Rectangular self-floating connector for space use

Abstract

The present invention discloses a rectangular self-floating connector for space use, comprising a housing and a floating horn-shaped interface. The horn-shaped interface has six degrees of freedom relative to the housing: floating in the X-axis, floating in the Y-axis, floating in the Z-axis, and rotating in the α-axis, β-axis, and γ-axis. Δα, Δβ, and Δγ are ≥ ±0.5°, ΔX, ΔY, and ΔZ, respectively, and are ≥ 2.29 mm, 1.27 mm, and 2.03 mm, respectively. This connector can be used on spacecraft. In space environments, when misalignment between the plug and socket occurs, its guide structure compensates for this misalignment, ensuring proper mating between the plug and socket.

Description

Technical Field

[0001] The invention relates to a floating electrical connector. Background Art

[0002] In 2013, the applicant developed a freely floating electrical connector. The specific structure can be found in Chinese patent CN103633492B. This connector can achieve floating in six degrees of freedom and can complete the connection even when the docking is not very precise. Now it is necessary to apply this structure to spacecraft. In space, the docking of connectors is completed by a manipulator, and the manipulator can only move according to the fixed trajectory set by the program. When the position error of the two connectors is large, the manipulator will cause damage when forcibly docking. In addition, there are long-term mechanical environments such as vibration and impact on the aircraft. The product is in a free motion state relative to the floating installation mechanism, which is prone to violent shaking and collision, resulting in product damage and failure. Therefore, the cooperation of the two connectors is required to allow for greater floating. Therefore, the existing structure needs to be optimized and designed to meet the greater floating requirements. In addition, the original structure also has the problem of loose nuts connected to the lower section of the limit column. Summary of the Invention

[0003] The technical problems to be solved by the present invention are: the problem that the floating range of the existing floating connector is insufficient and the problem that the connector limiting column nut is loose.

[0004] The technical solution of the present invention is:

[0005] A rectangular self-floating connector for space use comprises a housing and a floating trumpet-shaped interface. The trumpet-shaped interface has six degrees of freedom relative to the housing: floating in the X direction, floating in the Y direction, floating in the Z direction, rotating in the α direction, rotating in the β direction, and rotating in the γ direction. Δα, Δβ, and Δγ are specified, and ΔX, ΔY, and ΔZ are specified.

[0006] A fixing plate is installed in the cover through a flat spring, coil springs are installed in the countersunk holes at both ends of the fixing plate, and limit columns are installed at both ends of the flange of the trumpet-shaped interface. The middle section of the limit column cooperates with the coil spring, and the lower section of the limit column is connected with a nut. There is a fixing nail assembly hole on the side of the nut. The fixing nail is screwed into the fixing nail assembly hole to support the limit column.

[0007] The inclination angle of the trumpet opening of the trumpet interface is 30°.

[0008] When the trumpet-shaped interface moves in the X direction relative to the cover, the limit column first reaches its limit displacement and hits the stopper directly below it. The size of the limit column is 16.1 mm. When the flat spring is not compressed, the distance between the limit column and the stopper is greater than ΔX, which is 3.1 mm.

[0009] When the trumpet-shaped interface moves relative to the cover in the Y direction, the tail end of the trumpet-shaped interface shell first reaches the limit displacement and hits the baffle inside the cover. The distance between the tail end of the trumpet-shaped interface shell and the baffle in the Y direction is greater than ΔY, which is 2.15 mm.

[0010] When the trumpet-shaped interface moves in the Z direction relative to the cover, the coil spring first reaches the limit compression position and sticks to itself. The distance between the side edge of the trumpet-shaped interface shell flange and the cover is greater than the distance the coil spring needs to move to stick to itself, which is 2.95mm; the distance the coil spring needs to move to stick to itself is greater than ΔZ, which is 2.7mm.

[0011] The maximum rotation angle of the trumpet-shaped interface housing around the X-axis is 9°.

[0012] The maximum rotation angle of the trumpet-shaped interface housing around the Y axis is 2.2°.

[0013] The maximum rotation angle of the trumpet-shaped interface housing around the Z axis is 1.6°.

[0014] The flat spring has an initial deformation during assembly, and the reaction force generated by the initial deformation is greater than the maximum plugging force of the connector.

[0015] The semicircular raised portion at the top of the flat spring is processed into a curved cylinder.

[0016] Beneficial effects of the present invention:

[0017] This product can be used on spacecraft. In space, connector docking is performed by a robotic arm. The product operates in a harsh environment, often characterized by vibration, extreme cold, and extreme heat. Therefore, very high tolerances are imposed on the allowable docking errors. This product must meet alignment requirements of Δα ≥ ±0.5°, Δβ ≥ ±0.5°, Δγ ≥ ±0.5°, ΔX ≥ 2.29mm (overtravel), ΔY ≥ 1.27mm, and ΔZ ≥ 2.03mm. This means that when these misalignments occur between the plug and receptacle, the guide structure of this product must compensate for them, ensuring proper docking.

[0018] In order to facilitate the floating guidance of the product, reduce the friction and wear of the shell during the guidance process and reduce the friction reaction force, and meet the functional requirements of long product life and self-floating, it is necessary to reasonably design the bell-mouth guide angle at the same time, and the optimal angle is 30°.

[0019] After adjusting the position of the nut and the limit column, screw the fixing nail into the limit column to prevent the nut from loosening or falling off the limit column. The semicircular raised part at the top of the flat spring is processed into a curved cylinder to reduce the resistance in the β direction during floating and make the rotation smoother. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1Schematic diagram of the degrees of freedom of this structure.

[0021] Figure 2 This is a schematic diagram of the trumpet-shaped interface angle.

[0022] Figure 3 Schematic diagram for the design of X-axis degree of freedom dimensions.

[0023] Figure 4 Schematic diagram of the limiting column structure.

[0024] Figure 5 Schematic diagram of the nut structure.

[0025] Figure 6 Schematic diagram of the Y-degree of freedom dimension design.

[0026] Figure 7 Schematic diagram of the maximum compression position of the coil spring.

[0027] Figure 8 Schematic diagram of Z-axis freedom dimension design.

[0028] Figure 9 Schematic diagram for the design of the α-axis rotational freedom.

[0029] Figure 10 It is a β-rotation analysis model.

[0030] Figure 11 is the distribution diagram of β-direction rotational displacement obtained by simulation.

[0031] Figure 12 It is a γ-axis rotation analysis model.

[0032] Figure 13 This is the distribution diagram of the γ-axis rotational displacement obtained by simulation.

[0033] Figure 14 It is a structural diagram of a flat spring. DETAILED DESCRIPTION

[0034] Example 1:

[0035] Compared to the prior art (Chinese patent CN103633492B), the connector structure in this embodiment only adds a limit pin on the side of the nut at the lower end of the limit pin to hold the limit pin in place. A fixed plate is mounted inside the housing via a flat spring, and coil springs are installed in the countersunk holes at both ends of the fixed plate. The limit pins are installed at both ends of the flange of the trumpet-shaped interface. The middle section of the limit pin cooperates with the coil spring, and the lower section of the limit pin is connected to the nut. The side of the nut has a fixed pin assembly hole. The fixed pin is screwed into the fixed pin assembly hole to hold the limit pin in place. The flat spring is used to achieve automatic reset for X-direction floating, β-direction rotation, and γ-direction rotation. The coil spring inside the mechanism is used to achieve automatic reset for Y-direction floating, Z-direction floating, and α-direction rotation, thereby achieving automatic reset in six directions.

[0036] The preloaded spring's spring force should be higher than the force exerted when the plug and socket are engaged. This ensures that the plug and socket are properly mated before the overtravel function is achieved. Therefore, the flat spring's assembly preload should be designed based on the product's mating force. Comprehensive stress analysis should be conducted during the modeling process to design a reasonable safety margin. The semicircular protrusion at the top of the flat spring is machined into a curved cylinder to reduce resistance in the β direction during floating, ensuring smoother rotation.

[0037] The flat spring supports the socket housing in the alignment and inter-mating mechanism. During the connector mating process, the flat spring should be able to overcome the mating force generated by the contacts engaging the plug and socket until the header housings are properly mated and the contacts are engaged. Once the housings are properly mated, continued mating force applied in the mating direction will compress and deform the flat spring, thereby achieving the overtravel misalignment requirement. Therefore, the flat spring should have an initial deformation x during assembly, and the reaction force generated by this initial deformation should be greater than the maximum mating force requirement of the connector.

