A three-fold deployable shade based on planar mechanisms

Abstract

The application provides a three-fold unfolding shade based on a planar mechanism, which is used to solve the technical problems of low precision and low rigidity after unfolding of the existing unfolding shade and the limitation that the existing rigid shade can only be applied to a small size optical system. The three-fold unfolding shade based on the planar mechanism comprises a bottom plate, a lower shade, an upper shade and a locking device. The lower shade and the bottom plate are connected through two first elastic driving hinges, and the upper shade and the lower shade are connected through a second elastic driving hinge to form a planar three-link mechanism. The planar three-link mechanism is matched with the first pressing seat, the second pressing seat and the locking device. In the rocket launching process, the planar shade is folded three times to realize a small space volume. When the rocket reaches the expected position in orbit, the planar shade is unfolded from the three-fold folding state and is locked through the driving of the two sets of planar three-link mechanisms and the first and second elastic driving hinges.

Description

Technical Field

[0001] The invention relates to a deployable sunshade, in particular to a three-fold deployable sunshade based on a planar mechanism. Background Art

[0002] As the demand for space situational awareness increases, the aperture of space optical cameras has gradually increased, and the size of the components compatible with space optical cameras has also increased accordingly. Among them, the size of the sunshade, as the core component for realizing the functions of space optical cameras, has also increased significantly. Currently, most large-scale sunshades used in space orbit are one-piece structures and do not have a deployable function. However, due to the limitation of rocket space, the large envelope volume of large-scale sunshades has obvious drawbacks during rocket launch. Therefore, applying the concept of deployable sunshades to large-scale sunshades is a new approach to solve this problem.

[0003] In recent years, many researchers have proposed deployable sunshades, primarily combining rigid frames, elastic materials, and inflatable composite materials with flexible composite materials. However, these deployable sunshades suffer from low precision and rigidity after deployment. Space optical cameras require rigid sunshades with high rigidity. Existing solutions include a screw-driven cylindrical deployment method, but this can only be applied to smaller space optical systems. Summary of the Invention

[0004] The purpose of the present invention is to solve the limitations of low precision and low rigidity of existing deployable sunshades after deployment, and the technical problems that existing rigid sunshades can only be applied to smaller-sized space optical systems, and to provide a three-fold deployable sunshade based on a planar mechanism.

[0005] In order to achieve the above object, the technical solution provided by the present invention is as follows:

[0006] A three-foldable and deployable sunshade based on a planar mechanism, characterized by:

[0007] It includes a plane light shield, a bottom plate, two first elastic drive hinges and two second elastic drive hinges;

[0008] The planar light shield comprises an upper light shield portion and a lower light shield portion;

[0009] The upper portion of the light shield includes an upper planar substrate and two upper fixed side plates vertically connected to both sides of the upper planar substrate; the lower portion of the light shield includes a lower planar substrate arranged at the lower end of the upper planar substrate and two lower fixed side plates vertically connected to both sides of the lower planar substrate; a plurality of light-blocking strips are horizontally arranged on one side surface of the upper planar substrate and the lower planar substrate;

[0010] The outer sides of the two lower fixed side panels are connected to the upper surfaces of the two sides of the bottom panel via first elastically driven hinges; the outer sides of the two upper fixed side panels are connected to the outer sides of the two lower fixed side panels via corresponding second elastically driven hinges; the expansion angle of the first elastically driven hinge is 90 degrees, and the expansion angle of the second elastically driven hinge is 180 degrees;

[0011] An optical through hole is axially opened on the bottom plate, and the light blocking strip is located on the upper plane substrate and the lower plane substrate and faces the bottom plate when unfolded;

[0012] A first clamping seat is respectively provided on the outer side walls of the two lower fixed side panels, a second clamping seat is provided at the corresponding position on the outer side walls of the two upper fixed side panels, and two locking devices are provided at the corresponding positions on the bottom plate, which are used to lock the flat light shield in the folded state through the cooperation of the first clamping seat, the second clamping seat and the corresponding locking device.

[0013] Furthermore, the locking device includes a base and a locking rod provided on the base;

[0014] The first pressing seat and the second pressing seat are respectively provided with locking holes adapted to the locking rod;

[0015] A pyrotechnic detonating device is provided in the base. After the remote-controlled pyrotechnic detonating device is detonated, the locking rod is separated from the base, thereby realizing the separation of the locking device from the first pressing seat and the second pressing seat.

[0016] Furthermore, the first elastically driven hinge and the second elastically driven hinge are both vortex spring locking hinges.

[0017] Furthermore, the first elastic drive hinge is a sliding groove type vortex spring locking hinge, comprising a first fixing seat, a second fixing seat, a male hinge, a female hinge, a vortex spring, a pressing rod, a locking pin and a pressing torsion spring;

[0018] The first fixing seat is installed on the upper surface of the base, and the second fixing seat is installed on the outer side wall of the lower fixed side plate;

[0019] The female hinge is arranged on the first fixed seat and connected to the fixed end of the scroll spring, and the male hinge is arranged on the second fixed seat and connected to the movable end of the scroll spring, so as to make the male hinge rotate along the motion track of the movable end of the scroll spring;

[0020] A fixed shaft is installed on the female hinge, and a compression torsion spring is installed on the fixed shaft;

[0021] One end of the clamping rod is rotatably connected to the fixed shaft, and the other end is fixedly connected to the locking pin, and the locking pin is arranged corresponding to the male hinge;

[0022] A sliding groove is provided on the male hinge at a position corresponding to the locking pin, and a protrusion is provided on the male hinge below the sliding groove. The working end of the compression torsion spring presses against the locking pin, so that the locking pin cooperates with the sliding groove or the protrusion respectively when the male hinge moves to different positions.

[0023] The second elastic driven hinge has the same structure as the first elastic driven hinge. The first fixed seat in the second elastic driven hinge is installed on the outer wall of the lower fixed side plate, and the second fixed seat is installed on the outer wall of the upper fixed side plate; the driving torque of the scroll spring in the second elastic driven hinge is twice the driving torque of the scroll spring in the first elastic driven hinge.

[0024] Furthermore, the stiffness of the scroll spring in the first elastic drive hinge is greater than the stiffness of the scroll spring in the second elastic drive hinge.

[0025] Furthermore, the angles between the upper planar substrate and the upper surface of the corresponding light-blocking strip, and the angles between the lower planar substrate and the upper surface of the corresponding light-blocking strip are both obtuse angles, and the angles decrease from top to bottom.

[0026] The width of the upper fixed side plate and the width of the lower fixed side plate increase sequentially from top to bottom;

[0027] The inner side walls of the two upper fixed side plates and the inner side walls of the two lower fixed side plates are respectively in contact with the two ends of the corresponding light-blocking strips.

[0028] The beneficial effects of the present invention compared to the prior art are as follows:

[0029] 1. The present invention provides a three-fold expandable sunshade based on a planar mechanism, wherein two first elastically driven hinges with an expansion angle of 90 degrees are connected between the lower part of the sunshade and the base plate, and two second elastically driven hinges with an expansion angle of 180 degrees are connected between the upper part 11 of the sunshade and the lower part 12 of the sunshade to form a planar three-link mechanism. In conjunction with a first pressing seat, a second pressing seat and a locking device, the planar sunshade can be folded in three parts to achieve a smaller spatial volume during rocket launch. At the same time, when the rocket reaches the expected on-orbit position, the two sets of planar three-link mechanisms are driven by the first elastically driven hinge and the second elastically driven hinge to unfold and lock the planar sunshade from the three-folded state, providing new ideas for the on-orbit application of large-size sunshades and filling the gap in large-size, high-rigidity sunshades.

[0030] 2. The present invention provides a three-fold expandable light shield based on a planar mechanism. The first pressing seat, the second pressing seat and the locking device adopt a pyrotechnic unlocking device or a shape memory alloy unlocking device used in aerospace. When the light shield is in a fully retracted state, the first pressing seat, the second pressing seat and the locking device are used to fix the flat light shield to the base plate, thereby ensuring that the light shield can still meet the required rigidity in the fully locked state during the launch process.

