JP2003209423A - Environment resistant cover, antenna device using the same, and broadcasting tower - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radome function capable of securing easiness in work such as maintenance and holding the environment resistance of an antenna device. <P>SOLUTION: The antenna device is provided with a frame-like supporting member 3 fixed on a step bolt 2 for elevation mounted on a pole 1 for supporting a cover 4 and the cover 4 mounted on the supporting member 3 for covering the external part of the antenna device installed on the side of the pole 1, and the cover 4 has a polygonal cross section with the pole 1 as a center and overlays the external part of the antenna device such as antenna element 6. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an environment-resistant cover having a function of preventing snow, which covers an antenna device installed in a broadcasting tower or the like, an antenna device using the same, and a broadcasting tower.

[0002]

2. Description of the Related Art Conventionally, in a broadcasting tower exposed to wind, rain, snow, etc., a dielectric radome covers the outside of the antenna so that the antenna characteristics are not deteriorated or changed.

FIG. 11 is a diagram showing an installation state of an antenna device installed in a conventional broadcasting tower or relay tower. Figure 11
[FIG. 6] is a horizontal cross-sectional view as viewed from the vertical upper part. In FIG. 11, the antenna element 106, which is a twin loop antenna, is installed on the reflection plate 105. Step bolts 102 for raising and lowering are arranged at every 90 degrees on four sides of the column 101. Reflector 105
Are fixed to a columnar pillar 101. This reflector 10
In a state where 5 is fixed, the radome 104 is covered so as to cover the antenna element 106 and fixed on the reflection plate 105.

Further, in Patent Document 1, a plurality of antenna covers having flanges for joining each other are used to form a tubular structure having a substantially circular or polygonal cross section to cover the antenna and prevent wind pressure load. A reduced antenna cover is described.

[0005]

[Patent Document 1] Japanese Utility Model Laid-Open No. 60-90902

[0006]

However, the radome 104 of the conventional antenna device has a semi-cylindrical shape determined by the external shape of the antenna element 106 and the positional relationship with the reflecting plate 105, and this semi-cylindrical shape is the shape of the pillar 101. As well as a shape that protrudes in all directions,
Since the outer edge of the reflection plate 105 is exposed, an operator is caught on the protruding portion or the exposed portion during maintenance work, which causes difficulty in maintenance work and is also dangerous.

On the other hand, in addition to the above-mentioned shapes of the radome 104 and the reflecting plate 105, there are gaps between the adjacent reflecting plates 105 or between the reflecting plate 105 and the support 101, so that the wind is larger than the projected area. Under load,
There was also the problem that the amount of snow accreted during the snowfall was large. In particular, the wind load and the amount of snow accretion when the radome 104 is not installed are so large that they cannot be ignored.

When the radome 104 described above is not provided, the antenna element 106 is exposed,
In this case, the metal part of the maintenance worker may come into contact with the antenna element 106 and the like, and a short circuit may occur, which further increases the risk. Further, since the radome 104 cannot be protected against the environment, the antenna device itself such as the antenna element 106 needs to have sufficient environment resistance and mechanical strength.

Further, the shape of the radome 104 depends almost entirely on the shape of the antenna element 106, and when the antenna device including the antenna element 106 is replaced, the radome 104 itself must be newly created. It was a matter of flexibility and versatility.

On the other hand, in the antenna cover described in the above-mentioned Patent Document 1, the flanges of the adjacent antenna covers are aligned, and the bolts and the nuts are fastened together to form one large antenna cover. However, there is a problem in that the flange portion in the entire structure forms a large protrusion, and the wind pressure load cannot be sufficiently reduced by receiving the wind.

Further, the projections and the tips of bolts are
When raising and lowering for maintenance work, clothes and tools are caught, which increases the risk.Because one large radome is formed by joining the antenna covers together, removing one antenna cover from another There is a problem that the fixing of the antenna cover is weakened, and the risk of falling is increased.

The present invention has been made in view of the above,
It is possible to provide an environment-resistant cover having a radome function capable of ensuring workability and safety such as maintenance work and maintaining environment resistance of the antenna device, and an antenna device and a broadcasting tower using the same. To aim.

