JP2001085918A - Planar antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a planar antenna with a simple configuration that can surely prevent an antenna main body from vibrating. SOLUTION: The planar antenna is configured with reception sections 17, 18, 19 that receive a radio wave, a lower case 22 on which the reception sections 17, 18, 19 are placed via a packing 20 made of an elastic material and that is fitted to a roof panel or the like of an automobile, an upper case 12 mounted on the lower case 22 to cover an upper part of the lower case 22, a connection cable 15 that is extracted externally from the reception sections 17, 18, 19 through the lower case and the upper case, and a seal member 21 that air-tightly seals between the lower case and the upper case. The planar antenna is configured so that the packing 20 is provided with projections 20e supporting the reception sections 17, 18, 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar antenna used for receiving, for example, GPS.

[0002]

2. Description of the Related Art Conventionally, so-called GPS (Global Positionion), which is widely used as a positioning system, for example, has been known.
ng System) antenna system:
A planar antenna for receiving radio waves from a GPS artificial satellite is attached to a metal roof panel of an automobile by magnetic attraction, for example, and is configured as shown in FIG. 6, for example.

In FIG. 6, a planar antenna is a circuit board 1b on which an antenna element 1a and associated circuit elements are mounted.
The antenna body 1 can be attached to a roof panel or the like of a car by magnetic attraction in a state of being housed in a resin case for waterproofing and dustproofing. That is, the flat antenna body 1 whose surface opposite to the antenna element 1a is shielded by the shield box 1c is housed between the lower case 3 and the upper case 4, and is connected to the GPS device side by the cable 1d. It is supposed to be.

The lower case 3 is made of a synthetic resin. After the antenna main body 1 is accommodated in the upper concave portion 3b, the lower case 3 is combined with an upper case 4 that covers the entire surface of the lower case 3. A pair of permanent magnets 2L and 2R that are magnetically attracted to the surface of the roof panel are integrally mounted on both sides of the bottom surface of the lower case 3, and a ring-shaped packing is formed on the upper surface of the lower case 3. 6 has a cylindrical portion 3a with which it contacts. The cylindrical portion 3a is provided with a groove 8 through which the cable 1d is inserted.

On the other hand, the opening of the upper case 4
A cylindrical opening 4a into which the lower case 3 can be dropped is formed, and a cylindrical projection 4b extending toward the end face of the cylindrical portion 3a is integrally formed on the inner periphery of the cylindrical opening 4a. The tip of 4 b is pressed against the surface of the packing 6. And the cylindrical projection 4b
A plurality of engaging claws 4c arranged at equal angular intervals in the circumferential direction of the cylindrical projection 4b are integrally formed on the inner peripheral surface of the cylindrical portion 4a, and the cylindrical portion 3a corresponding to these engaging claws 4c is formed. A plurality of lock claws 3c which can be engaged with corresponding engagement claws 4c each having a pitch angle inclined in the circumferential direction are integrally formed on the lower case 3 on the outer peripheral surface of the lower case 3.

The permanent magnets 2L and 2R are integrally assembled on both sides of the bottom surface of the lower case 3 made of synthetic resin by insert molding or the like. Four rubber legs 7 having elasticity are inserted between the concave portion of the back yoke 9 and the permanent magnets 2L and 2R. The rubber leg 7 is a permanent magnet 2
L and 2R project below, and when mounting the planar antenna, the permanent magnets 2L and 2R do not damage the roof panel by abutting on the automobile roof panel before the permanent magnets 2L and 2R. ing.

[0007]

By the way, in the planar antenna having such a configuration, the antenna main body 1 is provided with a rubber packing (not shown) in order to suppress the vibration from the lower case 3. , On the upper surface of the lower case 3. However, the conventional packing has an upper surface formed as a flat surface, and the entire lower surface of the antenna main body 1 is in contact with the upper surface of the packing. For this reason, a good anti-vibration effect cannot be obtained, and the antenna main body may be damaged by vibration,
There has been a problem that reliability is reduced.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a planar antenna capable of reliably damping an antenna body with a simple configuration.