[0031] 3. In the present invention, the stiffness of the scroll spring in the first elastically driven hinge is greater than the stiffness of the scroll spring in the second elastically driven hinge, which can make the expansion speed of the first elastically driven hinge greater than the expansion speed of the second elastically driven hinge, ensuring that the second elastically driven hinge will not be subjected to excessive impact and damage during 180-degree expansion and locking. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic structural diagram of an embodiment of a three-foldable, deployable sunshade based on a planar mechanism according to the present invention;

[0033] Figure 2 Schematic diagram of a planar three-link mechanism formed by the lower portion of the light shield and the bottom plate via two first elastically driven hinges, and the upper portion of the light shield and the lower portion of the light shield via two second elastically driven hinges in an embodiment of the present invention;

[0034] Figure 3 Schematic diagram of the structure of the first elastic drive hinge in an embodiment of the present invention;

[0035] Figure 4 Schematic diagram of the locking process of the first elastically driven hinge in an embodiment of the present invention;

[0036] Figure 5 Schematic diagram of the unfolding process of the upper and lower parts of the light shield in an embodiment of the present invention Figure 1 ;

[0037] Figure 6 Schematic diagram of the unfolding process of the upper and lower parts of the light shield in an embodiment of the present invention Figure 2 .

[0038] The specific reference numerals are as follows:

[0039] 1. Plane light shield; 11. Upper part of light shield; 111. Upper plane substrate; 112. Upper fixed side plate; 12. Lower part of light shield; 121. Lower plane substrate; 122. Lower fixed side plate; 13. Light-blocking strip; 2. Bottom plate; 3. First elastically driven hinge; 31. First fixed seat; 32. Second fixed seat; 33. Male hinge; 34. Female hinge; 35. Volute spring; 36. Clamping rod; 37. Locking pin; 38. Clamping torsion spring; 4. Second elastically driven hinge; 5. First clamping seat; 6. Second clamping seat; 7. Locking device. DETAILED DESCRIPTION

[0040] In order to make the advantages and features of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] like Figure 1 As shown, a three-fold expandable sunshade based on a planar mechanism includes a planar sunshade 1, a bottom plate 2, two first elastically driven hinges 3 and two second elastically driven hinges 4.

[0042] The planar light shield 1 includes an upper portion 11 and a lower portion 12. The upper portion 11 includes an upper planar substrate 111 and two upper fixed side panels 112 vertically connected to either side of the upper planar substrate 111. The lower portion 12 includes a lower planar substrate 121 disposed at the lower end of the upper planar substrate 111 and two lower fixed side panels 122 vertically connected to either side of the lower planar substrate 121. A plurality of light-blocking strips 13 are horizontally disposed on one side of each of the upper and lower planar substrates 111, 121, and the inner side walls of the two upper and lower fixed side panels 112 and 122 respectively abut against the ends of the corresponding light-blocking strips 13. The angles between the upper planar substrate 111 and the upper surface of the corresponding light-blocking strip 13, and the angles between the lower planar substrate 121 and the upper surface of the corresponding light-blocking strip 13, are both obtuse, and these angles decrease from top to bottom. Accordingly, the widths of the upper fixed side panels 112 and the lower fixed side panels 122 increase from top to bottom. The angles between the upper planar substrate 111 and the lower planar substrate 121 and the upper surface of the lower light-blocking strip 13 are greater than their angles with the upper surface of the upper light-blocking strip 13, which can better suppress stray light.

[0043] The outer side walls of the two lower fixed side panels 122 are connected to the upper surfaces of both sides of the bottom plate 2 via first elastically driven hinges 3, and the lower end surface of the lower planar substrate 121 is clearance-matched with the corresponding positions on the upper surface of the bottom plate 2. The outer side walls of the two upper fixed side panels 112 are connected to the outer side walls of the two lower fixed side panels 122 via corresponding second elastically driven hinges 4. Preferably, the second elastically driven hinges 4 are arranged on the upper and lower fixed side panels 112, 122 at positions away from the bottom plate 2, and are used to enable the upper half of the planar sunshade 1 to fold outward. The first elastically driven hinge 3 has an unfolding angle of 90 degrees, and the second elastically driven hinge 4 has an unfolding angle of 180 degrees, so that the lower half of the planar sunshade 1 can be folded inward 90 degrees and the upper half of the planar sunshade 1 can be folded outward 180 degrees.

[0044] An optical through hole is axially opened on the base plate 2, and multiple light-blocking strips 13 are located on the upper plane substrate 111 and the lower plane substrate 121 facing the side of the base plate 2 when unfolded, for blocking stray light in the space. At the same time, this arrangement can make the light-blocking strips 13 located inside the plane light-blocking cover 1 when the plane light-blocking cover 1 is in the folded state, effectively avoiding interference contact with the light-blocking strips 13.

[0045] A first pressing seat 5 is provided on the outer wall of each of the two lower fixed side panels 122, and a second pressing seat 6 is provided at a corresponding position on the outer wall of each of the two upper fixed side panels 112. Two locking devices 7 are provided at a corresponding position on the bottom plate 2, which are used to lock the flat light shield 1 in the folded state through the cooperation of the first pressing seat 5, the second pressing seat 6 and the corresponding locking device 7. Specifically, the locking device 7 includes a base and a locking rod provided on the base, and a pyrotechnic detonating device is provided in the base. The first pressing seat 5 and the second pressing seat 6 are respectively provided with locking holes adapted to the locking rod. When the light shield needs to be opened, the pyrotechnic detonating device is remotely controlled to detonate, so that the locking rod is separated from the base, thereby realizing the separation of the locking device 7 from the first pressing seat 5 and the second pressing seat 6. The locking device 7 can be a pyrotechnic unlocking device commonly used in aerospace, a memory alloy unlocking device, or the like.

[0046] like Figure 2 As shown, a planar three-link mechanism is formed between the lower portion 12 of the sunshade and the base plate 2 via two first elastically driven hinges 3 with an unfolding angle of 90 degrees, and between the upper portion 11 of the sunshade and the lower portion 12 of the sunshade via two second elastically driven hinges 4 with an unfolding angle of 180 degrees. In conjunction with the first pressing seat 5, the second pressing seat 6 and the locking device 7, the planar sunshade 1 can be folded and collapsed in three parts during rocket launch to achieve a smaller spatial volume. When reaching the expected on-orbit position, the two sets of planar three-link mechanisms are driven by the first elastically driven hinge 3 and the second elastically driven hinge 4 to unfold and lock the planar sunshade 1 from the three-folded collapsed state, providing a new idea for the on-orbit application of large-size sunshades.

[0047] In this embodiment, the first elastic drive hinge 3 and the second elastic drive hinge 4 are both sliding groove type vortex spring locking hinges. Figure 3 As shown, taking the first elastically driven hinge 3 as an example, it includes a first fixed seat 31, a second fixed seat 32, a male hinge 33, a female hinge 34, a scroll spring 35, a clamping rod 36, a locking pin 37, and a compression torsion spring 38. The first fixed seat 31 is mounted on the upper surface of the base 2, and the second fixed seat 32 is mounted on the outer wall of the lower fixed side plate 122. The female hinge 34 is arranged on the first fixed seat 31 and connected to the fixed end of the scroll spring 35. The male hinge 33 is arranged on the second fixed seat 32 and connected to the movable end of the scroll spring 35, so as to rotate the male hinge 33 along the motion trajectory of the movable end of the scroll spring 35. A fixed shaft is mounted on the female hinge 34, and the compression torsion spring 38 is mounted on the fixed shaft. One end of the clamping rod 36 is rotatably connected to the fixed shaft, and the other end is fixedly connected to the locking pin 37, and the locking pin 37 is arranged corresponding to the male hinge 33. When the male hinge 33 is locked, a sliding groove is provided on the male hinge 33 at the position corresponding to the locking pin 37. A protrusion is provided on the male hinge 33 at a position below the sliding groove. The working end of the compression torsion spring 38 presses against the locking pin 37. When the male hinge 33 is in the initial state, the locking pin 37 slides into the sliding groove under the action of the compression torsion spring 38 for mechanical limit locking. When the male hinge 33 follows the scroll spring 35 to move away from the initial state, the locking pin 37 is pressed against the protrusion of the male hinge 33 under the action of the compression torsion spring 38. The second elastically driven hinge 4 has the same structure as the first elastically driven hinge 3, except that the first fixed seat in the second elastically driven hinge 4 is installed on the outer wall of the lower fixed side plate 122, and the second fixed seat is installed on the outer wall of the upper fixed side plate 112; accordingly, the driving torque of the spiral spring in the second elastically driven hinge 4 is twice the driving torque of the spiral spring 35 in the first elastically driven hinge 3. In addition, in this embodiment, it is preferred that the stiffness of the spiral spring 35 in the first elastically driven hinge 3 is greater than the stiffness of the spiral spring in the second elastically driven hinge 4, so as to make the expansion speed of the first elastically driven hinge greater than the expansion speed of the second elastically driven hinge, so as to ensure that the second elastically driven hinge 4 will not be subjected to excessive impact and damage during 180-degree expansion and locking.

[0048] The locking process of the vortex spring locking hinge is as follows Figure 4As shown, when the planar sunshade 1 is in the three-folded, stowed position, the scroll spring 35 continuously provides a driving torque to the scroll spring locking hinge in the unfolding direction. However, due to the action of the locking device 7, the scroll spring locking hinge is not unfolded. When the planar sunshade 1 reaches its intended on-orbit operating position following rocket launch, the locking device 7 is unlocked, and the lower portion 12 of the sunshade is driven to unfold under the action of the scroll spring 35. Simultaneously, the locking pin 37 remains compressed against the male hinge 33 by the action of the compression torsion spring 38. When the lower portion 12 of the sunshade is unfolded to the predetermined operating position, the locking pin 37 moves to the slot of the male hinge 33 and, under the action of the compression torsion spring 38, enters the slot and mechanically locks it. Correspondingly, the upper portion 11 of the sunshade is driven to unfold under the action of the scroll spring torque of the second elastic drive hinge 4. When the upper portion 11 of the sunshade is unfolded to the predetermined operating position, the corresponding locking pin enters the slot under the action of the compression torsion spring and mechanically locks it.

[0049] like Figure 5 、 Figure 6 The figure shows a schematic diagram of the process of unfolding the upper part 11 and the lower part 22 of the light shield using two symmetrically arranged planar three-link mechanisms. When the upper part 11 and the lower part 22 of the light shield are in a fully retracted state, that is, the upper part 11 and the lower part 22 of the light shield are fixed together with the base plate 2 through the clamping structure 7 and the first clamping seat 5 and the second clamping seat 6. When the planar light shield 1 reaches the expected on-orbit working position during rocket launch, the locking device 7 is unlocked to eliminate the fixed constraint. At this time, the spiral springs in the first elastic drive hinge 3 and the second elastic drive hinge 4 provide the planar three-link mechanism with an unfolding driving torque, driving the planar three-link mechanism to unfold according to its own motion trajectory, that is, driving the upper part 11 and the lower part 22 of the light shield to unfold respectively. After unfolding to the predetermined working position, the locking pins in the first elastically driven hinge 3 and the second elastically driven hinge 4 move to the corresponding sliding groove positions of the male hinges respectively, and enter the sliding grooves under the action of the compression torsion springs, thereby locking the first elastically driven hinge 3 and the second elastically driven hinge 4.

[0050] The above description is only used to illustrate the technical solution of the present invention, rather than to limit it. For ordinary professional and technical personnel in this field, the specific technical solutions recorded in the above embodiments can be modified, or some of the technical features therein can be replaced by equivalents. These modifications or replacements do not cause the essence of the corresponding technical solution to deviate from the scope of the technical solution protected by the present invention.

