JP2019041214A - On-vehicle antenna device - Google Patents

Abstract

To improve performance of an on-vehicle antenna device.SOLUTION: An on-vehicle antenna device includes: an antenna element 10; a substrate 46 with which the antenna element 10 is connected; a housing 44 which houses the substrate 46; and an earth bracket 22 to which the housing 44 is fixed. The earth bracket 22 has: a fixing structure for fixing itself to a vehicle body; and multiple housing bolt holes 42 into which a housing bolt 52 protruding from a bottom surface of the housing 44 is inserted. A local ground conductor in the substrate 46 is electrically connected with the housing bolt 52. The housing bolt 52 is inserted into any of the multiple housing bolt holes 42. The housing 44 is fixed to the earth bracket 22 by the housing bolt 52 and a nut attached to the housing bolt 52.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a vehicle-mounted antenna device, and more particularly to a structure for fixing and grounding an antenna device to a vehicle body.

  Various wireless devices such as a radio, an ETC, and a car navigation are mounted on the automobile. These wireless devices are connected to an in-vehicle antenna device having characteristics corresponding to the used frequency band. Some in-vehicle antenna devices are attached to spoilers, roofs, window glasses, window frames, etc. according to the shape and required characteristics.

  The following Patent Documents 1 to 4 describe antennas attached to automobile spoilers, roofs, window glasses, and window frames, respectively.

JP 2013-093744 A JP, 2006-208246, A JP 2014-011787 A JP 2013-1206086 A

  In general, an automobile body has different effects on the characteristics of the in-vehicle antenna device depending on its shape and the positional relationship with the in-vehicle antenna device. For this reason, the in-vehicle antenna device may not be able to obtain good characteristics depending on the shape of the body, the mounting position on the body, and the like.

  An object of this invention is to improve the performance of a vehicle-mounted antenna apparatus.

  The present invention comprises an antenna element, a substrate to which the antenna element is connected, a housing for housing the substrate, and a ground bracket to which the housing is fixed, and the ground bracket is attached to the vehicle body. A fixing structure for fixing, and a plurality of housing bolt holes, which are housing bolts protruding from the bottom surface of the housing, through which the housing bolts for fixing the housing to the ground bracket are passed. A local ground conductor on the substrate is electrically connected to the housing bolt, and the housing bolt is passed through one of the plurality of housing bolt holes. Features.

  Preferably, the casing bolt extends from the inside to the outside of the casing through a hole provided in the casing, and the casing bolt passes through one of the plurality of casing bolt holes. The housing is fixed to the ground bracket by body bolts and nuts attached to the housing bolts.

  Preferably, the fixing structure has a hole through which a vehicle body bolt for fixing the ground bracket to the vehicle body is passed.

  According to the present invention, the performance of the in-vehicle antenna device can be improved.

It is a figure which shows the antenna apparatus which concerns on embodiment of this invention. It is a figure which shows typically the state by which the antenna apparatus was mounted in the motor vehicle. It is a disassembled perspective view at the time of attaching an antenna apparatus to a body. It is a figure which shows the process of attaching an antenna components aggregate | assembly to a body. It is the figure which looked at the antenna component aggregate | assembly from the downward direction. It is the figure which looked at the antenna device from the upper part in the state where the front pillar outer was removed. It is a figure which shows the cross section of an antenna device. It is a figure which shows the structure which penetrated the housing | casing bolt from the upper side to the lower side of the housing | casing.

  FIG. 1 shows an antenna device according to an embodiment of the present invention. The antenna device includes an antenna element 10, an amplifier unit 12, and a coaxial cable 14. The antenna element 10 is formed by a U-shaped lead wire having both ends connected to the amplifier unit 12. That is, the conducting wire forming the antenna element 10 extends in a direction away from the amplifier unit 12 from one end connected to the amplifier unit 12, and then returns to the amplifier unit 12 side by folding back into a U shape. Is connected to the amplifier unit 12.

