JP2881102B2 - Antenna unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a GPS (Global)
The present invention relates to an antenna unit used as a vehicle-mounted antenna for receiving a Positioning System.

[0002]

2. Description of the Related Art As a navigation system for a vehicle, a device using a GPS for detecting a position of a vehicle by receiving a transmission radio wave from a stationary hygiene is becoming widespread. As this GPS receiving antenna, a microstrip patch antenna which is formed in a plate shape by providing an antenna conductor layer and a ground conductor layer with a copper foil or the like on the front and back surfaces of a dielectric substrate is used.

[0003] This flat antenna is disclosed in Japanese Patent Laid-Open No. 5-18 / 1993.
As described in, for example, Japanese Patent No. 3327, the antenna unit is incorporated in a case in a state where it is connected to a circuit board provided with an amplifier circuit and the like, and is mounted on a vehicle or the like in an assembled state as an antenna unit. It is.

[0004]

However, when assembling the antenna in the case as described above, the antenna and the circuit board are aligned and connected, and the antenna is further installed.
In order to form the antenna unit, it is necessary to fix the antenna and the circuit board in the casing using metal fittings or the like, which requires time and labor for assembly.

The present invention has been made in view of the above points, and has as its object to provide an antenna unit that can be easily assembled.

[0006]

An antenna unit according to the present invention comprises a flat antenna 1 having a through hole 2 vertically penetrating therethrough.
And through holes 4 vertically penetrating the circuit board 3, fixing pins 6 projecting upward into the lower case 5, and the antenna 1 is superimposed on the circuit board 3. The through hole 4 of the plate 3 and the through hole 2 of the antenna 1 are respectively inserted into the fixing pins 6, and the circuit board 3 and the antenna 1 are accommodated in the lower case 5, and the height of the fixing pins 6 is Up from hole 2
Set the size so that it does not protrude.
And the lower surface of the upper case 7 is pressed against the upper surface of the antenna 1.

In the present invention, the sealing member 8 surrounding the circuit board 3 and the outside of the antenna 1 can be sandwiched between the lower case 3 and the upper case 7.

[0008]

The through holes 4 of the circuit board 3 and the through holes 2 of the antenna 1 are inserted into the fixing pins 6 projecting from the lower case 5, respectively.
And can be positioned. By pressing the upper surface of the antenna 1 with the upper case 7 mounted on the lower case 3, the circuit board 3 and the antenna 1 can be sandwiched and fixed between the lower case 3 and the upper case 7.

[0009]

The present invention will be described below in detail with reference to examples. As shown in FIG. 3, the antenna 1 is provided with an antenna conductor layer 12 and an earth conductor layer 13 on the front and back surfaces of a dielectric substrate 11 by etching each copper foil using, for example, a double-sided copper-clad laminate. A strip patch antenna having a flat plate shape can be used.
In FIG. 3, reference numeral 14 denotes a through hole provided at the location of the antenna conductor layer 12.

The antenna 1 has a through hole 2 penetrating vertically.
Is drilled. The through holes 2 are provided at the four corners of the antenna 1 avoiding the antenna conductor layer 12 and the ground conductor layer 13 as shown in FIG. The circuit board 3 is made of a printed wiring board provided with an amplifier circuit, an earth circuit, and the like, and is formed in a circular shape in the embodiment of FIG. The upper surface of the circuit board 3 is covered with a copper foil except for the outer peripheral portion, and a resist 15 is applied to the surface thereof, and a connection pad portion 17 is formed except for a part of the resist 15. . The circuit board 3 is provided with a through hole 4 penetrating vertically at a position corresponding to the through hole 2 of the antenna 1.

The lower case 5 is formed in a circular shape from a metal material such as aluminum die cast. A circular enclosure wall 19 is integrally provided on the upper surface of the outer peripheral edge of the lower case 5, and a male screw 20 is formed on the outer peripheral surface of the enclosure wall 19. At least the upper and inner surfaces of the lower case 5 need only be formed of a conductor such as a metal, and the entire case does not necessarily need to be formed of a metal. A circular recess 21 is formed in the center of the upper surface of the lower case 5, and a metal fixing pin 6 protrudes from the upper surface of the lower case 5 at the periphery of the recess 21. The fixing pins 6 may be provided integrally with the lower case 5 at the same time when the lower case 5 is formed, or may be formed by attaching a separate member to the lower case 5. The fixing pins 6 are provided at positions corresponding to the through holes 2 of the antenna 1 and the through holes 4 of the circuit board 3.

The upper case 7 is formed of a thermoplastic plastic such as polycarbonate, fluororesin, or polyphenylene oxide (PPO), and is formed in a circular shape. A peripheral wall 22 hangs down from the lower surface of the outer peripheral end of the upper case 7 and is provided integrally therewith. A female screw 23 is formed on the inner peripheral surface of the peripheral wall 22. The central portion of the lower surface of the upper case 7 Yes recess 25 is provided, also seal such as a rubber sheet or film on the lower surface of the upper case 7 as over the entire circumference of the inner edge of the peripheral wall 22 material 8
Is attached.

Thus, when assembling the antenna unit, the circuit board 3 is set in the surrounding wall 19 of the lower case 5 by inserting the through holes 4 of the circuit board 3 into the fixing pins 6, and further, the antenna 1 is inserted through the through holes 4. The antenna 1 is set on the surrounding wall 19 of the lower case 5 by inserting the hole 2 into the fixing pin 6, and the antenna 1 is mounted on the circuit board 3. By inserting the through holes 4 of the circuit board 3 and the through holes 2 of the antenna 1 into the fixing pins 6 in this manner, the circuit board 3 and the antenna 1 can be positioned with respect to the fixing pins 6. That is, the circuit board 3 and the antenna 1 can be accurately positioned. The connection between the antenna 1 and the circuit board 3 is performed by inserting a power supply pin 24 passed through the through hole 14 of the antenna 1 into a power supply through hole 18 provided on the circuit board 3 and connecting to an amplifier circuit. The connection can be made by bringing the provided connection pad portion 17 into contact with the ground conductor layer 13 on the lower surface of the antenna 1 and connecting the ground portion.

