JP4629879B2 - Whip antenna and manufacturing method thereof - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a whip antenna, and more particularly to a structure of a whip antenna in which a lower portion of an element is electrically contacted to be fed.
[0002]
[Prior art]
Conventionally, portable wireless devices have been provided with an antenna outside or inside the housing 1, radiated radio waves from the antenna, and captured radio waves with the antenna to perform transmission / reception operations. In particular, as shown in FIG. 6, the cellular phone includes a whip antenna 2 that can be extended at the top of the casing 1 of the cellular phone.
[0003]
Further, a multi-stage whip antenna in which a small-diameter element 10 is disposed so as to be housed inside a large-diameter element 30, is telescopically housed, and has a short antenna length when housed in the portable wireless device 1. There is also. In such a multi-stage whip antenna, the lower part of the upper element 10 is in electrical contact with the lower element 30 to supply power to the upper element 10 so that the upper element 10 and the lower element 30 are integrated as one element. Configured to work.
[0004]
Conventionally, multi-stage telescopic antennas have been mainly called rod antennas used in broadcast receivers (so-called radios). In this rod antenna, the tip of the lower element is narrowed down, and a spring contact is provided inside the lower element so as to contact the outside of the upper element (for example, JP-A-9-307324).
[0005]
[Problems to be solved by the invention]
In the conventional rod antenna, the spring contact for contacting the lower element and the upper element is inserted into the lower element from the lower side and provided inside the tip of the lower element. Therefore, this spring contact rotates inside the lower element, the upper element and the lower element are temporarily separated, and the contact between both elements may become unstable.
[0006]
Further, since the contact spring is provided inside the tip of the lower element, it is difficult to fix the contact spring so as not to rotate inside the lower element. For example, if caulking, welding, or the like is performed from the outside of the lower element at the position of the spring contact, the shape of the spring contact may be distorted, and it may not be possible to ensure proper contact between the upper element and the lower element.
[0007]
As described above, when the contact between the upper element and the lower element becomes unstable, the electrical length of the antenna changes, the resonance frequency of the antenna changes, and the radiation efficiency from the antenna decreases.
[0008]
An object of the present invention is to provide a whip antenna capable of ensuring reliable contact of elements in a telescopic whip antenna.
[0009]
[Means for Solving the Problems]
In the first invention, the first element (upper element 10) slides in a cylindrical second element (lower element 30) having a diameter larger than that of the first element and is connected to each other so as to be able to expand and contract in the axial direction. In the whip antenna configured as described above, the first element includes at least a rod-shaped conductor (15), a covering portion (tube 16) that covers the rod-shaped conductor, and a spring that contacts the rod-shaped conductor and the second element. And a fixing portion (sleeve 19) fixed to the rod-shaped conductor, and the spring is between the covering portion and the fixing portion, and the covering portion is shorter than the natural length of the covering portion. The position of the fixing portion is determined so as to be disposed at a position where the fixing portion is placed.
[0010]
According to a second aspect of the invention, the first element (upper element 10) slides in a cylindrical second element (lower element 30) having a diameter larger than that of the first element and is connected to each other so as to be able to expand and contract in the axial direction. In the whip antenna configured as described above, the first element includes at least a rod-shaped conductor (15), a covering portion (tube 16) that covers the rod-shaped conductor, and a spring that contacts the rod-shaped conductor and the second element. The fixing portion (sleeve 19) is fixed to the rod-shaped conductor, and the position of the fixing portion is determined in a state where the spring presses the covering portion in the antenna tip direction. To do.
[0011]
According to a third aspect of the invention , the first element (upper element 10) slides in a cylindrical second element (lower element 30) having a diameter larger than that of the first element and is connected to each other so as to be able to expand and contract in the axial direction. In the whip antenna configured as described above, the first element includes at least a rod-shaped conductor (15), a covering portion (tube 16) that covers the rod-shaped conductor, and a spring that contacts the rod-shaped conductor and the second element. The first element includes a contact portion that restricts movement of the spring in the axial direction, and the spring includes the abutment portion that is fixed to the rod-shaped conductor. in the between the abutting portion and the stationary portion, so as to be disposed in a position to shorten the contact portion than the natural length of the spring, (while pressing the cover portion) Wherein the position of the fixed portion are determined.
[0013]
According to a fourth invention, in the third invention, the abutting portion is formed at an end portion (end surface of the tube 16) of the covering portion covering the rod-shaped conductor.
[0014]
According to a fifth invention, in the first to fourth inventions, the covering portion is made of a synthetic resin having elasticity capable of expanding and contracting in an axial direction of the first element.
[0015]
Sixth invention, in the first to fifth invention, the spring is characterized by a Turkey which have a stretchable elastic in the axial direction of the element.
[0016]
In a seventh aspect based on the first to sixth aspects, at least one end of the spring is a thin tube (cylindrical portion 18a at both ends), and the other portion has a large diameter (central large diameter portion 18b). ).
[0017]
An eighth invention is the sleeve (19) according to the first to seventh inventions, wherein the fixing portion is configured in a cylindrical shape into which the rod-shaped conductor can be inserted, and is fixed to the rod-shaped conductor by caulking. It is characterized by that.
[0018]
According to a ninth aspect of the invention, the first element (upper element 10) slides in a cylindrical second element (lower element 30) having a diameter larger than that of the first element and is connected to each other so as to be able to expand and contract in the axial direction. And at least a rod-shaped conductor (15), a covering portion (tube 16) covering the rod-shaped conductor, a spring (18) for contacting the rod-shaped conductor and the second element, and a fixed portion fixed to the rod-shaped conductor. And a step of covering the rod-shaped conductor with the covering portion, a step of inserting a spring into the rod-shaped conductor, and the fixing portion covering the spring. A step of fixing the fixing portion to the rod-shaped conductor in a state of being pressed against the portion.
[0019]
In a tenth aspect of the invention, the first element (upper element 10) slides in a cylindrical second element (lower element 30) having a diameter larger than that of the first element, and is connected to each other so as to be able to expand and contract in the axial direction. In addition, at least the rod-shaped conductor (15), a covering portion (tube 16) covering the rod-shaped conductor, a spring (18) for bringing the rod-shaped conductor and the second element into contact with each other, and fixing fixed to the rod-shaped conductor. parts a method of producing a whip antenna which is constituted by a (sleeve 19), the spring, so abuts the abutting portions, the step of inserting the rod-like conductor, the said fixing portion is the spring cover portion A step of fixing the fixing portion to the rod-shaped conductor in a state of being pressed.
[0020]
Operation and effect of the invention
In the first aspect of the invention, the spring of the first element is fixed portion is fixed so as to be disposed in a position to shorten the cover portion than the natural length of the cover portion, the position of the spring is determined by the fixing unit, the spring and since the spring is fixed in a state where the are in contact covering portion, without having to rotate between the fixing portion spring cover portion, the first element and the second element can be reliably contacted.
[0021]
In the second invention, since the spring of the first element presses the covering portion toward the tip of the antenna, the fixing portion is fixed, and the position of the spring is determined by the fixing portion, so the spring and the covering portion are in contact with each other. since the spring is fixed in a state without having to rotate between the fixing portion spring cover portion, the first element and the second element can be reliably contacted.
[0022]
In the third aspect of the invention, than the natural length of the spring of the first element is fixed portion fixed to be positioned to shorten the spring, the position of the spring is determined by the fixed part, abutting a spring Since the spring is fixed in a state where the part is in contact, the spring does not rotate between the abutting part and the fixed part, and the first element and the second element are reliably in contact with each other.
[0024]
In the fourth invention, since the abutting portion is formed at the end of the covering portion covering the rod-shaped conductor, it is not necessary to provide the abutting portion specially.
[0025]
In the fifth invention, since the covering portion is made of a synthetic resin having elasticity that can be expanded and contracted in the axial direction of the first element, the spring and the covering portion are reliably in contact with each other by the repulsive force of the covering portion, The rotation of the spring can be effectively suppressed.
[0026]
In the sixth invention, the spring has elasticity that can be expanded and contracted in the axial direction of the first element, and in the seventh invention, the spring has a cylindrical shape with both ends being thick and the central portion has a large diameter. since the spring has a stretchable elastic in the axial direction of the first element may be a spring and a covering portion or the fixed portion by the repulsive force of the spring to secure contact, to effectively prevent rotation of the spring .
[0027]
In the eighth aspect of the invention, the fixing part is configured in a cylindrical shape into which a rod-shaped conductor can be inserted, so that the fixing part can be easily manufactured. Furthermore, since the fixing portion is fixed to the rod-like conductor by caulking, the fixing portion can be easily attached.
[0028]
In the ninth aspect of the invention, there are a step of covering the rod-shaped conductor with the covering portion, a step of inserting a spring into the rod-shaped conductor, and a step of fixing the fixing portion to the rod-shaped conductor in a state where the spring is pressed against the covering portion. , since the spring is fixed in a state in which the spring and the coating unit is in contact, since the position of the spring is determined by the fixing unit, without having to rotate between the fixing portion spring cover portion, the first A whip antenna in which the element and the second element are in reliable contact can be manufactured.
[0029]
In the tenth invention, since the spring has a step of inserting into the rod-shaped conductor until it strikes the abutting portion, and a step of fixing the fixing portion to the rod-shaped conductor in a state where the fixing portion presses the spring against the covering portion , the spring since the spring in a state where the bets abutting portion comes into contact is fixed, since the position of the spring is determined by the fixing unit, without having to rotate between the fixing portion spring abutting portions, the first A whip antenna in which the element and the second element are in reliable contact can be manufactured.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Next, a first embodiment of the present invention will be described with reference to the drawings.
[0031]
FIG. 1 is a side view when the whip antenna according to the embodiment of the present invention is extended.
[0032]
In the whip antenna 2 according to the embodiment of the present invention, a lower element 30 is disposed below the upper element 10, and both elements are connected by a joint fitting 31 fixed to the tip of the lower element 30. Is configured to be housed in the lower element 30.
[0033]
The upper element 10 is configured with a rod-shaped conductor 15 as the center. When the rod-shaped conductor 15 is preferably formed of a superelastic alloy, an element that is not easily deformed by bending stress can be obtained. The periphery of the rod-shaped conductor 15 is covered with an insulating synthetic resin tube 16 so that the conductive metal element is not exposed.
[0034]
A synthetic resin cover 12 containing a coil element 11 is provided at the upper end of the upper element 10. A metal fitting 13 having a diameter larger than that of the upper element 10 is provided at the lower portion of the cover 12. The metal fitting 13 functions as a power supply metal fitting that contacts the support 50 attached to the housing 1 when the antenna is housed and supplies a high frequency signal to the coil element 11. Furthermore, a synthetic resin joint 14 is provided inside the metal fitting 13 to insulate and fix the upper element 10 and the metal fitting 13.
[0035]
The lower element 30 is configured such that a metal wire is spirally wound to form a hollow cylindrical element, and the upper element 10 can slide into and out of the space inside the lower element 30. . This wire has an oval cross-sectional shape in which the expansion / contraction direction of the whip antenna 2 is a long diameter (the radial direction of the element is a short diameter), and the lower element 30 is secured while maintaining the strength without reducing the cross-sectional area of the wire. The inner diameter is increased without increasing the outer diameter. The periphery of the lower element 30 is covered with an insulating synthetic resin tube 33 so that the conductive wire is not exposed.
[0036]
A joint fitting 31 is fixed to the upper end of the lower element 30, and the upper element 10 is restricted from sliding upward by abutting against a washer 17 attached to the upper element 10, which will be described later. The element 10 is configured so as not to fall out from the lower element 30. A metal fitting 34 having a diameter larger than that of the lower element 30 is provided at the lower end of the lower element 30, and the support 50 attached to the housing 1 and the metal fitting 34 come into contact with the lower element 30 when the antenna is extended. It functions as a power supply fitting that supplies signals.
