A closed-loop handrail for on-track maintenance

Abstract

The present invention discloses a closed-loop force handrail for on-orbit maintenance, comprising a fixed clamping mechanism, a universal unloading mechanism, an angle adjustment mechanism, a length adjustment mechanism, and an armrest grip structure; the fixed clamping mechanism can be reliably connected to the cabin structure of a spacecraft such as a space station, providing firm support for the closed-loop force handrail; the universal unloading mechanism can be used to buffer and unload the instantaneous excessive impact force exerted by astronauts on the handrail grip; the angle adjustment mechanism can adjust the end handrail to any angle within the semi-conical range of the fixed support point; the length adjustment mechanism has the functions of length adjustment and locking, so that the distance between the end handrail and the cabin wall handrail can be relatively changed; the handrail grip structure is designed with a grip suitable for astronaut gloves to grasp, which can provide a grip for astronauts. In the present invention, the universal swing characteristics of the ball joint are utilized to expand the direction of buffering and energy absorption, which can reduce the instantaneous impact force caused by astronauts on the cabin structure during the remote force application process.

Description

Technical Field

[0001] The present invention relates to the technical field of astronaut extravehicular auxiliary tools, and in particular to a closed-loop handrail for on-orbit maintenance. Background Art

[0002] To extend the lifespan of the in-orbit space station, my country's space station is equipped to allow astronauts to perform extravehicular maintenance on the Orbit Replacement Unit (ORU). Astronauts are transported outside the cabin to the maintenance site using a space robotic arm, using the arm to stabilize their bodies while performing ORU disassembly and installation and on-orbit maintenance operations. The space robotic arm consists of two parts: a large arm and a small arm. The large and small arms can operate independently or in combination. In the current three-module configuration of the space station, a combination of the large and small arms is often required to assist astronauts in on-orbit maintenance tasks. When the large and small arms are combined, the total length from the end of the arm to the connection with the cabin can reach 15 meters. The extremely long open-loop series mechanism reduces system rigidity, and even the slightest movement of the astronaut at the end of the robotic arm could cause the entire arm to shake. Therefore, a closed-loop force handrail is urgently needed to connect the end of the robotic arm to the cabin, closing the loop of the entire system and suppressing the arm's shaking. However, there are hundreds of large and small ORU devices outside the cabin, and their maintenance conditions are different. This places high demands on the versatility and adaptability of the force closed-loop handrail. By equipping 1 to 2 specifications of force closed-loop handrails, all operational requirements of the large and small robotic arms in the space station can be met under the cascade working conditions.

[0003] The space station's robotic arm integrates multiple important functions, including extravehicular operations for astronauts, monitoring of visiting spacecraft, and module docking. It is a vital component of my country's space station and can significantly enhance the station's functionality. However, the robotic arm is an open-chain system. During extravehicular operations carried out by astronauts, any movement caused by the astronauts at the end of the robotic arm will be transmitted to the base of the robotic arm, where it will be greatly amplified, significantly affecting the service life of the space station's robotic arm.

[0004] Therefore, there is an urgent need for a force-closed-loop armrest for the space station's robotic arm, capable of connecting the arm's tip to the cabin and adapting to all maintenance conditions. The basic concept and method of this paper is to design a closed-loop system with a human in the loop. Through the spring-damping system of the force-closed-loop armrest's universal unloading mechanism, the disturbance caused by the arm's tip shaking is absorbed and buffered. This not only protects the arm's root joints but also effectively assists astronauts in completing on-orbit maintenance operations. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the existing technology and to address the technical problem of insufficient end stiffness faced by the cascade of large and small robotic arms in the space station. An assist armrest that meets the closed loop of the robotic arm force transmission link is proposed. The armrest has the functions of ultra-large angle adjustment and multi-gear adjustment, can unload the inertial force of the end of the robotic arm, can achieve overload protection for the space station robotic arm, and can provide auxiliary assistance to astronauts during the on-orbit maintenance process.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A force closed-loop handrail for on-orbit maintenance comprises a fixed clamping mechanism, a universal force unloading mechanism, an angle adjustment mechanism, a length adjustment mechanism and an handrail grip structure; the fixed clamping mechanism can be reliably connected to the cabin structure of a spacecraft such as a space station, providing firm support for the force closed-loop handrail; the universal force unloading mechanism can be used to buffer and unload the instantaneous excessive impact force exerted by astronauts on the handrail grip; the angle adjustment mechanism can achieve adjustment of the end handrail to any angle within the semi-conical range of the fixed support point; the length adjustment mechanism has the functions of length adjustment and locking, so that the distance between the end handrail and the cabin wall handrail can be relatively changed; the handrail grip structure is designed with a grip suitable for astronaut gloves to grasp, which can provide a grip for astronauts.

[0008] Preferably, the fixing and clamping mechanism includes a fixing clamp, a sliding sleeve, a ratchet, a cam handle, a fixing seat, a fixing clamp flexible pad, a movable clamp flexible pad, a movable clamp, a tension spring, an eccentric nail, a pawl, a pawl compression spring, a top screw, an auxiliary sliding rod, a pawl shaft and a pull ring structure;

[0009] The ratchet and the fixed clamp are fixed on the fixed seat, and the sliding sleeve is fixed to the ratchet with a top screw. The movable clamp can slide along the sliding sleeve, and the cam handle is nested on the ratchet and can rotate around the axis of the sliding sleeve. The pawl is fixed to the cam handle through a pawl shaft pin, and a pawl compression spring is installed between the pawl and the cam handle. The eccentric nail is fixed to the end of the sliding sleeve, and the tension spring rod is fixed to the movable clamp, and the tension spring in the middle provides the reset force of the movable clamp. The rear end of the movable clamp is designed with a pull ring structure, and an auxiliary sliding rod is installed on the fixed clamp. The flat part of the pull ring structure can slide with the flat surface of the cam handle, and the side of the pull ring structure can slide up and down along the auxiliary sliding rod, and the auxiliary sliding rod is always in contact with the side of the pull ring structure.

