Rigidity-adjustable fuel filling butt-joint locking mechanism

Abstract

The invention discloses a rigidity-adjustable fuel filling butt-joint locking mechanism which comprises a support, a filling connecting shaft and four locking mechanisms, the four locking mechanisms are fixed to the four side walls of the support respectively, and the filling connecting shaft is perpendicularly inserted into the support and located in the middles of the four locking mechanisms. The locking mechanism comprises a stepping motor, a worm, a worm gear, an elastic clamping mechanism and a four-bar mechanism, the stepping motor is connected with the worm, the worm and the worm gear are in meshing transmission, the elastic clamping mechanism comprises a base, a spring and a locking head, the four-bar mechanism is connected with the worm gear, an electromagnet is arranged on the base, a magnet is arranged in the locking head, and the spring is connected with the locking head. An annular groove is formed in the middle of the filling connecting shaft, and the radian of the front end of the locking head is the same as that of the annular groove. According to the butt-joint locking mechanism for fuel filling, when fuel conveying is conducted on different satellites, the fuel conveying mechanism can be locked and released, the butt-joint position can be adjusted and corrected, and the clamping phenomenon in the butt-joint process is prevented.

Description

Technical Field

[0001] The invention belongs to the technical field of on-orbit fuel filling, and in particular relates to a fuel filling docking locking mechanism with adjustable stiffness. Background Art

[0002] With the development of aerospace technology, the life requirements of high-value satellites and space stations are getting higher and higher. On-orbit fuel refueling can replenish satellites that have run out of fuel, significantly improve space exploration capabilities, reduce the size of carriers, and reduce mission costs. However, existing on-orbit fuel refueling docking structures generally have problems such as large docking impact force, lack of effective buffering mechanism, insufficient impact load dispersion ability, poor locking synchronization, and low fault tolerance. For example, the cone-rod docking mechanism relies on rigid guide rod capture, which is prone to stress concentration due to collision; the electromagnetic locking device has a complex structure and there is a risk of spring jamming; although some mechatronic interfaces are comprehensive in function, the processing cost is high and it is difficult to adapt to miniaturization and modular mission requirements. In addition, the existing technology relies heavily on the operating accuracy of the robotic arm, which limits the flexibility of on-orbit autonomous maintenance, so it needs to be further improved. Summary of the invention

[0003] To solve the above problems, the present invention discloses a fuel filling docking locking mechanism with adjustable stiffness, which can lock, release, adjust and correct the docking position of the fuel delivery mechanism when different satellites are transporting fuel, so as to prevent jamming during docking.

[0004] To achieve the above object, the technical solution of the present invention is as follows: A fuel filling docking locking mechanism with adjustable stiffness comprises a bracket, a filling connecting shaft and a locking mechanism. The bracket is a square structure. There are four locking mechanisms, which are respectively fixed on the four side walls of the bracket. The filling connecting shaft is vertically inserted into the bracket and is located in the middle of the four locking mechanisms. The locking mechanism comprises a stepping motor, a worm, a worm wheel, an elastic clamping mechanism, a connecting rod and a four-bar mechanism. The stepping motor is fixed on the inner wall of the bracket. The stepping motor is connected to the worm through a coupling. The worm and the worm wheel are meshed for transmission. The elastic clamping mechanism comprises a base, a spring and a locking head. The two ends of the spring are respectively connected to the base and the locking head. The four-bar mechanism is connected to the worm wheel. One end of the four-bar mechanism is sleeved on the coupling through a connecting rod, and the other end is connected to the base. The locking head is a free end. An electromagnet is provided on the base. A magnet is provided inside the locking head. The front end of the locking head is arc-shaped. An annular groove is provided in the middle of the filling connecting shaft. The front end of the locking head has the same arc as the annular groove.

[0005] As a supplement to the present invention, the stepper motor is fixed on the inner wall of the bracket through a motor bracket.

[0006] As a supplement to the present invention, the four-bar mechanism includes connecting rod one, connecting rod two, connecting rod three, and connecting rod four. The connecting rod is a T-shaped structure, one end of the connecting rod is sleeved on the coupling, the other end is connected to the worm gear, and the third end is connected to the connecting rod four. The connecting rod one is connected to the worm gear, and the connecting rod one, connecting rod two, connecting rod three, and connecting rod four are connected in sequence, and the base is fixed on the connecting rod three.

[0007] As a supplement to the present invention, a wear-resistant layer is provided on the surface of the locking head.

[0008] As a supplement to the present invention, the front end of the filling connecting shaft is provided with a chamfer.

[0009] As a supplement to the present invention, angle-changing edges are provided at the upper and lower ends of the annular groove.

[0010] The beneficial effects of the present invention are: (1) The present invention adopts a locking mechanism with adjustable stiffness, combined with the buffering function of the elastic component, which can effectively disperse the impact force during the docking process, avoid stress concentration, and achieve large tolerance passive compliance.

[0011] (2) The locking mechanism can quickly lock and release the interface by compressing the flexible component, with low system delay and high operating efficiency.

