JPH01287621A - Mirror supporting mechanism - Google Patents

Abstract

PURPOSE:To prevent occurrence of an error in the supporting force of a mirror when a lever bends due to its dead weight by providing a mechanism which compensates the supporting force error produced when the lever deforms against the lever. CONSTITUTION:The supporting force error compensating mechanism 20 is fitted to the lever 7 and a counter weight 8 is made to displace by its dead weight by a prescribed quantity in the axial direction of the lever 7 so that the supporting force error produced by the deformation of the lever 7 can be compensated. Therefore, the axial and radial supporting force slightly increases by the displacement of the counter weight 8 on the lever 7, by such increases in the supporting force completely act to cancel the above-mentioned supporting force error produced by the bending of the lever 7. Therefore, the supporting force error can be suppressed to '0' even when the lever 7 bends due to its dead weight.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mirror support mechanism that supports the weight of a large mirror such as a telescope in the axial direction or radial direction.

[Conventional technology]

Figure 4 shows, for example, a deflection and stress analysis off a 4.2m primary mirror off an altazima mounted telescope,
Applied Optics/Vo1.19, No.
6/March 15, 1980 (Deflection a
nd 5tress analysis of a 4
．． 2m primary m1rror of an
altazimuth-mounted telesc
ope.

APPLIED 0PTIC3/Vo1.19. No,
6/15 March 1980). In the figure, 1 is a mirror, 2 is a mirror cell, and 3 is a mirror 1 that supports its own weight in the radial direction at multiple locations around it. A radial support mechanism, 4 is an axial support mechanism that supports the weight of the mirror 1 in the axial direction at multiple locations on the lower surface, 5 is the mirror 1
This is a positioning mechanism.

FIG. 5 shows details of the axial support mechanism 4. As shown in FIG.

In the figure, 6 is a link, 7 is a lever, 8 is a counterweight, 9 is a bottle joint as a first joint that swingably connects the link 6 and the mirror 1, and 11 is a link that swings the lever 7 and the mirror cell 2. This is a movably supported support shaft that is mounted on the mirror cell 2.

Moreover, FIG. 6 shows details of the radial support mechanism 3,
In the same figure, 12 is a link, 13 is a lever, 14 is a counterweight, 15 is a pin joint as a first joint that swingably connects the link 12 and Mi 2-1, and 16 is a bezel 12. A pin joint 17 serving as a second joint for pivotally connecting the lever 13 is a support shaft that pivotally supports the lever 13 and is attached to the mirror cell 2 .

Next, the operation will be explained. First, in the axial support mechanism 4 shown in FIG. 5, if the dead weight of the mirror 1 held by this mechanism is Wl, then the component W of the dead weight W1 in the axial direction can be expressed as follows from the figure.

wA=wI−θ・・・・・・・・・
(1) Here, Wl: Self-weight of the mirror 1 θ: Elevation angle of the mirror 1 On the other hand, the axial force FA that the axial support mechanism 4 acts on the mirror 1 is as follows.

Here, W2: Weight of counterweight 8 t1: Distance between bottle joint 10 and pin joint 11 t2: Distance between bottle joint 11 and counterweight 8 Therefore, weight W2 of counterweight 8 and
The dead weight of the mini 17-1 and the counterweight 8 can be combined in a comb type W person = FA), and the axial component of the dead weight of the mirror 1 can be supported by the axial support mechanism 4 regardless of the elevation angle of the mirror 1. Also, mirror 1 and mirror cell 2
Even if the mirror 1 expands and contracts somewhat due to differences in thermal expansion coefficients, no unreasonable force will directly act on the mirror 1 because the link 6 is provided.

On the other hand, as shown in FIG.
Now, assuming that the weight of the mirror 1 is Wl, the component wR of this weight in the radial direction can be expressed as follows, as shown in FIG.

W H= W 1 cx1sθ
Song/Song (1) Here, Wl: Self-weight of the mirror 1 θ: Elevation angle of the mirror 1 On the other hand, the radial force FR that the radial support mechanism acts on the mirror 1 is as follows.

Here, W3: Weight of counterweight 14 L3: Distance between pin joint 15 and pin joint 17 t4: Distance between pin joint 16 and counterweight 14 Therefore, weight W3 of counterweight 14 and
Combine the weight of mirror 1 and counterweight 14 (
WH=FB), and the radial component of the mirror 1's own weight can be supported by the radial support mechanism 3 regardless of the elevation angle of the mirror 1.

[Problem to be solved by the invention]

Since the conventional mirror support mechanism is constructed as described above, when the levers T and 13 are deformed by their own weight as shown in FIGS. 5 and 6, the counterweights 8 and 14 are
There were problems such as deviation of the position from the correct position, resulting in an error in the axial support force or radial support force. For example, this axial support force error Fe is determined as follows.

F, =-W2 bunch θ・δ2/11...
(4) Here, the deflection of the lever 7 is considered to be proportional to the component in the right angle direction of its own weight acting on the lever 7, and reaches its maximum at the elevation angle θ = 900, and this value When 620, the deformation δ2 at any elevation angle θ is δ2=δ2o θ...
...(5). Therefore, the bearing force error F.

can be expressed as follows.

Similarly, the radial support force error F. can be expressed as follows.

Here, δy Deflection of the lever 13 This invention was made to solve the above-mentioned problems, and its purpose is to provide a mirror support mechanism that does not cause support force errors even when the lever is bent by its own weight. do.

[Means to solve the problem]

In the mirror support mechanism according to the present invention, a supporting force error compensation mechanism is attached to the lever so that the counterweight is displaced by a predetermined amount in the axial direction of the lever due to its own weight, and the support force generated by the deformation of the lever is The structure is such that it compensates for force errors.

[Effect]

In the supporting force error compensation mechanism of this invention, the counterweight is displaced on the lever by its own weight, so that
Although the axial support force and radial support force increase somewhat due to this displacement, the increased support force acts to completely cancel each of the above-mentioned support force errors caused by the deflection of the lever.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 is a mirror, 2 is a mirror cell, 6 is a link, 7 is a lever, 8 is a counterweight, 9 is a pin joint as a first joint, 10 is a bottle joint as a second joint, 11 is a spindle These have the same structure and function as conventional axial support mechanisms. On the other hand, 18 is a slide bearing that allows the counterweight 8 to move smoothly along the axial direction of the lever 7. A coil spring 19 is connected at one end to the lever T and the counterweight 8, and is used to displace the counterweight 8 by a predetermined amount by its own weight. The slide bearing 18 and the coil spring 19 constitute a supporting force error compensation mechanism.

Next, the operation will be explained. First, when the weight 8 moves due to its own weight, the axial support force increases, and the amount of increase Fc is as follows.

Here, δy: Displacement amount of the counterweight 8 in the axial direction of the lever 7. Also, the deflection δ2 of the lever 7 is maximum when the elevation angle θ is 00. If that value is δyo, then the displacement at an arbitrary elevation angle θ δy can be expressed as follows.

δy=δyo(2)θ・
Concave curve (9) Therefore, the amount of increase Fc in supporting force is determined as follows.

Taking into account this increase, the supporting force error Fe t can be calculated from equation (6) and Kan's equation. As can be seen from this Qυ equation, the coil spring 19
By appropriately setting the spring constant of δyo ``δ2o, the supporting force error can be completely reduced to 0.

FIG. 2 shows another embodiment of the axial support mechanism shown in FIG. Here, whereas the above embodiment used a slide bearing 18 and a coil spring 19 as a mechanism for displacing the counterweight 8 in the axial direction of the lever 7, this example uses a plate spring as a mechanism. That is, 20
are two leaf springs, one end of which has a counterweight 8
The other end is attached to the lever 7, and the deformation of these leaf springs 20 causes the counterweight 8 to be
can be displaced in the axial direction of the lever T, and the leaf spring 2
By appropriately setting a spring constant of 0, it is possible to displace an arbitrary amount due to its own weight.

Therefore, even if the lever 7 bends due to its own weight, the supporting force error can be suppressed to O in the same manner as in the above embodiment.

FIG. 3 shows another embodiment in which the present invention is applied to a radial support mechanism, in which 21 is a slide bearing that allows the counterweight 14 to move in the axial direction along the lever 13, 22 is a coil spring, and one end of this is a slide bearing. is lever 13
The other end is fixed to the counterweight 14.