[0010] Preferably, the universal unloading mechanism includes a sleeve, a flexible clamp, a compression nut, a buffer butterfly spring, a hemispherical auxiliary rod, a slow-release washer, a hemispherical socket, an overload spring, a top ball, a rotating shaft and an overload rod;

[0011] The overload rod is fixed to the sleeve via a rotating shaft. The overload rod is connected to the sleeve pin and can rotate around the rotating shaft. One end of the top ball contacts the overload spring, and the other end presses on the arc surface of the side of the overload rod. The top ball can move along the sleeve groove. The overload spring provides a pre-tightening force to the overload rod when it is overloaded. The overload rod is fastened to the flexible clamp by a screw.

[0012] One end of the sleeve is designed with several interfaces connected to the overload rod around the entire circumference, and the other end is designed with a flange with threaded holes, which can be connected to the cabin interface. A boss is designed inside the sleeve to provide axial support for the buffer butterfly spring.

[0013] Preferably, the flexible clamp has a certain elasticity along the axial direction. When a large overload force is generated in a direction perpendicular to the hemispherical secondary rod, the overload rod in this direction will rotate to a certain angle. At the same time, under the pulling action of the flexible clamp, the overload rod adjacent to the direction will also be deformed to a certain angle.

[0014] The hemispherical socket structure on one side of the hemispherical socket is connected to the ball end of the hemispherical auxiliary rod. The hemispherical socket can rotate within a certain angle range relative to the hemispherical auxiliary rod. The other side of the hemispherical socket has a tooth groove structure. The overload rod is stuck in the tooth groove of the hemispherical socket. The shaft end of the hemispherical auxiliary rod is designed with a threaded structure and is fixed with a clamping nut.

[0015] Preferably, the auxiliary end of the hemispherical auxiliary rod cooperates with the hemispherical socket ball pair, the shaft end of the hemispherical auxiliary rod is designed with a threaded structure and fastened together with the clamping nut, and the hemispherical auxiliary rod can be made of, but not limited to, quenched stainless steel material;

[0016] Multiple series-parallel buffer butterfly springs are located inside the sleeve, one end of which is connected to the inner boss of the sleeve and the other end is connected to the compression nut;

[0017] The slow-release washer is located between the bottom surface of the sleeve and the hemispherical socket.

[0018] Preferably, the angle adjustment mechanism includes a two-axis turntable and a tooth-slot clamping mechanism, the two-axis turntable can adjust the angle in any direction, and the tooth-slot clamping mechanism can lock and unlock the angle at different lengths.

[0019] Preferably, the length adjustment mechanism includes an outer rod, a bevel pin, an inner rod, a V-shaped block, a control rod, a bevel pin compression spring, a bevel pin seat, a fixing sleeve, a self-locking spring, a sliding pin, a fixing sleeve, a limit block, a button spring, an anti-drop clamp, a guide pin, a movable sleeve and a button;

[0020] The inner rod is installed on the inner side of the outer rod, and the inner rod and the outer rod form a sliding fit, and the side of the outer rod is designed with several pin hole structures to facilitate the insertion and disengagement of the bevel pin; the bevel pin seat is fixed to the end of the inner rod, and the bevel pin seat is a rectangular inner cavity structure, the side of the rectangular inner cavity slides with the V-shaped block, and the bottom surface of the rectangular inner cavity slides with the bottom surface of the bevel pin, the bevel pin compression spring is located between the two bevel pins, and the two side surfaces of the V-shaped block slide with the bevels of the two bevel pins respectively; the fixed sleeve is installed at the end of the inner rod, and the inner rod is fixedly connected to the fixed sleeve through a guide pin, and a slide groove structure is designed around the movable sleeve to cooperate with the guide pin, and the movable sleeve can slide along the guide pin, and a square groove structure is designed on the movable sleeve to fix the limit block, and an axis end groove structure is designed on the sliding card pin, so that the sliding card pin and the movable The movable sleeve can produce a certain displacement without separating. Several spiral tooth structures are designed on the shaft end of the movable sleeve, and the shaft end of the fixed sleeve is designed with an incomplete spiral tooth structure, a sliding groove structure and an arc-shaped chip groove structure; the sliding pin is designed with a tooth surface structure that cooperates with the spiral tooth structure on the movable sleeve and the incomplete spiral tooth structure on the fixed sleeve. One end of the self-locking spring presses the sliding pin and is limited by the boss structure on the sliding pin. The other end presses the inner side of the fixed sleeve. The button is fixed at one end of the movable sleeve, and a hexagonal hole is designed on the button. One end of the button spring presses the button, and the other end presses the fixed sleeve. One end of the control rod is fixedly connected to the sliding pin, and the other end is designed with a circular boss structure that is mechanically connected to the V-shaped block. The anti-slip clamp is installed on the end face of the outer rod to prevent the inner rod from falling out of the outer rod.