[0037]
The support 50 is attached to the case 1 of the portable wireless device (the surface of the case is indicated by a broken line), is electrically connected to the transmission / reception unit of the portable wireless device, and supplies power to the whip antenna 2 Functions as a contact. The support 50 is positioned below the lower element 30 when the antenna is extended, and supplies power to the lower element 30 in contact with the metal fitting 34.
[0038]
FIG. 2 is a side view of the whip antenna according to the embodiment of the present invention when stored.
[0039]
FIG. 2 differs from FIG. 1 in that the whip antenna 2 is housed in the housing 1. Specifically, the upper element 10 is housed in a space inside the lower element 30, and the lower element 30 is housed in an antenna housing space provided inside the housing 1 (the housing surface is indicated by a broken line). Has been. Therefore, only the coil element 11 covered with the cover 12 protrudes from the housing 1 when the antenna is housed.
[0040]
When the antenna is accommodated, the upper element 10 is lowered so as to be accommodated in the lower element 30 until the joint 14 comes into contact with the joint fitting 31. The support 50 is located above the upper element 10 (below the cover 12 of the coil element 11), contacts the metal fitting 13, and supplies a high-frequency signal to the coil element 11.
[0041]
FIG. 3 is a side view of the upper element 10 of the whip antenna shown in FIG.
[0042]
Most of the rod-shaped conductor 15 constituting the upper element 10 is covered with the tube 16, but the lowermost portion is not covered with the tube 16, and the rod-shaped conductor 15 is exposed. A washer 17, a spring 18, and a sleeve 19 are inserted into the bar-shaped conductor 15 in this order from a position close to the tube 16 at the exposed portion of the bar-shaped conductor 15.
[0043]
The washer 17 is provided as a stopper for preventing the upper element 10 coming into contact with the joint fitting 31 from being detached, and as a stopper for preventing the spring 18 from entering between the rod-shaped conductor 15 and the tube 16 or biting into the tube 16. Yes. The spring 18 has a cylindrical portion 18a having an inner diameter matching the diameter of the rod-shaped conductor 15 at both ends and a large-diameter portion 18b at the center, and is in contact with the rod-shaped conductor 15 at the cylindrical portion 18a. The large diameter portion 18b is in contact with the inner wall of the lower element 30 located outside the upper element 10 to electrically contact the upper element 10 and the lower element 30. The sleeve 19 has a hollow cylindrical shape, and is inserted into the rod-shaped conductor 15 and fixed to the rod-shaped conductor 15 by caulking.
[0044]
The spring 18 has elasticity that expands and contracts in the axial direction by the action of the central large diameter portion 18b. The spring 18 is inserted into the rod-shaped conductor 15, but the spring 18 itself is not fixed to the rod-shaped conductor 15, and the mounting position of the spring 18 is determined by the sleeve 19 fixed to the rod-shaped conductor 15.
[0045]
Furthermore, since the tube 16 is made of a soft synthetic resin, it has elasticity that shrinks when pressed in the axial direction, and generates a repulsive force when pressed in the axial direction. In the present embodiment, the position of the spring 18 is regulated by the sleeve 19 so as to press the tube 16 to the position where the tube 16 is shorter than the natural length of the tube 16. Force is received from the tube 16.
[0046]
In the present embodiment, the sleeve 19 has a cylindrical shape, but may have another shape (for example, a U shape) as long as it can be fixed to the rod-shaped conductor 15. Further, the sleeve 19 is fixed to the rod-like conductor 15 by caulking, but may be fixed by other methods (for example, welding, bonding, etc.).
[0047]
Moreover, although both the tube 16 and the spring 18 have elasticity, you may comprise only one of the tube 16 and the spring 18 so that it may have elasticity.
[0048]
FIG. 4 is an exploded perspective view of the upper element 10 shown in FIG.
[0049]
In the upper element 10 in which the coil element 11, the cover 12, the metal fitting 13, the joint 14, the tube 16, and the like are assembled to the rod-shaped conductor 15, a washer 17 and a spring 18 are sequentially inserted into the rod-shaped conductor 15 exposed at the bottom. It is done. Finally, the sleeve 19 is inserted into the rod-shaped conductor 15, and the sleeve 19 is crimped to the rod-shaped conductor 15, whereby the washer 17, the spring 18, and the sleeve 19 are attached to the rod-shaped conductor 15.
[0050]
When the sleeve 19 is caulked to the rod-like conductor 15, the spring 18 is pressed in the direction of the tube 16, and the tube 16 and the spring 18 (or one of them) are pressed to a state shorter than the natural length, thereby the sleeve. By crimping 19, the spring 18 is strongly pressed against the tube 16 and the sleeve 19, and the rotation of the spring 18 can be prevented.
[0051]
FIG. 5 is a perspective view of the spring 18 shown in FIG.
[0052]
The spring 18 is formed by rounding a thin metal plate (18c) whose central portion is punched into a slit shape, and both ends that are rounded constitute a cylindrical portion 18a, and by inflating the punched central portion, The large diameter part 18b is comprised. Therefore, the spring 18 has elasticity that expands and contracts in the axial direction when the central large-diameter portion 18b expands or contracts.
[0053]
Thus, in the embodiment of the present invention, in the whip antenna that can slide and expand within the lower element 30 while the upper element 10 is in contact with the lower element 30, the upper element 10 includes the rod-shaped conductor 15, The tube 16 that covers the rod-shaped conductor 15, the spring 18 that contacts the rod-shaped conductor 15 and the lower element 30, and the sleeve 19 that is fixed to the rod-shaped conductor 15, the spring 18 includes the tube 16 and the sleeve 19. Since the position of the sleeve 19 is determined and fixed in a state where the tube 16 is pressed in the antenna tip direction so that the tube 16 is disposed at a position shorter than the natural length of the tube 16, the spring 16 is 18 does not rotate between the tube 16 and the sleeve 19 and the upper element 10 It can be reliably brought into contact with the section elements 30 transgression.
[0054]
Further, since the tube 16 is made of a synthetic resin, the tube 16 has elasticity capable of expanding and contracting in the axial direction of the upper element 10, so that the spring 18 and the tube 16 are reliably in contact with each other and the spring 18 is rotated. Can be effectively suppressed.
[0055]
Furthermore, the spring 18 has elasticity that can be expanded and contracted in the axial direction of the upper element 10, and both ends are in the form of a thin tube (18a) and the central portion has a large diameter (18b). Since the element 10 has elasticity that can be expanded and contracted in the axial direction, the spring 18 and the tube 16 or the sleeve 19 are reliably in contact with each other, and the rotation of the spring 18 can be effectively suppressed.
[0056]
Further, since the sleeve 19 is formed in a cylindrical shape into which the rod-shaped conductor 15 can be inserted, the sleeve 19 can be easily manufactured. Furthermore, since the sleeve 19 is fixed to the rod-shaped conductor 15 by caulking, the sleeve 19 can be easily attached.
[0057]
Further, the step of covering the upper element 10 with the rod-shaped conductor 15 with the tube 16, the step of inserting the spring 18 into the rod-shaped conductor 15, and the step of fixing the sleeve 19 to the rod-shaped conductor 15 with the spring 18 pressed against the tube 16. Since the position of the spring 18 is determined by the sleeve 19, the spring 18 does not rotate between the tube 16 and the sleeve 19, and the upper element 10 and the lower element 30. A whip antenna can be manufactured that makes reliable contact.
[Brief description of the drawings]
FIG. 1 is a side view of a whip antenna according to an embodiment of the present invention when extended.
FIG. 2 is a side view of the whip antenna shown in FIG. 1 when stored.
3 is a side view of the upper element of the whip antenna shown in FIG. 1. FIG.
4 is an exploded perspective view of the upper element shown in FIG. 3. FIG.
5 is a perspective view of the spring shown in FIG. 3. FIG.
FIG. 6 is a perspective view of a portable wireless device to which the antenna according to the present invention is applied.
[Explanation of symbols]
1 Portable radio (housing)
2 Whip antenna 10 Upper element 11 Coil element 12 Cover 13 Metal fitting 14 Joint 15 Rod-like conductor 16 Tube 17 Washer 18 Spring 18a Tubular portion 18b Large diameter portion 18c Large diameter portion 19 Sleeve 30 Lower element 31 Joint metal fitting 32 Wire rod 33 Tube 34 Metal fitting 50 support

Claims (10)

In the whip antenna, in which the first element is configured to slide in a cylindrical second element having a diameter larger than that of the first element and connected to each other so as to be able to expand and contract in the axial direction .
The first element includes at least a rod-shaped conductor, a covering portion that covers the rod-shaped conductor, a spring that contacts the rod-shaped conductor and the second element, and a fixing portion that is fixed to the rod-shaped conductor. And
The spring is positioned between the covering portion and the fixing portion, and the position of the fixing portion is determined such that the spring is disposed at a position that shortens the covering portion from a natural length of the covering portion. Whip antenna to do. In the whip antenna, in which the first element is configured to slide in a cylindrical second element having a diameter larger than that of the first element and connected to each other so as to be able to expand and contract in the axial direction .
The first element includes at least a rod-shaped conductor, a covering portion that covers the rod-shaped conductor, a spring that contacts the rod-shaped conductor and the second element, and a fixing portion that is fixed to the rod-shaped conductor. And
The whip antenna according to claim 1, wherein the position of the fixing portion is determined in a state where the spring presses the covering portion toward the tip of the antenna. In the whip antenna, in which the first element is configured to slide in a cylindrical second element having a diameter larger than that of the first element and connected to each other so as to be able to expand and contract in the axial direction.
The first element includes at least a rod-shaped conductor, a covering portion that covers the rod-shaped conductor, a spring that contacts the rod-shaped conductor and the second element, and a fixing portion that is fixed to the rod-shaped conductor. And
The first element has an abutting portion for restricting movement of the spring in the axial direction,
The spring is located between the abutting portion and the fixing portion, and the position of the fixing portion is determined so as to be disposed at a position that makes the contact portion shorter than the natural length of the spring. Whip antenna to do. 4. The whip antenna according to claim 3 , wherein the abutting portion is formed at an end portion of a covering portion that covers the rod-shaped conductor . The covering portion whip antenna according to any one of claims 1 to 4, characterized in that it is made of a synthetic resin having a stretchable elastic in the axial direction of the first element. The whip antenna according to any one of claims 1 to 5 , wherein the spring has elasticity that can expand and contract in an axial direction of the first element. The whip antenna according to any one of claims 1 to 6 , wherein at least one end of the spring has a cylindrical shape having a warp and the other part has a large diameter . The said fixing | fixed part is comprised by the cylinder shape which can insert the said rod-shaped conductor, It is a sleeve fixed to the said rod-shaped conductor by crimping, The one of Claim 1 to 7 characterized by the above-mentioned. The whip antenna described. The first element slides in a cylindrical second element having a diameter larger than that of the first element and is connected to be able to expand and contract in the axial direction, and at least a rod-shaped conductor and a covering portion covering the rod-shaped conductor; In the method of manufacturing a whip antenna constituted by a spring for bringing the rod-shaped conductor and the second element into contact with each other, and a fixed portion fixed to the rod-shaped conductor,
Covering the rod-shaped conductor with the covering portion;
Inserting a spring into the rod-shaped conductor;
A step of fixing the fixing portion to the rod-shaped conductor in a state where the fixing portion presses the spring against the covering portion;
A method of manufacturing a whip antenna. The first element slides in a cylindrical second element having a diameter larger than that of the first element and is connected to be able to expand and contract in the axial direction, and at least a rod-shaped conductor and a covering portion covering the rod-shaped conductor; In the method of manufacturing a whip antenna constituted by a spring for bringing the rod-shaped conductor and the second element into contact with each other, and a fixed portion fixed to the rod-shaped conductor,
Inserting the spring into the rod-shaped conductor so as to abut against the abutting portion;
A step of fixing the fixing portion to the rod-shaped conductor in a state where the fixing portion presses the spring against the covering portion;
A method of manufacturing a whip antenna.

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