JP2011249969A - Whip antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a whip antenna which has a reduced number of components, a short antenna length and a long effective length when being shortened and lengthened.SOLUTION: An antenna at least comprises a first element and a second element accommodated inside the first element. A spring member to slide the inner surface of the first element is provided in the bottom of the second element. By bending a metal thin plate, a cylindrical part is formed on both edges of the spring member and a large diameter part is formed in the cylindrical part. The large diameter part has a larger diameter than the cylindrical part and has spring property in its radial direction in order to configure the radius to be adjustable, and while the second element is attached inside the first element, the large diameter part energizes the inner side surface of the first element to outside, and a deformation part which has processed the second element to be a large diameter is provided in the bottom of the second element. The deformation part is provided inside the large diameter part in the position which contacts the bottom inner surface of the large diameter part.

Description

  The present invention relates to a whip antenna, and more particularly to a structure of a multi-stage whip antenna that supplies power to an element when an upper element and a lower element are electrically contacted by the action of a spring.

  Conventionally, two-stage whip antennas have been used for cellular phones, and in recent years, multi-stage whip antennas for receiving digital terrestrial television broadcast waves have also been used.

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

In the multi-stage whip antenna, the upper element and the lower element function as one element when the lower element is in electrical contact with the upper part of the lower element and power is supplied from the lower element to the upper element. It is configured as follows. For this reason, it has been proposed to provide a spring extending radially in the lower part of the upper element in order to stably contact the upper element and the lower element and to prevent both elements from wobbling when the element is extended. (See Patent Documents 2 and 3).
JP 2008-193437 A JP 2002-223111 A JP 2002-223112 A

  As described above, in the conventional multistage whip antenna, it is necessary to fix the spring by the fixing member in order to avoid the movement of the spring attached to the upper element in the axial direction. For example, in the element 40 of the whip antenna shown in FIG. 10, the cylindrical sleeve 44A is fixed to the lower end of the rod-shaped conductor 41, and the cylindrical sleeve 44B is sandwiched between the springs 42 that are arranged in contact with the sleeve 44A. It was fixed to the rod-shaped conductor 41. In this case, the effective length of the antenna when the element is extended is shortened by the length of the sleeve 44B, and the antenna sensitivity is lowered. Further, it is necessary to provide a separate sleeve 44B, and there is a problem that the cost increases due to an increase in the number of parts.

  In another spring fixing method, a washer is disposed at the lower end of the tube covering the side surface of the rod-shaped conductor 41, and the sleeve 44A is fixed to the rod-shaped conductor 41 so that the spring 42 abuts against the washer. (See Patent Document 3). Also in this case, it is necessary to provide separate members such as tubes and washers, and there is a problem that the cost increases due to an increase in the number of parts. In addition, the provision of the tube has a problem that the rod-like conductor 41 becomes thick and looks bad.

  Furthermore, when the tube is removed to make the element thinner, the spring fixing method disclosed in Patent Document 3 cannot be employed.

  As described above, the structure of the connection portion between the elements greatly affects the shortening and diameter reduction of the multistage whip antenna. For this reason, there is a demand for an antenna having a structure in which the effective length of the antenna can be increased while reducing the number of parts in the connection portion and shortening the length when the antenna is contracted.

  1st invention is an antenna provided with the 1st element and the 2nd element accommodated in the inside of the said 1st element at least, Comprising: The inner surface of the said 1st element is provided in the lower part of the said 2nd element The spring member is formed by bending a thin metal plate to form a cylindrical portion at both ends thereof and a large diameter portion between the cylindrical portions, the large diameter portion being The diameter of the cylindrical portion is larger than that of the cylindrical portion, and the diameter thereof is variable by having a spring property in the radial direction. In the state where the second element is mounted in the first element, The inner surface of the first element is urged outward, and a deformed portion obtained by processing the second element into a large diameter is provided at a lower portion of the second element. The lower inner surface of the large diameter portion It is provided at a position to abut.

  In a second aspect based on the first aspect, the second element is constituted by a rod-like or pipe-like conductor, and the deformed portion is formed by processing a part of the second element to have a large diameter. The outer diameter of the deformed portion is 0.01 mm or more larger than the diameter of the rod or pipe constituting the second element before processing.

  In a third aspect based on the first aspect or the second aspect, a part of the deforming portion is processed to have a large diameter by press working that pressurizes a side surface of a rod or a pipe constituting the second element.

