JPH045327B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a device for measuring the accuracy of a curved primary mirror surface of a parabolic antenna used in a ground station for satellite communication.

Conventional technology In recent years, parabolic antennas used in satellite communication ground stations, etc. have tended to use high frequencies called sub-millimeter waves, and as a result, high mirror accuracy is required. Conventionally, upright pole-type rotary gauges have been commonly used to measure the mirror surface accuracy of parabolic antennas.
This involves installing a rotating pole on the antenna axis of the antenna under test, protruding a boat-shaped arm from the pole, and protruding a displacement sensor such as a differential transformer from the arm against the mirror surface of the antenna under test to measure the mirror surface accuracy. However, in order to correct the zero value of the displacement sensor, a correction standard including a gauge plate with a mirror curve processed by a numerical control device (NC) is required, which increases the size of the device and increases costs. I was getting used to it.

Such a conventional specular surface measuring device is shown in FIGS. 4 and 5. First, in Figure 4, 1
2 is a parabolic antenna having a mirror surface 1a of the antenna to be measured, and 2 is an antenna support stand for supporting this antenna in a vertically movable manner. It has been installed in several places. 4, a surface plate for installing the measurement jig 3; 5, a rotating pole arranged on the central axis of the antenna 1; 6, a boat-shaped arm projecting in the radial direction from the rotating pole 5; 7, a boat-shaped arm 6 is a displacement sensor such as a differential transformer attached at several locations.

In order to correct the zero value of these displacement sensors 7, the measuring instrument 3 must be installed on the measuring instrument prototype 8, as shown in FIG. Measuring instrument prototype 8
On the surface plate 9, there is a curve 10 that coincides with the standard antenna mirror surface for zero value correction of the differential transformer.
A plate gauge 10 having a diameter is arranged. The plate gauge 10 was used to correct the zero value of each displacement sensor 7, and then the main mirror surface 1a of the antenna to be measured 1 was measured while rotating the arm as shown in FIG.

Problems to be Solved by the Invention According to the conventional antenna mirror surface measuring device as described above, a calibration standard 8 including a gauge 10 is required;
This not only increases the size of the equipment and increases costs, but also makes measurement work extremely difficult with the parabolic antenna installed. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a parabolic antenna mirror surface measuring device that can be miniaturized and cost-reduced, and can easily perform on-site measurement work.

Means for Solving the Problems According to the present invention, there is a mounting means for mounting a parabolic antenna as an object to be measured, and when the antenna is mounted on the mounting means, the rotation of the antenna is rotationally symmetrical. The pole is arranged so that the axis of symmetry is a rotating pole, and there is an arm provided in a plane containing the rotational center axis of the rotating pole so as to rotate with the pole by more than a required angle, and the antenna mounting means of the arm has a plane. There is a reference gauge and a sensor on the side to which the antenna is attached, the reference gauge has a side offset toward the arm by a certain dimension from a curve in the plane of the regular antenna mirror surface, and the sensor extends and retractably extends toward the antenna mirror surface. The adapter member has a surface that comes into contact with the side of the reference gauge when the parabolic antenna, which is the object to be measured, is placed on the arm without being placed on the mounting means. and a surface that abuts the contact and performs zero value correction of the contact.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 3.

A parabolic antenna 1 having a curved primary mirror surface 1a such as a paraboloid, which is the antenna surface to be measured, and an axis of rotational symmetry 1b is installed at a predetermined position on a surface plate 11 by a support means 2 that can be raised and lowered. Although only one supporting means 2 is shown in the figure, three supporting means 2 are installed in the circumferential direction of the antenna 1.

The support part 22 of the simple accuracy measurement jig 20 is set so that its rotating pole 21 coincides with the center line (rotational symmetry axis) 1b of the mirror surface 1a of the parabolic antenna 1 to be measured.
It is installed on the surface plate 11 via. rotating pole 2
1 is rotatably supported by a support portion 22 and rotated by a rotating means (not shown). A boat-shaped arm 23 extends radially from the rotating pole 21 by a required angle or more. This boat-shaped arm 23 has a straight arm portion 23a that extends straight from the rotating pole 21 in the radial direction;
Boat-shaped arm portion 23 extending along the antenna mirror surface
b, and a reinforcing member 23 that connects both.

