5, 17a, 17b formed in the tongue pieces 4, 16a, 16b are formed in the printed circuit board 40, and the coaxial connector 50 is fixed. The coaxial connector 50 may not have a waterproof structure. A central conductor of the coaxial connector 50 and an outer conductor (sleeve) surrounding the coaxial connector 50 are electrically connected (for example, soldered) to the printed circuit board 40, and the central conductor of the coaxial connector 50 is connected to the antenna element 1 on the printed circuit board 40. A conductor pattern for electrically connecting to the tongue piece 4 and a conductor pattern for connecting the outer conductor of the coaxial connector 50 to the tongue pieces 16a and 16b of the bracket 10 are formed (each conductor pattern). Is omitted).

  The case 30 is made of a resin, and forms a substantially rectangular parallelepiped internal space P whose one surface is opened in an integrated state with the base 20. The case 30 has a mounting portion 31 whose three side edges oppose the base 20 side. Mounting holes 32 corresponding to the screw holes 22 and 25 on the base 20 side are formed in the mounting portion 31. The mounting portion 31 is formed with a recess (not shown) that fits with the boss 23 on the base 20 side.

  Next, the overall configuration of the in-vehicle antenna will be described according to the assembly procedure of the in-vehicle antenna. First, as shown in FIG. 15A, the antenna element 1 is made to face the surface S1 of the base 20 on which the antenna element positioning boss 21 and the mounting screw hole 22 are formed, as shown in FIG. The positioning hole 2 of the antenna element 1 is fitted with the boss 21 and positioned so that one side of the antenna element 1 abuts against the stepped portions 26a and 26b of the base 20 without any gap. The screw 61 is screwed through the mounting hole 3 to the screw hole 22 at a position where the antenna element 1 does not overlap, and the central portion of the antenna element 1 is fixed to the base 20. At this time, the antenna element 1 is brought into surface contact with the base 20 without a gap so that no leakage occurs when a sealing material described later is filled.

  As shown in FIG. 16A, the bent portion 11 of the bracket 10 is opposed to the surface S3 in which the boss 24 for bracket alignment and the screw hole 25 for mounting of the base 20 shown in FIG. The positioning hole 14 is fitted with the boss 24 and positioned so that the edge of the bent portion 11 abuts against the stepped portions 27a and 27b of the base 20 without any gap, and the center position of the base 20 (the mounting portion 31 of the case 30). The screw 62 is screwed through the mounting hole 15 to the screw hole 25 at a position where the two bent portions 11 do not overlap, and the central portion of the bent portion 11 is fixed to the base 20. At that time, the bent portion 11 is brought into surface contact with the base 20 without a gap so that no leakage occurs when the sealing material described later is filled.

  Then, as shown in FIG. 16B, the printed circuit board 40 to which the coaxial connector 50 is connected and fixed in advance by soldering or the like is placed on the tongue pieces 4, 16a, 16b, and their screw holes 5, 17a, 17b. Then, a screw 63 is screwed through the mounting hole 41 of the printed circuit board 40, and the printed circuit board 40 is fixed to the tongue pieces 4, 16a, 16b. As a result, as shown in FIGS. 12 and 14, the tongue pieces 4, 16 a and 16 b are in close contact with the printed circuit board 40, and the central conductor of the coaxial connector 50 is connected to the tongue of the antenna element 1 via the conductive pattern of the printed circuit board 40. The outer conductor of the coaxial connector 50 is electrically connected to the tongue pieces 16 a and 16 b of the bracket 10 by another conductor pattern of the printed circuit board 40. Since the base portions of the tongue pieces 4, 16 a and 16 b are bent in an L shape, a predetermined interval is provided between the opposing surfaces of the base 20 and the printed board 40. That is, the printed circuit board 40 is fixed in a state having a space from the base 20 and the case 30 except for a connection portion between the antenna element 1 and the bracket 10. Note that electronic components such as chip capacitors may be mounted on the printed circuit board 40, but these electronic components are not shown.

  After mounting the printed circuit board 40 to the base 20, the case 30 is attached to the base 20 as shown in FIG. That is, the mounting portion 31 of the case 30 is overlapped with the antenna element 1, the bent portion 11 of the bracket 10, and the surface S <b> 2 of the base 20 (surface contact is made without any gap). At this time, the case 30 is positioned by fitting the boss 23 on the base 20 side into the recess of the mounting portion 31 of the case 30. Then, the screw 64 is screwed into the screw hole 22 on the base 20 side through the mounting hole 32 of the case 30 and the mounting hole 3 of the antenna element 1, and the screw 65 is passed through the mounting hole 32 of the case 30 and the mounting hole 15 of the bracket 10. The base 20 and the case 30 are tightened and integrated as shown in FIG. As a result, the antenna element 1 and the bracket 10 are sandwiched between the base 20 and the case 30. That is, the mounting portion 31 is in surface contact with the corresponding one side of the antenna element 1 and the bracket 10 without a gap, and the other surface side of the antenna element 1 and the bracket 10 corresponding to the mounting portion 31 is the surface S1 of the base 20. In addition, the surface contact with the surface S3 without any gap. 17A, the surface S2 of the base 20 is more than the other surfaces S1 and S3 (the portion where the antenna element 1 and the bracket 10 are disposed as shown in FIG. 1). Since the antenna element 1 and the bracket 10 are formed so as to be thicker than the antenna element 1 and the bracket 10, there is no step in the portion where the mounting portion 31 of the case 30 is in surface contact. In other words, the contact surface that contacts the attachment portion 31 of the case 30 formed by the surface S2 of the base 20, the antenna element 1, and the bracket 10 is flat. Therefore, the sealing material (generally having a high viscosity) does not leak to the outside when the sealing material is filled into the case 30 described later.

