JP2018028571A - Holding device, optical device, and mobile body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical element holding device which offers superior reliability by preventing deformation of an optical element during observation at launch and in outer space.SOLUTION: A holding member 1 for holding an object M1 comprises support members 32 and spacers 33 disposed between the object M1 and each support member 32, and is configured to allow the support members 32 to support the object M1 via the spacers 33, where the spacers 33 are made of a material that undergoes phase change from the solid phase to liquid phase so that the phase change of the spacers 33 releases the support.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a holding device, an optical device, and a moving body.

  The holding device that holds optical elements mounted on spacecraft such as artificial satellites has low rigidity in space and holds the optical elements to suppress the effects of thermal deformation, and withstands large accelerations when launching spacecraft. Therefore, it is required to hold the optical element with high rigidity. The device described in Patent Document 1 includes a support member made of a shape memory alloy that holds an optical element at launch and can release the hold by heat generated during observation in space. The device described in Patent Document 2 includes a support member that flexes and fixes a plate-like elastic body that elastically holds the optical element, and press-fixes the optical element to the bulkhead, and a releasing means thereof.

JP-A-4-275510 Japanese Patent No. 2590713

  The shape memory alloy described in Patent Document 1 is reversible in its holding and release, and can be deformed by applying unnecessary stress to the optical element, for example. The releasing means described in Patent Document 2 uses a mechanical driving force and may be disadvantageous in terms of reliability because of unstable factors such as an increase in frictional force in outer space.

  An object of the present invention is to provide an optical element holding device that is advantageous in terms of reliability, for example, by preventing deformation of the optical element during launch and observation in outer space.

In order to solve the above problems, the present invention is a holding device for holding an object, comprising: a support member;
A spacer disposed between the object and the support member, wherein the support member supports the object via the spacer, and the spacer is made of a material that changes phase from a solid phase to a liquid phase. The support is released by changing.

  ADVANTAGE OF THE INVENTION According to this invention, the deformation | transformation of an optical element can be prevented at the time of launch and observation in outer space, for example, and the optical element holding | maintenance apparatus advantageous in terms of reliability can be provided.

It is a figure which shows the structure of the optical apparatus which concerns on 1st Embodiment. It is a figure which shows the structure of the holding | maintenance apparatus which concerns on 1st Embodiment. It is a figure which shows a mode that the support of the mirror by a supporting member is cancelled | released. It is a figure which shows the other example of the temperature rising method of a spacer. It is a figure which shows the cavity into which a spacer flows in. It is a figure which shows a mode that the support of the mirror by the support member which concerns on 2nd Embodiment is cancelled | released. It is a figure which shows the other example of the temperature rising method of a spacer. It is a figure which shows the structure of the holding | maintenance apparatus which concerns on 3rd Embodiment. It is a figure which shows the structure of the holding mechanism which concerns on 3rd Embodiment.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic diagram showing a configuration of an optical device 100 on which a holding device according to a first embodiment of the present invention is mounted. The optical device 100 is, for example, a high-resolution Gregory reflection telescope for a solar observation satellite. The optical device 100 includes a housing 110 and an imaging unit 120. In the case 110, a primary mirror M1 and a secondary mirror M2 are held. The optical axis direction of the primary mirror M1 and the secondary mirror M2 is defined as the Z-axis direction, and the plane perpendicular thereto is defined as the XY plane. The observation light enters from the + Z direction and forms an image on the imaging unit 120.

  The optical device 100 is mounted on a moving body that is exposed to a large vibration such as an artificial satellite or an aircraft. For example, when the moving body is an artificial satellite, the optical element is held with high rigidity so that it can withstand the vibration of several tens of G at the time of launch, and the vibration is reduced to a desired orbit in outer space. To hold the optical element with low rigidity (support release). In space, since it is difficult to release support manually, high reliability for support release without human intervention is required.

  FIG. 2 is a schematic diagram illustrating the configuration of the holding device 1 according to the present embodiment. The holding device 1 includes a base 2 and a holding mechanism 3, and holds a mirror M such as a primary mirror M1 and a secondary mirror M2 of the optical device 100. The base 2 is connected to the housing 110 of the optical device 100. Alternatively, the housing 110 may be the base 2. The holding mechanism 3 includes a holding unit 31, a support member 32, and a spacer 33.

