JP4788794B2 - Front feed device and maintenance method thereof - Google Patents

Description

  The present invention relates to a front feed device for an antenna that is equipped with a plurality of frequency band feeding antennas and is driven by AZ / EL, and mainly has functions of multi-frequency band switching, polarization switching, and conical scanning, and is easy to maintain. The present invention relates to an excellent front feed device and a maintenance method thereof.

In a conventional antenna device sharing a multi-frequency band, a frequency selective mirror surface is provided between the reflecting mirror and the plurality of primary radiators, and a driving device that can change the incident angle of the radio wave on the frequency selective mirror surface is used. An antenna device has been proposed in which a single frequency selective mirror surface can be demultiplexed into frequencies of three or more frequency bands. (See Patent Document 1)
In addition, the Bent Cassegrain method is adopted, and a large third reflector is provided at the Cassegrain focal point at the bottom of the main reflector, and a large independent power feeding unit is provided at the antenna mount, thereby constructing an antenna device that shares multiple frequency bands. There is also.

JP 2000-349543 A

  In a conventional antenna device sharing a multi-frequency band, when a common power feeding unit is provided using a driving device capable of changing the angle of incidence of radio waves on the frequency selective mirror surface, the ratio band is small because the multi-frequency band common power feeding unit is used. Become. In addition, if the Bent Cassegrain method is adopted, a large third reflector is provided at the Cassegrain focal point at the bottom of the main reflector and a large independent power feeding unit is provided at the antenna mount. The burden on the frequency band switching device corresponding to the band and the antenna drive system is increased. Moreover, in both systems, since a large power feeding unit is arranged, it is difficult to drive the three operating performances of multi-frequency band switching, polarization switching, and conical scanning with the same drive system, and the independent 3 One drive system is provided, which raises the cost of the drive system and increases the complexity of the maintenance.

  The present invention has been made to solve the above-described problems, and is a front feed device disposed at the focal point of the main reflector, and has three functions of multi-frequency band switching, polarization switching, and conical scanning. It is an object of the present invention to obtain a front feed device that has a drive system that performs the above-described and has excellent maintainability and a maintenance method thereof.

  A front feed device according to a first aspect of the present invention is a front feed device supported by a stay at a focal point of a main reflector and having a horn of a plurality of frequency bands, a fixed base member fixed to the stay, and the fixed side A POL movable base member supported by the base member so as to be rotatable around the POL axis, a POL drive unit for rotating the POL movable base member by POL, and the POL movable base member can be displaced in the X-axis and Y-axis directions. A supported feeder frame, an XY drive unit that drives the feed unit frame in the X-axis and Y-axis directions, a protective cover that covers the POL drive unit and the XY drive unit and opens in the direction of the main reflector; A POL driving system access panel provided in the vicinity of the POL driving unit on the protective cover, and provided in the vicinity of the XY driving unit on the protective cover. It is obtained by an XY drive system access panel.

  According to a second aspect of the present invention, there is provided a maintenance method for the front feed device according to the first aspect, wherein the step of setting the main reflecting mirror at an elevation angle of 0 ° and the POL drive system access panel are removed. And a step of applying or spraying a lubricant to the POL shaft gear by rotating the POL by a handle shaft unit provided in the POL driving unit.

  According to a third aspect of the present invention, there is provided a maintenance method for a front feed device according to the first aspect, wherein the main reflecting mirror is set at an elevation angle of 0 °, the POL drive system access panel, and the XY. A step of removing the drive system access panel, and a step of applying or spraying a lubricant to the drive mechanism of the XY drive unit by rotating the POL by a handle shaft unit provided in the POL drive unit. is there.

  According to a fourth aspect of the present invention, there is provided a maintenance method for a front feed device according to the first aspect, wherein the main reflecting mirror is set at an elevation angle of 0 °, the POL drive system access panel, and the XY. A step of removing the drive system access panel, a step of setting the POL angle to a predetermined angle by a handle shaft unit provided in the POL drive unit, and a step of pulling out the power supply circuit unit from the power supply unit frame. is there.

  According to this invention, band switching, polarization switching, and conical scanning can be performed by the POL driving unit and the XY driving unit, and the antenna is set at an elevation angle of 0 ° and provided in the front feed device. The access panel is removed and opened, and the POL is driven to perform maintenance of the front feed device, so that the maintainability is improved.

1 is an overall configuration diagram of an antenna device including a front feed device according to Embodiment 1 of the present invention. It is the external view which expanded the front feed apparatus. It is sectional drawing of a front feed apparatus. It is a block diagram of a cable winding mechanism and a POL drive system. It is sectional drawing showing an XY drive part when rotating a POL axis | shaft. It is an external view showing the electric power feeding circuit part etc. at the time of attachment or detachment.

  Embodiment 1

  Hereinafter, a front feed device and a maintenance method thereof according to Embodiment 1 of the present invention will be described with reference to the drawings. 1 is an overall configuration diagram of an antenna device including a front feed device according to Embodiment 1 of the present invention. FIG. 2 is an enlarged external view of the front feed device.

  In FIG. 1, 1 is a main reflecting mirror, 2 is a front feed device provided near the focal point of the main reflecting mirror 1, and the front feed device 2 is supported by a plurality of stays 3. An EL turning part 4 including a back chamber is provided on the back surface of the main reflecting mirror 1 and supported on the AZ turning part 6 so as to be rotatable around an EL (attack angle) rotation axis 5. Further, the AZ turning portion 6 is supported on the mount portion 7 so as to be rotatable around an AZ (azimuth) rotation axis 8. The EL turning unit 4 and the AZ turning unit 6 are rotationally driven by an EL driving unit and an AZ driving unit (not shown). 1A shows the antenna device state when the elevation angle of the main reflector 1 is 90 °, and FIG. 1B shows the antenna device state when the elevation angle of the main reflector 1 is 0 °. Represents. An antenna device that controls satellites by receiving radio waves from artificial satellites, a telescope antenna device that captures radio waves from deep space, or a radio monitoring antenna that monitors and monitors radio waves from multiple satellites in the satellite orbit The size of antenna devices that receive weak radio waves from a distance, such as devices, is increasing, and the height from the lower surface of the mount 7 to the upper surface of the front feed device 2 reaches 10 m or more. In the state as shown in FIG. 1 (a), the maintenance workability of the front feed device 2 is extremely poor. Therefore, in the state shown in FIG. 1 (b), an aerial work cart 9 is installed below the front feed device 2 for maintenance. Make maintenance work possible.

  In FIG. 2, 10 is a stay seat portion for connecting the stay 3, and 11 is a stay ring for fixing the stay seat portion 10. The mechanical structure of the front feed device 2 is formed based on the staying 11. Reference numeral 12 denotes a POL drive system cover that houses the POL drive unit, and 13 denotes an XY drive system cover that houses the XY drive unit and the power feeding unit, both of which are attached to the staying 11. Reference numeral 14 denotes a POL drive system access panel attached to the POL drive system cover 12 by fastening parts such as screws, and 15 denotes an XY drive system access panel attached to the XY drive system cover 13 by fastening members such as screws. These covers and access panels protect the front feed device 2 from the external environment (sunlight, wind and rain, etc.) mainly in an antenna device installed outdoors, and generate rust, dust adhesion, etc. in the drive mechanism and power feeding section. prevent. The XY drive system cover 13 is opened in the direction of the main reflector.

  FIG. 3 is a cross-sectional view of the front feed device 2. In FIG. 3, 16 is a ring-shaped fixed base member fixed to the staying 11, and 17 is a POL movable base member supported by the fixed base member 16 via a bearing. The POL movable base member 17 is supported so as to be rotatable about an axis in the main reflector direction (Z axis shown in FIG. 3). The coordinate system (X, Y, Z) shown in FIG. 3 is an orthogonal coordinate system fixed to the center of the POL movable base member 17 for convenience, and two orthogonal axes (X, Y) are rotated around the Z axis by POL rotation. Rotate to. Reference numeral 18 denotes a POL shaft gear connected to the POL movable base member 17, reference numeral 19 denotes a POL drive motor, and the POL drive unit mainly includes a POL shaft gear 18 and a POL drive motor 18. Also, in the area 20 indicated by the dotted line, a POL driving cable winding mechanism for storing and routing electrical wiring between the staying 11 side and the POL movable base member 17 side (winding shown in FIG. 4A described later). XY driving cable winding mechanism (winding shown in FIG. 4B described later) that accommodates and routes the electrical wiring between the POL movable base member 17 side and the XY stage side in an area 21 indicated by a dotted line. Take-off mechanism). A cylindrical member 22 to which the cable winding mechanism is attached is connected to the POL movable base member 17.

  Further, in FIG. 3, reference numeral 23 denotes a Y-axis linear guide provided on the POL movable base member 17 and having a longitudinal direction in the Y-axis direction, and 24 is attached to the POL movable base member 17 via the Y-axis linear guide 23. A Y-axis movable stage 25 is a Y-axis ball screw. An X-axis linear guide 26 is provided on the Y-axis movable stage 24 and has a longitudinal direction in the X-axis direction, and 27 is a power feeding unit frame attached to the Y-axis movable stage 24 via the X-axis linear guide 26. An X-axis ball screw (not shown) is provided between the Y-axis movable stage 24 and the power feeding unit frame 27. A motor is provided on each of the Y-axis ball screw 25 and the X-axis ball screw, and the Y-axis direction position of the Y-axis movable stage 24 and the X-axis direction position of the power feeding unit frame 27 are controlled by rotationally driving the motors. Is set. Note that other linear motion mechanisms may be used as the linear motion mechanism that translates in the X-axis and Y-axis directions. The XY drive unit is mainly composed of a Y-axis linear guide 23, a Y-axis ball screw 25, an X-axis linear guide 26, an X-axis ball screw, and a motor provided on each ball screw shaft.

  Reference numeral 28 denotes a power supply circuit unit housed in the power supply unit frame 27, 29 denotes a plurality of horns provided at the tip of the power supply unit frame 27, and the horn 29 faces the main reflector 1. The plurality of horns 29 have different frequency bands and different shapes and sizes. For example, it comprises a plurality of horns such as an L band horn, an S band horn, a C band horn, a Ka band horn, and a Ku band horn. The power feeding circuit unit 28 includes high-frequency circuit components such as a waveguide, an amplifier, and a band pass filter connected to each horn 29, and a signal received by the power feeding circuit unit 28 is connected to the power feeding circuit unit 28. The coaxial cable is routed substantially on the Z-axis and passes through the hole provided in the central portion of the Y-axis movable stage 24 and the POL movable base member 17 from the power supply unit frame 27, Routing is performed from the stay seat portion 10 to the stay 3 in the cable winding mechanism described above.

  Further, the POL drive system access panel 14 and the XY drive system access panel 15 are positioned on the lower surface in the vertical direction of the front feed section 2 as shown in FIG. Removal of the POL drive system access panel 14 and the XY drive system access panel 15 from the work platform of the high work platform 9 by setting the height of the high work platform 9 installed below the front feed unit 2 to an appropriate height. Can be performed.

