JP2003309413A - On-vehicle antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle antenna capable of facilitating the earthing without giving an adverse effect onto the antenna performance in earthing the antenna placed in the hollow body. <P>SOLUTION: An antenna element 4 made substantially of a rigid body is placed in an air spoiler 2 consisting of a hollow body, one end of a flexible AV wire 13 electrically is connected to the antennae element 4, the core wire of a coaxial cable 15 is connected to the other end of the AV wire 13, a window 2c for exposing the shield wire of the coaxial cable 15 is formed in the vicinity of a connection part between the AV wire 13 and the core wire of the coaxial cable 15 to the air spoiler 2, and the shield wire is electrically connected for the earthing to a vehicle body through the window 2c. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular antenna provided in an exterior product made of a hollow body such as a vehicular air spoiler or a vehicular bumper.

[0002]

2. Description of the Related Art Conventionally, a vehicle is equipped with an antenna for receiving a radio or the like. In addition, by providing such an antenna inside an exterior part made of a resin hollow body such as a vehicle air spoiler or a vehicle bumper, it is possible to share a space and improve the appearance of the entire vehicle in appearance. Known (for example, Japanese Patent Laid-Open No. 9-14233).
No. 8, JP 2001-102826 A, etc.).

10 and 11 show Japanese Patent Laid-Open No. 2001-10.
An example of the vehicle antenna disclosed in Japanese Patent No. 2826 is shown.

FIG. 10 is a sectional view of a main part of a vehicle body and an air spoiler for a vehicle, and FIG. 11 is an explanatory view of a concrete arrangement example of antenna elements.

In FIG. 10, above the rear portion of the vehicle body 100, a hollow air spoiler 1 having a vertically aligned structure is provided.
01 is fixed. Also, this air spoiler 10
As shown in FIG. 11, a plurality of film-shaped antenna elements 10 corresponding to the medium to be received are provided inside the unit 1.
An antenna 108 in which 2 to 107 are arranged is provided.

Antenna element 10 of antenna 108
Nos. 2 to 107 are attached to the inner upper surface of the air spoiler 101 with an adhesive or the like. This is because the radio waves usually arrive from above the vehicle body 100, and the air spoiler 10
It is preferred to place it above 1.

The first feeder 110, which is connected to the antenna 108 via the power feeding portion 109, has a through hole 101a formed in the air spoiler 101 and a through hole 111 formed in the outer panel 111 constituting the vehicle body 100.
a and 112a formed on the inner panel 112 that constitutes the vehicle body 100, respectively, and are guided into the vehicle interior. A ground wire 110a for grounding to the vehicle body 100 extends from a part of the first feeder 110, and the tip of the ground wire 110a is fixed to the inner panel 112 with a screw 113.

Each antenna element 1 of the antenna 108
Nos. 02 to 107 are conductive patterns formed on the base film, and their dimensions and arrangement conditions are set in relation to the frequency of the medium to be received.

In this example, the antenna element 102 is for UHF, and the antenna element 103 is for FM and VHF.
Antenna element 104 for AM, antenna element 105 for FM and VHF, antenna element 106 for UHF, antenna element 107 for GPS
It is used for.

Here, the antenna element 107 for GPS is the other antenna elements 102-1.
Since the reception frequency band is significantly different from 06, it has an independent structure.

Each of these antenna elements 102 to 10
7 are formed on the base film 114 in a shape and arrangement relationship as shown in the drawing.

Generally, it is difficult for one antenna element to satisfactorily receive radio waves in a wide frequency band (a plurality of frequency bands). On the other hand, the shape of the antenna element is smaller as the frequency band to be received is higher. be able to.

Therefore, the antenna elements 102, 10
6 has a small size for the UHF band. Further, the antenna elements 103 and 105 are formed in a medium size for the VHF band. Further, the antenna element 104 is formed in a large size for the AM band. Further, the antenna element 107 is formed small for the GPS band.

Although all the antenna elements 102 to 107 are arranged inside the air spoiler 101, particularly the antenna elements 102 and 106 in the high frequency band (UHF band of TV broadcasting) are divided and the divided antennas are divided. By arranging the elements 102 and 106 at both ends in a state of being separated from each other, an effective diversity effect can be obtained.

That is, in general, when the frequency of a radio wave becomes high (the wavelength becomes short), the interference caused by the direct wave and the reflected wave changes at a short distance. This becomes a problem when receiving by a mobile body such as an automobile. As a countermeasure against this, there has been diversity reception from the past, and this is to select and switch the best antenna by utilizing the fact that the reception state changes depending on the position of the antenna among multiple antennas.