[0013]

In order to achieve the above object, the environment-resistant cover according to claim 1 is attached to the columnar body and a plurality of cover members for covering the outside of the antenna device installed in the columnar body. And a frame-shaped support member that is fixed to the step bolts for raising and lowering and that supports each cover member. Each cover member is independently supported by the support member and covers the entire outer surface of the antenna device. Characterize.

According to the first aspect of the present invention, the supporting member is fixed to the stepping bolts for raising and lowering attached to the columnar body, and each cover member is directly and independently supported by the supporting member. , Covering the entire outer surface of the antenna device installed on the side of the columnar body so as to provide the antenna device with a function as a radome for protecting it from the environment such as rain, rain, snow, etc. Instead, one type of radome is available. Here, since each cover member is independently supported by the support member, the strength can be increased as compared with the cover assembly structure formed by joining the cover members. Also,
Since each cover member does not have a flange part that joins adjacent cover members to each other, a large protrusion is not formed, wind load and amount of wind and snow can be reduced, and safety during maintenance work can be ensured. You can

The environment-resistant cover according to claim 2 is
In the above invention, the cover member covers the outside of the antenna device with a circular cross section around the columnar body, and the outer surface of the cover member has a hemispherical shape or a band shape having a semicircular cross section. Indentations or protrusions are provided, and the depressions or protrusions are linearly or spirally arranged along the outer surface.

According to the second aspect of the present invention, the outer surface of the cover member has a hemispherical or band-shaped depression or protrusion having a semicircular cross section, and the depression or protrusion is the outer portion. Arranged in a straight line or in a spiral along the surface, the air separation point along the outer surface is optimized to reduce the generation of variable lift.

The environment resistant cover according to claim 3 is
In the above invention, the cover member forms a polygon having five or more corners and covers the entire outer surface of the antenna device.

According to the third aspect of the present invention, the cover member has a polygonal shape with five or more corners so as to cover the entire outer surface of the antenna device, and air separation points along the outer surface are formed. Optimized to reduce the generation of fluctuating lift.

The environment-resistant cover according to claim 4 is
In the above-mentioned invention, the radius of the hemispherical or band-shaped depression or protrusion having a semicircular cross section is 0.5.
It is characterized by being 10 mm.

According to the fourth aspect of the invention, the radius of the hemispherical or band-shaped depression or protrusion having a semicircular cross section is set to 0.5 to 10 mm,
The air separation point is optimized as much as possible to reduce the generation of fluctuating lift.

Further, the environment-resistant cover according to claim 5 is
In the above invention, the cover member is provided with an opening / closing mechanism.

According to the fifth aspect of the present invention, the cover member can be opened and closed to prevent the cover member from dropping at the time of work and improve workability.

The environment-resistant cover according to claim 6 is
In the above invention, a water-repellent coating is applied to the outer surface of the cover member.

According to the invention of claim 6, a water-repellent coating is applied to the outer surface of the cover member so that snow, water droplets, etc., do not adhere to the outer surface of the environment-resistant cover.

The antenna device according to claim 7 is
It is characterized by being covered with the environment-resistant cover according to any one of claims 1 to 6.

According to the invention of claim 7, claims 1 to
Since it is covered with the environment-resistant cover according to any one of the sixth aspect, the effects of the first to sixth aspects described above can be obtained.

A broadcasting tower according to claim 8 has at least the columnar body fixed to the ground, and is provided with the antenna device according to claim 7, which is covered with the environment-resistant cover. To do.

According to the invention of claim 8, since the antenna device according to claim 7 is provided, the effects of claims 1 to 6 can be obtained.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of an environment-resistant cover, an antenna device using the same and a broadcasting tower according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a cutaway view showing the structure of an antenna device using an environment-resistant cover according to an embodiment of the present invention. 2 is a cutaway view of the antenna device shown in FIG. 1 as seen from the top plane. In FIG. 1 and FIG. 2, this antenna device is installed in the upper part of the broadcasting tower. This antenna device is arranged on four sides of the column 1 in the horizontal direction. Step bolts 2 for raising and lowering are installed on the horizontal direction of the support column 1 every 90 degrees on a horizontal plane.

An antenna device, which is a 4L antenna having four loops, is arranged between the step bolts 2.
In the antenna device, an antenna element 6 is provided on a reflection plate 5, and a broadcast radio wave in the UHF band is radiated from this antenna element 6.

On the other hand, a supporting member 3 having a frame-like structure is attached to the step bolt 2. This support member 3 is FR
A cover 4 made of P or ABS resin is supported.
The cover 4 has a polygonal shape in cross section and has substantially the same radius from the center of the pillar 1, and the upper and lower ends form a roof structure that is concentrated on the pillar 1 side. As a result, the entire antenna device attached to the four sides of the column 1 can be covered, and the antenna device can be protected from rain, wind, snow, etc. without degrading the function of the antenna. That is, the cover 4 has a versatile radome function that is not affected by the shape of the antenna device such as the antenna element 6. In particular, since the reflection plate 5 also enters the cover 4, workability and safety are also excellent.

FIG. 3 is a view showing a coupling relationship between the step bolt 2 attached to the column 1 and the support member 3. In FIG. 3, the support member 3 is fixed to the position of the step bolt 2 equidistant from the support 1, and the upper and lower parts are bent toward the support 1. The holes formed in the support member 3 except the step bolts 2 are screw holes for fixing the support member 3 and the cover 4.

Here, the attachment of the cover 4 to the step bolt 2 will be described with reference to FIGS. 4 and 5. In FIG. 4A, first, the step bolt 2 is attached to the column 1 with the piece 11 for attaching the support member inserted between the fixed nut 12 and the nut 13 that is screwed.

Then, as shown in FIG. 4B, the nut 13 is screwed to the nut 12 side, and the piece 11 is screwed.
Further, the support member 3 is inserted to the position of the piece 11 and fixed with the screw 14 (see FIG. 4D). Furthermore, FIG.
As shown in FIGS. 5A and 5B, the cover 4 is inserted to the position of the support member 3, and the space between the support member 3 and the cover 4 is screwed at a position corresponding to the screw 15 (see FIG. c)
reference). It should be noted that a cutout is provided at a portion of the cover 4 corresponding to the screw 14 to avoid interference with the screw 14.

Although the cover 4 has a polygonal cross section, it may have a circular cross section or a substantially circular cross section. By making the cross section polygonal or circular in this way, it is possible to reduce the wind load and also the amount of snow accretion, and reduce the mechanical strength applied to the broadcasting tower or the like in which the antenna device is installed. be able to. Furthermore, since the cross section is polygonal or circular and the reflector 5 and the like are not exposed to the outside, maintenance work is easy and accidents during work can be prevented. Furthermore, the reflector 5
Since the antenna device including itself is completely covered by the cover 4, there is no contact with the antenna device and the risk of short circuit or the like can be avoided.

Further, since the covers 4 are arranged adjacent to each other with the support member 3 interposed therebetween and are independently joined to the support member 3, even if one cover 4 is removed, the other covers 4 are adjacent to each other. Since there is no effect on the joining of the covers 4 and the shape of the entire cover 4 can be reliably maintained, and the other covers 4 do not drop, safety can be ensured. Since each cover 4 is directly joined by the supporting member 3, the strength of the entire cover can be increased as compared with the case where the strength of the entire cover is maintained as an assembly of the covers 4.

As described above, since the covers 4 are not directly joined to each other by flanges or the like, the number of protrusions is reduced, so that the safety during maintenance work can be ensured and the protrusions can be secured. Since there is no wind load, the wind load can be reduced.

Here, when air flows along the outer surface of the cover 4, fluctuating lift is generated, and Karman vortices are alternately generated on the downstream side of the air in the cover 4, causing the cover 4 to vibrate. The occurrence of this vibration can be reduced by optimizing the air separation points along the outer surface of the cover 4. FIG. 6 shows changes in the lift coefficient with time due to differences in the shape of the cover 4. FIG. 6 shows the case where the cross-sectional shape of the cover 4 is circular and the case where it is regular hexagonal. As shown in FIG. 6, it can be seen that the regular 24-sided polygon has a smaller lift coefficient and smaller vibration than the circular shape. This indicates that the air separation point is at an optimal position in the regular 24-sided polygon as compared to the circular shape. Therefore, compared with the case where the cross-sectional shape is circular, a regular polygon, especially a regular 2
The rectangular shape can realize a cover with less vibration. When the polygon has four corners, that is, a square, it is not preferable because the wind load is not sufficiently reduced, and a regular polygon having five or more corners is preferable. In particular, it is more preferable that the regular hexagon shown in FIG. 6 is used. Of course, it is preferable to properly set the number of angles depending on the difference in the wind velocity flowing into the cover 4, the outer diameter of the cover, and the like. That is, this angle may be set to an optimum angle based on the data of the environment in which the cover 4 is installed.