  One end of the coaxial cable 14 is connected to the amplifier unit 12, and the other end is connected to a wireless device in the passenger compartment. The radio wave signal received by the antenna element 10 is converted into a reception signal that is an electric signal by the antenna element 10 and input to the amplifier unit 12. The amplifier unit 12 amplifies the received signal and outputs it to the coaxial cable 14. The coaxial cable 14 transmits the reception signal output from the amplifier unit 12 to the communication device. The coaxial cable may supply power to the amplifier unit 12 from the wireless device.

  FIG. 2 schematically shows a state where the antenna device is mounted on the automobile. In the example shown in FIG. 2, the antenna element 10 is attached along the longitudinal direction of the front pillar 18 beside the front window 16, and the amplifier unit 12 is attached below the front pillar 18. . The body 20 (vehicle body) of the automobile is made of metal and acts as a ground conductor for the antenna device. The local ground conductor of the amplifier unit 12 is electrically connected to the body 20 by the structure in which the antenna device is attached to the body 20. Since the front pillar 18 is covered with the antenna device and the front pillar outer which is a design member formed of plastic resin or the like, the antenna device does not appear on the appearance.

  FIG. 3 shows an exploded perspective view when the antenna device is attached to the body 20 together with the front pillar outer 30 and the earth bracket 22. The earth bracket 22 has a function of fixing the amplifier unit 12 to the body 20 and grounding the amplifier unit 12 to the body 20. The earth bracket 22 is formed by pressing a metal plate or the like, and includes an amplifier fixing portion 24 to which the amplifier unit 12 is fixed and a protruding piece 26 protruding from the amplifier fixing portion 24. A bolt hole 281 for fixing the earth bracket 22 to the body 20 is formed in the protruding piece 26 as a fixing structure. The amplifier unit 12 is fixed to the upper surface of the amplifier fixing portion 24.

  The front pillar outer 30 is also formed with a bolt hole 282 for fixing itself to the body 20.

  With the amplifier unit 12 fixed to the earth bracket 22, the bolt hole 281 of the protruding piece 26 of the earth bracket 22 is overlapped with the bolt hole 283 of the body 20. Further, the front pillar outer 30 is overlapped from the upper side, and the bolt hole 282 of the front pillar outer 30 is overlapped with the bolt hole 281 of the protruding piece 26 of the ground bracket 22. The antenna element 10 is fixed to the lower surface of the outer front pillar 30.

  The ground bracket 22 is provided with a plurality of clips 32 protruding toward the front pillar outer 30. An insertion structure into which each clip 32 is inserted is formed on the lower surface of the front pillar outer 30. The clip 32 may be made of an elastic plastic resin. The shape of the clip 32 has a wedge shape, for example. In this case, the clip 32 may be configured such that the widest portion of the wedge shape is narrowed by pressing, and when released from the pressing, the shape returns to its original shape by elasticity. The insertion structure formed in the front pillar outer 30 has a structure for receiving the tip of each clip 32. The earth bracket 22 and the front pillar outer 30 are coupled by the clips 32 being inserted into the insertion structure.

  In a state where the earth bracket 22, the amplifier unit 12, and the front pillar outer 30 overlap with the body 20, the bolt hole 282 of the front pillar outer 30, the bolt hole 281 of the protruding piece 26 of the earth bracket 22, and the bolt hole 283 of the body 20. A vehicle body bolt 34 is passed through. Further, a nut 36 is attached from the front end of the vehicle body bolt 34 protruding below the body 20, and the ground bracket 22 and the front pillar outer 30 are fixed to the body 20 by the vehicle body bolt 34 and the nut 36.

  As shown in FIG. 4, the antenna unit may be fixed in advance to the lower surface of the outer front pillar 30 and the antenna unit may be fixed to the ground bracket in advance. The antenna part assembly 38 including the earth bracket, the amplifier unit, the antenna element, and the front pillar outer 30 configured as described above may be attached to the body 20. In this case, the bolt hole 282 of the outer front pillar 30, the bolt hole 281 of the protruding piece 26 of the earth bracket, and the bolt hole 283 of the body 20 are overlapped, and the vehicle body bolt 34 is passed through these bolt holes. The antenna component assembly 38 is fixed to the body 20 by the body bolts 34 and the nuts 36.