Further, it is ideal if the same receiving sensitivity can be obtained from all directions of 360 ° by the antenna alone (non-directional), but in reality, the receiving sensitivity decreases (directivity).
There is. The cause of the directivity may be a problem of the antenna itself or an interference with the vehicle body. The diversity reception described above is effective as a measure against directivity, but in order to obtain a sufficient effect, it is necessary that a plurality of antennas are arranged sufficiently apart.

The multipath and the disturbance of the directivity become more remarkable as the frequency becomes higher. That is, it slightly occurs in FM broadcasting and somewhat in the VHF band of TV broadcasting. Also TV
It frequently occurs in the UHF band of broadcasting. That is, among these frequency bands, diversity reception is most necessary in the case of the UHF band of TV broadcasting, and for this reason, a plurality of antennas must be arranged sufficiently apart.

Therefore, in this example, the air spoiler 10
Each antenna element 102 to 1 in a narrow space within
In the case of arranging 07, as described above, by arranging the UHF band antenna elements 102 and 106 of TV broadcasting, which most require diversity reception, at both ends of the air spoiler 101, a diversity effect is appropriately obtained. is doing.

[0019]

By the way, in the vehicle antenna constructed as described above, the first antenna for the signal line is used.
In addition to the feeder 110, a ground wire 110a is provided.

However, this ground wire 110a is
If wiring different from the feeder 110 is used, connection with many feeders 110 is troublesome.

Moreover, the ground wire 110a passes through all of the through hole 101a formed in the air spoiler 101, the through hole 111a formed in the outer panel 111, and the 112a formed in the inner panel 112.
After arranging so as to branch from the feeder 110 of
Since it is fixed to the inner panel 112 by the screw 113 for grounding to the vehicle body 100, the wiring work is troublesome, and fixing work both inside and outside the vehicle body is required.
There was a problem that the grounding work became complicated.

In order to solve the above-mentioned problems, the present invention provides a vehicle antenna which, when grounding an antenna arranged in a hollow body, can easily perform the grounding work without adversely affecting the antenna performance. The purpose is to do.

[0023]

In order to achieve the above object, a vehicle antenna according to the present invention comprises a first antenna element, which is substantially rigid and is arranged in a vehicle exterior component made of a hollow body. A flexible second antenna element having one end electrically connected to the first antenna element, a coaxial cable having a core wire connected to the other end of the second antenna element, and the second antenna An opening formed in the vehicle exterior product so as to expose the shielded wire of the coaxial cable near a connection portion between the element and the core wire of the coaxial cable, and the shielded wire is electrically connected to the vehicle body through the opening. The feature is that it is connected and grounded.

According to this structure, the first antenna element, which is substantially a rigid body, is arranged in the vehicle exterior component, which is a hollow body, and one end of the flexible second antenna element is the first. Is electrically connected to the antenna element of, and the core wire of the coaxial cable is connected to the other end of the second antenna element, and the shield wire of the coaxial cable is exposed in the vicinity of the connection portion between the second antenna element and the core wire of the coaxial cable. The opening to be formed is formed in the vehicle exterior part,
The shield wire is electrically connected to the vehicle body through this opening and grounded.

Further, the vehicle antenna of the present invention is characterized in that the shield wire is provided in the opening and is electrically connected to a bolt for fixing the vehicle exterior component to the vehicle body.

Further, in the vehicle antenna according to the present invention, the bolt is integrally provided on a conductive metal bracket that reinforces the periphery of the opening, and the shield wire is connected to the bolt via the bracket. It is characterized by being electrically connected.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of a vehicle antenna according to the present invention is applied to an antenna installed in an air spoiler equipped as a hollow body at a rear portion of a vehicle, and based on FIGS. 1 to 9. Explain.

In FIG. 9, reference numeral 1 is a vehicle body, and 2 is a hollow air spoiler fixed above the rear portion of the vehicle body 1.

As shown in FIG. 8, the air spoiler 2 has first, second, third and fourth windows 2 opening on the bottom surface.
a, 2b, 2c and 2d are formed. Further, on the bottom surface of the air spoiler 2, a plurality of fixtures 3 such as screws and clips for attaching the vehicle body are provided. Further, inside the air spoiler 2, an antenna element 4 for receiving radio waves, a retainer 5 holding the antenna element 4, a bracket 6 for fixing the retainer 5 to the air spoiler 2, and one end of the antenna element 4 are provided. A cable 7 serving as a power supply line fixed to the cable 7 and a connector 8 to which the other end of the cable 7 is connected.

The connector 8 can also be connected by inserting a power source or a signal line (not shown) of the high mount stop lamp SL mounted on the air spoiler 2 from the second window 2b. And such a connector 8 and a second
By sharing the window 2b of the above, it is not necessary to provide a dedicated connector or window for the high mount stop lamp SL.

FIG. 8 is a bottom view of a portion located on the right side of the vehicle from near the center of the vehicle when the air spoiler 2 is attached to the vehicle, but from the center of the vehicle on the left side of the vehicle when attached to the vehicle. The portion located at is basically mirror-symmetrical except for the installation state of the cable 9 connected to the connector 8.

Further, the antenna element 4 and the retainer 5
7A, as shown in FIG. 7A, the anti-vibration process is performed by being sandwiched between the cushions 10 in a superposed state. Further, as shown in FIG.
As shown in (B), a bracket 11 made of a conductive metal material is provided by insert molding, which reinforces the decrease in strength of the air spoiler 2 due to the formation of the third window 2c.

The antenna element 4 is formed of, for example, brass tin plating or reflow tin plating,
As shown in FIG. 6, a projection 4a for connecting one end of the cable 7 (the same applies to the cable 9) to one end thereof.
Is provided. Further, foldable tongue pieces 4b are erected at a plurality of appropriate positions on the antenna element 4. Further, the antenna element 4 is a strip-shaped monopole antenna in which the width of the other end side is gradually narrowed compared to the one end side provided with the protrusion 4a.

Specifically, in the present embodiment, as shown in FIG. 3, the total length a in the longitudinal direction from one end to the other end of the antenna element 4 is 345 mm, and the length b from one end to the tapered start end is 295 mm, the length c from one end to the step portion is 210 mm, and the width d of the bent portion from one end is 2
5 mm, the maximum width e is 30 mm, the width f including the bent portion is 60 mm, and the width g on the other end side of the step portion is 20 mm. As described above, the same antenna element 4 is used on the left and right sides, thereby forming diversity.

Then, such an antenna element 4
By using, as shown in FIG.
0-220MHz) and for UHF (470-770MH)
The two frequency bands of z) can be received well. It should be noted that the FM band (7
It is possible to receive even at 0 to 90 MHz).

By the way, in the above-mentioned embodiment, the shape of the antenna element 4 is disclosed as two steps and tapered, but it may be three steps or more, and the tapered shape is eliminated.
It is also possible to make steps.

The retainer 5 is made of, for example, ABS resin. Further, the retainer 5 is provided with a plurality of notched or hole-shaped engaged portions 5a, and the antenna element 4 is folded by positioning the tongue piece 4b of the antenna element 4 on the engaged portions 5a. And the retainer 5 are connected in a superposed state. Further, a screw hole 5b for fixing the bracket 6 is formed at one end of the retainer 5, and the screw hole 5b and the screw hole 6a of the bracket 6 are formed.
The bracket 6 is fixed to the retainer 5 by inserting a screw (not shown) in a state where they are aligned with each other.

The cable 7 includes an AV line 13 having a ring-shaped connection terminal 12 engaging with the protrusion 4a at one end, a coaxial cable 15 having a connector 14 connected to the connector 8 at one end, and these AV lines. 13 and a connecting member 16 that connects the other ends of the coaxial cables 15 to each other.

Similarly, the cable 9 includes an AV line 13 ', a connector (not shown), a coaxial cable 15', and a cable 7.
The same connecting member 16 as the above is provided.

The length of the AV line 13 having the function as an antenna element and having flexibility is 120 mm in the present embodiment (the AV line 1 of the other cable 9).
The length of 3'is 140 mm), but if the antenna element 4 needs to be adjusted at the design stage due to the positional relationship of the antenna element 4 on the left and right sides of the vehicle body, the AV line 13 (and the other cable 9) Adjustment is possible only by changing the length of the AV line 13 '). Further, the adjustment due to the installation height or the like due to the difference in vehicle type can be adjusted by changing the length of the AV line 13.

As shown in FIGS. 1 to 3, the connecting member 16 includes a heat-shrinkable tube 17 extending over the connecting end of the AV line 13 and the coaxial cable 15, and a holder 18 for holding the tube 17 near the center thereof. Is equipped with.

