JP2013093779A - Whip antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To elongate an effective length of an antenna by decreasing the number of components and the length of the antenna when reduced.SOLUTION: An antenna includes at least: a first element; and a second element stored inside the first element. A flange part formed to have a large diameter is disposed at a lower end of the second element. A spring member that slides along an inner surface of the first element is attached to a lower part of the second element so as to contact with the flange part. A large diameter part of the spring member energizes outward an inner surface of the first element in a state that the second element is attached to the inside of the first element. A hook part having a protrusion that protrudes radially inward is disposed at a lower part of the spring member so as to protrude from a lower end part thereof. The spring member is fixed to the second element by engagement of the protrusion with a lower end part of the second element.

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 in which an upper element and a lower element are electrically and mechanically connected 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 whip antenna element 30 shown in FIG. 8, a cylindrical sleeve 35A is fixed to the lower end of a pipe 31, and the cylindrical sleeve 35B is piped so as to sandwich a spring 32 disposed at a position in contact with the sleeve 35A. It was fixed to 31. In this case, the effective length of the antenna when the element is extended is shortened by the length of the sleeves 35A and 35B, and there is a problem that the antenna sensitivity is lowered. Further, it is necessary to provide separate members 35A and 35B, and there is a problem that the cost increases due to an increase in the number of parts.

  In another method of fixing the spring, a washer is arranged at the lower end of the tube covering the side surface of the pipe 31 and the spring 35 is fixed by fixing the sleeve 35A to the pipe 31 so that the spring 32 comes into contact with 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 pipe 31 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, Comprising: The lower end of the said 2nd element was formed in the large diameter A flange portion is provided, and a spring member sliding on the inner surface of the first element is attached to the lower portion of the second element so as to contact the flange portion, and the spring member bends the thin metal plate. Thus, a cylindrical part is formed at both ends thereof, and a large-diameter part is formed between the cylindrical parts, and the large-diameter part has a larger diameter than the cylindrical part and has a spring property in the radial direction. The diameter of the first element is variable, and the large diameter portion urges the inner surface of the first element to the outside in a state where the second element is attached to the first element, and the spring member Below that A hook portion having a protrusion portion protruding inward is provided so as to protrude from the lower end portion thereof, and the protrusion member and the lower end portion of the second element are engaged with each other, whereby the spring member is Fixed to 2 elements.

  In a second aspect based on the first aspect, the flange portion is provided with a notch through which the hook portion can pass.

  According to a third invention, in the first or second invention, the second element is constituted by a pipe for accommodating the third element therein, and the protrusion is formed by the spring member being the second element. The amount of protrusion is such that the tip of the pipe does not protrude from the inner diameter of the pipe when attached to the 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, and the element can be reduced in diameter.

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 3rd element 30 of a 1st embodiment of the present invention. It is a bottom view of the 3rd element 30 of a 1st embodiment of the present invention. It is a side view of the spring 32 of the 1st Embodiment of this invention. It is a side view of the state where the spring 32 was attached to the 3rd element 30 of the 1st Embodiment of this invention. It is sectional drawing of the state in which the spring 32 was attached to the 3rd element 30 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 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 3rd 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.

  Note that although a four-stage telescopic whip antenna will be described as an embodiment of the present invention, other stages (for example, two stages) of whip antennas may be used.

  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 is attached to the lower part of the pipe 21. When the spring comes into contact with the inner surface of the first element 10, the second element 20 slides stably inside the first element 10, and comes into stable electrical contact.

  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. 4) 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 is attached to the lower part of the rod-shaped conductor 41, and when the spring comes into contact with the inner surface of the third element 30, the fourth element 40 stably slides inside the third element 30, and electric Stable contact.

  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.

  2A is a side view of the pipe 31 of the third element 30 according to the first embodiment, and FIG. 2B is a bottom view thereof.

  The third element 30 is constituted by a pipe 31. The upper end 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 flange portion 34 formed by processing the pipe 31 into a large diameter is formed. The flange portion 34 may be processed to have a large diameter by pressing the pipe 31 in the axial direction, or a separate member may be attached to the pipe 31 to increase the diameter. It is desirable that the diameter of the flange portion 34 is approximately the same as the outer diameter of the cylindrical portion 32A of the spring 32.

  As shown in FIG. 2B, the flange portion 34 is partially cut away in the circumferential direction (34A). For this reason, the hook portion 32 </ b> C of the spring 32 passes through the notch 34 </ b> A of the flange portion 34, and the tip of the hook portion 32 </ b> C can be positioned below the lower end of the third element 30. That is, the width of the cutout portion 34A where the flange portion 34 is cut out is slightly larger than the width of the hook portion 32C. For this reason, as will be described later, the protrusion 32D provided at the tip of the hook portion 32C can be engaged with the lower end of the pipe 31.

  FIG. 3 is a side view of the spring 32 according to the first embodiment of the present invention.

  The spring 32 includes a cylindrical portion 32A at both ends, a large-diameter portion 32B between the cylindrical portions 32A, and a hook portion 32C protruding in the axial direction from one cylindrical portion 32A. The inner diameter of the cylindrical portion 32A is the same as or slightly larger than the outer diameter of the pipe 31 so that the pipe 31 can be inserted into the spring 32.