[0021] Preferably, the armrest grip structure comprises an armrest grip, a latch, an armrest bottom plate and an armrest side plate;

[0022] The armrest base plate is connected to the armrest handle through the armrest side panels on both sides. A pin is designed on the armrest side panels. The overall pin is L-shaped, and the part connected to the anti-pin-out switch is a hexagonal pyramid structure with a tapered surface. It is designed with a short side structure and a long side structure, which can effectively prevent misinsertion. The tapered structure can facilitate astronauts to complete the insertion operation.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0024] 1. In this application, the fixed clamping mechanism uses a cam clamping method to clamp the cabin wall handrail, and the ratchet pawl mechanism locks the clamping state to provide fixed support for the force closed-loop handrail; the universal unloading mechanism uses a combination of ball pairs and butterfly springs to achieve torque unloading; the angle adjustment mechanism uses a two-axis turntable and a toothed clamping mechanism to achieve angle adjustment and locking of the handrail in all directions. A multi-gear structure is used to achieve long-distance angle adjustment; the length adjustment mechanism uses a telescopic bayonet and a bayonet locking mechanism to adjust and lock the length of the handrail; the handrail grip structure can be grasped by astronauts at the end. This application uses a structural form in which the head and tail of the robotic arm are connected to the cabin body, which solves the problem of astronauts shaking at the end of the robotic arm when the large and small arms of the space station are cascaded.

[0025] 2. Compared with the traditional aluminum honeycomb buffer energy absorption structure, this application utilizes the universal swing characteristics of the ball pair and expands the direction of buffer energy absorption. After experimental verification, this method can reduce the instantaneous impact force caused by astronauts on the cabin structure during the remote force application process. The universal unloading mechanism has overload rods in various directions. One end of the overload rod is designed with a pit structure that cooperates with the top bead, and the other end is designed with a threaded hole connected to the flexible clamp. When the overload rod is subjected to a large overload force, the top bead is disengaged from the overload rod pit, and the overload rod rotates a certain angle around the rotating shaft. At the same time, the overload rod near this direction is also driven by the flexible clamp to rotate a small angle. At this time, the end will cause a large displacement of the product, so that the astronauts can feel a phenomenon similar to "slipping", which can remind the astronauts that they are applying too much force in orbit, thereby ensuring the safety of the cabin structure and the root adapter of the space station. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the on-track operation of a force closed-loop handrail provided in an embodiment of the present invention is shown;

[0027] Figure 2 It shows a composition diagram of a force closed-loop handrail provided according to an embodiment of the present invention;

[0028] Figure 3 It shows a composition diagram of a fixed clamping mechanism provided according to an embodiment of the present invention;

[0029] Figure 4 It shows a composition diagram of a universal unloading mechanism provided in an embodiment of the present invention;

[0030] Figure 5 An exploded view of a universal unloading mechanism according to an embodiment of the present invention is shown;

[0031] Figure 6 It shows a composition diagram of an angle adjustment mechanism provided according to an embodiment of the present invention;

[0032] Figure 7 It shows a composition diagram of a length adjustment mechanism provided according to an embodiment of the present invention;

[0033] Figure 8 It shows a composition diagram of an armrest handle provided in an embodiment of the present invention;

[0034] Figure 9 A force analysis diagram of a fixed clamping mechanism according to an embodiment of the present invention is shown;

[0035] Figure 10 Shows an open view of a fixed clamping mechanism provided according to an embodiment of the present invention;

[0036] Figure 11It shows a clamping diagram of a fixed clamping mechanism provided according to an embodiment of the present invention;

[0037] Figure 12 It shows the unloading bending moment diagram of the universal unloading mechanism provided in accordance with an embodiment of the present invention;

[0038] Figure 13 It shows the unloading torque diagram of the universal unloading mechanism provided in accordance with an embodiment of the present invention;

[0039] Figure 14 It shows a diagram of unloading tension / pressure of a universal unloading mechanism provided in accordance with an embodiment of the present invention;

[0040] Figure 15 It shows a structural diagram of a mobile card sleeve provided according to an embodiment of the present invention;

[0041] Figure 16 It shows a structural diagram of a fixed ferrule provided according to an embodiment of the present invention;

[0042] Figure 17 It shows a structural diagram of a sliding latch provided according to an embodiment of the present invention;

[0043] Figure 18 A diagram showing a latch structure according to an embodiment of the present invention is shown.

[0044] Legend:

[0045] Fixed clamping mechanism 1, universal unloading mechanism 2, angle adjustment mechanism 3, length adjustment mechanism 4, armrest grip structure 5. Fixed clamp 11, sliding sleeve 12, ratchet 13, cam handle 14, fixed seat 15, fixed clamp flexible pad 16, movable clamp flexible pad 17, movable clamp 18, tension spring 19, eccentric nail 111, pawl 112, pawl compression spring 113, top screw 114, auxiliary sliding rod 115, pawl shaft 116, pull ring structure 181, sleeve 21, flexible clamp 22, compression nut 23, buffer butterfly spring 24, hemispherical auxiliary rod 25, slow-release washer 26, hemispherical socket 27, overload spring 28, top ball 29, rotating shaft 211, overload rod 212, two-axis turntable 31, tooth groove clamping mechanism 32, outer rod 41, bevel pin 42, inner rod 43, V-shaped block 44, control rod 45, bevel Pin compression spring 46, inclined pin seat 47, fixed sleeve 48, self-locking spring 49, sliding pin 411, fixed sleeve 412, limit block 413, button spring 414, anti-slip clamp 415, guide pin 416, movable sleeve 417, button 418, shaft end groove structure 4111, tooth surface structure 4112, boss structure 4113, incomplete spiral tooth structure 4121, sliding groove structure 4122, arc-shaped chip groove structure 4123, slide groove structure 4171, square groove structure 4172, spiral tooth structure 4173, armrest grip 51, pin 52, armrest base plate 53, armrest side plate 54, short side structure 521, long side structure 522, tapered structure 523. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0047] See also Figure 1-3 , the present invention provides a technical solution:

[0048] like Figure 1As shown in the figure, the system for on-orbit maintenance using a space manipulator includes: a space station, a manipulator root adapter, a manipulator joint and arm rod, a manipulator end, a foot limiter, an astronaut, and a force closed-loop handrail (including a universal unloading mechanism). During the astronaut's extravehicular operation on the foot limiter, the disturbance force and torque generated by the astronaut's operation are transmitted to the manipulator root adapter through the manipulator's multiple flexible joints and arm rods. Since the entire force transmission link is long and has a certain elasticity, it is easy to cause a large shaking force at the end of the manipulator. In the microgravity environment of space, the shaking force will oscillate and superimpose repeatedly, which can easily cause material damage to the root adapter at the end of the manipulator and the nearby space station cabin structure. By adding a universal unloading mechanism containing a spring damping system to the entire force transmission link, the shaking of the manipulator end can be effectively alleviated, reducing the structural physical damage to the space station cabin structure and the root adapter.

[0049] A force closed-loop handrail for on-orbit maintenance comprises a fixed clamping mechanism 1, a universal force unloading mechanism 2, an angle adjustment mechanism 3, a length adjustment mechanism 4 and an handrail grip structure 5; the fixed clamping mechanism 1 can be reliably connected to the cabin structure of a spacecraft such as a space station, providing firm support for the force closed-loop handrail; the universal force unloading mechanism 2 can be used to buffer and unload the instantaneous excessive impact force exerted by astronauts on the handrail grip; the angle adjustment mechanism 3 can achieve adjustment of the end handrail to any angle within the semi-conical range of the fixed support point; the length adjustment mechanism 4 has the functions of length adjustment and locking, so that the distance between the end handrail and the cabin wall handrail can be relatively changed; the handrail grip structure 5 is designed with a grip suitable for astronaut gloves to grasp, which can provide a grip for the astronaut.

[0050] The force closed-loop handrail can buffer the forces and bending moments in all directions at the end of the robotic arm. The maximum transient impact force transmitted to the cabin does not exceed 650N, and the maximum transient bending moment does not exceed 110Nm.

[0051] Specifically, such as Figure 3 As shown, the fixed clamping mechanism 1 includes a fixed clamp 11, a sliding sleeve 12, a ratchet 13, a cam handle 14, a fixed seat 15, a fixed clamp flexible pad 16, a movable clamp flexible pad 17, a movable clamp 18, a tension spring 19, an eccentric nail 111, a pawl 112, a pawl compression spring 113, a top screw 114, an auxiliary sliding rod 115, a pawl shaft 116 and a pull ring structure 181;

[0052] The ratchet 13 and the fixed clamp 11 are fixed on the fixed seat 15, and the sliding sleeve 12 is fixed to the ratchet 13 using a top screw 114. The movable clamp 18 can slide along the sliding sleeve 12, and the cam handle 14 is nested in the ratchet 13 and can rotate around the axis of the sliding sleeve 12. The pawl 112 is fixed to the cam handle 14 through the pawl shaft pin, and a pawl compression spring 113 is installed between the pawl 112 and the cam handle 14. The eccentric nail 111 is fixed to the end of the sliding sleeve 12, and the tension spring rod is fixed to the movable clamp 18. The tension spring 19 in the middle provides the reset force of the movable clamp 18. The rear end of the movable clamp 18 is designed with a pull ring structure 181, and an auxiliary sliding rod 115 is installed on the fixed clamp 11. The flat part of the pull ring structure 181 can slide with the plane of the cam handle 14, and the side of the pull ring structure 181 can slide up and down along the auxiliary sliding rod 115, and the auxiliary sliding rod 115 is always in contact with the side of the pull ring structure 181.

[0053] Specifically, such as Figure 9 As shown in the figure, the force analysis diagram of the movable clamp 18 when the pull ring structure 181 is added to the fixed clamping mechanism 1 and when the pull ring structure 181 is not added, in the case of no pull ring structure, the cam handle 14 is in contact with the semicircular surface of the movable clamp 18 and is tangent, and the movable clamp 18 slides along the guide surface. The movable clamp 18 is subjected to the normal pressure F along the semicircular surface and the tangential friction force F f , both have a component force perpendicular to the guide surface. If this component force is too large compared to the component force along the guide surface, the cam handle 14 will be stuck, causing the mechanism to fail. Therefore, a pull ring structure 181 is added to the movable clamp 18, and an auxiliary sliding rod 115 is installed on the fixed clamp 11. The flat part of the pull ring structure 181 can be tangent to the cam handle 14, changing the normal pressure F and the tangential friction force F f The side portion of the pull ring structure 181 slides with the auxiliary sliding rod 115 to offset the tangential friction force F f , which increases the matching area of the movable clamp 18 sliding up and down, effectively improves the movement performance of the mechanism, and avoids the occurrence of the cam handle 14 getting stuck during the rotation process.

[0054] Specifically, such as Figure 4 As shown, the universal unloading mechanism 2 includes a sleeve 21, a flexible clamp 22, a compression nut 23, a buffer butterfly spring 24, a hemispherical auxiliary rod 25, a slow-release washer 26, a hemispherical socket 27, an overload spring 28, a top ball 29, a rotating shaft 211 and an overload rod 212;

[0055] The universal unloading mechanism 2 adopts the method of overload disengagement of the top ball to realize the universal overload unloading of the overturning moment; through the spring force of the buffer butterfly spring 24, the impact overload in the swing direction of the hemispherical auxiliary rod 25 and the overload unloading in the rotation direction of the hemispherical auxiliary rod 25 are unloaded; the slow-release washer 26 is used to dissipate the impact force in all directions.

[0056] The overload disengagement method of the top ball is adopted to realize the universal overload unloading of the overturning moment; the spring force of the buffer butterfly spring 24 is used to unload the impact overload in the swing direction of the ball pair rod and the overload unloading force in the rotation direction of the ball pair rod; the slow-release washer 26 is used to dissipate the impact force in all directions.

[0057] The overload rod 212 is fixed to the sleeve 21 via the rotating shaft 211. The overload rod 212 is pinned to the sleeve 21 and can rotate around the rotating shaft 211. One end of the top ball 29 contacts the overload spring 28, and the other end presses on the arc surface of the side of the overload rod 212. The top ball 29 can move along the groove of the sleeve 21. The overload spring 28 provides a preload force to the overload rod 212 when it is overloaded. The overload rod 212 is fastened to the flexible clamp 22 by screws.

[0058] One end of the sleeve 21 is designed with several interfaces for connecting to the overload rod 212. The other end is designed with a flange with threaded holes, which can be connected to the cabin interface. The sleeve 21 is designed with a boss inside to provide axial support for the buffer butterfly spring 24.

[0059] The flexible clamp 22 has a certain elasticity along the axial direction. When a large overload force is generated in a direction perpendicular to the hemispherical auxiliary rod 25, the overload rod 212 in that direction will rotate to a certain angle. At the same time, under the pulling action of the flexible clamp 22, the overload rod 212 adjacent to the direction will also be deformed to a certain angle.

[0060] The hemispherical socket structure on one side of the hemispherical socket 27 is connected to the ball and auxiliary end of the hemispherical auxiliary rod 25. The hemispherical socket 27 can rotate relative to the hemispherical auxiliary rod 25 within a certain angle range. The other side of the hemispherical socket 27 has a tooth groove structure. The overload rod 212 is stuck in the tooth groove of the hemispherical socket 27. The shaft end of the hemispherical auxiliary rod 25 is designed with a threaded structure and is fixed with the clamping nut 23.

[0061] The auxiliary end of the hemispherical auxiliary rod 25 is matched with the hemispherical socket 27. The shaft end of the hemispherical auxiliary rod 25 is designed with a threaded structure and is fastened together with the clamping nut 23. The hemispherical auxiliary rod 25 can be made of, but not limited to, stainless steel quenching material;

[0062] Specifically, such as Figure 12 As shown, when the sleeve 21 is subjected to a transient impact overload in any direction, the sleeve 21 will use the toothed contact portion of the overload rod 212 and the hemispherical socket 27 in that direction as a support point, and the hemispherical auxiliary rod 25 will rotate around the ball socket of the hemispherical socket 27. Due to the different rotation centers, the inner cavity of the sleeve 21 of the sleeve assembly will produce a certain displacement Δx relative to the axis of the hemispherical auxiliary rod 25, which is about 2 to 5 mm; under the tightening action of the clamping nut 23, the buffer butterfly spring 24 will produce a certain deformation to absorb part of the buffering energy.

[0063] Specifically, such as Figure 13As shown, when the sleeve assembly is subjected to torque in the direction of rotation along the axis of the hemispherical secondary rod 25, the overload rod 212 of the sleeve assembly moves upward along the slope of the tooth groove pit of the hemispherical socket 27, forcing the sleeve 21 to move along the axis of the hemispherical secondary rod 25. Similarly, under the compression of the clamping nut 23 on the hemispherical secondary rod 25, the buffer butterfly spring 24 undergoes a certain deformation, absorbing part of the buffering energy. When the sleeve 21 moves along the slope and out of the tooth groove pit, the sleeve 21 produces a circumferential angular rotation relative to the hemispherical socket 27. If the sleeve 21 continues to rotate, the overload rod 212 in the sleeve assembly will enter the tooth groove pit of the next hemispherical socket 27. The astronauts will sense the "slippage" in the torsional direction and will reduce the force in the torsional direction to protect the safety of the cabin wall structure.

[0064] Specifically, such as Figure 14 As shown, when the sleeve assembly is subjected to positive pressure along the axis of the hemispherical auxiliary rod 25, the buffer butterfly spring 24 on the hemispherical auxiliary rod 25 will produce a certain deformation, absorbing part of the overload energy and playing a buffering role. When the positive pressure is too large, the overload rod 212 will deform at a certain angle relative to the sleeve product, causing the astronaut to feel the power assist "let go" at the end, thereby reducing the force transmitted to the cabin and minimizing damage to the cabin structure. When the sleeve assembly is subjected to positive pressure along the axis of the hemispherical auxiliary rod 25, the release washer 26 dissipates and absorbs the overload force transmitted by the sleeve 21, thereby reducing the force transmitted to the cabin.

[0065] Multiple series-parallel buffer butterfly springs 24 are located inside the sleeve 21, one end of which is connected to the inner boss of the sleeve 21 and the other end is connected to the compression nut 23;

[0066] The preload of the buffer butterfly spring 24 can be adjusted by the compression nut 23, thereby ensuring that the universal unloading mechanism 2 has an initial force threshold. When the sleeve 21 swings relative to the ball socket and exceeds the force threshold, creating a certain angle with the ball socket, the compression nut 23 moves along the inner wall of the sleeve 21 toward the ball socket, compressing the buffer butterfly spring 24 and absorbing some of the overload energy.

[0067] The slow-release washer 26 is located between the bottom surface of the sleeve 21 and the hemispherical socket 27;

[0068] When the sleeve 21 applies positive pressure along the ball pair rod direction, it can buffer and release the elastic force applied to the sleeve 21. When the sleeve 21 swings relative to the hemispherical socket 27, it can buffer and release part of the overload force on the sleeve 21.

[0069] Specifically, such as Figure 6 As shown, the angle adjustment mechanism 3 includes a two-axis turntable 31 and a tooth-slot clamping mechanism 32. The two-axis turntable 31 can adjust the angle in any direction, and the tooth-slot clamping mechanism 32 can lock and unlock the angle at different lengths.

[0070] The angle adjustment range of the two-axis turntable 31 includes an adjustment range of 360° along the axial direction and 120° along the radial direction. It can adopt but is not limited to a U-shaped frame structure. The tooth groove clamping mechanism 32 can adapt to the gear adjustment within a range of 600mm and can be made of but is not limited to 2A12 metal material.

[0071] Specifically, such as Figure 7 、 Figure 15 、 Figure 16 and Figure 17 As shown, the length adjustment mechanism 4 includes an outer rod 41, a bevel pin 42, an inner rod 43, a V-shaped block 44, a control rod 45, a bevel pin compression spring 46, a bevel pin seat 47, a fixing sleeve 48, a self-locking spring 49, a sliding latch 411, a fixing sleeve 412, a limit block 413, a button spring 414, an anti-drop clamp 415, a guide pin 416, a movable sleeve 417 and a button 418;

[0072] The inner rod 43 is installed on the inner side of the outer rod 41, and the inner rod 43 and the outer rod 41 form a sliding fit. The side of the outer rod 41 is designed with several pin hole structures to facilitate the insertion and removal of the bevel pin 42; the bevel pin seat 47 is fixed to the end of the inner rod 43, and the bevel pin seat 47 is a rectangular inner cavity structure. The side of the rectangular inner cavity slides with the V-shaped block 44, and the bottom of the rectangular inner cavity slides with the bottom of the bevel pin 42. The bevel pin compression spring 46 is located between the two bevel pins 42, and the two sides of the V-shaped block 44 are respectively in contact with the bevels of the two bevel pins 42. Sliding fit; the fixed sleeve 48 is installed at the end of the inner rod 43, and the inner rod 43 is fixedly connected to the fixed sleeve 412 through the guide pin 416. The movable sleeve 417 is designed with a slide groove structure 4171 around it, which cooperates with the guide pin 416. The movable sleeve 417 can slide along the guide pin 416. The movable sleeve 417 is designed with a square groove structure 4172 to fix the limit block 413. The sliding pin 411 is designed with an axial end groove structure 4111, so that the sliding pin 411 and the movable sleeve 417 can produce A certain displacement is made without separation. The shaft end of the movable clamping sleeve 417 is designed with a plurality of spiral tooth structures 4173. The shaft end of the fixed clamping sleeve 412 is designed with an incomplete spiral tooth structure 4121, a sliding groove structure 4122 and an arc-shaped chip groove structure 4123. The sliding clamping pin 411 is designed with a tooth surface structure 4112 that cooperates with the spiral tooth structure 4173 on the movable clamping sleeve 417 and the incomplete spiral tooth structure 4121 on the fixed clamping sleeve 412. One end of the self-locking spring 49 presses the sliding clamping pin 411, and relies on the sliding clamping pin to lock the movable clamping sleeve 417. The boss structure 4113 on 411 is limited, and the other end is pressed against the inner side of the fixed sleeve 48. The button 418 is fixed to one end of the movable sleeve 417. A hexagonal hole is designed on the button 418. One end of the button spring 414 presses the button 418, and the other end presses the fixed sleeve 412. One end of the control rod 45 is fixedly connected to the sliding pin 411, and the other end is designed with a circular boss structure mechanically connected to the V-shaped block 44. The anti-slip clamp 415 is installed on the end face of the outer rod 41 to prevent the inner rod 43 from falling out of the outer rod 41.

[0073] The length adjustment mechanism can achieve length adjustment of no less than 4 gears, and the length between each gear can be but not limited to 80mm.

[0074] Specifically, such as Figure 8 and Figure 18 As shown, the armrest handle structure 5 includes an armrest handle 51, a latch 52, an armrest bottom plate 53 and an armrest side plate 54;

[0075] The armrest base plate 53 is connected to the armrest handle 51 through the armrest side panels 54 on both sides. A pin 52 is designed on the armrest side panel 54. The pin 52 is an L-shaped structure as a whole, and the part connected to the anti-pin-out switch is a hexagonal pyramid structure with a tapered surface. It is designed with a short side structure 521 and a long side structure 522, which can effectively prevent misinsertion. The tapered structure 523 can facilitate astronauts to complete the insertion operation.

[0076] Working process:

[0077] First, secure the force-closed-loop handrail to the space station's extravehicular handrail. The specific operation process is as follows: press the pawl 112 to unlock the cam handle 14. Rotate the cam handle 14 in the opposite direction. The movable clamp 18, under the tension of the tension spring 19, moves away from the fixed clamp 11, placing the fixed clamp 18 in the open position. Place the fixed clamp 11 and movable clamp 18 on either side of the extravehicular handrail. Rotate the cam handle 14 forward, causing the movable clamp 18 to press against the extravehicular handrail under the action of the cam handle 14. Simultaneously, the pawl 112 and ratchet 13 utilize the one-way self-locking principle to prevent the cam handle 14 from being unlocked in the opposite direction. Next, adjust the angle of the force-closed-loop handrail relative to the extravehicular handrail. This angle adjustment and locking is achieved by adjusting the two-axis turntable 31 and the toothed-slot clamping mechanism 32. Finally, the button 418 is pressed, and the movable sleeve 417 and the sliding latch 411 move downward until the sliding latch 411 comes out of the deep groove of the fixed sleeve 412. Under the action of the button spring 414, the spiral tooth structure 4173 on the movable sleeve 417 is separated from the tooth surface structure 4112 on the sliding latch 411. At the same time, under the elastic force of the self-locking spring 49, the teeth on both sides of the sliding latch 411 enter the shallow groove; the V-shaped block 44 moves downward, so that the bevel pin 42 comes out of the gear hole of the outer rod 41, and the length lock between the inner rod 43 and the outer rod 41 is released; pull the handrail to the appropriate length; and again Press the button 418, the mobile sleeve 417 and the sliding pin 411 move downward until the sliding pin 411 disengages from the shallow groove of the fixed sleeve 412. Under the elastic force of the button spring 414, the spiral tooth structure 4173 on the mobile sleeve 417 is separated from the tooth surface structure 4112 on the sliding pin 411. At the same time, under the elastic force of the self-locking spring 49, the teeth on both sides of the sliding pin 411 enter the deep groove; the V-shaped block 44 moves upward, and the bevel pin 42 slides outward under the action of the bevel pin compression spring 46, and is inserted into the pin shaft hole of the outer rod 41, locking the relative position of the inner rod 43 and the outer rod 41.

[0078] After the closed-loop armrest angle and length are adjusted appropriately, the astronaut grasps the armrest handle 51 to perform extravehicular maintenance operations. During these operations, disturbance forces and torques are rigidly transmitted through the closed-loop armrest handle structure 5 to the length adjustment mechanism 4 and angle adjustment mechanism 3, and finally to the universal unloading mechanism 2. Using the principles of spring energy absorption and damping energy dissipation, the disturbance forces and torques transmitted from the end of the manipulator arm are unloaded, thereby protecting the root joints of the space station's manipulator arm.

[0079] The above description of the embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A closed-loop handrail for on-track maintenance, characterized in that: The invention comprises a fixed clamping mechanism (1), a universal unloading mechanism (2), an angle adjustment mechanism (3), a length adjustment mechanism (4) and an armrest grip structure (5); the fixed clamping mechanism (1) can be reliably connected to the cabin structure of a spacecraft such as a space station, and provide a firm support for the force closed-loop armrest; the universal unloading mechanism (2) can be used to buffer and unload the instantaneous excessive impact force exerted by astronauts on the armrest grip; the angle adjustment mechanism (3) can realize the adjustment of the end armrest to any angle within the range of a semi-conical cone along the fixed support point; the length adjustment mechanism (4) has the functions of length adjustment and locking, so that the distance between the end armrest and the cabin wall armrest can be relatively changed; the armrest grip structure (5) is designed with a grip suitable for astronaut gloves to grip, and can provide grip for astronauts; The universal unloading mechanism (2) comprises a sleeve (21), a flexible clamp (22), a compression nut (23), a buffer butterfly spring (24), a hemispherical auxiliary rod (25), a slow-release washer (26), a hemispherical socket (27), an overload spring (28), a top ball (29), a rotating shaft (211) and an overload rod (212); The overload rod (212) is fixed to the sleeve (21) via a rotating shaft (211). The overload rod (212) is pin-connected to the sleeve (21) and can rotate around the rotating shaft (211). One end of the top ball (29) contacts the overload spring (28), and the other end presses on the arc surface of the side of the overload rod (212). The top ball (29) can move along the groove of the sleeve (21). The overload spring (28) provides a pre-tightening force for the overload rod (212) to be overloaded. The overload rod (212) is fastened to the flexible clamp (22) via a screw. One end of the sleeve (21) is designed with a plurality of interfaces connected to the overload rod (212) throughout its circumference, and the other end is designed with a flange with threaded holes connected to the cabin interface. A boss is designed inside the sleeve (21) to provide axial support for the buffer butterfly spring (24).

2. The closed-loop handrail for on-track maintenance according to claim 1, characterized in that: The fixing clamping mechanism (1) comprises a fixing clamp (11), a sliding sleeve (12), a ratchet (13), a cam handle (14), a fixing seat (15), a fixing clamp flexible pad (16), a movable clamp flexible pad (17), a movable clamp (18), a tension spring (19), an eccentric nail (111), a pawl (112), a pawl compression spring (113), a top screw (114), an auxiliary sliding rod (115), a pawl shaft (116) and a pull ring structure (181); The ratchet (13) and the fixing clamp (11) are fixed on the fixing seat (15), and the sliding sleeve (12) is fixed to the ratchet (13) using a top screw (114). The movable clamp (18) can slide along the sliding sleeve (12). The cam handle (14) is nested on the ratchet (13) and can rotate around the axis of the sliding sleeve (12). The pawl (112) is fixed to the cam handle (14) through a pawl shaft pin. A pawl compression spring (113) is installed between the pawl (112) and the cam handle (14). The eccentric nail (111) is fixed to the sliding sleeve (12). At the end of the sleeve (12), the tension spring rod is fixed on the movable clamp (18), and a tension spring (19) is used in the middle to provide the reset force of the movable clamp (18). The rear end of the movable clamp (18) is designed with a pull ring structure (181), and the fixed clamp (11) is installed with an auxiliary sliding rod (115). The plane part of the pull ring structure (181) can slide with the plane of the cam handle (14), and the side of the pull ring structure (181) can slide up and down along the auxiliary sliding rod (115), and the auxiliary sliding rod (115) is always in contact with the side of the pull ring structure (181).

