JPS60226201A - Antenna mounting structure - Google Patents

Abstract

PURPOSE:To improve the reception sensitivity of a radio set and the effect of rust proof by connecting an antenna earth to a car body via a mounting screw and a spring nut fixing an antenna base of a panel of the car body. CONSTITUTION:Since the antenna earth 17 faces a base hole 19 via an earth plate 17a in the antenna base 3, when the mounting screw 9 is screwed to a screw hole 25 of a terminal part 23 of a spring nut 7 and the base hole 19, while the screw 9 is connected to the earth plate 17a and the terminal part 23, a projection 27 of the screw part 23 rises with a reaction at the screwing and contacts strongly a rear side 1b of the car body panel 1 and is brought into metallic contact while breaking finally the coated face. Thus, the antenna earth wire 17 is grounded to the car body in the short route, the S/N at the reception is improved and the effect of ruse proof of the antenna mounting part is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to an antenna mounting structure most suitable for automobiles.

[Prior art] As a conventional antenna mounting structure, Utility Model Application No. 57-857
There are some as seen in Publication No. 07, for example, No.
As shown in the figure, an antenna base 105 made of synthetic resin, on which an antenna rod 103 is attached, is screwed to a vehicle body panel 101 such as a fender.

A synthetic resin screw grommet 111 is interposed between the mounting screw 107 of the screw fastening part and the mounting hole 109 of the vehicle body panel 101, and the antenna rod 103 and the vehicle body panel 1 are connected to each other.
It is installed in a securely insulated state from 01. For this reason, when the ground wire 117 of the antenna cord 115 connected to the antenna rod 103 and the cord wire 113 is grounded to the body, the ground wire 117 is extended long and fixed to the dash side panel etc. with screws 119. ing.

[Problem] In this mounting structure, the ground wire 1 for body ground
17, because it is longer, it tends to pick up noise from the blower motor (not shown), fan motor (not shown), ignition (not shown), etc., and this also causes the problem of a decrease in reception sensitivity. Ta. Therefore, by forming at least the contact part of the antenna base 105 that makes contact with the vehicle body panel 101 with metal, and directly attaching the ground wire 117 of the antenna cord 115 to the metal part of the antenna base 105 with a screw, the body ground can be shortened. This can be done with wiring, but on the other hand, since the car body panel 101 and the antenna base 105 are in metal contact via screws, the area around the screws will rust.
This was undesirable because there was a risk that the support of the base would be impaired by long-term use.

[Object of the Invention] Therefore, it is an object of the present invention to provide an antenna mounting structure that eliminates body grounding using a ground wire and requires only similar wiring, and is also preferable in terms of rust prevention.

[Structure of the Invention] In order to achieve the above-mentioned object, in the present invention, an insulated antenna base to which an antenna cord is attached is fixed to a vehicle body panel at least in one place with a mounting screw via a spring nut. The mounting screw is connected to the antenna ground wire and connected to a terminal portion provided on the spring collar 1- that breaks through the paint film on the back side of the vehicle body panel and makes metal contact.

[Function] In the above-mentioned mounting structure, since the earth wire for body grounding is connected to the vehicle body panel, the length of the earth wire becomes the shortest wiring.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings of FIGS. 1 to 6.

In the figure, 1 indicates a vehicle body panel such as a fender, and an antenna base 3 is attached to the panel 1.

The antenna base 3 is made of an insulating material made of synthetic resin or the like, and one end fits into the edge of the mounting hole 5 of the vehicle body panel 1, and the other end is fixed with a C mounting screw 9 via a spring nut 7. An extendable antenna rod 11, a cord wire 15 and a ground wire 17 of an antenna cord 13 are integrally insert-molded in the antenna base 3, and the - wire 15 is connected to the antenna rod 11 via a cord plate 15a. There is. Further, the ground wire 17 is connected to a ground plate 17a, and a mounting screw 9 screwed into a base hole 19 is inserted into the tip of the ground plate 17a.

On the other hand, the spring nut 7 is made of brass and has a U-shaped cross section that contacts the front side 1a and the back side 1b of the vehicle body panel 1.The spring nut 7 is made of brass and has a U-shaped cross section that contacts the front side 1a and the back side 1b of the vehicle body panel 1. The material 21 is coated so that metal contact does not occur.

The spring nut 7 has a terminal portion 23 cut and raised into a tongue shape, and the terminal portion main body is provided with a screw hole 25 into which a mounting screw 9 is screwed. Furthermore, a protrusion 27 that makes metal contact with the back side 1b of the vehicle body panel 1 is formed on the free end edge, and the terminal portion 23 is in a state separated from the vehicle body panel 1 before installation as shown in FIG. It is in.

In the antenna mounting structure configured in this way, the ground wire 17 of the antenna cord 13 is connected to the ground plate 17a.
Since it faces the base hole 19 through the mounting hole 5
When screwing the end side of the antenna base 3 engaged with the antenna base 3, insert the spring nut 7 on the end side and screw the mounting screw 9 into the base hole 19 and the screw hole 25 of the terminal part 23. .

When the mounting screw 9 is screwed in, the screw 9 connects with the earth plate 17a and the terminal part 23, while the protrusion 27 of the terminal part 23 rises upward (indicated by arrow A) due to the reaction when screwed into the vehicle body. It comes into strong contact with the back side 1b of the panel 1, eventually breaking the painted surface and coming into metal contact. In this case, the metal contact portion is on the back side 1be of the vehicle body panel 1 and is a point contact, so no rust occurs. Further, the ground wire 17 becomes the shortest wiring.

As a result, as shown in FIG. 5, antenna I of the present invention has increased sensitivity by approximately 0 dB over the conventional antenna II over the entire frequency range used in FM broadcasting. In addition, regarding noise, as shown in Figure 6, the antenna of the present invention (■) has a noise level of 10 dB1/3 compared to the conventional antenna (■).
Reduced. Therefore, the signal-to-noise ratio with the signal V improved, and reception in weak electric field areas became better.

[Effects of the Invention] As explained above, according to the antenna mounting structure of the present invention, the body ground of the earth wire can be wired in the shortest distance, so the receiving sensitivity and noise level of the in-vehicle radio are improved compared to the conventional one. At the same time, there is no possibility of rust occurring from the antenna mounting portion.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the antenna mounting structure of the present invention implemented on a car, Fig. 2 is a cross-sectional view of the main parts, Fig. 3 is a perspective view of the spacer, and Fig. 4 is a cross-sectional view of the antenna before installation. Figures 5 and 6
The figure shows comparison data of sensitivity and noise between the conventional antenna and the present invention, and FIG. 7 is a cross-sectional view similar to FIG. 2 showing the conventional antenna mounting structure. [Explanation of main symbols] 1... Vehicle body panel 3... Antenna base 7...
Spring nut 9...Mounting screw 11...Antenna 0 bolt 13...
・Antenna cord 15...Code line 17...Ground wire 23...Terminal part Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 City 1 rate ft order A≦(sscr) Water-saving detergent Page 8-Figure 7

Claims (1)

[Claims] An insulated antenna base with an antenna rod attached thereto is fixed to the vehicle body panel at least in one place via a spring nut with a mounting screw, and the mounting screw is connected to the antenna ground wire and attached to the spring nut on the vehicle body. Antenna mounting structure characterized by breaking the paint film on the back side of the panel and connecting to the terminal part that makes metal contact.