JP7361874B2 - support unit - Google Patents

Description

The present invention relates to a support unit. In particular, the present invention relates to a connection mechanism between a rod and a joint of a support unit that supports a reflector mounted on a spacecraft such as an artificial satellite.

In recent years, reflectors mounted on spacecraft such as artificial satellites have become larger. Non-Patent Document 1 discloses a technique for combining a plurality of split mirrors as if they were one mirror. When combining a plurality of divided mirrors, it is necessary to perform coarse adjustment to enable fine adjustment of the plurality of divided mirrors.

Cryogenic Nano-Actuator for JWST Robert M. Warden

In Non-Patent Document 1, countermeasures against distortion are not sufficient, and when the length of the rod supporting the segmented mirror is roughly adjusted, there is a possibility that distortion may remain in the connecting portion between the rod and the joint. Furthermore, if distortion remains in the joint between the rod that supports the split mirror and the joint, there is a possibility that the mirror surface accuracy of the reflecting mirror may be reduced.

The main object of the present invention is to prevent distortion from remaining in the joint between the rod that supports the split mirror and the joint.

A support unit according to the present invention is a support unit in which each of a plurality of split mirrors constituting a reflecting mirror is attached to a support stand in a tiltable manner,
A rod having an elongated rod main portion, and a rod end portion attached to each of both ends of the rod main portion by a screw mechanism formed at each of both ends of the rod main portion;
a joint that joins the rod, and a joint that connects each of both ends of the rod;
The joint is
a mounting portion for attaching the rod end portion, the mounting portion having a spherical contact surface in contact with the rod end portion;
The rod end is
One end is screwed into the screw mechanism of the rod main part, and the other end has a joint part formed with a spherical joint surface that contacts the contact surface,
The screw mechanism formed at the end of the rod main portion is a differential screw.

In the support unit according to the present invention, the joint includes an attachment portion to which the rod end is attached, and a spherical contact surface that contacts the rod end is formed. Further, the rod end portion has one end screwed into the screw mechanism of the rod main portion, and the other end includes a joint portion in which a spherical joint surface that contacts the contact surface is formed. Further, the screw mechanism formed at the end of the main rod portion is a differential screw. As described above, according to the support unit according to the present invention, since the spherical contact surface and the spherical joint surface are in contact with each other, the rod and the joint are moved by sliding between the contact surface and the joint surface. It is possible to absorb strain at the connecting portion of the rod and prevent residual strain from remaining at the connecting portion between the rod and the joint. In addition, since the rod end is screwed into the screw mechanism of the rod main part, by rotating the rod main part, the length between the nodes that make up the truss structure, that is, the length of the rod itself, can be roughly adjusted. be able to.

1 is a schematic diagram showing an example of a reflecting mirror according to Embodiment 1. FIG. 1 is a perspective view of a reflecting mirror device according to Embodiment 1. FIG. FIG. 3 is an external view of a rod and a joint according to Embodiment 1. An enlarged view of part A in FIG. 3. BB sectional view in FIG. 4. FIG. 3 is a diagram showing distortion absorption in the connection mechanism according to the first embodiment.

The present embodiment will be described below with reference to the drawings. In each figure, the same or corresponding parts are given the same reference numerals. In the description of the embodiments, the description of the same or corresponding parts will be omitted or simplified as appropriate. Further, in the following figures, the size relationship of each component may differ from the actual one. Further, in the description of the embodiments, directions or positions such as top, bottom, left, right, front, back, front, and back may be indicated. These notations are for convenience of explanation and do not limit the arrangement, direction, or orientation of the device, instrument, or component.

Embodiment 1.
***Explanation of configuration***
FIG. 1 is a schematic diagram showing reflecting mirrors 500 and 500a, which are examples of reflecting mirrors according to the present embodiment.
Specifically, the reflecting mirrors 500, 500a are used in optical telescopes mounted on spacecraft such as artificial satellites. As shown in FIG. 1, the large reflecting mirrors 500, 500a are formed by combining a plurality of divided mirrors 100, 100a as if they were one mirror.

FIG. 2 is a perspective view of a reflecting mirror device 510 according to this embodiment.
The reflecting mirror device 510 includes each of the plurality of segmented mirrors 100 constituting the reflecting mirror 500, and a support unit 200 that attaches each of the plurality of segmented mirrors 100 to the support base 300 in a tiltable manner.
The support unit 200 includes a rod 10 and a joint 20 connected by a connection mechanism 400. One end of the rod 10 is connected to the joint 20, and the other end is attached to the back surface of each of the plurality of split mirrors 100. Specifically, the rod 10 is made of reinforced plastic reinforced with carbon fiber. The joint 20 is fixed to a support base 300. The joint 20 is a component that connects the rod 10. Specifically, the joint 20 is formed of an extremely low thermal expansion alloy such as Super Invar.