  After that, as shown in FIG. 17B, the internal space P surrounded by the base 20 and the case 30 is filled with a casting resin 70 as a sealing material from the opening side of the case 30 and cured, so that the internal space P is watered. Seal tightly. The casting resin 70 is, for example, an epoxy resin, a urethane resin, or the like and has a high viscosity, so that it does not leak out of the internal space P. At this time, as shown in FIG. 13, the housing 51 of the coaxial connector 50 is buried in the casting resin 70, but the external connection portion of the coaxial connector 50 is exposed from the casting resin 70, and the printed circuit board 40 is exposed to the casting resin 70. Buried inside. In addition, since there is a gap between the base 20 and the printed circuit board 40, the casting resin surely goes around the printed circuit board 40.

  After the casting resin 70 is cured, strong waterproofing is ensured by adhesion between the casting resin 70 and each member. The printed circuit board 40 is wrapped with the casting resin 70 injected into the surrounding space, the outer periphery of the housing 51 of the coaxial connector 50 is also sealed (watertightly sealed) with the casting resin 70, and the mating waterproof connector and the connector 50 are fitted. By combining, the vehicle-mounted antenna is completely waterproof.

  The vehicle-mounted antenna assembled in this way is attached to the vehicle by fixing the mounting portion 12 of the bracket 10 to the metal frame inside the vehicle bumper (material such as resin that transmits radio waves) with a bolt.

  According to the present embodiment, the following effects can be achieved.

(1) The antenna element 1 and the bracket 10 are sandwiched between a base 20 and a case 30 as first and second insulator parts, and a sealing material is filled in the internal space P surrounded by them and in which the printed circuit board 40 is disposed. What is necessary is to perform waterproofing by filling the sealing material (casting resin) once, so that waterproofing can be realized with a simple and inexpensive structure.

(2) The antenna element 1 and the bracket 10 arranged on one side of the base 20 are formed with step portions 26a, 26b, 27a, 27b on the base 20, so that a predetermined interval is maintained and electrical insulation between the antenna element 1 and the bracket 10 is ensured. By mounting the antenna element 1 and the bracket 10 on the base 20 so as to be able to be secured and to be in contact with the stepped portions 26a, 26b, 27a, 27b, it is possible to accurately position them.

(3) The horizontal width of the mounting portion of the antenna element 1 and the bracket 10 to the base 20 is the same as the horizontal width of the base 20, and the size can be reduced.

(4) Since the printed circuit board 40 is provided at an interval with respect to the base 20, the casting resin 70 as a sealing material surely wraps around the printed circuit board 40, and the printed circuit board 40 is sealed with water. Can be reliably stopped.

(5) The external connection portion of the connector 50 is provided on the opening side of the case 30 (the opening side of the internal space P) and is exposed from the casting resin 70, and the specification of the connector 50 can be easily changed. Even when the shape of the connector 50 changes greatly, it can be easily handled by changing the opening shape of the case 3.

(6) The base 10 and the case 30 are structured so as to sandwich and cover only a part of the antenna element 1 and the bracket 10, and can be reduced in size as compared with the structure covering the entire antenna element 1 and manufactured with less material cost. Cost can be reduced.

  The present invention has been described above by taking the embodiment as an example. However, it is understood by those skilled in the art that various modifications can be made to each component and each processing process of the embodiment within the scope of the claims. By the way. Hereinafter, modifications will be described.

  In the embodiment, the coaxial connector is exemplified as the external output unit, but other connectors or connection means may be used. The antenna element has a shape that is changed according to the operating frequency, and is not necessarily flat.

DESCRIPTION OF SYMBOLS 1 Antenna element 2,14 Positioning hole 3,13,15,32,41 Mounting hole 4,16a, 16b Tongue piece part 5,17a, 17b, 22,25 Screw hole 10 Bracket 11 Bending part 20 Base 21,23 24 Boss 26a, 26b, 27a, 27b Stepped portion 30 Case 31 Mounting portion 40 Printed circuit board 50 Coaxial connector 70 Cast resin P Internal space

Claims (6)

An antenna element;
A bracket,
A first insulator component and a second insulator component sandwiching the antenna element and the bracket;
A printed circuit board disposed in an internal space surrounded by the first and second insulator components;
An external output part partially disposed in the internal space;
A vehicle-mounted antenna comprising a sealing material filled in the internal space.   The antenna element and the bracket disposed on one side of the first insulator component are insulated from each other by a step portion of the first insulator component and positioned at a predetermined interval, and the first insulator component 2. The vehicle-mounted antenna according to claim 1, wherein a contact surface in contact with the second insulator part formed by the antenna element and the bracket is flat.   The in-vehicle antenna according to claim 1 or 2, wherein a width of a portion where the antenna element and the bracket are attached to the first insulator part is equal to a width of the first insulator part.   The in-vehicle antenna according to any one of claims 1 to 3, wherein the printed circuit board is provided at an interval with respect to the first insulator component.   The external output unit is a connector attached to the printed circuit board, and an external connection portion of the connector is exposed to the opening side of the internal space. The vehicle-mounted antenna described.   The first insulator part is a base in contact with the antenna element and the back side of the bracket, and the second insulator part is in contact with the antenna element and the front side of the bracket and between the base and the base. The vehicle-mounted antenna according to claim 1, wherein the vehicle-mounted antenna is a case forming an internal space, and the base and the case cover only a part of the antenna element and the bracket.

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