JP2008153990A - Antenna unit for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately establish arrangement and shape of antennas to improve reception sensitivity. <P>SOLUTION: An antenna 31 for VICS bands and an antenna 32 for low VHF bands are arranged in parallel between a pair of reinforcement members 15 and 15. The antennas are provided at not a metal coupling member 16 but an internal space 5 of a back door A at the side of an aperture 8. The antennas extend in a vehicle cross direction, and are substantially horizontally separated each other in a fore and aft direction of a vehicle body b1. Further, the antenna 31 for VICS bands is placed at a position nearer to the coupling member 16 compared with the antenna 32, and the total length of the antenna 31 is established to a length almost equal to the length of the antenna 32. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an automobile antenna device, and more particularly to a technique for improving the reception sensitivity of an antenna.

  Currently, vehicles are provided with antenna devices for receiving various broadcast waves such as AM radio broadcast waves, FM radio broadcast waves, TV (UHF band and VHF band) broadcast waves, VICS, and the like.

  Patent Document 1 discloses a technique in which a plurality of film antenna elements corresponding to a reception target medium are arranged in an air spoiler that is a hollow structure to receive various broadcast waves.

Patent Document 2 discloses a technique in which a loop antenna is disposed along a peripheral edge portion of an inner panel in a space formed between a resin inner panel and an outer panel constituting the door panel. ing.
JP 2001-102826 A JP 2006-295712 A

  By the way, when the antenna is attached to the vehicle body or the like, the positional relationship between the metal member constituting the vehicle body and the antenna is important. In other words, if an antenna is placed near a metal member, radio wave interference may occur between the antenna and the metal member, resulting in noise reduction. Therefore, it is necessary to arrange the antenna at the optimum location and to set the shape of the antenna appropriately.

  The present invention has been made in view of such a point, and an object of the present invention is to increase reception sensitivity by appropriately setting the arrangement and shape of antennas.

  In order to achieve the above-described object, the present invention is characterized in that the positional relationship and shape of the VICS band antenna and the low VHF band antenna disposed in the internal space of the back door are appropriately set.

  Specifically, the present invention includes a VICS band antenna formed of a conductive wire, a low VHF band antenna formed of a conductive wire, a tailgate portion opened in a rear part of a vehicle body, and the tailgate portion. A vehicle door antenna device provided with a back door for opening and closing the door and a pair of left and right hinge members provided at the rear part of the vehicle body for opening and closing the back door, the following solution has been taken. .

That is, in the invention of claim 1, the back door has an inner space and an inner panel made of resin, each having an opening for a rear window, extending at least on the upper edge side of the opening in the vehicle width direction. A pair of back door bodies integrally joined to each other, and fixed to each other on the inner space side surface of the inner panel at both side edges and top edges in the vehicle width direction of the back door bodies, and A pair of reinforcing members attached to the hinge member, and a metal connecting member that connects the pair of reinforcing members in the internal space of the back door body,
The VICS band antenna and the low VHF band antenna extend in the vehicle width direction and in the front-rear direction in the internal space of the back door body between the pair of reinforcing members and on the opening side of the connecting member. And arranged side by side in at least one of the vertical directions,
The VICS band antenna is positioned closer to the connecting member than the low VHF band antenna, and the overall length is set to be substantially the same as the low VHF band antenna. Is.

  According to the first aspect of the present invention, since the VICS band antenna is positioned closer to the metallic connecting member than the low VHF band antenna in the internal space of the back door body, the low VHF band antenna is used for the VICS band. The antenna is disposed farther away from the coupling member than the antenna, and radio wave interference with the metal coupling member is suppressed, which is advantageous in increasing the reception sensitivity of the low VHF band antenna.

  In addition, since the total length of the VICS band antenna is set to be approximately the same as the low VHF band antenna, radio wave interference between the VICS band antenna and the metal connecting member can be minimized. This is advantageous in increasing the reception sensitivity.

  As described above, by arranging the VICS band antenna and the low VHF band antenna at the optimum locations and making the total length of the antennas substantially the same, the reception performance of both antennas, that is, the reception sensitivity can be improved. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the present invention.