Here, if a metal member is added to the upper surface of the antenna 1, there may be a problem in the antenna characteristics, performance, and the like (accordingly, if the antenna 1 is fixed with a screw or the like, the screw or the like projects on the upper surface of the antenna 1). Not preferred). Therefore, in the present invention, the height of the fixing pin 6 is set so as not to protrude upward from the through hole 2 of the antenna 1, and the upper end of the fixing pin 6 is retracted below the upper surface of the antenna 1 as shown in FIG. The characteristics and performance of the antenna 1 are not affected by the metal fixing pins 6.

Next, the upper case 7 is put on the lower case 5 and the male screw 20 and the female screw 23 are screwed together to attach the upper case 7 to the lower case 5. The antenna unit can be assembled as shown in FIG. When the upper case 7 is screwed and attached to the lower case 5 in this manner, the lower surface of the upper case 7 is pressed against the upper surface of the antenna 1 so that the antenna 1 and the circuit board 3 are connected to the lower case 5.
And the upper case 7 so as to be fixed.

As described above, since the antenna 1 and the circuit board 3 can be sandwiched and fixed between the lower case 5 and the upper case 7, there is no need to fix the antenna 1 and the circuit board 3 using metal fittings or the like. The antenna 1 and the circuit board 3 can be pressed between the lower case 5 and the upper case 7, and the warp and twist of the antenna 1 and the circuit board 3 can be reduced. And the connection pad portion 17 of the circuit board 3 and the ground conductor layer 1 of the antenna 1 are prevented.
3 can be stabilized.

When the upper case 7 is screwed and attached to the lower case 5 as described above, the surrounding wall 19 of the lower case 5
The sealing material 8 provided on the lower surface of the upper case 7 is in elastic contact with the lower surface of the upper case 7 over the entire length, and the antenna 1 and the circuit board 3 are sealed between the lower case 5 and the upper case 7 so that rainwater Etc. are surely prevented from entering. In the embodiment of FIG. 4, the sealing material 8 is provided on the entire surface from the inside of the peripheral wall 22 on the lower surface of the upper case 7 to the peripheral edge of the concave portion 25 , so that not only the upper surface of the surrounding wall 19 of the lower case 5 but also the antenna 1 The sealing material 8 is also elastically contacted with the upper surface, so that the effect of holding the antenna 1 by the upper case 7 can be enhanced.

The sealing material 8 is provided on the upper case 7 as described above.
In addition to the above, it may be provided on the upper surface of the surrounding wall 19 of the lower case 5, or may be provided on both the upper surfaces of the surrounding wall 19 of the upper case 7 and the lower case 5.

[0019]

As described above, according to the present invention, a through-hole penetrating vertically through a flat antenna and a through-hole vertically penetrating through a circuit board are protruded upward into a lower case. The antenna is placed on the circuit board, the through-hole of the circuit board and the through-hole of the antenna are inserted into the fixing pins, and the circuit board and the antenna are accommodated in the lower case. Therefore, the circuit board and the antenna can be positioned with reference to the fixing pin, and the circuit board and the antenna can be accurately aligned at the same time when the circuit board and the antenna are incorporated in the lower case. In addition, the upper case is mounted on the lower case and the lower surface of the upper case is pressed against the upper surface of the antenna, so the antenna and the circuit board are sandwiched between the lower case and the upper case and fixed without using brackets etc. Do Bets can be, to simplify the number of parts and man-hours for assembly, it is capable of the cost as well as improve productivity. Moreover, the height of the fixing pin
Is set so that it does not protrude upward from the antenna hole.
Therefore, the upper end of the fixing pin is located below the top of the antenna.
Uses metal fixing pins without retracting and protruding.
The characteristics and performance of the antenna
Will not be affected.

Also, since the sealing material surrounding the outside of the circuit board and the antenna is sandwiched between the lower case and the upper case, the antenna and the circuit board are sealed between the lower case and the upper case, and the rainwater is removed. Etc. can be reliably prevented from entering.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of the present invention.

FIG. 2 is an exploded perspective view of the embodiment.

FIG. 3 is a sectional view of the antenna according to the first embodiment;

FIG. 4 is a sectional view of another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antenna 2 Through hole 3 Circuit board 4 Through hole 5 Lower case 6 Fixing pin 7 Upper case 8 Sealing material

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yoshihiro Maeda 1048 Odomo Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (56) References JP-A-5-183327 (JP, A) JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01Q 13/00-13/28 H01Q 23/00 H01Q 1/32

Claims (2)

(57) [Claims] 1. A plate-like antenna is provided with a through-hole penetrating vertically and a circuit board is provided with a through-hole penetrating vertically, and a fixing pin projecting upward in a lower case is provided. The antenna is overlaid on the circuit board, the through-hole of the circuit board and the through-hole of the antenna are inserted into the fixing pins , and the circuit board and the antenna are housed in the lower case.
An antenna unit characterized in that it is set so as not to protrude upward from the through hole of the antenna, the upper case is mounted on the lower case, and the lower surface of the upper case is pressed against the upper surface of the antenna. 2. The antenna unit according to claim 1, wherein a seal member surrounding the outside of the circuit board and the antenna is sandwiched between the lower case and the upper case.