  In a fourth aspect based on the first aspect or the second aspect, the deforming portion is processed to have a large diameter by press working that pressurizes a rod or pipe constituting the second element in the axial direction.

  In a fifth aspect based on the first or second aspect, a part of the deformed portion is processed to have a large diameter by knurling a rod or a pipe constituting the second element.

  In a sixth aspect based on the first to fifth aspects, a sleeve that contacts the lower end of the spring member is fixed to the lower end of the second element.

  According to the present invention, the number of parts for restricting the movement of the spring in the axial direction can be reduced, and an increase in cost can be suppressed. In addition, the effective length of the antenna when the element is extended can be increased.

It is a side view at the time of expansion | extension of the whip antenna of the 1st Embodiment of this invention. It is a side view of the 4th element 40 of a 1st embodiment of the present invention. It is a side view of the 3rd element 30 of a 1st embodiment of the present invention. It is sectional drawing of the upper part of the 3rd element 30 in the state where the 4th element 40 of the 1st Embodiment of this invention is extending | stretching. It is an enlarged view near the deformation | transformation part 45 of the 4th element 40 of the 1st Embodiment of this invention. It is AA sectional drawing which shows the shape of the deformation | transformation part 45 of the 4th element 40 of the 1st Embodiment of this invention. It is sectional drawing of the upper part of the 2nd element 20 in the state where the 3rd element 30 of the 1st Embodiment of this invention is extending | stretching. It is BB sectional drawing which shows the shape of the deformation | transformation part 35 of the 3rd element 30 of the 1st Embodiment of this invention. It is a side view at the time of expansion | extension of the whip antenna of the 2nd Embodiment of this invention. It is a side view of the conventional 4th element.

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

  FIG. 1 is a side view of the whip antenna according to the first embodiment of the present invention when extended.

  The multi-stage whip antenna of the first embodiment includes a first element 10, a second element 20 accommodated in the first element 10, a third element 30 accommodated in the second element 20, and a first element The fourth element 40 is housed inside the three elements 30, and the first element 10, the second element 20, the third element 30, and the fourth element 40 are arranged in this order from the support fitting 50 side.

  The first element 10 is constituted by a metal pipe 11, a tip end of a flat metal fitting 12 is provided at the lower end of the pipe 11, and a support portion 16 is provided at the upper part of the pipe 11. 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 11 is provided below the base portion 13. When the antenna is extended, the support unit 15 is held in contact with the inner surface of the support metal fitting 50 so that the antenna protrudes outside the casing of the portable wireless device. The support portion 15 may be configured by processing a part of the base portion 13 to have a large diameter or by attaching another member to the base portion 13.

  The support portion 16 at the top of the first element 10 has a diameter larger than that of the pipe 11 (substantially the same diameter as the support portion 15). Hold inside. Since the pipe 11 between the support portion 15 and the support portion 16 has a smaller diameter than the support portions 15 and 16, the support metal fitting 50 can move smoothly between the support portion 15 and the support portion 16.

  The support portion 16 is molded into a large diameter by pressurizing the pipe 11 in the axial direction. Thus, by deforming 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 50 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 50, and the antenna is held by the support metal 50 when the spring comes into contact with the outer peripheral surfaces of the support portions 15 and 16. Note that the contact between the spring and the outer peripheral surface of the pipe 11 is slight.

  The second element 20 is constituted by a metal cylindrical pipe 21. The outer diameter of the pipe 21 is slightly smaller than the inner diameter of the pipe 11 so that the second element 20 can move in the axial direction inside the first element 10. A spring 22 is attached to the lower part of the pipe 21. When 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 and makes electrical contact stably.

  The third element 30 is constituted by a metal cylindrical pipe 31. The outer diameter of the pipe 31 is slightly smaller than the inner diameter of the pipe 21, and the third element 30 can move in the axial direction inside the second element 20. A spring 32 (see FIG. 7) is attached to the lower part of the pipe 31. When the spring 32 comes into contact with the inner surface of the second element 20, the third element 30 slides stably inside the second element 20 and makes electrical contact stably.

  The fourth element 40 is constituted by a rod-shaped conductor 41. The outer diameter of the rod-shaped conductor 41 is slightly smaller than the inner diameter of the pipe 31, and the fourth element 40 can move in the third element 30 in the axial direction. A spring 42 (see FIG. 4) is attached to the lower part of the rod-shaped conductor 41. When the spring 42 comes into contact with the inner surface of the third element 30, the fourth element 40 slides stably inside the third element 30 and makes electrical contact stably.