  FIG. 1 shows an automobile B provided with a back door A according to an embodiment of the present invention, and FIG. 1 shows a state where the back door A is opened by a pair of left and right damper stays C. As shown in FIGS. 2 and 3, the back door A has a resin outer panel 1 formed with a rear window opening 8 and a resin inner panel 3 on the upper edge side of the opening 8. A back door body 7 integrally joined so as to have an internal space 5 extending in the width direction is provided, and inner ends of both ends in the vehicle width direction of the upper end portion of the back door body 7 have a pair of left and right hinge members 9, 9. Via the upper end edge of the opening b2 (tailgate part) of the rear part of the metal body b1 of the automobile B, and the back door A is pivoted up and down around the hinge members 9 and 9 as an opening. The part b2 is configured to be openable and closable. Here, an adhesive is used as a means for joining the outer panel 1 and the inner panel 3 constituting the back door A, or they are joined by hot plate welding, vibration welding, high frequency welding or the like.

  The damper stage C includes a tube 11 in which a gas is sealed, and a rod 13 that is inserted into the tube 11 so as to expand and contract and is constantly urged by the gas pressure. A base end of a certain tube 11 is pivotally attached to the vehicle body b1 so as to be swingable outside the opening b2.

  A pair of substantially L-shaped reinforcing members 15 made of a metal plate are fixedly arranged on the inner space 5 side surface of the inner panel 3 at both the side edge and the upper edge in the vehicle width direction of the back door body 7. The upper end of the reinforcing member 15 is connected to the hinge member 9 and the lower end is connected to the inner panel 5 side surface of the inner panel 3 by fastening with bolts.

  Specifically, as shown in FIG. 4, a metal weld nut 19 is welded to the surface of the upper end of the reinforcing member 15 on the inner space 5 side, and one hinge of the reinforcing member 15 and the hinge member 9 is welded. The reinforcing member 15 and the hinge member 9 are connected via the bolt 18 and the inner panel 3 by sandwiching the inner panel 3 between the plate 9 a and fastening with the metal bolt 18.

  On the other hand, a metal weld nut 20 is welded to the upper end edge of the opening b2 at the rear part of the vehicle body b1 of the automobile B, and the other hinge plate 9b of the hinge member 9 is fastened to the vehicle body b1 by a metal bolt 22. Thus, the vehicle body b1 and the hinge member 9 are connected. In FIG. 4, 9c is a hinge shaft that rotatably connects the one hinge plate 9a and the other hinge plate 9b.

  The reinforcing member 15 is formed with a positioning projection 27 that protrudes toward the inner panel 3, and the positioning projection 27 passes through the inner panel 3 and the one hinge plate 9a to pass through the compartment of the back door A. Projects from the side surface.

  The positioning protrusion 27 is for appropriately positioning the hinge member 9 and the reinforcing member 15 on the inner panel 3 when the back door A is assembled to the vehicle body b1.

  In addition, the reinforcing member 15 has screw holes in a boss portion (not shown) in which an appropriate number of portions extending in the longitudinal direction protrude from the inner space 5 side of the inner panel 3 at appropriate positions in the longitudinal direction. It is screwed together and fastened.

  The upper ends of the pair of left and right reinforcing members 15 are connected by a metal (conductive) connecting member 16 having a concave cross section that extends in the vehicle width direction and opens upward. That is, the connecting member 16 connects the pair of reinforcing members 15 and 15 in the internal space 5 of the back door body 7. Further, the connecting member 16 functions as a door reinforcing member by fastening an appropriate number of locations in the vehicle width direction to the inner space 5 side surface of the inner panel 3 by rivets 17, 17,.

  The tip of the rod 13 of the damper stay C is attached to a bracket 14 provided on the outer surface of the inner panel 3 so as to be rotatable (swingable), and the lower end of the damper stay C is the lower end of the reinforcing member 15 and the inner panel 3. The back door main body 7 is always urged in the opening direction by the damper stay C.