  FIG. 5 shows a view of the antenna component assembly 38 as viewed from below. A plurality of antenna element fixing structures 40 are arranged on the front pillar outer 30. The antenna element fixing structure 40 has, for example, a structure in which the antenna element 10 is fixed to the lower surface of the front pillar outer 30 by sandwiching the antenna element 10 that is a conducting wire between the antenna element 10 and the front pillar outer 30. A plurality of antenna element fixing structures 40 that are suitable for fixing the antenna element 10 are selected according to the shape in which the antenna element 10 is stretched around the lower surface of the front pillar outer 30, and the antenna is fixed by the selected antenna element fixing structure 40. The element 10 may be fixed. In this case, a larger number of antenna element fixing structures 40 than those shown in FIG. 4 may be distributed in the front pillar outer 30.

  FIG. 6 shows a view of the antenna device as seen from above with the front pillar outer virtually removed. The amplifier fixing portion 24 of the ground bracket 22 is provided with housing bolt holes 42 for fixing the housing of the amplifier unit 12 to the ground bracket 22 at a plurality of different positions. In the example shown in FIG. 6, two of the four housing bolt holes 42 appear. The other two housing bolt holes 42 overlap the amplifier unit 12, and the amplifier unit 12 is fixed to the earth bracket 22 by one of the housing bolt holes 42. The ground bracket 22 is fixed to the body 20 and electrically connected to the body 20 by a vehicle body bolt 34 that passes through a bolt hole provided in the protruding piece 26 and a nut attached to the vehicle body bolt 34. .

  FIG. 7 shows a cross section taken along line AA in FIG. The housing 44 of the amplifier unit 12 is formed of a conductive material such as metal. A substrate 46 is disposed inside the housing 44 in a posture facing the bottom plate 56 at a distance from the bottom plate 56 of the housing 44. The substrate 46 may be supported on the bottom plate 56 by a columnar member (not shown) and fixed to the bottom plate 56 via the columnar member. The substrate 46 is provided with an amplifier circuit 62 that amplifies the signal received by the antenna element 10 and outputs the amplified signal to the coaxial cable 14.

  The antenna element 10 penetrates through an antenna element fixing component 48 provided on the left side surface of the housing 44 in the drawing and extends from the outside to the inside of the housing 44. The antenna element fixing component 48 fixes the antenna element 10 to the side surface of the housing 44. The tip of the antenna element 10 is connected to the substrate 46.

  The tip of the coaxial cable 14 is connected to the substrate 46. The coaxial cable 14 extends from the inside to the outside of the housing 44 through the cable fixing component 50 provided on the right side surface of the housing 44 in the drawing. The cable fixing component 50 fixes the coaxial cable 14 to the side surface of the housing 44.

  The head of the housing bolt 52 is fixed to the upper surface side of the bottom plate 56 of the housing 44 by welding or the like. The bottom plate 56 of the housing 44 is provided with a bottom plate hole 60 through which the housing bolt 52 passes. The housing bolt 52 protrudes from the bottom surface of the housing 44 through the bottom plate hole 60.

  The substrate 46 has a ground pattern as a local ground conductor. The amplifier circuit 62 is locally grounded to the ground pattern. The ground pattern is electrically connected to the housing 44 by metal parts and wiring inside the housing 44, and is further electrically connected to the housing bolt 52 via the housing 44. Further, the ground pattern may be directly electrically connected to the housing bolt 52.

  The housing bolt 52 protruding downward from the housing 44 is passed through one of the plurality of housing bolt holes 42 provided in the earth bracket 22. A nut 64 is attached to the housing bolt 52 protruding downward from the ground bracket 22 from the tip thereof, and the housing 44 is fixed to the ground bracket 22. As described above, the earth bracket 22 is fixed to the body and is electrically connected to the body.