  A cap 43 is attached to the upper end of the rod-shaped conductor 41. The cap 43 has a larger diameter than the rod-shaped conductor 41, and the entire fourth element 40 is accommodated inside the third element 30 by the cap 43 coming into contact with the upper end of the third element 30 when the fourth element 40 is accommodated. Is prevented. Further, when the antenna 43 is accommodated, the cap 43 abuts on the support metal fitting 50, thereby preventing the entire antenna from being accommodated in the housing.

  FIG. 2 is a side view of the fourth element 40 according to the first embodiment.

  The fourth element 40 is constituted by a rod-shaped conductor 41. A cap 43 is attached to the tip of the rod-shaped conductor 41. The rod-shaped conductor 41 may be composed of a metal rod or a metal pipe.

  A spring 42 is attached to the lower end of the rod-shaped conductor 41. In addition, a deformed portion 45 is formed in the lower portion of the rod-shaped conductor 41. The deformed portion 45 is formed by deforming the rod-shaped conductor 41 in the cross-sectional direction and processing it into a large diameter. As shown in FIGS. 4 and 5, the deforming portion 45 is provided on the lower side of the large diameter portion 42 </ b> B of the spring 42 and at a position in contact with the inner surface of the large diameter portion 42 </ b> B of the spring 42. Various shapes can be employed for the deformable portion 45, and variations thereof will be described later with reference to FIG.

  FIG. 3 is a side view of the third element 30 according to the first embodiment.

  The third element 30 is constituted by a pipe 31. The tip of the pipe 31 is processed into a small diameter by, for example, drawing. This is to prevent the fourth element 40 sliding inside the third element 30 from falling out of the third element 30 when the element is extended.

  At the lower end of the pipe 31, a stopper 34 is formed by processing the pipe 31 into a large diameter. The stopper 34 is configured by processing the pipe 31 to have a large diameter by expanding the lower end of the pipe 31 in the radial direction. Note that another member may be attached to the pipe 31 to increase the diameter.

  A deformed portion 35 obtained by processing the pipe 31 into a large diameter is formed at the lower portion of the pipe 31. As shown in FIG. 7, the deforming portion 35 is provided below the large-diameter portion 32 </ b> B of the spring 32 and at a position in contact with the inner surface of the large-diameter portion 32 </ b> B of the spring 32. Various shapes can be employed for the deformable portion 35, and variations thereof will be described later with reference to FIG.

  FIG. 4 is a cross-sectional view of the upper portion of the third element 30 in a state where the fourth element 40 of the first embodiment is extended.

  A spring 42 is attached to the lower part of the rod-shaped conductor 41 constituting the fourth element 40. The spring 42 has a substantially cylindrical shape, and a cylindrical portion that contacts the outside of the rod-shaped conductor 41 is formed at both ends in the axial direction, and a large-diameter portion 42B having spring properties is formed in the middle. When the large diameter portion 42 </ b> B of the spring 42 comes into contact with the inner surface of the third element 30, the fourth element 40 slides stably inside the third element 30.

  A sleeve 44 is attached to the lower end of the rod-shaped conductor 41 by caulking, for example. The outer diameter of the sleeve 44 is larger than the inner diameter of the spring 42. For this reason, the spring 42 does not fall off the rod-shaped conductor 41 by contacting the upper end of the sleeve 44.

  The deformed portion 45 formed at the lower portion of the rod-shaped conductor 41 is provided at a position where it comes into contact with the lower inner surface of the large-diameter portion 42 </ b> B of the spring 42. Deformation part 45 should just have a length of about 0.5 millimeters.

  FIG. 5 is an enlarged view of the vicinity of the deformable portion 45 of the fourth element 40 according to the first embodiment. In FIG. 5, the pipe 31 and the spring 42 show the cross section.

  As described above, the deformable portion 45 formed at the lower portion of the rod-shaped conductor 41 is provided at a position where it abuts on the lower inner surface of the large-diameter portion 42B of the spring 42.

  The spring 42 includes a cylindrical portion 42A at both ends and a large diameter portion 42B between the cylindrical portions 42A, and the metal plate constituting the large diameter portion 42B is curved outward. There is a space inside. A spring 42 is disposed at a position where the deformable portion 45 contacts the lower inner surface of the metal plate that forms this space.

  Thus, in the assembled state of the fourth element 40, the spring 42 is fixed at a position sandwiched between the sleeve 44 and the deforming portion 45, and the movement in the axial direction is restricted. That is, the lower end of the spring 42 is in contact with the upper end of the sleeve 44, and the inner surface of the spring 42 is in contact with the deformed portion 45, thereby preventing the spring 42 from moving from a predetermined position of the rod-shaped conductor 41.

  When the fourth element 40 is extended, the upper end of the spring 42 contacts the inner surface of the tip of the third element 30. Since the tip of the pipe 31 of the third element 30 is processed to have a small diameter, the fourth element 40 is prevented from falling off from the third element 30.

  FIG. 6 is an AA cross-sectional view showing the shape of the deformed portion 45 of the fourth element 40 of the first embodiment.

  FIG. 6A shows an example of the deformable portion 45, in which the deformable portion 45 is formed by processing the diameter of the rod-shaped conductor 41 in a specific direction and decreasing the diameter in the orthogonal direction. The spring 42 is securely fixed when the diameter of the thickened wire is larger than the original diameter d of the rod-shaped conductor 41 by 0.01 mm or more. The deforming portion 45 shown in FIG. 6A can be formed by pressing the deformed portion of the rod-shaped conductor 41 from the lateral direction.

  FIG. 6B shows another example of the deformable portion 45, and the deformed portion 45 is formed by processing a part of the diameter of the rod-shaped conductor 41 to be thick. The spring 42 is securely fixed when the diameter of the thickened wire is larger than the original diameter d of the rod-shaped conductor 41 by 0.01 mm or more. The deforming portion 45 shown in FIG. 6B can be formed by pressing in the axial direction while only the portion that becomes the deforming portion 45 of the rod-shaped conductor 41 is released.

  FIG. 6C shows another example of the deformed portion 45, in which the deformed portion 45 is formed by processing a part of the diameter of the rod-shaped conductor 41 to be thick. The spring 42 is securely fixed when the diameter of the thickened wire is larger than the original diameter d of the rod-shaped conductor 41 by 0.01 mm or more. That is, in the deformed portion 45 shown in FIG. 6C, a portion having a diameter larger than d and a portion having a diameter smaller than d are repeated along the outer periphery. The deformed portion 45 shown in FIG. 6C can be formed by knurling the portion of the rod-like conductor 41 that becomes the deformed portion 45.

  If the rod-shaped conductor 41 is composed of a superelastic alloy rod, the deformed portion 45 can be formed by using a normal metal processing technique such as pressing or knurling.

  If the diameter of the deformed portion 45 is about d + 0.01 mm, it can be absorbed by the clearance between components without interfering with the large-diameter portion 42B of the spring 42, and the spring property of the spring 42 is not affected.

  FIG. 7 is a cross-sectional view of the upper portion of the second element 20 in a state where the third element 30 of the first embodiment is extended.

  A spring 32 is attached to the lower part of the pipe 31 constituting the third element 30. The spring 32 has a substantially cylindrical shape, and both end portions in the axial direction form a cylindrical portion 32A in contact with the outside of the pipe 31, and an intermediate portion in the axial direction forms a large diameter portion 32B having a large diameter. When the large diameter portion 32 </ b> B of the spring 32 comes into contact with the inner surface of the second element 20, the third element 30 slides stably inside the second element 20.

  As described above, the stopper 34 is formed at the lower end of the pipe 31. The outer diameter of the stopper 34 is larger than the inner diameter of the spring 32.

  The deforming portion 35 formed at the lower portion of the pipe 31 is provided at a position where it comes into contact with the lower inner surface of the large-diameter portion 32B of the spring 32. Deformation part 35 should just have a length of about 0.5 millimeters.

  As described above, the movement of the spring 32 in the axial direction is restricted by the stopper 34 and the deforming portion 35. That is, the lower end of the spring 32 is in contact with the upper end of the stopper 34, and the inner surface of the spring 32 is in contact with the deforming portion 35, thereby preventing the spring 32 from moving from a predetermined position of the pipe 31.

  When the third element 30 is extended, the upper end of the spring 32 comes into contact with the inner surface of the tip of the second element 20. As with the pipe 31 of the third element 30, the tip of the pipe 21 of the second element 20 is processed to have a small diameter so that the third element 30 does not fall out of the second element 20.

  Although the structure for attaching the spring 32 at the connection portion between the third element 30 and the second element 20 has been described with reference to FIG. 7, the structure for attaching the spring 22 at the connection portion between the second element 20 and the first element 20 is also applicable. Similarly, a deformation portion is provided in the pipe 21 of the second element 20.