  The holding portion 31 is a bipod type holding portion in which two high-rigid rod-like members are combined into a square shape as one set, and is provided at three positions in the present embodiment. In the present embodiment, each rod-shaped member has a cutout portion with reduced rigidity on the mirror M side (optical element side) and the base 2 side. A bar-like member having such a notch is generally called a flexure or an elastic hinge, and literally functions as a hinge or a joint. Flexures and elastic hinges are friction-free joints and therefore do not have unexpected behavior such as hysteresis.

  The holding unit 31 can position the mirror M with respect to the base 2 with six degrees of freedom (X, Y, Z, θX, θY, θZ). Further, the thermal expansion of the mirror M, the base 2 and the housing 110 is alleviated by the rod-shaped member, and unexpected deformation of the mirror M can be mitigated.

  The support member 32 fixes the mirror M to the base 2 via the spacer 33. The support member 32 prevents the mirror M and the holding unit 31 from being vibrated and damaged by a large random vibration such as several tens of G when the holding device 1 mounted on the artificial satellite is launched. The support member 32 supports the mirror M to prepare for strong vibrations when the artificial satellite is launched, and releases the support of the mirror M when it is in a stage of observation in a desired orbit in space. That is, at the time of observation, the mirror M is fixed to the base 2 only by the holding unit 31.

  In the present embodiment, the support is released by utilizing the phase change of the spacer 33 from the solid phase to the liquid phase. This release of support is an irreversible release, and unnecessary stress due to repeated release and support is not applied to the mirror M or the like, and deformation is prevented. Further, the phase change occurs when the temperature applied to the spacer 33 rises, and is advantageous in terms of reliability in order to be applied to a satellite in outer space where manual support cannot be received.

  FIG. 3 is a diagram showing, in chronological order, how the support of the mirror M by the support member 32 is released. FIG. 3A is a diagram showing a state where the mirror 33 is fixed in a state where the spacer 33 is in a solid phase. FIG. 3B is a diagram illustrating a state in which the spacer 33 changes to the liquid phase. (C) of FIG. 3 is a figure which shows a mode that the spacer 33 changed into the liquid phase and the support of the mirror M was cancelled | released.

  As shown in FIG. 3, the support member 32 includes a plurality of hollow portions 321 into which the spacers 33 that have changed to the liquid phase flow. The plurality of cavities 321 are tubular cavities having a plurality of openings provided on the surface of the support member 32 on the side in contact with the spacer 33. The inner surface S1 of the plurality of hollow portions 321 is subjected to a surface treatment such that the wettability with the spacer 33 is higher than the wettability with the contact surface S2 between the spacer 33 and the mirror M. For this reason, when the temperature rises to a temperature at which the spacer 33 is melted, the melted spacer 33 is repelled on the surface of the mirror M as shown in FIG. 3B, and is sucked into the plurality of cavities 321 by capillary action. Is removed from the mirror M. Finally, as shown in FIG. 3C, the spacer 33 flows into the plurality of cavities 321, and a gap is formed between the mirror M and the support member 32 to release the support. The volume of the plurality of cavities 321 is determined by the amount of inflow of the spacer 33 into the plurality of cavities 321 necessary for releasing the support.

  Since the holding device 1 of the present embodiment is used in the optical device 100 for solar observation satellites, the surface of the mirror M is heated by sunlight when observing the sun. The melting of the spacer 33 is performed using heat transfer or radiation from the mirror M. For example, when the temperature of the holding device 1 rises to about 70 ° C. during solar observation, the support of the support member 32 can be released at an appropriate timing by using a material having a melting point of about 60 ° C. for the spacer 33. .

  Wood metal is well known as an alloy with a melting point around 60 ° C., but it must be noted that it contains toxic cadmium. In addition to wood metal, many types of low melting point alloys generally having a melting point of around 60 ° C. are commercially available.

  FIG. 4 is a diagram showing another example of the method for raising the temperature of the spacer 33. In this example, the support member 32 includes a heat generating portion 34 for positively heating the spacer 33. Further, when the holding device 1 or the optical device 100 includes a control unit that determines the release of the support after the completion of the launch and controls the heat generation unit 34, the release of the support by the heat generation unit 34 can be freely controlled. Moreover, the freedom degree of design, such as melting | fusing point of the spacer 33, can be raised. Further, it can be more advantageous in terms of reliability that causes the phase change of the spacer than using the heat of sunlight. The completion of the launch is determined by the control unit based on information related to the acceleration of the holding device 1 or the optical device 100, for example. Further, the control unit may control the heat generating unit 34 based on the output (altitude, trajectory, attitude) of the control unit (moving body control unit) that controls the operation of the moving body on which the optical device 100 is mounted. .

  A method of using Sn-3.5Ag, which is lead-free solder, as an example of the spacer 33 used for the support member 32 having the configuration shown in FIG. 4 will be described. The melting temperature of Sn-3.5Ag is 221 ° C. The temperature of the support member 32 is raised above the melting point of the spacer 33 using the heat generating part 34. The inner surface S1 of the plurality of hollow portions 321 is subjected to gold plating that improves the wettability with the solder. Table 1 shows the wettability of the Sn-3.5Ag gold-plated surface. On the other hand, the chrome plating is applied to the contact surface S2 with the mirror M as a coating that prevents the solder from getting wet. As a coating that is difficult to wet, an oxide film such as nickel or molybdenum can be used in addition to chromium. Here, the wettability between the members varies depending on the composition of the atmosphere and the atmospheric pressure. For this reason, when evaluating the wettability, it is desirable to evaluate the wettability in a vacuum state equivalent to the actual outer space.

  If the depth of the plurality of cavities 321 is 10 mm, the force that the spacer 33 flows into the plurality of cavities 321 by capillary action is about 8 mN. The timing at which the support by the support member 32 is released is a spaceless space. For this reason, the spacer 33 sufficiently flows into the plurality of cavities 321 even with a force of 8 mN.

  On the other hand, since the solder is hard to get wet on the contact surface S2 with the mirror M and the contact angle is 90 degrees or more, the spacer 33 is repelled on the contact surface S2, so that a plurality of contact angles are obtained. It becomes easy to flow into the hollow portion 321. As shown in FIG. 5, the plurality of hollow portions 321 may be a cylinder 322 having a circular opening. In this case, the flow of the spacer 33 into the plurality of hollow portions 321 (cylinder 322) is a general capillary phenomenon. If the inner diameter of the cylinder 322 in FIG. 5 is 1.0 mm, the force flowing into the cylinder 322 of the spacer 33 by the capillary phenomenon is about 2.5 mN. The timing at which the support of the support member 32 is released is a spaceless space. Therefore, the spacer 33 sufficiently flows into the plurality of cavities 321 (cylinders 322) even at about 2.5 mN.

  Support and release by the support member 32 in the holding device 1 of the present embodiment is positive using the heat generating portion 34 as shown in FIG. 4 even when the method of raising the temperature of the spacer 33 is passive as shown in FIG. Either method of heating is irreversible. Although the melted spacer 33 flows into the plurality of cavities 321 and the support of the mirror M is released, conversely, even if the spacer 33 is hardened from the inflowed state, the mirror M cannot be supported again. Further, even if the spacer 33 is melted once again, the relationship between the wetting of the spacer 33 and the plurality of cavities 321 and the surface tension does not change, so the spacer 33 does not come out of the plurality of cavities 321. That is, once the spacer 33 is melted and the support is released, it does not shift to the support state again.

  Since the support member 32 of the present embodiment is irreversible in support and release of support, deformation can be prevented without applying unnecessary stress to the object to be held. Further, there are few mechanical configurations for releasing the support, which can be advantageous in terms of reliability. As described above, according to this embodiment, it is possible to provide an optical element holding device that is advantageous in terms of reliability by preventing deformation of the optical element at the time of launch and observation in outer space.