  The metal plate constituting the large-diameter portion 32B is curved outward, the spring 32 is attached to the pipe 31, and the third element 30 is inserted into the second element 20, and the outside of the large-diameter portion 32B. The side surface contacts the inner surface of the second element 20. As a result, the elements are electrically connected, and the elements are maintained in the extended state or the stored state by the frictional force generated in the contact portion.

  The hook portion 32C has a tongue-like shape protruding downward from the large diameter portion, and a protrusion 32D protruding toward the inner diameter side is provided at the tip. The protrusion 32D can be formed by bending the tip of the hook portion 32C in the radial direction or by bending the tip of the hook portion 32C in the axial direction.

  FIG. 4 is a side view showing the third element 30 to which the spring 32 of the first embodiment of the present invention is attached, and FIG. 5 is a sectional view thereof.

  The spring 32 is inserted from the upper part of the pipe 31. Then, the hook portion 32 </ b> C of the spring 32 passes through the flange portion 34 by the notch 34 </ b> A of the flange portion 34 and reaches the lower end of the pipe 31. In this state, the protrusion 32D of the hook portion 32C engages with the lower end of the pipe 31. As shown in FIG. 5, the tip of the protrusion 32 </ b> D has a size that does not protrude inward from the inner diameter of the pipe 31. Therefore, the protrusion 32D does not prevent the fourth element 40 from sliding inside the pipe 31.

  FIG. 6 is a cross-sectional view of the upper portion of the second element 20 in a state in which the third element 30 of the first embodiment is extended.

  As described above, the 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. The large diameter portion 32 </ b> B of the spring 32 is in contact with the inner surface of the second element 20, and the third element 30 slides stably inside the second element 20.

  In FIG. 6, the large diameter portion 32 </ b> B of the spring 32 does not seem to be in contact with the inner surface of the second element 20, but this is a problem in the direction shown in the figure, and in fact both are in contact with each other. doing.

  As described above, the flange portion 34 is formed at the lower end of the pipe 31. The outer diameter of the flange portion 34 is larger than the inner diameter of the spring 32. Further, the protrusion 32D of the hook portion 32C engages with the lower end of the pipe 31.

  Thus, the downward movement of the spring 32 is restricted by the flange portion 34, and the upward movement is restricted by the engagement between the lower end of the pipe 31 and the protrusion 32D. Accordingly, the spring 32 is prevented from moving from a predetermined position of the pipe 31, and the spring 32 is stably held on 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. 6, the structure for attaching the spring 22 at the connection portion between the second element 20 and the first element 20 is also described. Similarly, a hook having a protrusion at the lower end of the spring can be provided to restrict the movement of the spring.

  The antenna of the embodiment of the present invention is characterized by a spring connecting elements. Although this characteristic portion will be described with respect to a spring provided in the third element 30 and connecting between the third element 30 and the second element 20, the same structure can be adopted for springs provided in other elements. .

  As described above, according to the first embodiment, since the axial movement of the spring 32 is restricted by the flange portion 34 and the protrusion 32D of the spring 32, it is necessary to provide another member for fixing the spring. Therefore, the number of parts can be reduced, and an increase in cost can be suppressed.

  Further, it is not necessary to press the end of the spring 32 with a separate member sleeve, and the space for attaching the spring can be shortened. For this reason, it is possible to lengthen the effective length of the antenna when the element is extended while shortening the length of the antenna when the element is accommodated. Furthermore, the outer shape of the antenna element can be reduced.

  Next, a second embodiment of the present invention will be described. FIG. 7 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 is attached to the upper part of the pipe 21. As the spring comes into contact with the inner surface of the first element 10, the second element 20 slides stably 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. 4) is attached to the upper 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.

  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 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 described in the first embodiment is the same. However, in the second embodiment, the upper and lower sides of each element are opposite to those in the first embodiment described above. Therefore, the top and bottom are reversed in FIGS.

  As described above, according to the second embodiment, the axial movement of the spring 32 is restricted by the flange portion 34 and the protrusion 32D of the spring 32 as in the first embodiment described above. There is no need to provide a separate member for fixing the spring, the number of parts can be reduced, and an increase in cost can be suppressed. Further, it is not necessary to press the end of the spring 32 with a separate member sleeve, and the space for attaching the spring 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.

10 First element 11 Pipe 12 Foldable metal fitting 13 Base part 14 Shaft 15 Support part 16 Support part 20 Second element 21 Pipe 30 Third element 31 Pipe 32 Spring 32A Cylindrical part 32B Large diameter part 32C Hook part 32D Projection 34 Flange 40 4th element 41 Bar-shaped conductor 43 Cap

Claims (3)

An antenna comprising at least a first element and a second element housed inside the first element,
The lower end of the second element is provided with a flange portion formed in a large diameter,
A spring member that slides on the inner surface of the first element is attached to the lower portion of the second element so as to contact the flange portion,
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,
The spring member is provided with a hook portion having a protruding portion that protrudes inward in the diameter so as to protrude from the lower end portion thereof,
The whip antenna, wherein the spring member is fixed to the second element by engaging the protrusion and the lower end of the second element.   The whip antenna according to claim 1, wherein the flange portion is provided with a notch through which the hook portion can pass. The second element is composed of a pipe for accommodating the third element therein,
3. The whip antenna according to claim 1, wherein the protruding portion has a protruding amount that does not protrude from an inner diameter of the pipe in a state where the spring member is attached to the second element.

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