The AV line 13 is provided with a jacket 13a and a core wire 13b, as shown in FIG. 1 (B). The coaxial cable 15 includes an outer jacket 15a, a mesh-shaped shield wire 15b exposed by removing the outer jacket 15a,
An insulator 15c exposed by removing the shield wire 15b and a core wire 15d covered with the insulator 15c are provided.

The tube 17 is made of a heat-shrinkable material. An adhesive layer (not shown) is provided on the inner surface of the tube 17. The adhesive layer is formed of a material that is hardened after being heat-melted into a cylindrical shape and is positioned on the inner surface of the tube 17, but the adhesive layer is not particularly limited thereto.

From the outside of the tube 17, the holder 18
Tongue-shaped holding leg 18 for holding the V-line 13 by fitting
a, a tongue-shaped holding leg portion 18b for holding the coaxial cable 15 by fitting from the outside of the tube 17, and gaps 18c and 18d between the holding leg portions 18a and 18b, and an opening edge of the third window 2c. A pair of holding pieces 18e and 18f for holding the vicinity of the holding portion, a holding portion 18g provided on the base side of one holding piece 18e, and one holding piece 18e and a bolt 19 (see FIG. ) Reference)) and a fixing hole 18h that is fixed via (see FIG.

The bracket 11 is made of a conductive metal material having a relatively high strength (strength adjustment by material or thickness), and as shown in FIG. 4, the third window 2c cooperates with the air spoiler 2. And is insert-molded when the air spoiler 2 is molded. Also, the bracket 1
The vehicle body 1 is provided with a bolt 20 for fixing the vehicle body, whereby the vehicle body 1 is grounded via the shield wire 15b, the holder 18, the bracket 11, and the bolt 20.

Therefore, the bracket 11 has the third window 2c.
In addition to having a function as a reinforcement of, it can also have a function of a fixing member of the holder 18 and a grounding member,
In particular, it is not necessary to provide a dedicated member for grounding. Since only the cable having a lower impedance than the cable 7 is interposed between the shield wire 15b and the vehicle body 1, the shield wire 15b is substantially directly connected to the vehicle body 1 and grounded. This also allows
It is also prevented that the ground portion of the shield wire 15b adversely affects the antenna performance of the entire element including the antenna element 4 and the AV wire 13 as the second element.

In the above structure, the air spoiler 2 is formed as a hollow product with the windows 2a, 2b, 2c and 2d opened and the bracket 11 and the like inserted.

On the other hand, the antenna element 4 and the retainer 5
The antenna unit is configured by mounting the bracket 6 and the cushion 10 in a state where they are overlapped with each other.

On the other hand, the tube 17 having the ring-shaped connection terminal 12 provided at one end of the AV line 13 and the connector 14 provided at one end of the coaxial cable 15 (may be later), and the adhesive layer provided on the inner surface of the tube 17 is used as the AV line 13. Or coaxial cable 15
One of the core wires 13b and 15d is previously inserted and soldered.

At this time, the coaxial cable 15 has a jacket 15a.
Is removed to expose the shield wire 15b, the shield wire 15b is twisted together, and the tip of the insulator 15c is removed to expose the core wire 15d.

Further, a hole 17 provided in the tube 17
After exposing the twisted portion of the shielded wire 15b from a, the tube 17 is heat-shrinked, and at the same time, the adhesive layer is melted and then cured.

After that, the tube 17 is positioned between the holders 18, and the holding legs 18a and 18b are fitted to the AV.
The wire 13 and the coaxial cable 15 are held by the holder 18,
The twisted end of the shielded wire 15b is the AV wire 13.
The cable 7 is held by the holding portion 18g by being tilted to the side.

At this time, the tube 17 and the AV are attached by the adhesive layer.
Since the wire 13 and the tube 17 and the coaxial cable 15 are adhered to each other, no gap is generated, and even if there is a fit by the holding legs 18a and 18b, the gap is prevented from being generated. The airtightness is maintained.
Also, the hole 17a is highly stretchable, and the shield wire 15
Even if b is inserted into the hole 17a, the shield wire 15b and the hole 17a
There is no gap between the a and the a.

The cable 7 can be attached to the antenna unit by fitting the connection terminal 12 into the projection 4a.

To install the antenna unit with the cable 7 in the air spoiler 2, the cable 7 side is inserted from the first window 2a (the wire from the second window 2b to the first window 2a side). To the cable 7
You may tie it in and draw in. ).

Next, in the third window 2c, the bracket 1
After the holder 18 is attached and fixed to the connector 1, the connector 8 and the connector 1 are inserted from the second window 2b while positioning the holder 18 with the fourth window 2d.
4 is joined and fixed in the air spoiler 2 by a bracket 6 or the like.