According to this embodiment, due to its own weight, the kalanta weight 14
When Fd moves, the radial supporting force increases, and the amount of increase Fd is as follows.

Here, the amount of displacement W3 in the axial direction of the counterweight 14: the weight of the counterweight 14 Also, the deflection δ2 of the lever 13 is maximum when the elevation angle θ is 900.If the value is δ2o, then any elevation angle θ The displacement δ2 at can be expressed as follows.

δ2=θ within δ2o...
(9) Therefore, the increase in supporting force iFd is determined as follows.

Taking into account this increase, the supporting force error Fd' is calculated (6
), From equation (9), it becomes. As can be seen from this αυ equation, the coil spring 22
By appropriately setting the spring constant of δzo=δyo, the supporting force error can be completely reduced to O.

In the above embodiment, the counterweight 14 is connected to the lever 1.
Although the slide bearing 21 and the coil spring 22 are used as the supporting force error compensation mechanism, which is a mechanism for displacing the bearing force in the axial direction of the bearing 3, a leaf spring similar to that shown in Fig. 2 may be provided in place of these. , the same effect as the above embodiment is achieved.

〔Effect of the invention〕

As described above, according to the present invention, by providing a supporting force error compensation mechanism when the lever is deformed, the counterweight is displaced in the axial direction of the lever by its own weight, so that the deflection K of the lever is Therefore, a support mechanism can be obtained in which the supporting force error caused by this can be completely compensated for, and the supporting force error becomes zero.

Furthermore, even if the lever is allowed to deflect a lot, this deflection K
This lever does not require a high degree of rigidity, since the resulting errors can be compensated for. Therefore, there is an effect that the weight of this lever can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a front view of the main parts of a mirror support mechanism according to one embodiment of the invention, FIG. 2 is a front view of the main parts of the support mechanism according to another embodiment of the invention, and FIG. A front view of main parts of a support mechanism showing another embodiment, FIG. 4 is a partially cutaway front view of a conventional support mechanism, and FIG. 5 is a partial front view of a conventional axial support mechanism.
FIG. 6 is a front view of a portion of a conventional radial support mechanism. 1 is a mirror, 2 is a mirror cell, 6 is a link, 7 is a lever, 8 is a counterweight, 9 is a first joint (bin joint)
, 10 is a second joint (bin joint), 11 is a spindle, 12 is a link, 13 is a lever, 14 is a counterweight, 15
is the first joint (bin joint), 16 is the second joint (bin joint), 1γ is the support shaft, 18.19 is the supporting force error compensation mechanism,
18 is a slide bearing, 19 is a coil spring, 20 is a leaf spring (support force error compensation mechanism), 21.22 is a support force error compensation mechanism, 21 is a slide bearing, and 22 is a coil spring. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Patent and patent applicant: Mitsubishi Electric Corporation! − Agent Patent attorney 1) Hiroshi Sawa Akira 1, -τ: (2 others) I Mi"7-10'
, f2ng'rC pin 6'J1'y) Fig. 2 12: ゛F 13-Level- 16; Indication of the incident: Patent Application No. 117000/1983 2,
Name of the invention Mirror support mechanism 3, Person making the correction Representative Moriya Shiki 4, Agent Postal code 105 Address
1-4-10-6 Nishi-Shinbashi, Minato-ku, Tokyo Contents of amendment (1) The phrase ``Analysis off'' in the second line of page 2 of the specification is amended to read ``Analysis off''. (2) "Off An" in the third line of page 2 of the specification should be amended to read "Off An." (3) Formula (7) in the third line of page 7 of the specification is corrected as follows. (4) Amend 200 on page 11, line 18 of the specification. that's all

Claims (1)

[Claims] a link whose one end is connected to the mirror via a first joint;
A lever whose one end is connected to the other end of this link via a second joint, a support shaft attached to the mirror cell to swingably support this lever, and a counter attached to the other end of the lever. 1. A mirror support mechanism having a weight, wherein the lever is provided with a supporting force error compensating mechanism for compensating for a supporting force error caused by deformation of the lever.