A fine adjustment mechanism 31 for finely adjusting the split mirror 100 is provided between the back surface of the split mirror 100 and the rod 10. Furthermore, a coarse adjustment mechanism 32 for coarsely adjusting the split mirror 100 is provided at each end of the rod 10 .

The support unit 200 has a truss structure made up of six rods 10. Alignment adjustment of the segmented mirror 100 requires fine adjustment with drive resolution on the order of nanometers. Also, before fine adjustment, coarse adjustment is required so that it falls within the stroke of fine adjustment. Note that the alignment adjustment includes adjustment in the translational direction (three shift axes) in the X, Y, and Z directions shown in FIG. 1, and adjustment in the rotational direction (three tilt axes) in the RX, RY, and RZ directions.

In the coarse adjustment, the rod 10 is rotated by the coarse adjustment mechanism 32 to adjust the length between the nodes forming the truss structure, thereby making it possible to adjust the alignment of the reflecting mirror device 510, which is a split mirror SUBASY.

FIG. 3 is an external view of the rod 10 and joint 20 according to this embodiment.
FIG. 4 is an enlarged view of section A in FIG. 3.
FIG. 5 is a sectional view taken along line BB in FIG.
A connecting mechanism 400 between the rod 10 and the joint 20 according to the present embodiment will be described using FIGS. 3 to 5.

The connecting mechanism 400 is a mechanism that connects the rod 10 and the joint 20.
The rod 10 has an elongated rod main portion 11 and a rod end portion 13 attached to the end of the rod main portion 11. The rod main portion 11 has a cylindrical shape, and a rod end portion 13 is screwed into each of the opposite ends. The rod end 13 is also referred to as an end fitting.

Here, the rough adjustment mechanism 32 will be explained.
The coarse adjustment mechanism 32 is provided at each end of the rod 10. The coarse adjustment mechanism 32 is realized by a screw mechanism between the rod main portion 11 and the rod end portion 13. The screw mechanism at one end of the rod 10 is a right-handed screw, and the screw mechanism at the other end of the rod 10 is a left-handed screw. Alternatively, the screw mechanism may be realized by a differential screw.

One end of the rod end portion 13 is screwed into the end of the rod main portion 11. One end is the end of the rod end 13 on the rod main portion 11 side. A threaded portion 131 is formed at one end of the rod end portion 13 .
In this way, since the rod end portion 13 is screwed into the rod main portion 11, by rotating the rod main portion 11, the length between the nodes forming the truss structure, that is, the length of the rod 10 itself can be changed. Adjustments can be made.
Thereafter, by making fine adjustments using the fine adjustment mechanism 31, alignment adjustment of the reflecting mirror device 510 becomes possible.
After adjusting the length of the rod 10, the rod main portion 11 and the rod end portion 13 are fixed by fastening with a nut 12.

Next, the connection mechanism 400 will be explained.
The rod end portion 13 includes a joint portion 132 in which a spherical joint surface 321 that contacts the contact surface 211 of the joint 20 is formed at the other end. The other end is the end of the rod end 13 on the joint 20 side.
As shown in FIG. 4, a working hole 133 is formed in the rod end 13 for attaching a joint connector 14, which will be described later. A through hole 322 is formed in the joint portion 132 from the surface of the working hole 133 on the joint 20 side toward the joint 20 . The through hole 322 is formed along the axial direction of the rod 10.

The joint 20 includes a mounting portion 210 to which the rod end 13 is mounted. The attachment portion 210 is formed with a spherical contact surface 211 that contacts the joint portion 132 of the rod end portion 13 . Further, the attachment portion 210 is formed with a connection hole 212 into which a connector connection portion 142 described later is inserted. The connecting hole 212 is formed along the axial direction of the rod 10 from the contact surface 211 . The connecting hole 212 communicates with a through hole 322 formed in the rod end 13.

The connection mechanism 400 includes a joint connector 14 that connects the joint portion 132 of the rod end portion 13 and the attachment portion 210 of the joint 20.
The joint connector 14 includes a connector connecting portion 142 that is fixed to the attachment portion 210 while passing through a through hole 322 formed in the joint portion 132 . The joint connector 14 also includes a connector head 141 that stops at the edge of the through hole 322. In other words, the joint connector 14 includes a connector head 141 and a connector connecting portion 142 extending from the connector head 141.

The rod end 13 includes a spherical washer 323 between the edge of the through hole 322 and the connector head 141. The spherical washer 323 is a washer that is divided into two stages, and the divided surface forms a spherical surface (spherical surface).

Next, the process of connecting the rod 10 and the joint 20 will be explained.
The operator brings the joint surface 321 of the rod 10 and the contact surface of the joint 20 into contact with each other, thereby causing the through hole 322 and the connecting hole 212 to communicate with each other. Then, the operator installs the spherical washer 323 through the work hole 133. Then, the operator passes the connector connecting portion 142 of the joint connector 14 through the spherical washer 323 and the through hole 322, and locks it in the connecting hole 212.
Through the above connection process, the rod 10 and the joint 20 are connected.

***Explanation of effects of this embodiment***
FIG. 6 is a diagram showing the structure when distortion occurs in the coupling mechanism 400 according to the present embodiment.
Normally, when no distortion occurs in the support unit 200, the rod 10, the joint connector 14, and the joint 20 are arranged substantially linearly along the axial direction of the rod 10, as shown in FIG. However, when the length of the rod 10 changes due to rough adjustment, the rod 10, joint connector 14, and joint 20 are not arranged substantially in a straight line, causing distortion, as shown in FIG.

In the coupling mechanism 400 according to the present embodiment, the rod 10 and the joint 20 are attached so that the contact surface 211 and the joint surface 321 are slidable. That is, since the joint surface 321 and the contact surface 211 are in contact with each other in a smooth spherical shape, they can slide. In other words, the joint surface 321 and the contact surface 211 can move smoothly. Here, the portion where the joint surface 321 and the contact surface 211 are in contact with each other in a smooth spherical shape is defined as the first sliding portion 401 .
Since the coupling mechanism 400 according to the present embodiment includes the first sliding portion 401, the distortion between the rod 10 and the joint 20 can be absorbed, and no distortion remains.

Furthermore, in the coupling mechanism 400 according to the present embodiment, the diameter of the coupling hole 212 is larger than the diameter of the connector coupling portion 142. Further, the diameter of the through hole 322 is larger than the diameter of the connector connecting portion 142. Therefore, according to the coupling mechanism 400 according to the present embodiment, as shown in FIG. This deviation can be absorbed.

Furthermore, the coupling mechanism 400 according to the present embodiment includes a spherical washer 323 between the edge of the through hole 322 and the connector head 141. A portion of the spherical washer 323 where the divided surfaces are in contact with each other in a smooth spherical shape is defined as a second sliding portion 402 . Since the coupling mechanism 400 according to the present embodiment includes the second sliding portion 402, even if the connector head 141 is tilted, the displacement can be absorbed by the spherical washer 323. Therefore, according to the coupling mechanism 400 according to the present embodiment, even if the connector head 141 is tilted due to distortion, as shown in FIG. 6, the displacement can be absorbed by the spherical washer 323.

As described above, in the reflecting mirror device according to the present embodiment, no distortion remains even when the alignment adjustment of the split mirror on the order of millimeters is performed using the rough adjustment mechanism. Furthermore, since the rod main portion and the rod end portion are fastened together with a nut, there is an effect that the rod main portion and the rod end portion can withstand the satellite launch load. Further, there is no need to use an actuator such as a motor, and alignment adjustment using a coarse adjustment mechanism can be performed simply and at low cost.

***Other configurations***
In this embodiment, the connection mechanism mainly applied to a reflecting mirror mounted on an artificial satellite has been described. However, this connection mechanism is applicable to any structure having a rod and a joint.

Of the first embodiment described above, a plurality of parts may be combined and implemented. Alternatively, one part of this embodiment may be implemented. In addition, this embodiment may be implemented in any combination, either in whole or in part.
That is, in Embodiment 1, it is possible to freely combine each embodiment, to modify any component of each embodiment, or to omit any component in each embodiment.

The embodiments described above are essentially preferable examples, and are not intended to limit the scope of the present invention, the scope of applications of the present invention, and the scope of uses of the present invention. The embodiments described above can be modified in various ways as necessary.

10 rod, 11 rod main part, 12 nut, 13 rod end, 14 joint connector, 20 joint, 31 fine adjustment mechanism, 32 coarse adjustment mechanism, 100, 100a split mirror, 131 threaded part, 132 joint part, 133 working hole , 141 connector head, 142 connector connection part, 200 support unit, 210 attachment part, 211 contact surface, 212 connection hole, 300 support stand, 321 joint surface, 322 through hole, 323 spherical washer, 400 connection mechanism, 401 No. 1 sliding part, 402 second sliding part, 500, 500a reflecting mirror, 510 reflecting mirror device.

Claims (1)

In a support unit that attaches each of the plurality of split mirrors constituting the reflecting mirror to a support stand in a freely tiltable manner,
A rod having an elongated rod main portion, and a rod end portion attached to each of both ends of the rod main portion by a screw mechanism formed at each of both ends of the rod main portion;
a joint that joins the rod, and a joint that connects each of both ends of the rod;
The joint is
a mounting portion to which the rod end is attached, the mounting portion having a spherical contact surface in contact with the rod end;
The rod end is
One end is screwed into the screw mechanism of the rod main part, and the other end has a joint part formed with a spherical joint surface that contacts the contact surface,
A support unit in which the screw mechanism formed at the end of the rod main part is a differential screw.

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