[0009]

According to the present invention, there is provided a receiving section for receiving a radio wave, and the receiving section is mounted via a packing made of an elastic material and attached to a roof panel or the like of an automobile. Lower case, and an upper case attached to the lower case so as to cover the upper part of the lower case,
In a planar antenna including a connection cable that is drawn out from a receiving unit through the lower case and the upper case to the outside, and a seal member that keeps the space between the lower case and the upper case airtight, the packing includes: This is achieved by a planar antenna comprising a plurality of protrusions for supporting a receiving unit.

[0010] According to the above configuration, the receiving section is mounted on the lower case via the packing, and the receiving section is supported only by the projection provided on the packing. Even if the vibration from the car is transmitted from the lower case to the packing, the vibration is absorbed by the projections, and almost no vibration is transmitted from the packing to the receiving section via the projections. The vibration effect is improved, and the reliability of the planar antenna is improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. 1 to 5 show an embodiment of the planar antenna according to the present invention. 1 and 2, the planar antenna 11 has a flat rectangular upper case 12 in which an antenna element to be described later is accommodated, and an aluminum ground sheet 13 is adhered to the bottom. Openings 13a are provided at four corners of the ground sheet 13 so that the rubber legs 14 protrude when the planar antenna 11 is mounted (see FIG. 5). The upper case 12 is provided with an inverted U-shaped groove 16 through which the cable 15 is inserted on one of the four sides.

The planar antenna 11 includes a planar antenna element (receiver) 17, an LNA (low noise amplifier) board 18 on which the planar antenna element is mounted,
Shield case 19, rubber packing (seal member) 20 having rubber legs 14, seal member 21 for sealing a mounting portion of cable 15, bottom plate 2 as lower case
2 are stored.

The bottom plate 22 is formed by pressing a metal plate made of a magnetic material such as stainless steel.
The magnet mounting part is integrated. The bottom plate 22 is attached such that four screws 23 are screwed into the upper case 12 to close the bottom opening of the upper case 12. Then, at the time of assembling, after the bottom plate 22 is screwed to the bottom of the upper case 12 with screws 23, the ground sheet 13 is attached to the lower surface of the bottom plate 22.

As shown in FIG. 3, the bottom plate 22 has a rectangular sheet portion 24 which is in contact with the rubber packing 20.
Four insertion holes 25 provided outside the seat portion 24 and through which the screws 23 are inserted, and rectangular insertion holes 26 provided at four corners outside the seat portion 24 and through which the rubber legs 14 are inserted;
A pair of permanent magnets 27 and 2 magnetically attracted to a car body
8 (27a, 27b, 28a, 28b).

The magnet mounting portions 29, 30 are formed corresponding to the dimensions and shapes of the permanent magnets 27, 28, respectively, and function as a back yoke when the permanent magnets 27, 28 are mounted. 28 increases the magnetic attraction force.

Further, as shown in FIGS. 2 and 3, the bottom plate 22 is provided at a portion where the seal member 21 contacts.
A projection 31 formed in parallel with the seat 24 and a support 32 for supporting the cable 15 at a predetermined height are provided. The convex portion 31 works together with the sheet portion 24 to press the portion of the rubber packing 20 through which the cable 15 is inserted so as to enhance the sealing effect on the cable 15. The support portion 32 is formed integrally with the bottom plate 22 so as to protrude into a notch 32 a provided on a side edge of the bottom plate 22.

As shown in FIG. 4, the rubber packing 20 includes a flat plate portion 20a having an area facing the bottom plate 22 and abutting on the sheet portion 24, and a sheet portion 2a.
4 is engaged with a contact portion 20b formed in a rectangular frame shape corresponding to the support portion 32 inside the upper case 12 and a seat portion 33 inside the upper case 12 formed so as to correspond to the seat portion 24. Parallel projection 20c whose mounting position is regulated
A quadrangular support portion 20d for supporting the rubber legs 14 integrally formed at the four corners of the flat plate portion 20a;
and a plurality (four in the illustrated case) of projections 20e integrally formed so as to slightly project upward from the upper surface defined by the abutting portion 20b of FIG. This projection 2
Reference numeral 0e abuts on the lower surface of the shield case 19 as a receiving portion or an antenna body, thereby supporting the shield case 19 in a state of being lifted from the flat plate portion 20a of the rubber packing 20.

The planar antenna 11 according to the embodiment of the present invention
Is configured as described above, and the rubber leg 14 of the rubber packing 20 is inserted through the insertion hole 26 in a state where the planar antenna element 17, the LNA substrate 18, and the shield case 19 are housed inside the upper case 12. Bottom plate 22
Is aligned with the bottom opening of the upper case 12, and the screw 23 is tightened to assemble the planar antenna 11 as shown in FIGS.

Here, since the shield case 19 is supported on the flat portion 20a of the rubber packing 20 in a state of being raised by the projection 20e, the flat antenna 11 is mounted on a vehicle body such as a roof panel of an automobile. When used, even if vibrations from an automobile are transmitted from the bottom plate 22 of the planar antenna 11 to the rubber packing 20, the projections 20e absorb the vibrations. Therefore, the vibration of the automobile is hardly transmitted to the receiving portion or the antenna main body composed of the planar antenna element 17, the LNA substrate 18, and the shield case 19, so that the vibration can be reliably prevented. As a result, the planar antenna element 17 and the LNA substrate 18 are prevented from causing a failure such as a contact failure due to vibration, and the reliability of the planar antenna 11 is improved.

In the above embodiment, for example, the GP
Although the planar antenna for S has been described, it is apparent that the present invention is not limited to this and can be applied to planar antennas for other applications.

[0021]

As described above, according to the present invention, the receiving section is mounted on the lower case via the packing, and the receiving section is supported only by the projection provided on the packing. Therefore, even if the vibration from the car on which the planar antenna is mounted is transmitted from the lower case to the packing, the vibration is absorbed by the projection, and almost the vibration is transmitted from the packing to the receiving unit via the projection. Since the signal is not transmitted, the vibration isolating effect of the receiving unit is improved, and the reliability of the planar antenna is improved.

Thus, according to the present invention, the antenna body can be reliably prevented from vibration by a simple structure.
A very good planar antenna can be provided.

[Brief description of the drawings]

FIG. 1 is an exploded sectional view showing an embodiment of a planar antenna according to the present invention.

FIG. 2 is an enlarged sectional view of the planar antenna of FIG.

3A and 3B show a bottom plate used in the planar antenna of FIG. 1, wherein FIG. 3A is a plan view and FIG. 3B is a side view.

4A and 4B show a rubber packing used in the planar antenna of FIG. 1, wherein FIG. 4A is a bottom view, FIG. 4B is a left side view, FIG. 4C is a plan view, and FIG. , And (E) are front views.

FIG. 5A shows an attached state of the planar antenna of FIG. 1, and FIG.
Is a side view, and (B) is a bottom view.

FIG. 6 is an exploded perspective view showing a configuration of an example of a conventional planar antenna.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Planar antenna 12 Upper case 13 Ground sheet 14 Rubber leg 15 Cable (connection cable) 17 Planar antenna element (receiver) 18 LNA board (receiver) 19 Shield case (receiver) 20 Rubber packing (packing) 20e Projection 21 Seal Member 22 Bottom plate (lower case)

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Shinobu Oguma 95th Iizuka-shi, Iizuka-cho, Minami-Akita-gun, Akita 95-2, F-term in Akita Mitsumi Co., Ltd. 5J045 AB02 AB09 CA04 DA10 KA02 MA04 NA06 5J046 AA05 AA14 AA15 AB00 AB13 CA10 MA09 MA13 QA02 5J047 AA05 AA14 AA15 AB00 AB13 EB01 EB04

Claims (1)

[Claims] 1. A receiving unit for receiving a radio wave, a lower case in which the receiving unit is mounted via a packing made of an elastic material and is attached to a roof panel of an automobile, and a lower case for covering an upper part of the lower case. An upper case attached to the case, a connection cable drawn out from the receiver through the lower case and the upper case, and a seal member for hermetically holding the lower case and the upper case. A planar antenna, comprising: a plurality of projections for supporting a receiving unit, wherein the packing includes a plurality of projections.