  FIG. 4 is a configuration diagram of the cable winding mechanism and the POL drive system. 4A shows the POL driving cable winding mechanism as seen from the AA section of FIG. 3, and FIG. 4B shows the XY driving cable winding mechanism and the POL driving as seen from the BB section of FIG. Represents a system. In FIG. 4 (a), 30 is a POL cable bearer that follows POL rotation, 31 is a fixed cable clamp that connects the POL cable bearer 30 to the staying 11 side, and 32 is on the POL movable base member 17 side. It is a movable side cable clamp which connects the cable bear for POL. In FIG. 4B, reference numeral 33 denotes an XY cable bear following the X axis drive, 34 denotes a fixed cable clamp for connecting the XY cable bear 33 to the POL movable base member 17 side, and 35 denotes a Y axis. This is a movable cable clamp for connecting an XY cable bear 33 to the movable stage 24 side.

  The movable side of the POL cable bear 30 is attached to the cylindrical member 22 by the movable cable clamp 32, and the fixed side of the XY cable bear 33 is located in the vicinity of the attachment location (position near the offset in the Z-axis direction). It is attached to the cylindrical member 22 by the fixed cable clamp 34, and each cable bear moves following the displacement in each of the POL drive and the XY drive. The movable cable clamp 35 portion shown in FIG. 4B moves only in the X-axis direction along the long hole 36 in the center portion in accordance with the XY drive. It is also possible to move only in the direction. Furthermore, if the movable cable clamp 35 is connected to the power feeding unit frame 27, the movable cable clamp 35 moves to both XY axes in accordance with the XY drive. It can also be. Here, the XY driving winding mechanism includes a moving side that moves only in the X-axis direction, a moving side that moves only in the Y-axis direction, and a moving side that moves in both XY axes. The cable is routed through the holes shown in FIG.

  The POL drive unit in FIG. 4B will be described. The POL shaft gear 18 is provided in the circumferential portion around the Z axis necessary for POL driving (naturally, it may be provided for the entire circumference). The POL drive motor 19 is fixed to the fixed base member 16, and a pinion is attached to the tip of the rotating shaft of the POL drive motor 19. The pinion and the POL shaft gear 18 mesh with each other, and the POL drive motor 19 is driven to rotate the POL movable base member 17 around the Z axis. Reference numeral 37 denotes a handle shaft unit having a gear meshing with the POL shaft gear 18 and an output shaft for outputting POL rotation. The handle shaft unit shown in FIG. 4 (b) includes axis conversion for converting POL drive (rotation drive around the Z axis) to an output shaft around the axis orthogonal to the Z axis by combining two bevel gears. It is a waste. At an elevation angle of 0 ° (see FIG. 1B), the handle shaft unit 37 is disposed so as to be positioned on the lower side in the vertical direction in the front feed portion 2, and the direction of the output shaft of the POL shaft gear 18 is substantially vertical. The shaft end protrudes substantially vertically downward. Similarly to the handle shaft unit 37, the POL drive motor 19 is also arranged so as to be positioned on the lower side in the vertical direction in the front feed portion 2 at the elevation angle 0 ° position (see FIG. 1B). With this arrangement, as shown in FIG. 4B, the POL drive system access panel 14 is positioned in the vicinity of the POL drive unit.

  With this arrangement, when the POL drive system access panel 14 is removed, the POL drive motor 19 and the handle shaft unit 37 are exposed, and the output shaft of the handle shaft unit 37 can be rotated using a tool such as a crank handle. . Maintenance work such as replacement when the POL drive motor 19 fails, inspection of the appearance of the POL shaft gear 18 (inspection of corrosion, cracking, wear, etc.), replenishment of lubricant, and the like can be performed. In particular, the POL shaft gear 18 can perform maintenance over the entire circumference by rotating the output shaft of the handle shaft unit 37.

  FIG. 5 is a cross-sectional view showing the XY drive unit when the POL shaft is rotated. 5A shows the CC cross section of FIG. 3 at a POL angle of 0 °, and FIG. 5B shows the CC cross section of FIG. 3 at a POL angle of 90 °. Reference numeral 38 denotes a Y-axis motor attached to the screw shaft of the Y-axis ball screw 25, 39 denotes an X-axis ball screw, and 40 denotes an X-axis motor attached to the screw shaft of the X-axis ball screw 39. The XY drive system access panel 15 is located on the lower surface in the vertical direction of the front feed portion 2 as shown in FIG. 3 at the elevation angle of 0 ° in FIG. 1B, and in the state of FIG. The Y-axis ball screw 25 and the Y-axis motor 38 are located near the drive system access panel 15, and the X-axis ball screw 39 and the X-axis motor 40 are located near the XY drive system access panel 15 in the state of FIG. . When the XY drive system access panel 15 is removed, the ball screw and the motor can be accessed from the opened window. Specifically, maintenance is performed on the Y-axis ball screw 25 and the Y-axis motor 38 in a state where the POL angle is 0 ° shown in FIG. 5A, and an X-axis ball screw is shown in the state where the POL angle is 90 ° shown in FIG. 39 and the X-axis motor 40 can be maintained. The maintenance work includes, for example, replacement when each motor fails, inspection of the appearance of each ball screw (inspection for corrosion, cracking, wear, etc.), replenishment of lubricant, and the like. The POL angle is changed by rotating the output shaft of the handle shaft unit 37 using a tool such as a crank handle as described above.

  Further, the power feeding circuit unit 28 can be attached and detached in a state where the POL angle is 90 ° as shown in FIG. FIG. 6 is an external view showing a power supply circuit unit and the like when being attached and detached. The opening 41 provided in the power feeding unit frame 27 opens vertically downward with a POL angle of 90 °. By providing a guide rail inside the power feeding unit frame 27, loosening the fixing bracket, pulling out the feeding circuit portion 28 vertically downward, inserting it vertically upward and tightening the fixing bracket, the feeding circuit portion 28 can be attached and detached. . By attaching and detaching the power feeding circuit section 28 in this way, maintenance such as replacement and repair of parts accompanying failure of the high frequency circuit in the power feeding circuit section 28 or aging deterioration can be performed.

  Here, the maintenance method of the front feed apparatus 2 will be described collectively. First, the antenna device is set to an elevation angle 0 ° state shown in FIG. An aerial work platform 9 is arranged directly below the front feed device 2 to set the height of the work platform. By removing the POL drive system access panel 14 and the XY drive system access panel 15, a work opening window is formed in the front feed device 2. If the POL drive motor 19 is broken from the opening window formed by removing the POL drive system access panel 14, the POL drive motor 19 is replaced. An appearance inspection (inspection for corrosion, cracking, wear, etc.) of the POL shaft gear 18 is performed. Further, the output shaft of the handle shaft unit 37 is rotated by POL rotation using a tool such as a crank handle, and a lubricant is applied to or sprayed on the POL shaft gear 18. The output shaft of the handle shaft unit 37 is rotated using a tool such as a crank handle to set the POL angle to 0 °. In this state, the Y-axis motor 38 is replaced when the Y-axis motor 38 is broken from the opening window formed by removing the XY drive system access panel 15. Appearance inspection (inspection of corrosion, cracking, wear, etc.) of the Y-axis ball screw 25 is performed, and a lubricant is applied to or sprayed on the Y-axis ball screw 25. The output shaft of the handle shaft unit 37 is rotated using a tool such as a crank handle to set the POL angle to 90 °. When the X-axis motor 40 is out of order, the X-axis motor 40 is replaced. Appearance inspection (inspection of corrosion, cracking, wear, etc.) of the X-axis ball screw 39 is performed, and a lubricant is applied to or sprayed on the X-axis ball screw 39. Further, in the state where the POL angle is 90 °, when a repair is necessary due to an output abnormality of the power feeding circuit unit 28, the fixing bracket of the power feeding circuit unit 28 is loosened and the power feeding circuit unit 28 is moved along the guide rail to the power feeding unit frame 27. Pull out from. After parts replacement and repair, the feeder circuit portion 28 is inserted into the feeder portion frame 27 along the guide rail, and the fixture is fastened and fixed.