By the way, it has been stated that the cross-sectional shape of the cover 4 is preferably a regular polygon of 5 or more, rather than a circular shape. However, even when the cross-sectional shape is circular or substantially circular, the air separation point is optimal. Can be converted. That is, the cover 4
On the outer surface side of the above, a hemispherical depression (dimple) having a cross-sectional shape of a radius of about 0.5 to 10 mm is provided.
With this depression, the air separation point along the outer surface of the cover 4 can be optimized, the generation of fluctuating lift can be reduced, and the wind load and the snow accretion amount can be reduced. Of course, as shown in FIG. 7, the dimples 21 may be provided on the outer surface side of the cover 4, which is a regular polygon, to further optimize the air separation point and reduce the generation of the variable lift. . Note that a projection may be provided instead of the hemispherical depression. Furthermore, the depressions 21 or the protrusions may be arranged in a straight line in the vertical direction, that is, in the vertical direction, or so as to surround the column 1.
You may make it arrange | position in a spiral shape.

Further, as shown in FIG. 8, a band-shaped depression 22 having a semicircular cross section with a radius of about 0.5 to 10 mm.
May be provided. By this depression 22,
Similar to the recess 21 described above, the air separation point along the outer surface of the cover 4 can be optimized to further reduce the generation of the variable lift. Instead of the band-shaped depression 22, a band-shaped protrusion may be provided. Furthermore, the depressions 22 or the protrusions may be arranged in a straight line in the vertical direction, that is, in the vertical direction, or may be arranged spirally so as to surround the support column 1.

The outer surface of the cover 4 may be coated or coated with a water repellent paint. By applying a water-repellent coating, water droplets and the like do not adhere to the outer surface of the cover 4, the load load on the support 1 and the like can be reduced, and the environmental resistance of the cover 4 itself can be increased.

By the way, in the above-mentioned antenna device, the cover 4 can be removed, but if it is left as it is, it is necessary to hang the removed cover 4 on any place. For this reason, as shown in FIG. 9, the hinge 30 is provided in the vicinity of the support member 3 so that each cover 4 can be opened and closed.
It is possible to improve workability when removing the.
To open and close the cover 4, the screw 1 on the one support member 3 side
This is done by removing 5. Therefore, FIG.
It is also possible to open and close in the direction opposite to that shown in. That is,
The left and right can be opened and closed, further improving workability. Further, instead of disposing the hinges 30 in a distributed manner, the cover 4 itself may have a hinge structure which rotates about the shaft 4a as shown in FIG.

[0044]

As described above, according to the first aspect of the invention, the supporting member is fixed to the step bolts for raising and lowering mounted on the columnar body, and the respective cover members are adjacent to each other via the supporting member. It is arranged and directly supported by a support member, and by this support, it has a function as a radome that covers the entire outer surface of the antenna device installed on the columnar body side and protects the antenna device from the environment such as wind, rain and snow. In particular, there is an effect that one type of radome can be used regardless of the antenna element shape and the antenna mounting radius. Further, since each cover member is independently supported by the support member, there is an effect that the strength can be increased as compared with the cover aggregate structure formed by joining the cover members. Further, since the cover members are only arranged adjacent to each other with the support member interposed therebetween, a large protrusion is not formed in joining the cover members, the wind load and the amount of wind and snow can be reduced, and the safety during maintenance work can be improved. The effect that it can be secured is exhibited.

According to a second aspect of the present invention, the outer surface of the cover member has a hemispherical shape or a band-shaped depression or projection having a semicircular cross section, and the depression is
Alternatively, the protrusions are arranged linearly or spirally along the outer surface, and by optimizing the air separation point along the outer surface, it is possible to reduce the generation of the variable lift.

Further, according to the invention of claim 3, the cover member has a polygonal shape having a number of corners of 5 or more so as to cover the entire outer surface of the antenna device, and the air separation point along the outer surface. There is an effect that it is possible to reduce the occurrence of fluctuating lift by optimizing.