[0038] like Figure 1 , this connection needs to meet the floating requirements in six degrees of freedom: Δα≥±0.5°, Δβ≥±0.5°, Δγ≥±0.5°, ΔX≥2.29mm, ΔY≥1.27mm, ΔZ≥2.03mm. In order to facilitate the floating guide of the product, reduce the friction and wear of the shell during the guide process and reduce the friction reaction force, and meet the functional requirements of long product life and self-floating, it is necessary to reasonably design the guide angle at the same time. The optimal angle is 30° (see Figure 2 , that is, the bell mouth angle is 60°).

[0039] 1) Overtravel (ΔX) design

[0040] The overtravel (ΔX) is the maximum displacement of the socket shell relative to the cover in the opposite direction of X. As can be seen from the structure of this product, the overtravel (ΔX) is determined by the length of the limit column. Figure 3 It can be seen that when the size of the limit column is controlled at 16.1mm, the distance between the limit column and the stop block is 3.1mm in the initial state (the flat spring is not compressed), which is the maximum displacement of the socket shell in the opposite direction of X. This displacement is the overtravel of the inter-insertion device, which meets the product technical indicator requirement of ΔX≥2.29mm.

[0041] The structure of the limiting column is as follows Figure 4, divided into three sections: upper, middle and lower. The upper thread 1 is fixed with the mounting hole of the socket shell; the middle section 2 is matched with the center hole of the coil spring; the lower thread 3 is matched with the nut. The gap between the shell and the nut is adjusted by adjusting the screwing length of the nut. A certain gap is required to ensure that the baffle is not clamped and can float; in the initial state, there is a distance of 3.4mm between the bottom surface 4 of the limit column and the lower block, that is, the product's movement limit in the X direction is 3.4mm, which exceeds the requirement of overtravel ΔX=2.29mm.

[0042] The structure of the nut is as follows Figure 5 In addition to the screw hole in the center for cooperating with the limit column, a fixing nail assembly hole is also opened on the side. After the nut and the limit column are adjusted to the position, the fixing nail is screwed into the fixing nail assembly hole to support the limit column.

[0043] 2) Y-axis alignment difference (ΔY) design

[0044] The misalignment in the Y direction (ΔY) is related to two factors: the floating distance of the coil spring itself and the distance between the end of the socket housing and the baffle in the Y direction. The smaller of the two distances is the magnitude of the misalignment in the Y direction. Figure 8 As shown, it is 2.15mm, which meets the product technical indicator requirement of ΔY≥1.27mm.

[0045] The outer and inner diameters of the coil spring are given by the dimensions of the baffle and the limit post. If the thickness of the coil spring is designed to be 0.4 mm, the distance the coil spring needs to move to keep itself in contact is approximately 2.7 mm according to simulation analysis.

[0046] 3) Z-direction alignment difference (ΔZ) design

[0047] The misalignment in the Z direction (ΔZ), i.e., along the width of the connector's rectangular cross-section, is also related to two factors. One is the floating distance of the coil spring itself, which is exactly the same as in the Y direction. The other is the distance from the side edge of the socket housing flange to the cover in the Z direction. The smaller of these two distances is the magnitude of the misalignment in the Y direction. The distance from the side edge of the socket housing flange to the cover in the Z direction is shown in Figure 7 As shown, it is 2.95mm, which exceeds the 2.7mm distance that the coil spring needs to move to keep itself in close contact, that is, the actual ΔZ = 2.7mm. The design size meets the product technical indicator requirement of ΔZ ≥ 2.03mm.

[0048] 4) Alignment error (Δα) design

[0049] The alignment difference (Δα) in the α direction, i.e., the rotation around the connector axis, is achieved by the coil spring. When the two ends of the socket housing flange move in the two directions of the Z axis, the rotation in the α direction is achieved. The rotation in the α direction is limited by the compression movement distance of the coil spring. When ΔX ≥ 2.29 mm, ΔY ≥ 1.27 mm, and ΔZ ≥ 2.03 mm are satisfied, the simplified motion trajectory is shown in FIG. Figure 9 As shown, when the center of the socket flange mounting hole can only move within the circle with a radius of 2.7mm as shown in the figure, it can be seen that the maximum angle of rotation of the socket housing around the X-axis (α direction) is 9°, which meets the product technical indicator requirement of Δα≥±0.5°.