  As shown in FIG. 3, a concave portion 1a extending in the vehicle width direction is formed at a position above the opening 8 in the outer panel 1, and a high-mount stop lamp 35 is attached to the concave portion 1a. Further, the periphery of the opening 8 of the outer panel 1 is adhered to the periphery of the rear window glass 36 to close the opening 8.

  As shown in FIGS. 1 and 2, the vehicle B receives radio (FM, AM broadcast), TV broadcast radio waves, VICS (Vehicle Information and Communication System), etc., and the received signal Is provided to an information communication device 41 (see FIG. 7) such as a car navigation system, a radio, and a television in the vehicle interior via a tuner 40 (see FIG. 7).

  This antenna device includes a low frequency band antenna for receiving a broadcast wave in a low frequency band. Specifically, the low frequency band antenna includes a VICS band antenna 31 for receiving radio FM waves and VICS band radio waves having a frequency band of 76 MHz to 90 MHz, and a VHF (30 MHz to 300 MHz frequency band). It is composed of a low VHF band antenna 32 for receiving a low VHF charged wave such as 1CH to 3CH of a TV broadcast wave that is a frequency band of 88 MHz to 108 MHz among radio waves in a very high frequency band. . The dimensions of these antennas 31 and 32 are set in relation to the frequency of the reception target medium.

  As shown in FIG. 3, the VICS band antenna 31 and the low VHF band antenna 32 that form the low frequency band antenna are made of a linear conductive wire made of stainless steel and having a wire diameter of about 3 mm. b1 are spaced apart in the front-rear direction and are arranged in parallel in the vehicle width direction in the inner space 5 of the back door A between the pair of reinforcing members 15 and 15 and behind the connecting member 16 (on the opening 8 side). It is arranged to extend.

  Here, as a feature of the present invention, the VICS band antenna 31 is positioned closer to the connecting member 16 than the low VHF band antenna 32, and the overall length is substantially the same as the low VHF band antenna 32. (See FIG. 5).

  The antennas 31 and 32 are arranged substantially horizontally. For example, the rear low VHF band antenna 32 is arranged below the front VICS band antenna 31 in the vertical direction. On the contrary, the rear low VHF band antenna 32 may be disposed above the front VICS band antenna 31. In short, the two antennas 31 and 32 may be arranged in parallel in a manner separated from at least one of the front-rear direction and the vertical direction. Hereinafter, the arrangement of the antennas 31 and 32 will be described.

  As shown in FIGS. 3 and 5, support ribs 3a, 3a,... Projecting toward the outer panel 1 so as to extend in the vertical direction are provided on the surface of the inner panel 3 on the inner space 5 side. A plurality are arranged at intervals in the width direction.

  Between the plurality of support ribs 3a, 3a,..., Connecting ribs 3b, 3b extending in the vehicle width direction with a space in the vertical direction are juxtaposed, and the plurality of support ribs 3a, 3a,. .. and the connecting ribs 3b, 3b,. Here, the support rib 3 a and the connecting rib 3 b are integrally formed with the inner panel 3.

  As shown in FIG. 6, antenna receiving grooves 3c, 3c,... Having a substantially U-shaped cross section along the connecting rib 3b are provided at the projecting side ends of the plurality of support ribs 3a, 3a,. Each is formed.

  Of the antenna receiving grooves 3c, 3c,... Formed in the support rib 3a, the front antenna receiving grooves 3c, 3c,. The low VHF band antenna 32 is housed in the housing grooves 3c, 3c,.

  These antennas 31 and 32 are held by the clip 22 so as not to drop out of the antenna receiving grooves 3c, 3c,. The clip 22 is formed by bending a spring wire, and both antennas are used to hold the holding portion 22a for holding the connecting rib 3b, the VICS band antenna 31 and the low VHF band antenna 32. And an annular holding portion 22b having an inner diameter substantially the same as the outer diameters of 31 and 32. In addition, the clearance gap between the clamping parts 22a and 22a is formed smaller than the plate | board thickness of the connection rib 3b.

  And as shown in FIG. 3, both the antennas 31 accommodated in the antenna accommodating grooves 3c, 3c,... Are widened against the elastic force by expanding the gap between the holding portions 22a, 22a of the clip 22. , 32 is pushed into the holding portion 22b. Then, by holding the connecting rib 3b with the holding portion 22a while holding both the antennas 31 and 32 with the holding portion 22b of the clip 22, both the antennas 31 and 32 are removed from the antenna receiving grooves 3c, 3c,. It does not fall out.

  Three clips 22 are attached to the VICS band antenna 31 at intervals in the vehicle width direction. Similarly, three low VHF band antennas 32 are attached at intervals in the vehicle width direction.

  Here, the protrusion height of the support rib 3a from the inner panel 3 surface is such that both antennas 31 and 32 interfere with the inner space 5 side surface of the outer panel 1 in a state where the outer panel 1 and the inner panel 3 are joined together ( It is set so as to be close to a position where it does not abut. In this way, both antennas 31 and 32 can be disposed at the highest position in the internal space 5 of the back door A, which is advantageous in improving the reception sensitivity.

  As shown in FIG. 5, at one end (right side in FIG. 5) of the VICS band antenna 31 and the low VHF band antenna 32, a received signal is transmitted through a tuner 40 to a car navigation system, a radio, a TV, etc. Two shielded wires 25, 25 leading to the information communication device 41 are attached.

  The shield wire 25 is constituted by a coaxial cable in which an inner conductor 25a with a sheath is wrapped with an outer conductor 25b made of a thin metal conductor, and further provided with an outer sheath. The external conductor 25b prevents electromagnetic and electrostatic noise from the outside from entering the internal conductor 25a. Further, the antennas 31 and 32 can be grounded by pulling out a part of the metal conducting wire constituting the external conducting wire 25b and using it as a grounding wire for grounding to the vehicle body b1. At the front end of the shield wire 25 on the antenna side, the external conductor 25b is peeled off and the internal conductor 25a is exposed, and the internal conductor 25a and one end of the antennas 31 and 32 are brazed. 31 and 32.

  The shield lines 25 and 25 wired from the VICS band antenna 31 and the low VHF band antenna 32 are bundled as one connection wiring to be connected to the tuner 40 and then wired in the vehicle interior. .

  FIG. 8 is a graph showing experimental data 1 and 2 in which the reception sensitivity is measured when the arrangement of the VICS band antenna 31 and the low VHF band antenna 32 and the overall length thereof are changed in the automobile antenna device according to the present embodiment. FIG.

  In FIG. 8, column A is a visual representation of the relationship between the arrangement of the VICS band antenna 31 and the low VHF band antenna 32 and the total length thereof. When the antenna 31 is disposed on the front side in the front-rear direction of the vehicle body b1 and the low-VHF band antenna 32 is disposed on the rear side in the front-rear direction of the vehicle body b1. It shows that it is data of.

  In FIG. 8, experimental data 1 is obtained by measuring reception sensitivity using the automobile antenna device according to the embodiment of the present invention, and the VICS band antenna 31 is ahead (front side) of the low VHF band antenna 32. And the overall length is set to be substantially the same as the low VHF band antenna 32.

  The experimental data 2 is a graph showing the reception sensitivity when the low VHF band antenna 32 is positioned in front of the VICS band antenna 31 and the total length is set to be substantially the same as the VICS band antenna 31. It is shown. In this case, although the reception sensitivity of the VICS band antenna 31 is higher than that of the experimental data 1, the reception sensitivity of the low VHF band antenna 32 is greatly deteriorated. The VICS band antenna 31 is advantageous in suppressing radio wave interference by being separated from the metal connecting member 16, but the low VHF band antenna 32 is located forward, that is, made of metal. This is considered to be because radio wave interference occurred between the low VHF band antenna 32 and the connecting member 16 by being arranged on the side closer to the connecting member 16.