The boat-shaped arm 23 (23b) has a curve (side) 2 that matches the radial curve of the regular antenna mirror surface.
A reference gauge 24 having a diameter 4a is mounted such that this side 24a is offset upwardly by a certain distance t from the regular antenna mirror surface.

Further, as shown in FIGS. 1 and 3, displacement sensors such as differential transformers 27 are attached to the reference gauge 24 at several positions in the radial direction via differential transformer mounting blocks 26. It is being Contactor 27a of differential transformer 27 (Fig. 3)
extends downward toward the mirror surface 1a of the parabolic antenna 1 to be measured.

Note that when the side 24a of the reference gauge 24 is set to have a constant interval t in the normal direction to the regular antenna mirror surface, the differential transformer 27
It is desirable that the contact 27a (FIG. 3) extends in the direction normal to the mirror surface 1a of the antenna to be measured.

When zeroing the differential transformer 27,
A simple adapter 28 as shown in FIG. 3 is assembled to the reference plate gauge 24 at a position corresponding to the differential transformer 27 using a positioning dowel pin 29. This adapter 28 has a surface 28a that comes into contact with the reference side 24a of the reference plate gauge 24, and
It has a surface 28b separated from this surface 28a by the predetermined distance (distance) t, and the position where the tip of the contactor 27a of the differential transformer 27 contacts this surface 28b is corrected as a zero value.

When measuring the mirror surface 1a of the antenna to be measured, the adapter 28 is removed, and the accuracy of the mirror surface 1a is measured by the differential transformer displacement sensor 27 while rotating the rotating pole 21 and the boat-shaped arm 23 as appropriate.

Note that it is also possible to carry this measuring jig 20 to the site where the parabolic antenna is installed, set it at a predetermined position, and measure the mirror surface accuracy at the site. Furthermore, before assembling the parabolic antenna 1 as shown in FIG. 2, it is also possible to measure the mirror surface accuracy of each fan-shaped piece 1c constituting the antenna 1. Furthermore, when measuring the mirror surface accuracy of parabolic antennas having different curved surfaces, it is sufficient to simply replace the reference plate gauge 24 and the adapter 28.

Effects of the Invention According to the present invention, there is no need for a calibration standard as in the past, so the measuring device can be downsized, costs can be reduced, and zero value calibration of displacement sensors such as differential transformers can be easily performed. This simplifies the measurement adjustment work, improves the reliability of the measurement work, and makes it easier to perform the measurement work at the site where the parabolic antenna is installed.

[Brief explanation of drawings]

FIG. 1 is an enlarged side cross-sectional view taken along the line 2 in FIG. 2 of the specular surface measurement device for a parabolic antenna according to the present invention, FIG. 4 and 5 are side sectional views of a conventional parabolic antenna mirror surface measuring device. DESCRIPTION OF SYMBOLS 1... Parabolic antenna, 1a... Antenna mirror surface, 1b... Central axis line, 20... Measurement jig (device), 21... Rotating pole, 23... Boat-shaped arm,
24... Reference gauge, 27... Displacement sensor (differential transformer), 28... Adapter member.

Claims (1)

[Claims] 1. There is a mounting means for mounting the parabolic antenna 1 which is the object to be measured, and when the antenna is mounted on the mounting means, the pole 21 is arranged so that the axis of rotational symmetry 1b of the antenna, which is rotationally symmetrical, becomes a rotating pole. There is an arm 23 which is arranged so as to rotate by a required angle or more together with the pole in a plane containing the rotation center axis of the rotary pole, and a reference gauge 24 and a sensor 27 are mounted on the side of the arm facing the antenna mounting means. There is,
The reference gauge has a side 24a that is offset toward the arm side by a certain dimension t from the curve in the plane of the regular antenna mirror surface 1a, and the sensor has a contact 2 that extends and retractably extends toward the antenna mirror surface 1a.
7a, the adapter member 28 has a surface 28a that contacts the side of the reference gauge when the parabolic antenna, which is the object to be measured, is placed on the arm without being placed on the mounting means. and a surface 28b that abuts the contactor 27a and performs zero value correction of the contactor.