(Second Embodiment)
FIGS. 6A to 6C are diagrams showing, in chronological order, how the mirror M is unfixed by the support member 32 according to the second embodiment. The support member 32 of this embodiment includes a spacer cover (accommodating member) 35 and an elastic member 351. FIG. 6A is a diagram illustrating a state in which the spacer 33 supports the mirror M in a solid state. FIG. 6B is a diagram illustrating a state where the support of the mirror M is released due to the phase change of the spacer 33 to the liquid phase. FIG. 6C is a diagram illustrating a state in which the phase change of the spacer 33 is finished and the support of the mirror M is released.

  The spacer cover 35 is disposed between the spacer 33 and the mirror M. The spacer cover 35 and the support member 32 are connected by an elastic member 351. The surface of the spacer cover 35 opposite to the object side surface (surface on the support member side) is provided with an opening, and the support member 32 comes into contact with the spacer 33 from the opening, and the spacer 33 and the spacer cover are provided. The mirror M is supported via 35. In this embodiment, the elastic member 351 is a spring, and accumulates an elastic force (restoring force) that applies a force toward the support member 32 to the spacer cover 35 in a state where the mirror M in FIG. 6A is fixed. doing. In FIG. 6A, the spacer 33 is solid, and the spacer cover 35 does not move due to the elastic force of the elastic member 351. In FIG. 6B, the spacer cover 35 is moved to the support member 32 side so that the spacer 33 is melted by the temperature rise and the spacer cover 35 and the support member 32 are separated by the elastic force of the elastic member 351. The support of the mirror M is released. In FIG. 6C, the elastic member 351 returns to its original shape, and the elastic force does not accumulate.

  Also in the present embodiment, as in the first embodiment, changes in support and release of the support member 32 are irreversible. Once the spacer 33 is melted and enters the state of FIG. 6C, even if the temperature changes and the phase of the spacer 33 changes, the spacer 33 deforms the elastic member 351 (stretches the spring) and the spacer cover. No force is generated to push 35 back to the mirror M side.

On the other hand, in order to prevent the melted spacer 33 from floating and adhering to the mirror M, it is necessary to confine the melted spacer 33 in the space between the spacer cover 35 and the support member 32. Therefore, the volume of the spacer cover 35 that accommodates the spacer 33 is set to be equal to or larger than the volume of the liquid phase spacer 33 (the volume that accommodates the spacer 33 is represented as V ₂ , and the volume of the liquid phase spacer 33 is represented as V ₁ ). Thereby, even if the phase change of the spacer 33 is completed as shown in FIG. 6C, the spacer 33 is confined in the space between the spacer cover 35 and the support member 32. Even when V ₁ ≦ V ₂ is not possible, leakage of the spacer 33 can be prevented by providing the support member 32 with a plurality of hollow portions 321 as shown in FIG.

  Similarly to the first embodiment, the spacer 33 may be actively heated to raise the temperature. Also in this case, the support and release of the mirror M are irreversible. FIG. 7 is a diagram illustrating the structure of the holding mechanism 3 including the heat generating portion 36. When the heat generating portion 36 is provided, even if the phase of the spacer 33 changes from the state of FIG. 6C, the spacer 33 deforms the elastic member 351 and generates a force that pushes the spacer cover 35 back to the mirror M side. There is nothing. The holding device 1 according to the present embodiment also has the same effect as that of the first embodiment.

(Third embodiment)
FIG. 8 is a schematic diagram illustrating a configuration of the holding device 1 according to the third embodiment. In the present embodiment, a spacer 37 using a material having sublimation properties is used. A typical material having sublimability is iodine. Further, the holding mechanism 3 of the present embodiment includes a scattering prevention unit 38, a cold and a wrap 39.

  When the spacer 37 is sublimated to become a gas (gas phase state), the support of the mirror M by the support member 32 is released. On the other hand, there is a concern that the sublimated spacer 37 floats in the space and adheres to the mirror M. Therefore, the scattering prevention unit 38 and the cold trap (capturing member) 39 prevent the sublimated spacer 37 from adhering to the mirror M. The scattering prevention unit 38 is disposed between the mirror M and the spacer 37, and has a shape such that the sublimated spacer 37 is guided to the cold trap 39. The cold trap 39 is provided at a position away from the mirror M, and cools and captures the sublimated spacer 37. The scattering prevention unit 38 is made of a flexible material to prevent deformation of the mirror M, and is sandwiched between the mirror M and the support member 32 after the spacer 37 is sublimated.