  Although not shown, the arrangement of the pair of antennas 31 and 32 in the experimental data 1 and the experimental data 2 in FIG. 8 is changed so that the length of the other antenna is shortened with respect to one antenna. In both cases, the receiving sensitivity of the antenna with the shorter length was worse than that of the experimental data 1. For example, the same arrangement as the pair of antennas 31 and 32 in the experimental data 1 of FIG. 8, that is, the VICS band antenna 31 is disposed on the front side in the longitudinal direction of the vehicle body b1, and the low VHF band antenna 32 is disposed on the rear side in the longitudinal direction of the vehicle body b1. In this case, when the total length of the VICS band antenna 31 is set shorter than that of the low VHF band antenna 32, the reception sensitivity of the shorter VICS band antenna 31 is lower than the reception sensitivity of the experimental data 1. It was. Hereinafter, although description is abbreviate | omitted, it is the same also about arrangement | positioning of a pair of antennas 31 and 32, and other combinations of the full length.

  As described above, according to the antenna apparatus for an automobile according to the present embodiment, the VICS band antenna 31 is closer to the metal connecting member 16 than the low VHF band antenna 32 in the internal space 5 of the back door A. Therefore, the low VHF band antenna 32 is arranged farther from the connecting member 16 than the VICS band antenna 31, and the occurrence of radio wave interference with the connecting member 16 is suppressed. This is advantageous in increasing the reception sensitivity of the band antenna 32.

  Further, since the total length of the VICS band antenna 31 is set to be substantially the same as that of the low VHF band antenna 32, radio wave interference between the VICS band antenna 31 and the connecting member 16 can be minimized. This is advantageous in increasing the reception sensitivity.

  Thus, by arranging the VICS band antenna 31 and the low VHF band antenna 32 at the optimum locations and making the total length of both antennas 31 and 32 substantially the same, the reception performance of both antennas 31 and 32, That is, reception sensitivity can be improved.

  As described above, the present invention provides a highly practical effect that the reception sensitivity can be increased by appropriately setting the arrangement and shape of the antenna. high.

It is a side view of the rear part of a vehicle body in a state where the back door of the automobile according to the embodiment of the present invention is opened. It is drawing of the state which opened the back door of FIG. 1 and looked up from the back side. It is sectional drawing in the III-III line | wire of FIG. 2, It is drawing which shows the state which closed the back door. FIG. 4 is a view corresponding to FIG. 3 taken along line IV-IV in FIG. 2. It is a top view for demonstrating arrangement | positioning of the antenna in internal space. It is a perspective view explaining the procedure which attaches an antenna to the support rib of an inner panel. It is a schematic diagram which shows the state which connected the antenna to the information communication equipment. It is a graph which shows the receiving sensitivity based on arrangement | positioning and the full length of an antenna.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer panel 3 Inner panel 5 Internal space 7 Back door main body 8 Opening part 9 Hinge member 15 Reinforcement member 16 Connection member 31 VICS band antenna 32 Low VHF band antenna A Back door B Automobile b1 Car body b2 Opening part (tail gate part)

Claims (1)

A VICS band antenna formed of a conductive wire;
A low VHF band antenna formed of a conductive wire;
A tailgate opening at the rear of the vehicle body,
A back door for opening and closing the tailgate,
An automobile antenna device provided with a pair of left and right hinge members that are provided at the rear of the vehicle body and support the back door so as to be opened and closed,
The back door is integrally joined so that a resin inner panel and an outer panel, each having an opening for a rear window, have an internal space extending in the vehicle width direction at least on the upper edge side of the opening. A pair of reinforcements attached to the pair of hinge members and fixed to the back door body and the inner panel side surfaces of the inner side panel of the back door body on both side edges and upper edge in the vehicle width direction. A member and a metal connecting member that connects the pair of reinforcing members in the internal space of the back door body,
The VICS band antenna and the low VHF band antenna extend in the vehicle width direction and in the front-rear direction in the internal space of the back door body between the pair of reinforcing members and on the opening side of the connecting member. And arranged side by side in at least one of the vertical directions,
The VICS band antenna is positioned closer to the connecting member than the low VHF band antenna, and the overall length is set to be substantially the same as the low VHF band antenna. Automotive antenna device.

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