In this state, part of the antenna element 4 can be seen from the fourth window 2d, so that the antenna element 4 and the holder 18, and the holder 18 and the second window 2d can be seen from the fourth window 2d. A continuity test between the window 2b and the connector 14 can be performed, and disconnection after assembly can be confirmed.

The windows 2a to 2d are preferably closed with tape or the like when the vehicle body is fixed. Also, the first
Since the third windows 2a to 2c are hidden by the high mount stop lamp SL when the vehicle body is fixed, they cannot be seen from the outside including the above-mentioned tape. Similarly, the fourth window 2d is hidden from the outside by the vehicle body 1.

In the above embodiment, an example in which the vehicle antenna is attached to the air spoiler 2 is disclosed.
For example, it is needless to say that the present invention can be applied to all hollow products (particularly, resin molded products) equipped with vehicle bodies such as rear bumper RB.

[0060]

According to the vehicle antenna of the present invention, since it is configured as described above, when the antenna arranged in the hollow body is grounded, its grounding work can be performed without adversely affecting the antenna performance. Can be done easily.

[Brief description of drawings]

1A and 1B show a vehicle antenna according to an embodiment of the present invention, FIG. 1A is a front view of a joint portion, and FIG. 1B is a front view of a joint portion with a holder removed.

FIG. 2 is a front view of a cable showing the vehicle antenna according to the exemplary embodiment of the invention.

FIG. 3 is a front view of a main part of the vehicle antenna according to the embodiment of the present invention, in which a cable is joined to an element.

FIG. 4 is a perspective view of a main part of the vehicle antenna according to the embodiment of the present invention, showing a state in which a holder is attached to a reinforcing bracket.

FIG. 5 shows a vehicle antenna according to an embodiment of the present invention, and is a graph chart of receiving sensitivity by elements.

FIG. 6 is an exploded perspective view of the antenna unit showing the vehicle antenna according to the exemplary embodiment of the invention.

FIG. 7 shows a vehicle antenna according to an embodiment of the present invention, (A) is a cross-sectional view of the air spoiler near the main part of the antenna unit, and (B) is one of the air spoilers at the joint between the bracket and the holder. It is sectional drawing which abbreviate | omitted the part.

FIG. 8 is a bottom view showing the vehicle antenna according to the embodiment of the present invention, in which a part of the air spoiler is omitted.

FIG. 9 is a perspective view of the vehicle body showing the vehicle antenna according to the exemplary embodiment of the invention, in a state where an air spoiler is attached.

FIG. 10 is a cross-sectional view of a main part of a vehicle body and a vehicle air spoiler, showing a conventional vehicle antenna.

FIG. 11 is a diagram illustrating a conventional vehicle antenna and an example of a specific arrangement of antenna elements.

[Explanation of symbols]

2 air spoiler (exterior part for vehicle), 2c third window (opening), 4 antenna element (first antenna element), 11 bracket, 13 AV line (second antenna element), 15 coaxial cable, 15b
Shielded wire, 15d core wire, 20 volts.

Continued front page    (72) Inventor Noriyuki Hiramatsu             Kojima, 3-30 Shimoichiba-cho, Toyota-shi, Aichi             Press Industry Co., Ltd. (72) Inventor Junzo Oe             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F term (reference) 3D020 BA13 BC13 BC17 BD02 BD05                 5J046 AA01 AA07 AA08 AA09 AA12                       AA19 AB13 MA09 TA04                 5J047 AA01 AA07 AA08 AA09 AA12                       AA19 AB13 EA01

Claims (3)

[Claims] 1. A first antenna element, which is substantially rigid and is arranged in a vehicle exterior component that is a hollow body, and has flexibility, one end of which is electrically connected to the first antenna element. A second antenna element, a coaxial cable having a core wire connected to the other end of the second antenna element, and a shielded wire of the coaxial cable in the vicinity of a connecting portion between the second antenna element and the core wire of the coaxial cable. And an opening formed in the vehicle exterior component so as to expose the vehicle exterior, and the shield wire is electrically connected to the vehicle body through the opening to be grounded. 2. The vehicle antenna according to claim 1, wherein the shield wire is electrically connected to a bolt provided in the opening for fixing the vehicle exterior component to the vehicle body. . 3. The bolt is integrally provided on a conductive metal bracket that reinforces the periphery of the opening,
The vehicle antenna according to claim 2, wherein the shield wire is electrically connected to the bolt via the bracket.