JP2010109689A - Antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive multi-stage whip antenna that is small in the number of components and easy to assemble. <P>SOLUTION: The antenna is provided with at least: a first element; a second element housed inside the first element; and a support member holding the first element when the antenna is extended and when the antenna is housed. At the lower end part of the first element, a first large diameter part is provided in which an external diameter is larger than a pipe member. At the upper end part of the first element, a second large diameter part in which the pipe member is formed into a larger external diameter. When the first element is extended, the outer periphery surface of the first large diameter part contacts with the inner side of the support member, so that the lower end of the first element is held by the support member. When the first element is housed, the outer periphery surface of the second large diameter part contacts with the inner side of the support member, so that the upper end of the first element is held by the support member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a multistage whip antenna, and more particularly to an antenna having a lower stage element having a large-diameter portion for holding an antenna.

  Conventionally, a two-stage whip antenna has been used for mobile phones. In recent years, multistage whip antennas for receiving terrestrial digital television broadcast waves are also used.

  A whip antenna for a cellular phone has a flexible structure with elements in which a coiled pipe is formed by windings in order to improve the resistance to lateral force. On the other hand, the terrestrial digital whip antenna is provided with a hinge at a lower portion thereof so that the extending direction of the antenna can be adjusted. For this reason, since there exists escape with respect to the force from a horizontal direction, an antenna can be comprised with a metal pipe.

As a multistage whip antenna for receiving such terrestrial digital television broadcast waves, an antenna described in Patent Document 1 has been proposed.
JP 2008-193437 A

  In such a multistage whip antenna, there is a demand for an antenna having a structure that is configured by an inexpensive pipe and that can accommodate the entire antenna.

  In addition, the above-described whip antenna for telephone call ensures the performance by allowing the coil antenna at the tip to protrude out of the housing during storage, so the length of the element to be stored is relatively short. An antenna may be used. On the other hand, since the terrestrial digital whip antenna does not require performance during storage, it is desired that all of the elements be stored in the housing. For this reason, since the length of the element to be accommodated is relatively long and the accommodation space is short, a three-stage whip antenna is often used.

  Furthermore, since the whip antenna for a call described above needs to supply power to the coil antenna at the tip when stored, it is necessary to hold the antenna directly under the coil antenna (the uppermost element). On the other hand, since the terrestrial digital whip antenna does not require performance during storage, the flexibility of the holding position of the antenna during storage is high.

  Furthermore, in the case of an antenna made of a metal pipe, the element can be molded more easily than an antenna made of a coiled pipe. In particular, in a three-stage whip antenna, it is desired that the middle element is housed in the lower element.

  An object of the present invention is to provide a multi-stage whip antenna having a structure that is configured by an inexpensive pipe and can accommodate the entire antenna.

  A first invention is an antenna comprising at least a first element, a second element housed inside the first element, and a support member that holds the first element when the antenna is extended and housed. A spring member that slides on the inner surface of the first element is provided at a lower end portion of the second element, and the first element is configured by a hollow pipe member, and the lower end of the first element The portion is provided with a first large-diameter portion having an outer diameter larger than that of the pipe member, and the upper end portion of the first element is provided with a second large-diameter portion formed by molding the pipe member to a large outer diameter. When one element is extended, an outer peripheral surface of the first large-diameter portion is in contact with an inner surface of the support member, whereby a lower end of the first element is held by the support member, During storage of the first element, by the outer peripheral surface of the second large diameter portion is in contact with the inner surface of the support member, the upper end of the first element, characterized in that it is held by the support member.

  The second invention is characterized in that the second large diameter portion is molded to have a large diameter by pressing the pipe member in the axial direction.

  The third invention is characterized in that when the second element is extended, the spring member is in contact with the inner surface of the first element below the second large diameter portion.

  According to a fourth aspect of the present invention, the second element is composed of a rod-shaped member that is hollow or filled inside, and the spring member includes a tube portion that is attached to the outer periphery of the rod-shaped member, and a spring having a larger diameter than the tube portion. And the outer shape of the tube part is larger than the inner diameter of the tip of the second large diameter part.

  In a fifth aspect of the present invention, the second element is configured by a hollow pipe member, and the antenna includes a third element housed inside the second element. A tip member larger than the inner diameter of the second element is provided, and the support member is attached to a housing, and when the antenna is housed, the second large diameter portion comes into contact with the support member, whereby the tip member The first, second and third elements are housed in the housing, leaving

  According to the first invention, the second large-diameter portion of the tip portion of the first element, which has conventionally been constituted by another member, is formed by molding the pipe member into a large outer diameter, so that it is constituted by a pipe, A multi-stage whip antenna that can accommodate the whole was realized. In addition, the number of parts can be reduced, the assembly of the antenna can be simplified, and the cost of the antenna can be reduced.

  According to the second invention, since the second large diameter portion is formed into a large diameter by pressurizing the pipe member in the axial direction, the processing of the large diameter portion is performed as compared with the conventional example in which another member is assembled. Accuracy can be improved.