Further, according to the invention of claim 4, the radius of the hemispherical or band-shaped depression having a semicircular cross section or the projection is set to 0.5 to 10 mm so that the air is as much as possible. Since the peeling point is optimized and the generation of the variable lift is reduced, it is possible to reliably reduce the load applied to the antenna device and the mounting column.

Further, according to the invention of claim 5, the cover member can be opened and closed, the cover member can be prevented from dropping at the time of work, and the workability can be improved.

According to the invention of claim 6, a water-repellent coating is applied to the outer surface of the cover member so that snow and water droplets do not adhere to the outer surface of the environment-resistant cover and the flow resistance is also increased. In some cases, it can be reduced, so
It is possible to reduce the load applied to the antenna device and the mounting column.

According to the invention of claim 7, claim 1
Since it is covered with the environment-resistant cover according to any one of items 1 to 6, the effects of the above-described items 1 to 6 are obtained.

According to the invention of claim 8, claim 7 is provided.
Since the antenna device according to claim 1 is provided, the effects of claims 1 to 6 are obtained.

[Brief description of drawings]

FIG. 1 is a cutaway view showing a configuration of an antenna device having an environment-resistant cover according to an embodiment of the present invention.

2 is a cutaway view of the antenna device shown in FIG. 1 as seen from above.

3 is a diagram showing a connection relationship between a step bolt and a support member of the antenna device shown in FIG.

FIG. 4 is a view showing the order of attaching the covers to the step bolts, and (d) is a sectional view taken along the line AA.

FIG. 5 is a view showing the order of attaching the covers to the step bolts, and (c) is a sectional view taken along line BB.

FIG. 6 is a diagram showing a change over time in a lift coefficient due to a difference in shape of a cover.

FIG. 7 is a view showing an example in which dimples are provided on the outer surface of the cover.

FIG. 8 is a view showing an example in which a band-shaped recess is provided on the outer surface of the cover.

FIG. 9 is a cross-sectional view showing a structure of an antenna device in which a cover can be opened and closed by using a hinge.

FIG. 10 is a diagram showing a partial structure of an antenna device in which the cover itself has a hinge structure.

FIG. 11 is a cutaway view showing a structure of a conventional antenna device.

[Explanation of symbols]

1 prop 2 step bolt 3 Support members 4 cover 5 reflector 6 antenna elements 11 pieces 12,13 nuts 14,15 screws 21,22 dimples 30 hinges

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Isamu Yamagata             2-6-1, Marunouchi, Chiyoda-ku, Tokyo             Kawa Electric Industry Co., Ltd. F-term (reference) 5J046 AA10 AA14 AB11 CA04 CA07                       RA01 RA06 RA12 RA13                 5J047 AA10 AA14 AB11 BC03 BC15

Claims (8)

[Claims] 1. A plurality of cover members for covering the outside of an antenna device installed in a columnar body, and a frame-shaped supporting member fixed to step lifting bolts attached to the columnar body and supporting each cover member. And an environmental protection cover, wherein each cover member is independently supported by the support member and covers the entire outer surface of the antenna device. 2. The cover member has a circular cross section around the columnar body and covers the outside of the antenna device, and an outer surface of the cover member has a hemispherical shape or a semicircular cross section. The environment-resistant cover according to claim 1, further comprising a recess or a protrusion, wherein the recess or the protrusion is linearly or spirally arranged along the outer surface. 3. The environment-resistant cover according to claim 1, wherein the cover member forms a polygon having five or more corners and covers the entire outer surface of the antenna device. 4. The radius of the hemispherical or band-shaped depression or projection having a semicircular cross section is 0.5 to 10
The environment-resistant cover according to claim 2, wherein the environment-resistant cover is mm. 5. The environment-resistant cover according to claim 1, wherein the cover member includes an opening / closing mechanism. 6. The environment-resistant cover according to claim 1, wherein a water-repellent coating material is applied to an outer surface of the cover member. 7. An antenna device covered by the environment resistant cover according to claim 1. Description: 8. A broadcasting tower comprising the antenna device according to claim 7, which has at least the columnar body fixed to the ground and is covered with the environment-resistant cover.