  FIG. 9 is a view showing the structure of the holding mechanism 3 when the sublimation spacer 37 of this embodiment is used in the holding mechanism 3 having the configuration as in the second embodiment shown in FIG. In this case, the scattering prevention unit 38 is not necessary due to the space between the spacer cover 35 and the support member 32. In addition, a cold trap 39 that supplements the spacer 37 that can flow out of the space is disposed in the opening of the space. The holding device 1 according to the present embodiment also has the same effect as that of the first embodiment.

  In the above embodiment, an example in which a mirror is used as an optical element has been described. However, for example, any of a lens, a parallel plate glass, a prism, a Fresnel zone plate, a kinoform, a binary optics, and a hologram may be used. The present invention can also be applied to a holding device that holds an object other than an optical element. In the embodiment described above, the support member 32 fixes the mirror M from the side surface, but the mirror M may be fixed from the same surface as the surface held by the holding unit 31. Moreover, although the example in which the supporting member has a plurality of cavities has been described above, the number of the cavities may be one.

(Other embodiments)
As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

DESCRIPTION OF SYMBOLS 1 Holding device 3 Holding mechanism 31 Holding part 32 Support member 33 Spacer M1 Primary mirror

Claims (17)

A holding device for holding an object,
A support member;
A spacer disposed between the object and the support member,
The support member supports the object via the spacer;
The spacer is made of a material that changes phase from a solid phase to a liquid phase, and the support is released when the spacer changes the phase.   The said support member is provided with the tubular cavity part which has an opening part in the surface side which contact | connects the said spacer, The said phase-changed spacer flows in into the said cavity part from the said opening part. Holding device.   The holding device according to claim 2, wherein the opening is circular.   4. The holding device according to claim 2, wherein wettability of the inner surface of the hollow portion with respect to the phase-changed spacer is higher than wettability of the object with respect to the phase-changed spacer. A housing member for housing the spacer;
The housing member is disposed between the object and the support member, and has an opening on a surface on the support member side,
The housing member and the support member are connected by an elastic member,
The support member is in contact with the spacer from the opening of the storage member, and supports the object via the spacer and the storage member.
When the spacer changes in phase, the housing member moves toward the support member so that the housing member and the object are separated by the restoring force of the elastic member, and the support is released. The holding device according to any one of claims 1 to 4.   The holding device according to claim 5, wherein a volume of the housing member is equal to or greater than a volume of the phase-changed spacer. A holding device for holding an object,
A support member;
A spacer disposed between the object and the support member,
The support member supports the object via the spacer;
The spacer is made of a material that changes phase from a solid phase to a gas phase, and the support is released when the spacer changes the phase.   The holding device according to claim 7, further comprising a capturing member that captures the phase-changed spacer.   The holding device according to claim 8, wherein the capturing member cools and captures the phase-changed spacer.   The holding device according to claim 7, further comprising a member that guides the phase-changed spacer to the capturing member. A housing member for housing the spacer;
The housing member is disposed between the object and the support member, and has an opening on a surface on the support member side,
The housing member and the support member are connected by an elastic member,
The support member is in contact with the spacer from the opening of the storage member, and supports the object via the spacer and the storage member.
When the spacer changes in phase, the housing member moves toward the support member so that the housing member and the object are separated by the restoring force of the elastic member, and the support is released. The holding device according to claim 7, wherein:   The holding device according to claim 1, wherein the support member includes a heat generating portion that transfers heat to the spacer.   The holding device according to claim 12, further comprising a control unit that controls the heat generating unit.   The holding device according to claim 13, wherein the control unit controls the heat generating unit based on information on acceleration of the holding device. An optical element;
The holding device according to any one of claims 1 to 14, which holds the optical element;
An optical device comprising:   A moving body comprising the optical device according to claim 15. A moving body control unit for controlling the operation of the moving body;
The mobile body according to claim 16, wherein the control section controls the heat generating section based on an output of the mobile body control section.

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