JP2001024415A - Transmission and reception cap antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable and inexpensive cap antenna which is obtained by resin-molding a cap antenna by W injection molding or two color molding and forming a coil-shaped antenna on the surface of the molding by plating. SOLUTION: A primary resin molded article 3 of which plating performance is superior is constituted by forming a female screw 1 on the inside face and a screw groove 2 on the outside face at the upper part of the bottom part, and a secondary resin molding 4 is constituted by operating W injection molding or two color molding to a valley part 2b of the screw groove 2 of the primary resin molding 3 of non-plating resin materials so that the valley part 2b of the screw groove can be filled. Plating is operated to a mounting part 2a of the screw groove 2 and the female screw 1 on the bottom face and inside of the primary resin molding 3, and the mounting part 2a of the screw groove 2 is formed as a coil-shaped antenna 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electric and electronic equipment parts,
For example, the present invention relates to a transmitting / receiving cap antenna for a built-in antenna weak radio, and particularly to a transmitting / receiving cap antenna in which a cap antenna is resin-molded by W injection or two-color molding and a coil-shaped antenna is formed by plating on the surface of a molded product. The present invention relates to the manufacturing method.

[0002]

2. Description of the Related Art The present applicant has filed a Japanese Patent Application No. Hei 10-35831.
In No. 6, by installing a coiled antenna inside the tire valve cap located at the tip of the valve stem, radio waves are efficiently emitted, the influence of the wheel design is minimized, and the transmission performance is significantly improved. A tire pressure warning device that can be improved is proposed.

FIG. 4 is a longitudinal sectional view of a conventional cap antenna. This cap antenna 10 is provided with a cap body 12 by insert-molding a metal nut 11, and a wire is wound around the outer surface of the cap body 12 to form a coil-shaped antenna 13.
The terminal of the antenna 13 and the end of the metal nut 11 are connected to the solder
4, and thereafter, a covering portion 15 integrated with the cap body 12 is formed by, for example, mold casting. The antenna 13
Has adjusted the length of the conductor wound in a coil shape to the required performance.

[0004]

However, the conventional cap antenna has not only a large number of parts but also a metal nut 11 and a coiled antenna 13 formed by winding a conductive wire, and the production process is complicated and the production efficiency is low. There was a problem. In addition, some parts require a mold, which raises a problem that the product cost is increased. Further, in the soldering operation, a slight displacement of the antenna occurs due to heating and pressurizing during the soldering, so that it is difficult to form an accurate conductive antenna circuit, and the reliability is unstable.

There is also known an injection molding method in which a conductor paste is printed on a resin film, an adhesive is applied, drying and firing are repeated, and a transfer film is insert-molded to form an antenna. In the case of forming a three-dimensional circuit such as the cap antenna of the present invention, the film does not follow the molded shape, and the film is torn, so that there are restrictions on the shape and the shape portion where the undercut portion appears Could not follow the shape.

[0006]

SUMMARY OF THE INVENTION The present invention provides a transmitting / receiving cap antenna in which a cap antenna is resin-molded by W injection or two-color molding, and a coiled antenna is formed on the surface of the molded product by plating. Accordingly, it is an object of the present invention to provide a highly reliable and inexpensive cap antenna.

That is, the first invention of the present application is a primary resin molded product excellent in plating property, in which a female screw 1 is formed on the inner surface and a screw groove 2 is formed on the outer surface upward from the bottom. The secondary resin molded product 4 is formed by W injection molding or two-color molding with a non-plating resin material so as to fill the thread groove 2b of the screw groove 3 with the thread groove 2b,
The transmitting / receiving cap antenna according to claim 1, wherein the thread portion 2a, the bottom surface, and the internal thread 1 on the inner surface of the primary resin molded product are plated to form the thread portion 2a on the coil-shaped antenna 5. is there.

In the second invention of the present application, a plurality of through holes 6 connected to the valleys 2b of the screw grooves are provided near the outer peripheral edge of the upper surface of the primary resin molded product 3 for secondary molding. 2. The transmission / reception cap antenna according to claim 1, wherein the resin flows into the screw valley portion 2b from the through hole 6.

In a third aspect of the present invention, a resin cover (7) is hermetically integrated with an outer surface of a secondary resin molded product (4) to provide weather resistance, corrosion resistance and appearance design. The transmission / reception cap antenna according to claim 1 or 2, wherein the transmission / reception cap antenna has improved characteristics and the like.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a transmitting / receiving cap antenna according to the present invention, FIG. 2 is a perspective view of a primary resin molded product viewed from above, and FIG. 3 is a perspective view of a secondary resin molded product viewed from below. . The cap antenna of the present invention has a structure shown in FIG.
A secondary resin molded product shown in FIG. 3 is formed by subjecting the secondary resin molded product 3 to W injection or two-color molding, and a coil-shaped antenna 5 is provided on the surface of the secondary resin molded product.
Is formed by plating.

The primary resin molded product 3 is shown in FIGS.
As shown in FIG. 1, a female screw 1 is formed on the inner surface, and a screw groove 2 is formed on the outer surface upward from the bottom.
A plurality of through-holes 6 are provided near the outer peripheral edge of the upper surface of the primary resin molded product 3 and are connected to the valleys 2b of the screw grooves. It can be easily poured into the thread valley 2b.

The material of the primary resin molded product 3 may be a resin having excellent plating properties, for example, a thermoplastic resin such as acrylonitrile butadiene styrene, modified polyphenylene oxide, or the like, if heat resistance such as solder mounting is required. And a thermoplastic resin such as liquid crystalline polyester and polyphenylene sulfide. Further, the primary resin molded product 3 may be subjected to chemical etching or physical surface treatment suitable for the material as necessary.

The secondary resin molded product 4 is shown in FIGS.
As shown in the figure, the upper surface portion of the primary resin molded product 3 and the valley portion 2b of the screw are filled by W injection or two-color molding. The material of the secondary resin molded product 4 must be a non-plated resin material and appropriately selected in consideration of various physical properties depending on the intended use of the antenna circuit. For example, polycarbonate resin, polyamide-
6 resin, polypropylene resin or the like can be used.

In the state of the secondary resin molded product 4, the coil-shaped antenna 5 is formed, for example, by electroless copper plating on the crest 2 a of the thread groove, the bottom surface, and the internal thread 1 of the primary resin molded product. It is formed by applying. The plating is for forming a conductive film having an appropriate thickness by a conventionally known method.

The cover 7 made of resin is hermetically integrated with the outer surface of the secondary resin molded product 4 to protect the coiled antenna 5 and to provide the weather-resistant and corrosion-resistant functions of the transmitting / receiving cap antenna. And the appearance and design are improved.
Note that the resin cover 7 is not always necessary, and may be used as needed.

[0016]

The cap antenna of the present invention is formed by resin molding by W injection or two-color molding, and the coil-shaped antenna is formed on the surface of the molded product by plating. Compared with the antenna, the number of parts is small and the production process is simplified, so that the antenna can be produced at low cost. In addition, since the conventional soldering work is not required, the instability of the reliability due to the positional deviation that occurs when heating and pressing by this work can be eliminated. Further, by providing the protective cover, the weather resistance function, the corrosion resistance function, the appearance design, and the like as the cap antenna can be improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a transmitting / receiving cap antenna according to the present invention.

FIG. 2 is a perspective view of a primary resin molded product viewed from above.

FIG. 3 is a perspective view of a secondary resin molded product viewed from below.

FIG. 4 is a longitudinal sectional view of a conventional cap antenna.

[Explanation of symbols]

1 internal thread 2 thread groove
2b Root of thread groove 2a Crest of thread groove 3 Primary resin molded product
4 Secondary resin molded product 5 Coiled antenna 6 Through hole
7 Resin cover 10 Cap antenna 11 Metal nut
12 Cap body 13 Coiled antenna 14 Solder
15 Coating part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F055 AA12 BB20 CC60 DD11 EE40 FF31 FF34 GG01 GG11 HH19 5J046 AA05 AA19 AB00 AB06 AB12 PA01 QA02

Claims (3)

[Claims] An internal plating (1) has a female screw (1) formed on an inner surface thereof, and a screw groove (2) is formed on an outer surface upward from a bottom portion. In the valley (2b) of the screw,
A secondary resin molded product (4) is formed by W injection molding or two-color molding with a non-plating resin material so as to fill the valley portion (2b) of the screw groove, and a screw groove of the primary resin molded product is formed. A transmitting / receiving cap antenna characterized in that the crest (2a), the bottom surface, and the internal screw (1) on the inner surface are plated, and the crest (2a) of the screw is formed in a coil-shaped antenna (5). 2. In the vicinity of the outer peripheral edge of the upper surface of the primary resin molded product (3),
A plurality of through holes (6) connected to the valleys (2b) of the screw grooves are provided, and resin for secondary molding is formed through holes.
2. The transmitting / receiving cap antenna according to claim 1, wherein said cap is adapted to flow into a thread valley (2b) from (6). 3. A resin cover (7) is hermetically integrated with an outer surface of a secondary resin molded product (4) to improve weather resistance, corrosion resistance and appearance design. The transmission / reception cap antenna according to claim 1 or 2, wherein: