JPH0536766B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a support mechanism for a main reflector of a telescope, and particularly to a support mechanism for a main reflector of a large reflecting astronomical telescope.

<Prior Art and Problems to be Solved by the Invention> As a conventional main reflecting mirror support mechanism of a telescope, the one shown in FIGS. 6 and 7, for example, is known. Reference numeral 1 denotes a large reflecting astronomical telescope, and a main reflecting mirror 3 is housed in a metal case 4 and supported at the bottom of a lens barrel 2 of the large reflecting astronomical telescope 1. If there is a clearance (gap) between the main reflecting mirror 3 and the case 4, the optical axis A of the main reflecting mirror 3 will be shifted, so there is a demand for the two to be in close contact with each other without any gaps. However, since the main reflector 3 is made of glass and has a different thermal expansion coefficient from the metal case 4, if there is no clearance at all, the main reflector 3 may be tightened by the case 4 depending on the temperature. As a result, the reflecting surface 3a of the main reflecting mirror 3 may be distorted and the reflected image may be adversely affected, or in the worst case, the main reflecting mirror 3 may be broken.

In this way, supporting the main reflecting mirror 3 needs to satisfy the two conflicting demands mentioned above.
To the applicant's knowledge, there is no main reflector support mechanism that completely satisfies the above requirements.

The present invention has been made by paying attention to such conventional technology, and it is an object of the present invention to provide a main reflecting mirror support mechanism for a telescope that can completely satisfy the above-mentioned requirements.

<Means for Solving the Problems> The main reflecting mirror support mechanism of the telescope according to the present invention has the following features:
In order to achieve the above purpose, receiving plates are arranged at equiangular triangular positions around the main reflecting mirror placed at a certain height on the support flange, and between the receiving plate and the main reflecting mirror. A support made of crystalline plastic having a higher coefficient of thermal expansion than metal is interposed, and the outer surface of the main reflecting mirror is abutted and supported on the contact surface of the support, A concave portion is formed in the center of the abutment surface so that the main reflecting mirror does not come into contact with it, and a predetermined gap l is secured between both ends of the back surface of the support and the receiving plate.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described based on FIGS. 1 to 5. Incidentally, the same reference numerals are given to the parts common to the conventional one, and redundant explanation will be omitted.

Lens barrel 5 of the large reflective astronomical telescope according to this embodiment
is placed vertically on the lifting device 6 for assembly or disassembly (see FIG. 2). A support flange 7 is attached to the bottom of the lens barrel 5. On this support flange 7,
Curved receiving plates 8 are removably erected at equiangular triangular positions. Two supports 9 made of ``crystalline plastic'' (trade name) are attached to each of the receiving plates 8, and are made of ``crystalline plastic'' that are in contact with the outer surface of the main reflecting mirror 3.

Further, a mounting table 10 on which the main reflecting mirror 3 is mounted and for adjusting the horizontality is screwed into the bottom surface of the support flange 7 at equiangular triangular positions with screws 11 so as to be movable up and down. The main reflecting mirror 3 needs to have a certain height L that allows a person's hands to enter due to the installation work of the main reflecting mirror 3. Therefore, by placing it on this mounting table 10, the height L can be ensured. Efforts are being made to maintain levelness.

The main reflecting mirror 3 has an outer surface supported by a support 9 and a bottom surface supported by a mounting table 10.
The upper part of the outer periphery is pressed by the annular body 12. That is, the three legs 13 provided on the annular body 12 are inserted from above into the mounting holes 14 provided with the support flange 7, and the nuts 15 are attached to the lower ends of the legs 13, thereby supporting the main reflecting mirror 3. is completed.

Countermeasures against thermal expansion (see FIGS. 3a to 3c) Next, countermeasures against thermal expansion in the support mechanism for the main reflecting mirror 3 as described above will be explained using FIGS. 3a to 3c.

For convenience of explanation, a comparative example using a conventional metal support 16 is shown in FIGS. 3a and 3b. FIG. 3a shows a state in which the metal support 16 is supported in close contact with the outer surface of the main reflecting mirror 3. and,
When the ambient temperature of the main reflecting mirror 3 rises from the state shown in FIG. 3a, as shown in FIG. is larger, so support flange 7
The length d1 of the outward expansion of
A gap d3 corresponding to d1-d2 is created. The metal support 16 itself also undergoes some thermal expansion toward the main reflecting mirror 3 on the inside, but the thermal expansion of the support flange 7 is overwhelmingly larger, so much so that it cancels (fills) the gap d3. isn't it. However, the support body 9 made of DURACON (trade name) according to the present invention shown in FIG. It is possible to cause a large thermal expansion toward , filling the gap d3. Therefore, the support 9 made of Zyuracon (trade name) can be used both at low and high temperatures.
is always in contact with the outer surface of the main reflector 3, and the main reflector 3
can be reliably supported. Note that the shape of the support 3 can be used to cope with sudden changes in temperature that the thermal expansion of the support 9 cannot keep up with. That is, there is a recess 17 on the contact surface of the support 3 that is not in contact with it, and a predetermined gap l (see FIG. 1) between the back surface of the support 9 and the receiving plate 8.
Because they are provided separately, even if the temperature around the main reflector 3 suddenly drops and the support 9 is pressed against the outer surface of the main reflector 3 with a strong force, the support 9 will not bend. Easy to deform, main reflector 3
Distortion, deformation and damage can be avoided.

Next, assembly and disassembly of the main reflecting mirror 3 will be explained.

Assembly (see Figure 4) As mentioned above, it is necessary to horizontally support the main reflecting mirror 3 at a certain height L above the support flange 7, so for assembling the main reflecting mirror 3, a support corresponding to the height L is required. Use a block gauge B with a height of That is, first, the block gauge B is set at equiangular triangular positions on the support flange 7, and the main reflecting mirror 3 is placed on it. When the main reflecting mirror 3 is placed on the block gauge B, a constant height L and horizontality are maintained perfectly. From this state, the support flange 7
Turn the screw 11 of the mounting table 10 screwed into the
The mounting table 10 is gradually raised to bring the upper part of each mounting table 10 into contact with the bottom of the main reflecting mirror 3.
Then, if you remove block gauge B,
The mounting table 10 replaces the block gauge B,
The above-mentioned height L and horizontality are secured as is on the mounting table 1.
0 will be taken over.

Disassembly (see FIG. 5) The main reflecting mirror 3 sometimes needs to be removed from the lens barrel 5 for re-plating the reflecting surface 3a. In such a case, after the lens barrel 5 is set on the lifting device 6, the support flange 7 is removed from the lens barrel 5, the lifting device 6 is lowered, and only the support flange 7 is taken out. Then, the annular body 12 and the receiving plate 8 are respectively removed from the taken out support flange 7. In this case, the main reflecting mirror 3 is simply placed on the mounting table 10, but since the constant height L of the main reflecting mirror 3 is maintained, the part corresponding to this height L cannot be touched. , the main reflecting mirror 3 can be easily lifted up, and transported as it is to the plating work site. Conventionally, consideration was not given to providing this height L, so it required 4 to 5 workers to remove the main reflector 3, but in the case of the present invention, it can be disassembled and carried by one person. can. In addition, if the main reflector is 60 cm or more, it will be heavy.
Since it weighs over 100kg, two people are required in that case. In addition, in the above explanation, the main reflecting mirror was used as an example, but
The present invention can also be applied to a sub-reflector.

In the above explanation, Diyuracon (trade name) was used as an example of a crystalline plastic, but if the coefficient of thermal expansion is higher than that of metal, Diyuracon (trade name)
It doesn't have to be.

<Effects of the Invention> The main reflecting mirror support mechanism of the telescope according to the present invention has the following features:
Because of the content as explained above, even if the ambient temperature of the reflecting mirror changes, the reflecting surface of the reflecting mirror will not be distorted or the optical axis will not shift. Also,
The main reflecting mirror can be easily assembled and disassembled, and the reflecting mirror can be easily re-plated.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a main reflector support mechanism according to an embodiment of the present invention, Fig. 2 is a side view showing the main reflector support mechanism mounted on a lifting device, and Fig. 3a is a metal support. Figure 3b is a side view corresponding to Figure 3a showing the state at high temperature; Figure 3c is a support made of crystalline plastic. Figure 4 is a side view showing the reflector mounted on the block gauge; Figure 5 is a side view showing the support flange removed from the lens barrel. , 6th
This figure is a side view showing a conventional large reflecting astronomical telescope, and FIG. 7 is a side view showing a conventional main reflecting mirror support mechanism. 3... Main reflecting mirror, 7... Support flange, 9...
Support, L...height.

Claims (1)

[Claims] 1. A receiving plate 8 is arranged at equiangular triangular positions around the main reflecting mirror 3 arranged at a constant height on the support flange 7, and the receiving plate 8 and the main reflecting mirror 3 are A support 9 made of crystalline plastic having a higher coefficient of thermal expansion than metal is interposed between the two, and the outer surface of the main reflecting mirror 3 is abutted and supported by the contact surface of the support 9. A recess 17 is formed in the center of the contact surface of the support 9 and does not come into contact with the main reflecting mirror 3, and a predetermined gap l is ensured between both ends of the back surface of the support 9 and the receiving plate 8. A telescope main reflector support mechanism characterized by: