Hinge and deployment structure

Abstract

The hinge (100) comprises a membrane-like member (111) made of a first fiber material having two fiber orientations, and a membrane-like member (112) made of a second fiber material having two fiber orientations. The two fiber orientations of the first fiber material are symmetrical with respect to the longitudinal direction of the membrane-like member (111). The two fiber orientations of the second fiber material are symmetrical with respect to the longitudinal direction of the membrane-like member (112). The angle that each of the two fiber orientations of the first fiber material makes with the longitudinal direction of the membrane-like member (111) is different from the angle that each of the two fiber orientations of the second fiber material makes with the longitudinal direction of the membrane-like member (112).

Description

[Technical field]

[0001] The present disclosure relates to hinges and deployment structures using the hinges. [Background technology]

[0002] The satellite is equipped with many deployable structures, including solar array paddles. Hinges are mainly used as a means for connecting members of a deployable structure. The hinge is required to have a mechanism that provides the driving force for deployment, to ensure sufficient rigidity as a structural member after deployment, and to be lightweight.

[0003] Patent Document 1 discloses a technology for improving the bending radius by using a hinge made of flexible composite fiber. Prior Art Document 2 discloses a technique in which a flexible tape is used as a hinge. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 61-50100 [Patent Document 2] Special Publication No. 3-502566 Summary of the Invention [Problem to be solved by the invention]

[0005] When hinges used in deployable structures for satellites are made from flexible tape-shaped materials, there is a problem of low rigidity. In a tape spring hinge that can increase rigidity by increasing the cross section, it is necessary to avoid collision of the tapes and unstable deployment behavior caused by the difference in the inner and outer diameters of the two opposing tapes. For this reason, tape spring hinges have significant structural constraints, such as making the tape portion longer and narrowing the tape spacing. Therefore, tape spring hinges have a problem of low design freedom. Another problem with tape spring hinges is that the structure becomes larger. Furthermore, tape spring hinges have problems with the deployment angle of the hinge becoming smaller and the thickness of the associated structure becoming smaller. Thus, the conventional technology has a problem in that it is not possible to realize a lightweight hinge that has a deployment force and high rigidity after deployment.

[0006] One of the main objectives of the present disclosure is to solve the above-mentioned problems. Specifically, the main objective of the present disclosure is to realize a lightweight hinge that has a deployment force and high rigidity after deployment. [Means for solving the problem]

[0007] The hinge according to the present disclosure comprises: A first elastic plate-like body made of a first fiber material having two fiber orientations; and a second elastic plate-like body made of a second fiber material having two fiber orientations; The two fiber orientations of the first fiber material are symmetrical with respect to the longitudinal direction of the first elastic plate-like body, The two fiber orientations of the second fiber material are symmetrical with respect to the longitudinal direction of the second elastic plate-like body; The angle that each of the two fiber orientations of the first fiber material makes with the longitudinal direction of the first elastic plate-like body is different from the angle that each of the two fiber orientations of the second fiber material makes with the longitudinal direction of the second elastic plate-like body. Effect of the Invention

[0008] According to the present disclosure, it is possible to realize a lightweight hinge that stores elastic energy to have a deployment force and has high rigidity after deployment. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a diagram showing an example of a hinge according to the first embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of a hinge according to the first embodiment. [Diagram 3] FIG. 3 is a diagram showing an example of fiber orientation of a membrane member according to the first embodiment. [Figure 4] FIG. 2 is a diagram showing an example of a cross section of the hinge according to the first embodiment in a bent state. [Diagram 5] FIG. 4 is a diagram showing the radius of curvature in the unfolded state according to the first embodiment. [Figure 6] FIG. 4 is a diagram showing a radius of curvature of a single tip according to the first embodiment. [Figure 7] FIG. 4 is a diagram showing the radius of curvature of a tip of a hinge according to the first embodiment. [Figure 8] 10A and 10B are diagrams illustrating an example of a hinge according to a second embodiment. [Figure 9] FIG. 11 is a diagram showing an example of a solar array paddle according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] In the description of the embodiments and the drawings, the same elements and corresponding elements are denoted by the same reference numerals. Descriptions of elements denoted by the same reference numerals will be omitted or simplified as appropriate.

[0011] Embodiment 1 In this embodiment, a hinge to be used by bending will be described. The hinge according to this embodiment has at least two membrane members made of a fiber-reinforced composite material. At least two of the membrane members face each other. In addition, at least two types of fiber orientations exist in the two or more membrane members facing each other. For example, when two membrane members face each other, the fiber orientations of the respective membrane members are different. In addition, when three membrane members face each other, the fiber orientation of one membrane member is different from the fiber orientations of the other two membrane members. Even when four or more membrane members face each other, at least two types of fiber orientations exist similarly. The hinge according to the present embodiment stores elastic energy to generate a deployment force, and is lightweight and has high rigidity after deployment.

[0012] ***Configuration Description*** 1 and 2 show a hinge 100 according to the present embodiment in an unfolded state.

[0013] The hinge 100 is used as a connecting member for deployable structures such as solar panels. The hinge 100 is composed of a film member 111, a film member 112, and a fixture 113, for example, as shown in FIG. Moreover, as shown in FIG. 2, the hinge 100 may be formed only by the film-like members 111 and 112 without using the fixing device 113. The film member 111 and the film member 112 face each other. The fiber-reinforced composite material of the membrane member 111 has a fiber orientation 121 . The fiber-reinforced composite material of the membrane member 112 has a fiber orientation 122 . The fiber orientation 121 and the fiber orientation 122 will be described in detail later. 1 indicates the longitudinal direction of the film member 111 and the film member 112. In FIG.

[0014] The membrane members 111 and 112 are each made of a fiber-reinforced composite material, and the fibers are plain woven. The membrane member 111 and the membrane member 112 are each a plate-like body having elasticity. The longitudinal direction of the membrane member 111 and the membrane member 112 is significantly longer than the lateral direction. The cross section of membrane member 111 perpendicular to the longitudinal direction of membrane member 111 is curved with both side portions protruding from the cross section. Similarly, the cross section of membrane member 112 perpendicular to the longitudinal direction of membrane member 112 is also curved with both side portions protruding from the cross section. The film member 111 corresponds to a first elastic plate member, and the film member 112 corresponds to a second elastic plate member. The fiber reinforced composite material constituting the membrane member 111 corresponds to the first fiber material, and the fiber reinforced composite material constituting the membrane member 112 corresponds to the second fiber material.

[0015] 1, one end of membrane member 111 and one end of membrane member 112 are fixed by fastener 113a. The other end of membrane member 111 and the other end of membrane member 112 are fixed by fastener 113b. When there is no need to distinguish between fixture 113a and fixture 113b, they will be collectively referred to simply as fixture 113. 1 corresponds to the first fixing portion, and the fixing portion 113b corresponds to the second fixing portion. The following explanation will be given based on hinge 100 composed of membrane member 111, membrane member 112, and fastener 113 shown in Figure 1, but the explanation given in this embodiment also applies to hinge 100 composed of membrane member 111 and membrane member 112 shown in Figure 2.

[0016] FIG. 3 shows a fiber orientation 121 of the membrane member 111 and a fiber orientation 122 of the membrane member 112 . 3(a) shows a fiber orientation 121 of the membrane member 111. FIG. 3(b) shows a fiber orientation 122 of the membrane member 112.

[0017] The fiber reinforced composite material of the membrane member 111 has two fiber orientations as fiber orientations 121. The fiber reinforced composite material of the membrane member 112 has two fiber orientations as fiber orientations 122. The fiber orientation angle shown in FIG. 3 is based on the longitudinal direction A of the membrane members 111 and 112. The two fiber orientations of the membrane member 111 are symmetrical with respect to the longitudinal direction A. In the example of Fig. 3(a), the membrane member 111 has two fiber orientations 121, "56 degrees" and "-56 degrees" with respect to the longitudinal direction A. The two fiber orientations of the membrane member 112 are symmetrical with respect to the longitudinal direction A. In the example of Fig. 3(b), the membrane member 112 has two fiber orientations 122, "45 degrees" and "-45 degrees" with respect to the longitudinal direction A. In this manner, in this embodiment, the angles that each of the two fiber orientations of the membrane member 111 makes with the longitudinal direction A are different from the angles that each of the two fiber orientations of the membrane member 112 makes with the longitudinal direction A. In the example of FIG. 3, the angle that each of the two fiber orientations of the membrane member 111 makes with the longitudinal direction A is larger than the angle that each of the two fiber orientations of the membrane member 112 makes with the longitudinal direction A.

[0018] In this embodiment, it is assumed that carbon fiber reinforced plastic is used as the fibers of the fiber reinforced composite material. Specifically, it is assumed that a carbon fiber reinforced plastic having a fiber volume fraction of 50% is used, in which the fiber is carbon fiber (T300 manufactured by Toray) and the resin is epoxy resin. However, the fibers of the fiber-reinforced composite material are not limited to this.

[0019] FIG. 4 is a schematic cross-sectional view of the hinge 100 according to the present embodiment in a stored state.

[0020] In Fig. 4, the membrane member 111 is the compression side (inside) and the membrane member 112 is the tension side (outside). That is, in Fig. 4, the membrane member 111 and the membrane member 112 are folded in the longitudinal direction A in Fig. 1 so that the membrane member 111 is the compression side and the membrane member 112 is the tension side. By bending the film members 111 and 112 in this manner, the film members 111 and 112 are elastically deformed, and elastic energy is stored. When the hinge 100 starts to bend, the compression side is first largely deformed and bent. Next, the compression side collides with the tension side, and the film-like members 111 and 112 start to come into contact with each other. After that, the tension side also undergoes a large deformation. In this embodiment, the radius of curvature of the single tip of the film member 111 and the radius of curvature of the single tip of the film member 112 are different. In this embodiment, the radius of curvature of the single tip of film member 111 is smaller than the radius of curvature of the single tip of film member 112 . In this embodiment, it is possible to bend film members 111 and 112 without causing plastic deformation or destruction until fasteners 113a and 113b come into contact with each other. The plastic deformation and destruction occur due to a large repulsion or buckling caused by contact between the membrane member 111 and the membrane member 112. In this embodiment, the radius of curvature of the single tip of the membrane member 111 is different from the radius of curvature of the single tip of the membrane member 112, so that the plastic deformation and destruction do not occur.

[0021] For example, when any of the following conditions is met, the single tip curvature radii of the membrane member 111 and the membrane member 112 become the same. (1) The material of the membrane member 111 and the membrane member 112 is a fiber-reinforced composite material having only perpendicular fiber orientation, which is found in general woven fabrics, and the radius of curvature of the membrane member 111 and the membrane member 112 in the expanded state is the same. (2) The materials of the membrane members 111 and 112 are fiber-reinforced composite materials having the same fiber orientation even if they are not perpendicular to each other, and the radii of curvature of the membrane members 111 and 112 in the expanded state are the same. (3) The material of the membrane members 111 and 112 is metal, and the radii of curvature of the membrane members 111 and 112 in the expanded state are the same. If the individual tip curvature radii of membrane-like members 111 and 112 are the same, membrane-like members 111 and 112 will collide while bending the hinge, and will rebound strongly as they restrain each other, causing membrane-like members 111 and 112 to enter an unstable deformed state.

[0022] Here, the unfolded state radius of curvature is the radius of curvature in a direction perpendicular to the longitudinal direction A of the membrane members 111 and 112 in the unfolded state. Specifically, the unfolded state radius of curvature is the radius of curvature corresponding to the curved surface indicated by reference numeral 201 in FIG.

[0023] The radius of curvature in the longitudinal direction A is the tip radius of curvature. The radius of curvature of the tip of each of the film-like members 111 and 112 when they are folded individually is the radius of curvature of the tip of each of the film-like members 111 and 112. Specifically, the radius of curvature of the tip of each of the film-like members 111 and 112 is the radius of curvature corresponding to the curved surface 202 in FIG. The radius of curvature of the single tip is a radius of curvature that can be theoretically calculated once the material and shape of the membrane member are determined. The radius of curvature of the single tip can be calculated using the formula by JC Yee et al. (American Institute of Aeronautics and Astronautics Paper 2004-1819, formula (24)). The radius of curvature of the tip of the membrane-like member 111 and the membrane-like member 112 when they are folded as a hinge is the radius of curvature of the hinge tip. Specifically, the radius of curvature of the hinge tip is the radius of curvature corresponding to the curved surface indicated by the reference numeral 203 in FIG. 7. The radius of curvature of the hinge tip is the radius of curvature in the vicinity of the center 114 of the folded portion where the membrane-like member 111 and the membrane-like member 112 come into contact. In other words, the radius of curvature of the hinge tip is the radius of curvature in the longitudinal direction of the hinge when the hinge is folded. The radius of curvature of the hinge tip is influenced by the radius of curvature of the single member tip until the membrane-like member 111 and the membrane-like member 112 collide, and after the collision, is influenced by the hinge folding angle at the time of storage.

[0024] In this embodiment, the radius of curvature of membrane member 111 in the expanded state is 15 mm, and the radius of curvature of membrane member 112 in the expanded state is 12.5 mm. The radius of curvature of the tip of the membrane member 111 alone is 8.6 mm. The radius of curvature of the tip of the membrane member 112 alone is 12.5 mm. The distance between the ridges of film member 111 and film member 112 is 12 mm, and the length of fixture 113 that affects the bending is 66 mm.

[0025] For example, consider the case of bending a hinge made of two membrane-like members with the same radius of curvature at the tip of each member. If you try to bend the two membrane-like members until the two fixing devices come into contact, the resistance at the contact points will be large, and a large load will be required to bend them. If the two membrane-like members cannot deform uniformly due to the constraint of contact, large deformation will occur locally. This will result in destruction or plastic deformation due to the load exceeding the yield strength. If breakage or plastic deformation occurs, the shape after deployment cannot be restored, and the function as a hinge is lost. In addition, the load required for folding becomes significantly larger, which requires a larger restraining device to maintain the folded state. As a result, the hinge becomes heavier.

[0026] It is also possible to make the radius of curvature of the individual tips of the two membrane-like members different by making the radius of curvature of the two membrane-like members in the expanded state different. However, if the radius of curvature of the two membrane-like members in the expanded state is made different enough to make the radius of curvature of the individual tips different, the rigidity of the membrane-like member with the smaller radius of curvature of the individual tip in the expanded state will be higher. As a result, the membrane-like member will be more difficult to bend. This will increase the rebound at the bending point, which will increase instability.

[0027] In contrast, in the present embodiment, two film members with different fiber orientations are used, that is, the angle between the fiber orientation of film member 111 and the longitudinal direction A is different from the angle between the fiber orientation of film member 112 and the longitudinal direction A. Because the angles between the two membrane-like members are different, the radius of curvature of the individual tips of the two membrane-like members when they are bent is different. This makes it possible to greatly alleviate the constraint caused by the contact of the two membrane-like members when they are bent. This reduces the stress generated in each membrane-like member, and also reduces the load required for bending. As a result, it becomes possible to bend the hinge without compromising its function as a hinge.

[0028] ***Description of the Effects of the Embodiment*** In this way, in this embodiment, by using two membrane-like members with different fiber orientations, it is possible to realize a lightweight hinge that stores elastic energy, has deployment force, and has high rigidity after deployment.

[0029] ***Variations*** In this embodiment, the ends of the film-like members 111 and 112 are clamped in a fastener 113 and fixed in place by screws. The membrane member 111 and the membrane member 112 may be fixed by other methods. The membrane member 111 and the membrane member 112 may be fixed by other mechanical fastening methods, such as rivets, fittings, etc. Also, the membrane member 111 and the membrane member 112 may be fixed by adhesive. In this embodiment, a configuration is assumed in which film members 111 and 112 are connected to the solar cell panel via fasteners 113. Alternatively, the film members 111 and 112 may be directly connected to the solar cell panel without the fasteners 113 .

[0030] In this embodiment, the fiber-reinforced composite material of the membrane members 111 and 112 is a woven fabric with fibers oriented in two directions. The fiber-reinforced composite material of the membrane members 111 and 112 may be a biaxial or higher axial, such as triaxial, woven fabric. Furthermore, the woven fabric used as the fiber-reinforced composite material may be in the form of a two-dimensional plane or a braid. In addition, in fiber-reinforced composite materials, fiber orientation may be achieved by laminating unidirectionally oriented materials.

[0031] In this embodiment, the film members 111 and 112 are made of prepreg in which a plain-woven carbon fiber cloth in which biaxial carbon fibers are woven at right angles to each other is impregnated with epoxy resin. The membrane member 111 is obtained by applying a tensile load to the prepreg to deform the prepreg until the fiber orientation of the membrane member 111 ("56 degrees" and "-56 degrees") is obtained. One layer of prepreg is laminated, and the prepreg is shaped into a pipe-shaped mold so as to obtain the fiber orientation of the membrane member 111. The prepreg is then heated and cured, and the membrane member 111 is obtained by machining to give it a shape. In the prepreg, the two carbon fibers are perpendicular to each other, so the fiber orientation of the membrane member 112 (45 degrees and -45 degrees) is obtained from the beginning. For this reason, the membrane member 112 is made of prepreg as it is.

[0032] In the present embodiment, prepreg is used as the material for the film members 111 and 112, but a method of injecting resin after shaping fibers may also be used. For example, RTM (Resin Transfer Molding) may also be used. Moreover, as the fiber cloth, in addition to the plain weave, a twill weave or a satin weave may be used. Furthermore, in this embodiment, tensile deformation is assumed as a method for obtaining fiber orientation in the membrane member 111, but fiber orientation in the membrane member 111 may also be obtained by a weaving method.

[0033] In this embodiment, the film members 111 and 112 are made of a fiber-reinforced composite material made of carbon fiber. Alternatively, inorganic fibers such as glass fibers and basalt fibers may be used, and organic fibers such as aramid fibers may be used.

[0034] In this embodiment, the base material of the fiber-reinforced composite material of the membrane members 111 and 112 is a thermosetting epoxy resin. Alternatively, other thermosetting resins such as cyanate resin and vinyl ester resin may be used. Thermoplastic resins such as PEEK (polyether ether ketone) and PA (polyamide) may also be used. Metals such as aluminum and copper may also be used. Furthermore, the combination of fibers and base materials of the fiber-reinforced composite materials of the film member 111 and the film member 112 may be different.

[0035] In this embodiment, two membrane members are assumed, but three or more membrane members may be used. As an example of a case where three or more film members are used, a state in which an additional film member is disposed between film member 111 and film member 112 is considered. Also, a state in which additional film members are disposed in parallel beside film member 111 and beside film member 112 is considered.

[0036] Embodiment 2 In this embodiment, the differences from the first embodiment will be described with reference to the drawings. The matters not explained below are the same as those in the first embodiment. In this embodiment, the film member 111 and the film member 112 are integrated together.

[0037] FIG. 8 shows the hinge 100 according to the present embodiment in an unfolded state. The hinge 100 according to this embodiment is made up of a film member 111, a film member 112, an end portion 131a and an end portion 131b. The membrane member 111, the membrane member 112, the end portion 131a and the end portion 131b are made of a fiber-reinforced composite material and are integrated together. In this embodiment, end 131a corresponds to a first fixed portion, and end 131b corresponds to a second fixed portion. When there is no need to distinguish between end 131a and end 131b, they will be collectively referred to simply as end 131.

[0038] In the first embodiment, the fixing portion that fixes the membrane member 111 and the membrane member 112 is a fixing tool 113 that is independent from the membrane member 111 and the membrane member 112 . In this embodiment, the fixing portion that fixes the membrane member 111 and the membrane member 112 is formed as an end portion 131 integrally with the membrane member 111 and the membrane member 112 . In this embodiment, carbon fiber and thermosetting epoxy resin are used for film member 111, film member 112, and end portion 131. Carbon fiber and thermosetting epoxy resin are continuously molded at the boundary between film member 111 and end portion 131. Carbon fiber and thermosetting epoxy resin are also continuously molded at the boundary between film member 112 and end portion 131. The shapes and fiber orientations of the membrane members 111 and 112 are the same as those in the first embodiment.

[0039] The hinge 100 according to this embodiment is made using the same prepreg as in the first embodiment. The same prepreg piece is shaped and molded near the boundary between the film member 111 and the end portion 131, and near the boundary between the film member 112 and the end portion 131. In this way, a hinge 100 is obtained in which the film member 111, the film member 112, and the end portion 131 are integrated.

[0040] In this embodiment, the carbon fiber and the thermosetting epoxy resin are continuously molded at the boundary between the film member 111 and the end portion 131 and at the boundary between the film member 112 and the end portion 131 . However, it is not necessary that both the carbon fiber and the thermosetting epoxy resin are continuous. The carbon fiber may be partial, or only the thermosetting epoxy resin may be continuous. The types of fiber and resin used at end 131a and end 131b may be different.

[0041] Embodiment 3 In this embodiment, a deployable structure connected by the hinge 100 shown in the first and second embodiments is shown. FIG. 9 shows a solar paddle 000 equipped with a solar panel 001 . In FIG. 9, a solar cell panel 001 is a deployable structure connected by a hinge 100 according to the first or second embodiment. A deployable structure using hinge 100 according to the first or second embodiment is lightweight, has a deploying force, and has high rigidity after deployment.

[0042] Although the first to third embodiments have been described above, two or more of these embodiments may be combined for implementation. Alternatively, one of these embodiments may be partially implemented. Alternatively, two or more of these embodiments may be partially combined and implemented. Furthermore, the configurations and procedures described in these embodiments may be modified as necessary. [Explanation of symbols]

[0043] 100 hinge, 111 membrane member, 112 membrane member, 113 fixture, 113a fixture, 113b fixture, 114 center of folded portion, 121 fiber orientation, 122 fiber orientation, 131 end, 131a end, 131b end.

Claims

1. a first elastic plate-like body made of a first fiber material having two fiber orientations; a second elastic plate-like body made of a second fiber material having two fiber orientations; The two fiber orientations of the first fiber material are symmetrical with respect to the longitudinal direction of the first elastic plate-like body, two fiber orientations of the second fiber material are symmetrical with respect to the longitudinal direction of the second elastic plate-like body; an angle formed by each of the two fiber orientations of the first fiber material with respect to the longitudinal direction of the first elastic plate-like body is different from an angle formed by each of the two fiber orientations of the second fiber material with respect to the longitudinal direction of the second elastic plate-like body; The hinge has the first elastic plate-like body and the second elastic plate-like body spaced apart from each other in a direction perpendicular to the longitudinal direction.

2. 2. The hinge of claim 1, wherein the angle formed by each of the two fiber orientations of the first fiber material with the longitudinal direction of the first elastic plate-like body is greater than the angle formed by each of the two fiber orientations of the second fiber material with the longitudinal direction of the second elastic plate-like body.

3. 2. The hinge according to claim 1, wherein the radius of curvature of the tip of the first elastic plate member is different from the radius of curvature of the tip of the second elastic plate member.

4. 4. The hinge according to claim 3, wherein the radius of curvature of the tip of the first elastic plate is smaller than the radius of curvature of the tip of the second elastic plate.

5. 2. The hinge according to claim 1, wherein the radius of curvature of the first elastic plate-like body in an expanded state is different from the radius of curvature of the second elastic plate-like body in an expanded state.

6. 6. The hinge according to claim 5, wherein the radius of curvature of the first elastic plate-like body in an expanded state is larger than the radius of curvature of the second elastic plate-like body in an expanded state.

7. 2. The hinge according to claim 1, wherein the first elastic plate and the second elastic plate are disposed opposite each other.

8. 8. The hinge according to claim 7, wherein the first elastic plate and the second elastic plate are bent so that the first elastic plate is on the inside and the second elastic plate is on the outside.

9. 8. The hinge according to claim 7, comprising a first fixing portion that fixes one end of the first elastic plate-like body and one end of the second elastic plate-like body that are arranged opposite each other, and a second fixing portion that fixes the other end of the first elastic plate-like body and the other end of the second elastic plate-like body that are arranged opposite each other.

10. 10. The hinge according to claim 9, wherein the first fixing portion and the second fixing portion are integrally formed with the first elastic plate-like body and the second elastic plate-like body.

11. 2. A hinge as described in claim 1, wherein a cross section of the first elastic plate perpendicular to the longitudinal direction of the first elastic plate is curved with both sides of the cross section protruding, and a cross section of the second elastic plate perpendicular to the longitudinal direction of the second elastic plate is curved with both sides of the cross section protruding.

12. A deployable structure using the hinge according to any one of claims 1 to 11.

Images