  The housing 44 is fixed using a plurality of housing bolt holes 42 that have good antenna device characteristics. The characteristics of the antenna device include a directivity characteristic indicating a received signal level for each direction viewed from the antenna device, a received signal level (reception sensitivity) output from the amplifier unit 12 when a radio wave having a certain intensity arrives, and the like. is there.

  According to such a configuration, the amplifier circuit 62 provided on the substrate 46 is electrically connected to the body via the ground pattern, the housing 44, the housing bolt 52, and the earth bracket 22. Since the body acts as a ground conductor, the antenna device is grounded to the body.

  In general, an automobile body has different effects on the characteristics of an antenna device depending on its shape and the positional relationship with the antenna device. For this reason, the antenna device may not obtain good characteristics depending on the shape of the body, the attachment position to the body, and the like. In the vehicle-mounted antenna device according to the present embodiment (device in which the antenna device is combined with the ground bracket), the plurality of housing bolt holes are fixed by using the antenna device with good characteristics. Therefore, the characteristics of the in-vehicle antenna device are improved for a plurality of vehicle types having different body shapes. As a result, the components of the in-vehicle antenna device are made common for a plurality of vehicle types.

  In the above description, the example in which the head of the housing bolt 52 is fixed to the bottom plate 56 of the housing 44 has been described. The housing bolt 52 may penetrate from the upper side to the lower side of the housing 44. The structure of the antenna device in this case is shown in FIG. The upper plate 54 of the housing 44 is provided with an upper plate hole 68 through which the housing bolt 52 is passed. The substrate 46 is provided with a substrate hole 58 through which the housing bolt 52 passes. The housing bolt 52 is inserted into the housing 44 through the upper plate hole 68, and protrudes below the housing 44 through the substrate hole 58 and the bottom plate hole 60. The lower surface of the head of the housing bolt 52 is in contact with the upper surface of the upper plate 54. The housing bolt 52 protruding downward from the housing 44 is passed through one of the plurality of housing bolt holes 42 provided in the earth bracket 22. A nut 64 is attached to the housing bolt 52 from its tip, and the housing 44 is fixed to the earth bracket 22. According to such a configuration, the housing bolt 52 does not need to be fixed in advance to the housing 44 by welding or the like, and therefore manufacturing may be simplified depending on factory equipment.

  In the above, an example in which the antenna device is attached to the front pillar has been taken up. The antenna device may be attached to other positions of the body such as a rear pillar.

10 antenna element, 12 amplifier unit, 14 coaxial cable, 16 front window, 18 front pillar, 20 body, 22 earth bracket, 24 amplifier fixing part, 26 projecting piece, 281, 282, 283 bolt hole, 30 front pillar outer, 32 Clip, 34 Car body bolt, 36, 64, 66 Nut, 38 Antenna component assembly, 40 Antenna element fixing structure, 42 Housing bolt hole, 44 Housing, 46 Substrate, 48 Antenna element fixing component, 50 Cable fixing component, 52 Housing bolt, 54 top plate, 56 bottom plate, 58 substrate hole, 60 bottom plate hole, 62 amplifier circuit, 68 top plate hole.

Claims (3)

An antenna element;
A substrate to which the antenna element is connected;
A housing for housing the substrate;
An earth bracket to which the housing is fixed,
The earth bracket is
A fixing structure that fixes itself to the vehicle body,
A housing bolt protruding from the bottom surface of the housing, and having a plurality of housing bolt holes through which a housing bolt for fixing the housing to the ground bracket is passed,
A local ground conductor on the substrate is electrically connected to the housing bolt;
The vehicle-mounted antenna device, wherein the housing bolt is passed through any of the plurality of housing bolt holes. The in-vehicle antenna device according to claim 1,
The housing bolt extends from the inside to the outside of the housing through a hole provided in the housing,
The vehicle body characterized in that the housing is fixed to the earth bracket by the housing bolt that has passed through any of the plurality of housing bolt holes and a nut attached to the housing bolt. Antenna device. The in-vehicle antenna device according to claim 1 or 2,
The fixing structure is
A vehicle-mounted antenna device comprising a hole through which a vehicle body bolt for fixing the ground bracket to the vehicle body is passed.

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