JP2000022417A - Antenna for communication device for mobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of production processes and to prevent a joint part from being bent by providing a stopper projection part of a diameter smaller than the inner diameter of a cylindrical part inside the hollow cylindrical part of a whip antenna side terminal part, embedding the cylindrical part space of a round rod-shaped power feeding terminal with the joint part and embedding the whip antenna terminal part. SOLUTION: A power feeding terminal 2 integratedly has a hollow cylindrical part 11 at the terminal part on the side of a whip antenna 3 and integratedly has a stopper projection part 12 of the diameter smaller than the inner diameter of the cylindrical part 11 inside the cylindrical part 11 of the same diameter as that of the power feeding terminal. The cylindrical part space of the power feeding terminal 2 is embedded with a resin-made joint part 4, and the terminal part of the whip antenna 3 on the side of a helical antenna 1 is embedded and formed. The joint part 4 is formed a little thinner than the power feeding terminal 2. The power feeding terminal 2 is formed into the shape of actually round rod and the strength of the power feeding terminal 2 is improved. The power feeding terminal 2 is provided with a large diameter part 13 for reinforcement near the attachment of the helical antenna 1 to further improve the strength. The stopper projection part 12 of the cylindrical part 11 is embedded in the resin of the joint part 4 and the strength is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna used for a mobile communication device such as a portable telephone.

[0002]

2. Description of the Related Art In recent years, mobile communication devices such as portable telephones have rapidly spread due to their convenience. These devices use an antenna that can be pulled out of the device housing when in use and pushed into the device housing when not in use. This type of antenna usually consists of a combination of an elongated whip antenna (rod antenna) and a short helical antenna attached to its tip (US Pat. No. 5,204,687). The whip antenna and the helical antenna are electrically insulated, and when pulled out of the equipment housing, the whip antenna operates as the equipment antenna, and when pushed into the equipment housing, the helical antenna operates as the equipment antenna It has become.

[0003] In this type of antenna for mobile communication equipment, the following structure has been proposed as a structure for connecting a helical antenna and a whip antenna. The feeding terminal of the helical antenna is a hollow sleeve,
After connecting the hollow sleeve and the end of the whip antenna with a resin joint, a helical antenna is connected to the hollow sleeve (Japanese Patent Laid-Open No. 7-99404). A female screw portion is formed on the whip antenna side of the power supply terminal of the helical antenna, and a male screw portion formed at the end of the whip antenna is screwed and connected to the female screw portion (Japanese Patent Application Laid-Open No. 8-84017).

[0004]

However, in the above-described structure, the strength of the power supply terminal is not sufficient because the power supply terminal is a hollow sleeve. When a drop test of the mobile phone is performed with the antenna pushed in, the helical projecting to the outside is obtained. When the antenna lands first, there is a problem that the power supply terminal is bent or broken at the base of the helical antenna. In addition, in the structure, since the screw connection is performed within the limited outer diameter, it is difficult to secure the strength of the female screw portion or the male screw portion, and a load is applied to the antenna head in a lateral direction with the antenna pulled out. In such a case, there may be a problem that the joint between the power supply terminal and the joint is bent or broken. In addition, both have a complicated structure and require many steps to connect the helical antenna and the whip antenna, resulting in an increase in cost.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a helical antenna in which a power supply terminal or a joint between a power supply terminal and a joint portion is unlikely to be bent or broken, and can be manufactured with a small number of steps. An object of the present invention is to provide an antenna for a mobile communication device.

[0006]

SUMMARY OF THE INVENTION In order to achieve this object, the present invention provides a helical antenna, a power supply terminal connected to one end of the helical antenna, and a resin terminal provided on the opposite side of the power supply terminal from the helical antenna. In a mobile communication device antenna having a whip antenna connected via a joint part, the power supply terminal is formed in a solid round bar shape, and a hollow cylindrical portion is provided at an end on the whip antenna side. The joint portion further has a retaining projection having a diameter smaller than the inner diameter of the cylindrical portion, and the joint portion fills the space in the cylindrical portion of the power supply terminal and the end portion of the whip antenna. It is characterized by being formed in.

Further, in the present invention, it is preferable that the retaining projection of the power supply terminal has an outer diameter of a tip portion larger than an outer diameter of a base portion.