  In the AZ / EL-driven multi-frequency band shared antenna described above, multi-frequency band switching (horn switching) for switching to a horn of a required frequency band, and rotating the feeding system part around the antenna pointing axis, depending on each satellite Polarization switching to switch to the polarization angle, and rotating the feeding system part around the antenna directing axis, swinging the antenna beam conically, and performing a conical scan that detects the satellite direction based on the received intensity at each position.

  Multi-frequency band switching is performed by driving the XY driving unit so that the position of the horn to be used among the plurality of horns 29 is in the vicinity of the focal position of the main reflecting mirror 1. Polarization switching is set by driving the POL drive. Conical scan is used by the XY drive unit while the antenna directivity direction is driven in a predetermined direction by the AZ / EL drive unit, and the antenna directivity direction is largely moved within a specific directivity direction area by the AZ / EL drive unit. The position of the horn to be driven is driven in a small circular shape near the focal position of the main reflecting mirror 1. With such a conical scan, communication satellites are captured or tracked, or a predetermined area is searched to monitor radio wave emission states from a plurality of satellites.

  Multi-frequency band switching, polarization switching, and conical scanning can be performed by the front feed device arranged at the focal point of the main reflector that is configured and functions as described above, and an antenna is set at an elevation angle of 0 °. Since the access panel provided in the front feed device is removed and opened, and inspection and maintenance can be performed while driving POL, the maintainability is improved.

DESCRIPTION OF SYMBOLS 1 Main reflecting mirror 2 Front feed apparatus 3 Stay 12 POL drive system cover 13 XY drive system cover 14 POL drive system access panel 15 XY drive system access panel 16 Fixed side base member 17 POL movable base member 18 POL shaft gear 19 POL drive motor 23 Y-axis linear guide 24 Y-axis movable stage 25 Y-axis ball screw 26 X-axis linear guide 27 Feeder frame 28 Feeder circuit part 29 Horn 37 Handle shaft unit 38 Y-axis motor 39 X-axis ball screw 40 X-axis motor

Claims (4)

In a front feed device supported by a stay at the focal point of the main reflector and having a horn of a plurality of frequency bands, a fixed base member fixed to the stay, and a fixed base member rotatably supported around the POL axis POL movable base member, a POL drive unit for rotating the POL movable base member by POL, a power feeding unit frame supported by the POL movable base member so as to be displaceable in the X-axis and Y-axis directions, and the power feeding unit frame An XY drive unit for driving the X axis and the Y axis direction, a protective cover that covers the POL drive unit and the XY drive unit and opens in the direction of the main reflector, and the vicinity of the POL drive unit on the protective cover A POL drive system access panel provided on the protective cover and an XY drive system access panel provided in the vicinity of the XY drive unit on the protective cover. The front feed apparatus according to. 2. The maintenance method for a front feed device according to claim 1, wherein the step of setting the main reflecting mirror at an elevation angle of 0 [deg.], The step of removing the POL drive system access panel, and a handle provided in the POL drive unit. A maintenance method comprising: a step of performing POL rotation by a shaft unit and applying or spraying a lubricant to a POL shaft gear. A maintenance method for a front feed device according to claim 1, wherein the main reflector is set at an elevation angle of 0 °, the POL drive system access panel and the XY drive system access panel are removed, A maintenance method comprising the step of applying POL rotation by a handle shaft unit provided in the POL drive unit and applying or spraying a lubricant to the drive mechanism of the XY drive unit. A maintenance method for a front feed device according to claim 1, wherein the main reflector is set at an elevation angle of 0 °, the POL drive system access panel and the XY drive system access panel are removed, A maintenance method comprising: a step of setting a POL angle to a predetermined angle by a handle shaft unit provided in the POL driving unit; and a step of pulling out a power feeding circuit unit from the power feeding unit frame.

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