3. The closed-loop handrail for on-track maintenance according to claim 1, characterized in that: The flexible clamp (22) has a certain elasticity along the axial direction. When a large overload force is generated in a direction perpendicular to the hemispherical auxiliary rod (25), the overload rod (212) in this direction will rotate to a certain angle. At the same time, under the pulling action of the flexible clamp (22), the overload rod (212) adjacent to the direction will also be deformed to a certain angle. The hemispherical socket structure on one side of the hemispherical socket seat (27) is connected to the ball end of the hemispherical auxiliary rod (25). The hemispherical socket seat (27) can rotate within a certain angle range relative to the hemispherical auxiliary rod (25). The other side of the hemispherical socket seat (27) has a tooth groove structure. The overload rod (212) is stuck in the tooth groove of the hemispherical socket seat (27). The shaft end of the hemispherical auxiliary rod (25) is designed with a threaded structure and is fixed with the clamping nut (23).

4. The closed-loop handrail for on-track maintenance according to claim 3, characterized in that: The auxiliary end of the hemispherical auxiliary rod (25) cooperates with the ball pair of the hemispherical socket (27), and the shaft end of the hemispherical auxiliary rod (25) is designed with a threaded structure and is fastened together with the clamping nut (23). The hemispherical auxiliary rod (25) can be made of, but not limited to, stainless steel quenching material; A plurality of series-parallel buffer butterfly springs (24) are located inside the sleeve (21), one end of which is connected to the inner boss of the sleeve (21) and the other end of which is connected to the clamping nut (23); The slow-release washer (26) is located between the bottom surface of the sleeve (21) and the hemispherical socket (27).

5. The closed-loop handrail for on-track maintenance according to claim 4, characterized in that: The angle adjustment mechanism (3) comprises a two-axis turntable (31) and a tooth-slot clamping mechanism (32), wherein the two-axis turntable (31) enables adjustment of the angle in any direction, and the tooth-slot clamping mechanism (32) enables locking and unlocking of angles at different lengths.

6. The closed-loop handrail for on-track maintenance according to claim 5, characterized in that: The length adjustment mechanism (4) comprises an outer rod (41), a bevel pin (42), an inner rod (43), a V-shaped block (44), a control rod (45), a bevel pin compression spring (46), a bevel pin seat (47), a fixing sleeve (48), a self-locking spring (49), a sliding latch (411), a fixing sleeve (412), a limit block (413), a button spring (414), an anti-drop clamp (415), a guide pin (416), a movable sleeve (417) and a button (418); The inner rod (43) is installed on the inner side of the outer rod (41), and the inner rod (43) and the outer rod (41) form a sliding fit. The side of the outer rod (41) is designed with a plurality of pin hole structures to facilitate the insertion and removal of the bevel pin (42); the bevel pin seat (47) is fixed to the end of the inner rod (43), and the bevel pin seat (47) is a rectangular inner cavity structure. The side surface of the rectangular inner cavity is in sliding fit with the V-shaped block (44), and the bottom surface of the rectangular inner cavity is in sliding fit with the bottom surface of the bevel pin (42). The bevel pin compression spring (46) is located between the two bevel pins (42), and the two side surfaces of the V-shaped block (44) are respectively in sliding fit with the bevels of the two bevel pins (42). The fixed sleeve (48) is installed at the end of the inner rod (43), and the inner rod (43) is fixedly connected to the fixed sleeve (412) through the guide pin (416). The movable sleeve (417) is designed with a sliding groove structure (4171) around it, which cooperates with the guide pin (416). The movable sleeve (417) can slide along the guide pin (416). The movable sleeve (417) is designed with a square groove structure (4172) to fix the limit block (413). The sliding pin (411) is designed with an axial end groove structure (4111), so that the sliding pin (411) and the movable sleeve (417) are fixed. A certain displacement can be generated without separation. The shaft end of the movable sleeve (417) is designed with a plurality of spiral tooth structures (4173), and the shaft end of the fixed sleeve (412) is designed with an incomplete spiral tooth structure (4121), a sliding groove structure (4122) and an arc-shaped chip groove structure (4123); the sliding card pin (411) is designed with a tooth surface structure (4112) that cooperates with the spiral tooth structure (4173) on the movable sleeve (417) and the incomplete spiral tooth structure (4121) on the fixed sleeve (412). One end of the self-locking spring (49) presses the sliding card pin (411), and the sliding card pin is locked. The boss structure (4113) on (411) is limited, and the other end presses the inner side of the fixed sleeve (48). The button (418) is fixed to one end of the movable sleeve (417). A hexagonal hole is designed on the button (418). One end of the button spring (414) presses the button (418) and the other end presses the fixed sleeve (412). One end of the control rod (45) is fixedly connected to the sliding pin (411), and the other end is designed with a circular boss structure and mechanically connected to the V-shaped block (44). The anti-slip clamp (415) is installed on the end face of the outer rod (41) to prevent the inner rod (43) from falling out of the outer rod (41).

7. The closed-loop handrail for on-track maintenance according to claim 6, characterized in that: The armrest handle structure (5) comprises an armrest handle (51), a latch (52), an armrest bottom plate (53) and an armrest side plate (54); The armrest bottom plate (53) is connected to the armrest grip (51) through the armrest side plates (54) on both sides. The armrest side plates (54) are designed with a latch (52). The latch (52) is an L-shaped structure as a whole. The portion connected to the anti-dropout switch is a hexagonal pyramid structure with a tapered surface. The short side structure (521) and the long side structure (522) are designed to effectively prevent mis-insertion. The tapered structure (523) can facilitate astronauts to complete the insertion operation.

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