The present invention also provides a helical antenna, a power supply terminal connected to one end of the helical antenna, and a whip antenna connected to a side of the power supply terminal opposite to the helical antenna via a resin joint. In the antenna for a mobile communication device, the power supply terminal has a solid round bar shape, has a hollow cylindrical portion at the end on the whip antenna side, and further has an inner peripheral surface of the cylindrical portion. Has an inward retaining protrusion at an axial end or intermediate portion thereof, and the joint is formed so as to fill the space in the cylindrical portion of the power supply terminal and to bury the end of the whip antenna. It is also possible to adopt a configuration that has been performed.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. [Embodiment 1] FIG. 1 shows an embodiment of the present invention. In the figure, 1 is a helical antenna having a quarter wavelength, 2 is a power supply terminal connected to one end of the helical antenna 1, and 3 is a power supply terminal 2 connected to a power supply terminal 2 via a joint 4 made of resin.
/ 4 wavelength whip antenna, 5 is whip antenna 3
Is a power supply terminal attached to the lower end of the whip antenna 3, and 7 is a holder fixed to the housing 8 of the mobile communication device. The helical antenna 1 is maintained at a constant pitch by a head resin portion 9 which is filled inside the circumscribed cylindrical surface, and a resin coating 10 is applied to the outer periphery.

In this mobile communication device antenna, the power supply terminal 2 of the helical antenna 1 has a solid round bar shape. The round rod-shaped power supply terminal 2 integrally has a hollow cylindrical portion 11 at the end on the whip antenna 3 side, and a retaining projection 12 having a diameter smaller than the inner diameter of the cylindrical portion 11 in the cylindrical portion 11. Have. The cylindrical portion 11 has the same outer diameter as the power supply terminal 2,
The retaining projection 12 has a mushroom shape (a frusto-conical shape is also possible) in which the outer diameter of the tip is larger than the outer diameter of the base.

The joint 4 made of resin fills the space inside the cylindrical portion 11 of the power supply terminal, and the whip antenna 3
Of the helical antenna 1 is embedded. The joint part 4 is formed slightly thinner than the power supply terminal 2. This is for smooth insertion of the power supply terminal 2 into the holder 7. A large-diameter portion 13 for reinforcement is formed in the vicinity of the helical antenna 3 mounting portion of the power supply terminal 2.

When the power supply terminal 2 is formed in a solid round bar shape as described above, the strength of the power supply terminal 2 is increased. Therefore, communication is performed with the whip antenna 3 retracted (the power supply terminal 2 is inserted into the holder 7). Even when an impact load is applied to the head of the antenna (the part incorporating the helical antenna 1) due to dropping of the device, the power supply terminal 2 does not bend or break near the mounting portion of the helical antenna 1. Further, since the power supply terminal 2 has the large-diameter portion 13 provided near the mounting portion of the helical antenna 1, the strength of this portion is further improved, and the power supply terminal 2 is harder to bend or break.

At the joint between the power supply terminal 2 and the joint 4, the retaining projection 12 in the cylindrical portion 11 is embedded in the resin of the joint 4, so that the strength of that portion is reduced. Even if a load is applied to the head of the antenna from the lateral direction with the whip antenna 3 pulled out, the problem that the joint between the power supply terminal 2 and the joint part 4 is broken or bent hardly occurs. In addition, retaining projection 12
Is surrounded by the hollow cylindrical portion 11, the resin around the retaining protrusion 12 is restrained by the metal cylinder 11 having higher rigidity, and the resin around the retaining protrusion 12 is Deformation and breakage of the resin can be prevented.

In the case of this antenna, it is inefficient to form the retaining projection 12 in the cylindrical portion 11 of the power supply terminal 2 by shaving. For this reason, in the example of FIG. 2, the retaining projection 12 is formed by press-fitting a rivet into a hole formed in the bottom of the cylindrical portion 11. In this way, the formation of the retaining projection 12 is simple.

Next, an example of the dimensions and materials of each part of the antenna is as follows. Helical antenna 1 is 0.
4 mm spring steel wire with copper plating wire diameter 4.5 mm,
It is wound about 8 turns at a pitch of 1.5 mm (the material of the helical antenna may be a nickel-plated spring steel wire or a copper alloy wire). One end of the helical antenna 1 is fixed to one end of the power supply terminal 2 by tightening, crimping, crimping, soldering, or the like utilizing the elasticity of the wire. The material of the power supply terminal 2 is an aluminum alloy (brass or stainless steel is also possible). The outer diameter of the power supply terminal 2 is 2.
7 mm, inner diameter of cylindrical part 11 is 2.4 mm, length is 3.0 mm, protrusion
The length of 12 was 1.6 mm, the outer diameter of the base was 1.0 mm, and the outer diameter of the tip was 1.2 mm. The whip antenna 3 uses a superelastic alloy wire such as a Ni-Ti alloy and has an outer diameter of 0.8 mm. The resin of the joint portion 4 is preferably high in strength and low in dielectric constant, such as engineering plastic. In this embodiment, nylon 66 is used.

Next, a method of manufacturing the antenna having the above configuration is shown in FIG.
This will be described with reference to FIG. With the power supply terminal 2 connected to one end of the helical antenna 1, the power supply terminal 2 is divided into two molds.
Held at 21, the helical antenna 1 is set in the first cavity 22 of the mold 21. The whip antenna 3 is
It is held by the mold 11 so that its end is located in the second cavity 23 of the mold 21. An interval of about 3 mm is provided between the whip antenna 3 and the feed terminal 2. The inner diameter of the first cavity 21 is 0 to 0.05 from the outer diameter of the helical antenna 1.
mm, the helical antenna 1
The helical antenna 1 is pressed down by the mold 11 so as not to move.

In this manner, the resin is injected into the cavities 22 and 23 to form the head resin portion 9 and the joint portion 4. In this embodiment, the resin temperature is 200 ° C. and the injection pressure is 80MP.
a. Thereafter, a resin coating 10 for the head portion is formed. Since the joint part 4 and the head resin part 9 can be simultaneously formed in the antenna of the present invention, the manufacture is simple.

In this embodiment, nylon 66 is used for the joint portion 4 and the head resin portion 9. However, nylon 12, polyimide resin, polyacetal, polyetherketone or the like may be used. Further, in this embodiment, the protective coating 5 of the whip antenna 3 is formed after forming the joint portion 4. However, the protective coating 5 of the whip antenna 3 can be formed by using a mold 21 as shown in FIG. , Can be formed simultaneously with the joint portion 4.

[Embodiment 2] FIG. 4 shows another embodiment of the present invention. This antenna is different from that shown in FIG. The stopper projection 14 is formed. Retaining projection
14 may be continuous or discontinuous in the circumferential direction. Since the configuration other than the above is the same as that of the first embodiment,
The same portions are denoted by the same reference numerals. With such a configuration, the same effect as in the first embodiment can be obtained.

[Embodiment 3] FIG. 5 shows another embodiment of the present invention. This antenna is different from that of FIG. 1 in that the retaining projection 12 in the cylindrical portion 11 of the feeding terminal 2 is eliminated, and instead, the antenna extends inward to the axially intermediate portion of the inner peripheral surface of the cylindrical portion 11. The stopper projection 14 is formed. The retaining projection 14 may be continuous in the circumferential direction or may be discontinuous. Since the configuration other than the above is the same as that of the first embodiment, the same portions are denoted by the same reference numerals. With such a configuration, the same effect as in the first embodiment can be obtained.

[0021]

As described above, in the antenna for mobile communication equipment according to the present invention, the power supply terminal has a high strength because the power supply terminal is in the shape of a solid round bar, and the power supply terminal comes off within the cylindrical portion at the end of the power supply terminal. Since the stopper projection or the stopper projection is embedded in the resin of the joint, the coupling strength between the power supply terminal and the joint is high. Therefore, even if an impact force is applied to the head of the antenna with the whip antenna retracted, the power supply terminal is less likely to bend or break, and even if a lateral load is applied to the antenna head with the whip antenna pulled out. There is an advantage that a problem in which a joint portion between the power supply terminal and the joint portion is bent or broken hardly occurs. In addition, since it can be manufactured with a small number of steps, the cost can be reduced.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view showing a preferred structure of a main part of the antenna of FIG. 1;

FIG. 3 is an exemplary sectional view showing an example of a method of manufacturing the antenna of FIG. 1;

FIG. 4 is a sectional view showing another embodiment of the antenna according to the present invention.

FIG. 5 is a sectional view showing still another embodiment of the antenna according to the present invention.

FIG. 6 is a sectional view showing another example of the method for manufacturing an antenna according to the present invention.

[Explanation of symbols]

 1: Helical antenna 2: Feeding terminal 3: Whip antenna 4: Joint part 9: Head resin part 10: Resin coating 11: Cylindrical part 12: Retaining projection 13: Large diameter part 14: Retaining projection

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 5J046 AA06 AA10 AA19 AB06 AB12 JA01 5J047 AA06 AA10 AA19 AB06 AB12 FA11

Claims (3)

[Claims] 1. A helical antenna, a power supply terminal connected to one end of the helical antenna, and a whip antenna connected to the power supply terminal on the opposite side of the helical antenna via a resin joint. In the mobile communication device antenna, the power supply terminal has a solid round rod shape, has a hollow cylindrical portion at the end on the whip antenna side, and further has a diameter smaller than the inner diameter of the cylindrical portion in the cylindrical portion. Mobile communication device, characterized in that the joint portion is formed so as to fill a space inside the cylindrical portion of the power supply terminal and to embed an end of a whip antenna. Antenna. 2. An antenna for a mobile communication device according to claim 1, wherein the retaining projection of the power supply terminal has an outer diameter at a tip end portion larger than an outer diameter at a base portion. 3. A helical antenna, a power supply terminal connected to one end of the helical antenna, and a whip antenna connected to a side of the power supply terminal opposite to the helical antenna via a resin joint. In the mobile communication device antenna, the power supply terminal has a solid round rod shape, has a hollow cylindrical portion at the end on the whip antenna side, and further has an axial direction of an inner peripheral surface of the cylindrical portion. The joint portion is formed so as to fill the space in the cylindrical portion of the power supply terminal and to embed the end portion of the whip antenna. An antenna for a mobile communication device.