  According to a third invention, when the second element is extended, the spring member is in contact with the inner surface of the first element below the second large diameter portion. Sticking can be prevented and the linearity of the antenna element can be improved. Moreover, since the linearity of the antenna element is high, the operability when the antenna is stored can be improved.

  According to the fourth invention, since the outer shape of the tube portion of the spring member is larger than the inner diameter of the tip of the second large diameter portion, the second element is the first element without providing a retaining washer as in the prior art. It is possible to prevent the user from getting out of the machine.

  According to the fifth invention, since the first, second and third elements are housed in the housing, leaving the tip member of the third element, the length when extended is short and the antenna is short when stored. can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As an embodiment of the present invention, a portable three-stage whip antenna for receiving digital terrestrial broadcasting will be described. However, the present invention is not limited to a three-stage whip antenna, but a two-stage whip antenna or a four-stage or more whip antenna. Even so, any antenna using a metal pipe as a lower element can be applied.

  FIG. 1 is an external view of a multistage whip antenna according to an embodiment of the present invention when extended.

  The multistage whip antenna according to the embodiment of the present invention includes a first element 10, a second element 20 accommodated in the first element 10, and a third element 30 accommodated in the second element 20.

  The first element 10 is formed with a metal cylindrical pipe portion 11 in the middle, and a flat metal tip 12 is provided at the lower end of the pipe portion 11, and a support portion 16 is provided above the pipe portion 11. Prepare. A base portion 13 is coupled to a lower portion of the retractable metal fitting 12 by a shaft 14 so as to form a hinge portion. A support portion 15 having a diameter larger than that of the pipe portion 11 is provided below the base portion 13. The support unit 15 holds the antenna outside the casing by contacting the inner surface of the support metal fitting 40 when the antenna is extended. The support unit 15 may be configured by attaching another member to the base unit 13.

  The support portion 16 at the top of the first element 10 has a diameter larger than that of the pipe portion (substantially the same diameter as the support portion 15). Hold inside. In addition, since the pipe part 11 between the support part 15 and the support part 16 is smaller in diameter than the support parts 15 and 16, the support metal fitting 40 can move between the support part 15 and the support part 16 smoothly.

  The support part 16 is molded into a large diameter by pressurizing the pipe part 11 in the axial direction. Thus, by processing the support portion 16 into a large diameter by press working, it is not necessary to configure the support portion 16 as a separate part, the number of parts can be reduced, and the processing cost of the first element 10 can be reduced. .

  The support metal fitting 40 is attached to a housing (the outer surface of the housing is indicated by a broken line). A spring is attached to the inner surface of the support metal fitting 40, and the antenna is held by the support metal fitting 40 when the spring comes into contact with the outer peripheral surfaces of the support portions 15 and 16. In addition, this spring has slight contact with the outer peripheral surface of the small-diameter pipe portion 11.

  In the state shown in FIG. 5, the support portion 16 at the tip of the first element 10 and the support metal fitting 40 are fitted, and the first element 10 is housed in the housing.

  The second element 20 is configured by a metal cylindrical pipe portion 21. The outer diameter of the pipe portion 21 is slightly smaller than the inner diameter of the pipe portion 11, and the second element 20 can move in the axial direction inside the first element 10. A spring 22 (see FIGS. 2 and 3) is attached to the lower portion of the second element 20. When the spring 22 comes into contact with the inner surface of the first element 10, the second element 20 stably slides inside the first element 10. A ring 23 is attached to the upper portion of the pipe portion 21.

  The third element 30 is constituted by a rod portion 31, a spring 32 (see FIG. 4) is attached to the lower portion of the rod portion 31, and a cap 33 is attached to the upper portion of the rod portion 31. The cap 33 has a larger diameter than the rod portion 31 and prevents the entire third element 30 from being housed inside the second element 20 by the cap 33 coming into contact with the upper end of the second element 20 when the antenna is housed. is doing.

  2 and 3 are cross-sectional views of the first element 10 in a state where the second element 20 is extended. In FIG. 2, only the first element 10 is shown in a sectional view, but in FIG. 3, both the first element 10 and the second element 20 are shown in a sectional view.

  The support portion 16 is molded by pressing the pipe portion 11 in the axial direction, and the outer diameter thereof is larger than the outer diameter of the pipe portion 11, and the inner diameter thereof is larger than the inner diameter of the pipe portion 11.

Specifically, the support portion 16 at the tip of the pipe portion 11 is press-molded by the following process.
(1) A core rod having a diameter substantially equal to the inner diameter is inserted into the pipe.
(2) Assemble the outer mold in the shape of the support portion 16.
(3) The pipe is pressurized in the axial direction by a press.

  The spring 22 has a substantially cylindrical shape, and an intermediate portion in the axial direction swells to a large diameter. When the intermediate portion of the spring 22 comes into contact with the inner surface of the first element 10, the second element 20 slides stably inside the first element 10. As a result, the second element 20 is not immediately stored in the first element 10 when the antenna is extended, but is stably held.