  FIG. 8 is a BB cross-sectional view showing the shape of the deformed portion 35 of the third element 30 according to the first embodiment.

  FIG. 8A shows an example of the deformable portion 35, in which the deformable portion 35 is formed by increasing the diameter in a specific direction of the pipe 31 and reducing the diameter in the orthogonal direction. The spring 32 is securely fixed when the diameter of the thickened portion is larger than the original diameter d of the pipe 31 by 0.01 millimeter or more. The deformable portion 35 shown in FIG. 8A can be formed by inserting a mandrel into the pipe 31 other than the portion that becomes the deformable portion 35 and then pressing the portion of the pipe 31 that becomes the deformable portion 35 from the lateral direction. it can.

  FIG. 8B shows another example of the deforming portion 35, in which the deforming portion 35 is formed by processing a part of the diameter of the pipe 31 to be thick. The spring 32 is securely fixed when the diameter of the thickened portion is larger than the original diameter d of the pipe 31 by 0.01 millimeter or more. The deforming portion 35 shown in FIG. 8B can be formed by inserting a mandrel into the pipe 31 and then pressing in the axial direction while releasing only the portion of the pipe 31 that becomes the deforming portion 35.

  FIG. 8C shows another example of the deforming portion 35, in which the deforming portion 35 is formed by processing a part of the pipe 31 with a large diameter. The spring 32 is securely fixed when the diameter of the thickened portion is larger than the original diameter d of the pipe 31 by 0.01 millimeter or more. That is, in the deformed portion 35 shown in FIG. 8C, a portion having a diameter larger than d and a portion having a diameter smaller than d are repeated along the outer periphery. The deformed portion 35 shown in FIG. 8C can be formed by knurling the portion that becomes the deformed portion 35 of the pipe 31.

  If the pipe 31 is composed of a stainless steel pipe, the deformed portion 35 can be formed by using a normal metal processing technique such as pressing or knurling.

  If the diameter of the deforming portion 35 is about d + 0.01 mm, the deformation can be absorbed by the clearance between components without interfering with the large diameter portion 32B of the spring 32, and the spring property of the spring 32 is not affected.

  As described above, according to the first embodiment, the deformed portion obtained by machining the pipe 21 into a large diameter, the deformed portion 35 obtained by machining the pipe 31 into a large diameter, and the deformed portion obtained by machining the rod-shaped conductor 41 into a large diameter. By providing the portion 45, the movement of the springs 32, 42, etc. in the axial direction is restricted, so there is no need to provide a separate member for fixing the spring, the number of parts can be reduced, and the increase in cost can be suppressed. Can do.

  Further, the axial movement of the spring can be restricted without pressing the upper end of the spring with the sleeve of another member, and the length remaining in the lower element when the upper element is extended can be shortened. For this reason, it is possible to increase the effective length of the antenna when the element is extended while shortening the length of the antenna when the element is contracted.

  Specifically, compared with the conventional configuration shown in FIG. 10, the length at the time of contraction can be shortened by 1 millimeter, and the length at the time of extension can be lengthened by 4 millimeters.

  Also, the tube of the upper element can be deleted, the element can be made thinner, and the appearance can be improved.

  Next, a second embodiment of the present invention will be described. FIG. 9 is a side view when the whip antenna according to the second embodiment is extended.

  The multi-stage whip antenna of the second embodiment is different from the multi-stage whip antenna of the first embodiment described above, from the support metal fitting 50 side, the fourth element 40, the third element 30, the second element 20, the first In the order of the elements 10, that is, the small diameter elements are arranged on the lower side, and the large diameter elements are arranged on the upper side.

  The multi-stage whip antenna of the second embodiment includes a first element 10, a second element 20 accommodated in the first element 10, a third element 30 accommodated in the second element 20, and a first element A fourth element 40 accommodated inside the three elements 30 is provided.

  The first element 10 is constituted by a metal pipe 11, and a cap 43 is attached to the upper end of the pipe 11. The cap 43 is thicker than the outer diameter of the pipe 11 and prevents the entire antenna from being housed inside the housing by the cap 43 coming into contact with the support metal fitting 50 when the antenna is housed.

  The pipe 11 includes a support portion 16 at an upper portion thereof. The support part 16 has a diameter larger than that of the pipe 11 and holds the antenna inside the casing by contacting the inner surface of the support metal fitting 50 when the antenna is accommodated.

  The support portion 16 is molded into a large diameter by pressurizing the pipe 11 in the axial direction. Thus, by deforming 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 second element 20 is constituted by a metal cylindrical pipe 21. The outer diameter of the pipe 21 is slightly smaller than the inner diameter of the pipe 11 so that the second element 20 can move in the axial direction inside the first element 10. A spring 22 is attached to the upper part of the pipe 21. 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.

  The third element 30 is constituted by a metal cylindrical pipe 31. The outer diameter of the pipe 31 is slightly smaller than the inner diameter of the pipe 21, and the third element 30 can move in the axial direction inside the second element 20. A spring 32 (see FIG. 7) is attached to the upper portion of the pipe 31. When the spring 32 comes into contact with the inner surface of the second element 20, the third element 30 slides stably inside the second element 20.

  The fourth element 40 is constituted by a rod-shaped conductor 41. The outer diameter of the rod-shaped conductor 41 is slightly smaller than the inner diameter of the pipe 31, and the fourth element 40 can move in the third element 30 in the axial direction. A spring 42 (see FIG. 4) is attached to the upper portion of the rod-shaped conductor 41.

  The rod-shaped conductor 41 includes a tiltable metal fitting 12 having a flat tip at the lower end. 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 11 of the first element 10 (substantially the same diameter as the support portion 16) is provided below the base portion 13. When the antenna is extended, the support unit 15 is held in contact with the inner surface of the support metal fitting 50 so that the antenna protrudes outside the casing of the portable wireless device. The support unit 15 may be configured by attaching another member to the base unit 13.

  Since the pipe 11 has a smaller diameter than the support portions 15 and 16, the support metal fitting 50 can move smoothly between the support portion 15 and the support portion 16.

  In the second embodiment, the structure shown in FIGS. 2 to 8 described in the first embodiment is the same, but in the second embodiment, the top and bottom of each element is the first described above. Since the arrangement is opposite to that of the first embodiment, the upper and lower sides are reversed in FIGS. 2, 3, 4, and 7.

  As described above, according to the second embodiment, the axial movement of the springs 32, 42, etc. is provided by providing the deforming portions 35, 45, etc., as in the effect of the first embodiment. Therefore, the number of parts can be reduced, and an increase in cost can be suppressed. Further, since the length in which the lower element is accommodated when the upper element is extended can be shortened, the effective length of the antenna when the element is extended can be increased. In addition, the tube of the upper element can be deleted, the element can be thinned, and the appearance can be improved.

DESCRIPTION OF SYMBOLS 10 1st element 11 Pipe 12 Fallable metal fitting 13 Base part 14 Shaft 15 Support part 16 Support part 20 2nd element 21 Pipe 30 3rd element 31 Pipe 32 Spring 40 4th element 41 Rod-shaped conductor 42 Spring 43 Cap 50 Support metal fitting

Claims (6)

An antenna comprising at least a first element and a second element housed inside the first element,
Provided below the second element is a spring member that slides on the inner surface of the first element,
The spring member is formed by bending a thin metal plate to form a cylindrical portion at both ends thereof, and a large diameter portion between the cylindrical portions,
The large diameter portion is configured to be variable in diameter by having a larger diameter than the cylindrical portion and having a spring property in the radial direction thereof,
With the second element attached in the first element, the large diameter portion biases the inner surface of the first element outward,
A deformed portion obtained by processing the second element into a large diameter is provided below the second element.
2. The whip antenna according to claim 1, wherein the deformable portion is provided at a position in contact with a lower inner surface of the large diameter portion inside the large diameter portion. The second element is constituted by a rod-like or pipe-like conductor,
The deformation portion is formed by processing a part of the second element into a large diameter,
2. The whip antenna according to claim 1, wherein an outer diameter of the deforming portion is 0.01 mm or more larger than a diameter of a rod or pipe constituting the second element before processing.   3. The whip antenna according to claim 1, wherein a part of the deforming portion is processed to have a large diameter by press working that pressurizes a side surface of a rod or a pipe constituting the second element. 4.   3. The whip antenna according to claim 1, wherein the deformable portion is processed to have a large diameter by press working that pressurizes a rod or pipe constituting the second element in an axial direction.   3. The whip antenna according to claim 1, wherein a part of the deformed portion is processed into a large diameter by knurling a rod or a pipe constituting the second element.   The whip antenna according to any one of claims 1 to 5, wherein a sleeve that contacts the lower end of the spring member is fixed to a lower end portion of the second element.

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