[0050] 5) β-alignment error (Δβ) design

[0051] The alignment difference (Δβ) in the β direction, i.e., the rotation around the Y direction (the length direction of the rectangular cross section of the connector), is achieved by the flat spring. When the compression amounts of the two flat springs are inconsistent, rotation may occur until the edge of the baffle contacts the inner cavity of the housing and is locked, thus establishing a Figure 10 In the simulation analysis model shown, the external components are fixed and a 1 N·m torque is applied to the axis in the middle of the baffle. Because the entire structure needs to be compressed downward during rotation, the vertical displacement of the middle part is not restricted. When the XYZ three-axis floating capacity is met, that is, when the above dimensions are met, the final displacement distribution is as follows: Figure 11 By comparison, the displacement difference between the two points marked in the figure is 0.33mm. Since half the baffle width is 8.5mm, the rotation angle is arcsin(0.33 / 8.5) = 2.2°. This means that the actual achievable β-alignment error is Δβ = ±2.2°, meeting the product's technical specification requirement of Δβ ≥ ±0.5°.

[0052] 6) Design of γ-alignment error (Δγ)

[0053] The alignment difference (Δγ) in the γ direction, i.e., the rotation around the Z direction (the width direction of the connector's rectangular cross section), is also achieved by the flat spring. Since the middle of the flat spring contacts the baffle with a circular surface, the baffle can deflect within a limited range. The rotation limit position is when the edge of the baffle contacts the step of the housing. Figure 12 In the simulation analysis model shown, the external components are fixed and a 1 N·m torque is applied to the axis in the middle of the baffle. Because the entire structure needs to be compressed downward during rotation, the vertical displacement of the middle part is not restricted. When the XYZ three-axis floating capacity is met, that is, when the above dimensions are met, the final displacement distribution is as follows: Figure 13 The displacement on the lower edge of the limit position is about 1mm. Half the baffle length is 35mm, so the rotation angle is arcsin(1 / 35) = 1.6°. This means that the actual achievable γ-alignment error is Δγ = ±1.6°, meeting the product's technical specification requirement of Δγ ≥ ±0.5°.

Claims

1. A rectangular self-floating connector for space use, comprising a housing and a floating trumpet-shaped interface, characterized in that: The trumpet-shaped interface has six degrees of freedom relative to the housing: X-direction floating, Y-direction floating, Z-direction floating, α-direction rotation, β-direction rotation, and γ-direction rotation, and Δα≥±0.5°, Δβ≥±0.5°, Δγ≥±0.5°, ΔX≥2.29mm, ΔY≥1.27mm, ΔZ≥2.03mm. A fixed plate is installed in the housing through a flat spring, and coil springs are installed in the countersunk holes at both ends of the fixed plate. Limiting columns are installed at both ends of the flange of the trumpet-shaped interface, the middle section of the limiting column cooperates with the coil spring, the lower section of the limiting column is connected to a nut, and there is a fixing nail assembly hole on the side of the nut. After the fixing pin is screwed into the fixing pin assembly hole, it presses against the limit column. The inclination angle of the trumpet opening of the trumpet interface is 30°. When the trumpet interface moves in the X direction relative to the cover, the limit column first reaches the limit displacement and hits the stopper directly below it. The size of the limit column is 16.1mm. When the flat spring is not compressed, the distance between the limit column and the stopper directly below it is greater than ΔX, which is 3.1mm; the flat spring has an initial deformation during assembly, and the reaction force generated by the initial deformation is greater than the maximum insertion force of the connector. The semicircular protrusion at the top of the flat spring is processed into a curved cylinder.

2. The rectangular self-floating connector for space use according to claim 1, characterized in that: When the trumpet-shaped interface moves relative to the housing in the Y direction, the tail end of the trumpet-shaped interface shell first reaches the limit displacement and hits the baffle inside the housing. The distance between the tail end of the trumpet-shaped interface shell and the baffle is greater than ΔY, which is 2.15 mm.

3. The rectangular self-floating connector for space use according to claim 2, characterized in that: When the trumpet-shaped interface moves in the Z direction relative to the cover, the coil spring first reaches the limit compression position and sticks to itself. The distance between the side edge of the trumpet-shaped interface shell flange and the cover is greater than the distance the coil spring needs to move to stick to itself, which is 2.95mm; the distance the coil spring needs to move to stick to itself is greater than ΔZ, which is 2.7mm.

4. The rectangular self-floating connector for space use according to claim 3, characterized in that: The maximum rotation angle of the trumpet-shaped interface housing around the X-axis is 9°.

5. The rectangular self-floating connector for space use according to claim 4, characterized in that: The maximum angle of rotation of the trumpet-shaped interface housing around the Y axis is 2.2°, and the maximum angle of rotation of the trumpet-shaped interface housing around the Z axis is 1.6°.

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