Claims

1. A three-foldable, expandable sunshade based on a planar mechanism, characterized by: It comprises a planar light shield (1), a bottom plate (2), two first elastic drive hinges (3) and two second elastic drive hinges (4); The planar light shield (1) comprises a light shield upper portion (11) and a light shield lower portion (12); The upper portion (11) of the light shield comprises an upper planar substrate (111) and two upper fixed side plates (112) vertically connected to both sides of the upper planar substrate (111); the lower portion (12) of the light shield comprises a lower planar substrate (121) arranged at the lower end of the upper planar substrate (111) and two lower fixed side plates (122) vertically connected to both sides of the lower planar substrate (121); a plurality of light blocking strips (13) are horizontally arranged on one side surface of each of the upper planar substrate (111) and the lower planar substrate (121); The outer side walls of the two lower fixed side panels (122) are connected to the upper surfaces of both sides of the bottom panel (2) through first elastically driven hinges (3); the outer side walls of the two upper fixed side panels (112) are connected to the outer side walls of the two lower fixed side panels (122) through corresponding second elastically driven hinges (4); the unfolding angle of the first elastically driven hinge (3) is 90 degrees, and the unfolding angle of the second elastically driven hinge (4) is 180 degrees; An optical through hole is axially opened on the bottom plate (2); the light blocking strip (13) is located on the side of the upper plane substrate (111) and the lower plane substrate (121) facing the bottom plate (2) when unfolded; A first pressing seat (5) is respectively provided on the outer side walls of the two lower fixed side plates (122), a second pressing seat (6) is provided at a corresponding position on the outer side walls of the two upper fixed side plates (112), and two locking devices (7) are provided at corresponding positions on the bottom plate (2) for locking the plane light shield (1) in a folded state through the cooperation of the first pressing seat (5), the second pressing seat (6) and the corresponding locking devices (7).

2. The three-foldable, expandable sunshade based on a planar mechanism according to claim 1, characterized in that: The locking device (7) comprises a base and a locking rod arranged on the base; A pyrotechnic detonating device is provided in the base; The first pressing seat (5) and the second pressing seat (6) are respectively provided with locking holes adapted to the locking rods.

3. The three-foldable, expandable sunshade based on a planar mechanism according to claim 1 or 2, characterized in that: The first elastically driven hinge (3) and the second elastically driven hinge (4) are both vortex spring locking hinges.

4. The three-foldable, expandable sunshade based on a planar mechanism according to claim 3, characterized in that: The first elastic drive hinge (3) is a sliding groove type vortex spring locking hinge, comprising a first fixed seat (31), a second fixed seat (32), a male hinge (33), a female hinge (34), a vortex spring (35), a pressing rod (36), a locking pin (37) and a pressing torsion spring (38); The first fixing seat (31) is mounted on the upper surface of the base (2), and the second fixing seat (32) is mounted on the outer side wall of the lower fixed side plate (122); The female hinge (34) is arranged on the first fixed seat (31) and connected to the fixed end of the spiral spring (35); the male hinge (33) is arranged on the second fixed seat (32) and connected to the movable end of the spiral spring (35), so as to enable the male hinge (33) to rotate along the motion track of the movable end of the spiral spring (35); A fixed shaft is installed on the female hinge (34), and a compression torsion spring (38) is installed on the fixed shaft; One end of the pressing rod (36) is rotatably connected to the fixed shaft, and the other end is fixedly connected to the locking pin (37), and the locking pin (37) is provided corresponding to the male hinge (33); A sliding groove is provided on the male hinge (33) at a position corresponding to the locking pin (37), and a protrusion is provided on the male hinge (33) at a position below the sliding groove. The working end of the compression torsion spring (38) presses against the locking pin (37) so as to enable the locking pin (37) to cooperate with the sliding groove or the protrusion respectively when the male hinge (33) moves to different positions. The second elastic drive hinge (4) has the same structure as the first elastic drive hinge (3); the first fixing seat in the second elastic drive hinge (4) is mounted on the outer side wall of the lower fixed side plate (122), and the second fixing seat is mounted on the outer side wall of the upper fixed side plate (112); the driving torque of the volute spring in the second elastic drive hinge (4) is twice the driving torque of the volute spring (35) in the first elastic drive hinge (3).

5. The three-foldable, expandable sunshade based on a planar mechanism according to claim 4, characterized in that: The stiffness of the volute spring (35) in the first elastic drive hinge (3) is greater than the stiffness of the volute spring in the second elastic drive hinge (4).

6. The three-foldable, expandable sunshade based on a planar mechanism according to claim 1, characterized in that: The angle between the upper plane substrate (111) and the upper surface of the corresponding light-blocking strip (13), and the angle between the lower plane substrate (121) and the upper surface of the corresponding light-blocking strip (13) are both obtuse angles, and the angles decrease from top to bottom. The width of the upper fixed side plate (112) and the width of the lower fixed side plate (122) increase sequentially from top to bottom; The inner side walls of the two upper fixed side plates (112) and the inner side walls of the two lower fixed side plates (122) respectively abut against the two ends of the corresponding light-blocking strips (13).

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