  The inner diameter of the tip of the support portion 16 is made smaller than the outer diameter of the cylinder of the spring 22. For this reason, when the antenna is extended, the end of the spring 22 and the inside of the upper end of the support 16 contact each other, and the second element 20 does not come out of the first element 10. Conventionally, a washer is disposed at the upper end of the spring 22 to prevent the spring 22 from being pulled out. However, in the antenna of the present embodiment, the washer can be deleted, and the number of parts can be reduced. This is because, in the present embodiment, as described above, since the support portion 16 is formed by pressing a metal pipe, the diameter of the tip of the support portion 16 can be controlled with high accuracy.

  When the antenna is extended, the spring 22 is attached to the second element 20 so that the large-diameter portion of the spring 22 is positioned below the support portion 16. As described above, when the second element 20 is extended, the positional relationship between the first element 10 and the second element 20 is determined by contacting the end of the spring 22 and the inside of the upper end of the support portion 16. For this reason, by changing the length of the cylindrical portion above the large-diameter portion of the spring 22, the position where the large-diameter portion of the spring 22 abuts on the pipe portion 11 (the lower portion of the support portion 16) can be changed. . That is, the length from the upper end of the spring 22 to the large diameter portion is made longer than the support portion 16. For this reason, the second element 20 is held by the first element 10 at two points of the tip of the first element 10 and the contact point of the spring 22 and is stably held by the second element 20. Further, the first element 10 and the second element 20 do not rattle, and the linearity of the element can be ensured.

  FIG. 4 is a cross-sectional view of the upper portion of the second element 20 with the third element 30 extended.

  As described above, the third element 30 is formed by the rod portion 31, the spring 32 is attached to the lower end of the rod portion 31, and the cap 33 is attached to the tip of the rod portion 31. The rod part 31 may be constituted by a metal rod or a metal pipe.

  The spring 32 has a substantially cylindrical shape, and an intermediate portion in the axial direction swells to a large diameter. When the intermediate portion of the spring 32 is in contact with the inner surface of the second element 20, the third element 30 slides stably inside the second element 20.

  The tip of the pipe portion 21 of the second element 20 is processed to have a small diameter (for example, cutting). The ring 23 is attached to the pipe portion 21 by being inserted into the small diameter portion and crimped from the outside. Thus, by attaching the ring 23, the outer diameter of the second element 20 becomes uniform, and the entire second element 20 can be stored in the first element 10. The tip of the ring 23 has a small diameter, and the upper end of the spring 32 is in contact with the inner surface of the tip of the third element 30 so that the third element 30 housed in the second element 20 does not fall out. ing. A washer may be disposed on the upper end of the spring 32.

1 is an external view of a multistage whip antenna according to an embodiment of the present invention. It is sectional drawing of the 1st element 10 in the state where the 2nd element 20 of embodiment of this invention is extending | stretching. It is sectional drawing of the 1st element 10 in the state where the 2nd element 20 of embodiment of this invention is extending | stretching. It is sectional drawing of the upper part of the 2nd element 20 of the state which the 3rd element 30 of embodiment of this invention is extending | stretching. It is an external view which shows the state at the time of accommodation of the 1st element 10 of embodiment of this invention.

Explanation of symbols

10 1st element 11 Pipe part 12 Fallable metal fitting 13 Base part 14 Shaft 15 Support part 16 Support part 20 2nd element 21 Pipe part 22 Spring 23 Ring 30 3rd element 31 Rod part 32 Spring 33 Cap

Claims (5)

An antenna comprising at least a first element, a second element housed inside the first element, and a support member that holds the first element when the antenna is extended and housed;
The lower end of the second element is provided with a spring member that slides on the inner surface of the first element,
The first element is composed of a hollow pipe member inside,
The lower end portion of the first element is provided with a first large diameter portion having an outer diameter larger than that of the pipe member,
The upper end portion of the first element is provided with a second large diameter portion obtained by molding the pipe member to a large outer diameter,
When the first element is extended, the lower end of the first element is held by the support member by contacting the outer peripheral surface of the first large diameter portion with the inside of the support member.
When the first element is housed, the upper end of the first element is held by the support member by the outer peripheral surface of the second large diameter portion coming into contact with the inside of the support member.   2. The antenna according to claim 1, wherein the second large-diameter portion is formed to have a large diameter by pressing the pipe member in the axial direction.   3. The antenna according to claim 1, wherein when the second element is extended, the spring member is in contact with an inner surface of the first element below the second large diameter portion. The second element is composed of a rod-shaped member that is hollow or filled inside,
The spring member is constituted by a tube portion attached to the outer periphery of the rod-shaped member, and a spring portion having a larger diameter than the tube portion,
4. The antenna according to claim 1, wherein an outer shape of the tube portion is larger than an inner diameter of a tip of the second large-diameter portion. The second element is constituted by a pipe member having a hollow inside,
The antenna includes a third element housed inside the second element,
A tip member larger than the inner diameter of the second element is provided at the tip of the third element,
The support member is attached to a housing;
When the antenna is housed, the first, second, and third elements are housed in the housing with the second large diameter portion coming into contact with the support member, leaving the tip member. The antenna according to any one of claims 1 to 4.

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