[0012] (3) The locking mechanism can realize adaptive and manual position correction, implement limit protection, prevent jamming, ensure a smooth docking process, reduce satellite docking accuracy requirements, and have high reliability.

[0013] (4) The present invention has a simple structure and can reduce processing and procurement costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0015] Figure 2 It is a front structural schematic diagram of the locking mechanism in an embodiment of the present invention.

[0016] Figure 3 It is a schematic diagram of the reverse structure of the locking mechanism in the embodiment of the present invention.

[0017] Figure 4 It is a structural schematic diagram of the mechanism insertion used in the embodiment of the present invention.

[0018] Figure 5 It is a schematic diagram of the structure of the mechanism used in the embodiment of the present invention when locked.

[0019] Figure 6 It is a schematic diagram of the structure of the electromagnet after being energized in an embodiment of the present invention.

[0020] Figure 7 It is a schematic diagram of the structure of adjusting the locking position downward according to an embodiment of the present invention.

[0021] Figure 8 It is a schematic diagram of the structure of adjusting the locking position upward according to an embodiment of the present invention.

[0022] Fig. 9 It is a schematic diagram of the angle change edge described in the present invention.

[0023] Fig.10 Schematic diagram of stress analysis of the filling mechanism in the embodiment of the present invention.

[0024] List of Figure Symbols: 1. Bracket, 2. Filling connecting shaft, 3. Locking mechanism, 4. Motor bracket, 5. Connecting rod, 6. Worm, 7. Worm wheel, 8. Connecting rod one, 9. Connecting rod two, 10. Locking head, 11. Spring, 12. Stepper motor, 13. Connecting rod four, 15. Magnet, 16. Electromagnet, 17. Connecting rod three, 18. Base, 19. Coupling, 20. Annular groove, 21. Chamfer, 22. Angle changing edge. DETAILED DESCRIPTION

[0025] The present invention will be further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0026] As shown in the figure, the fuel filling docking locking mechanism with adjustable stiffness described in the present invention includes a bracket 1, which fixes the locking mechanism 3 in the docking channel and is installed on the target spacecraft; the filling connecting shaft 2 is used for fuel delivery and is installed on the service spacecraft; there are four locking mechanisms 3, which realize the locking function through the locking head 10 and the spring 11, one end of the spring 11 is fixed on the locking head 10, and the other end is fixed on the base 18; the stepper motor 12 is fixed to the bracket 1 through the motor bracket 4; the stepper motor 12 rotates to control the meshing of the worm 6 and the worm wheel 7 to transmit the staggered axis power, so that the four connecting rods 5, the connecting rod 1 8, the connecting rod 2 9 and the connecting rod 3 17 are formed. The rod mechanism rotates, and the connecting rod 5 is installed on the rotating shaft of the stepping motor 12, and is integrally connected with the base 18 through the connecting rod four 13. The rotation of the worm gear 7 drives the connecting rod one 8 to rotate, and the rotation of the connecting rod one 8 drives the connecting rod two 9 to swing. The connecting rod two 9 will drive the base 18 to move back and forth, realizing reciprocating motion within a certain range, and realizing an adjustable correction locking position; the electromagnet 16 is installed on the base 18, and the magnet 15 is installed in the locking head 10. When the electromagnet 16 is energized, the magnet 15 will be attracted, and the compression spring 11 will be released. After the electromagnet 16 stops energizing, the spring will be released, so that the spring 11 returns to its original length for locking. This design facilitates manual control of the docking and plugging process.

[0027] The process of using the device to lock is as follows: the filling connection shaft 2 enters the docking channel, first squeezes the locking head 10, the spring 11 is compressed, and when the locking head 10 contacts the annular groove 20 area of ​​the filling connection shaft 2, the spring 11 extends to achieve locking. After the fuel filling is completed, the electromagnet 16 is energized to attract the magnet installed on the locking head 10 to compress the spring 11 and release the lock (to avoid the possible jamming caused by the contact between the locking head 10 and the filling connection shaft 2). After the filling connection shaft 2 is pulled out, the power supply to the electromagnet 16 is stopped, the attraction disappears, and the spring 11 returns to its original length.

[0028] If the locking position is incorrect during the docking process, the stepper motor 12 can be used to rotate the control link 3 17 to swing up and down, and the locking position can be adjusted to achieve controllable manual calibration.

[0029] Figure 1 During the on-track filling and docking process, the filling connecting shaft 2 is sent to the upper position of the locking mechanism 3 in the predetermined docking channel by the mechanical arm, and the four docking locking mechanisms 3 are fixed on the bracket 1 respectively.

[0030] Figure 2 It is a front structural diagram of the locking mechanism in the embodiment of the present invention. The two ends of the spring 11 are respectively fixed on the locking head 10 and the base 18; the stepper motor 12 is fixed on the bracket 1 through the motor bracket 4, and the connecting rod 5 is installed on the rotating shaft of the stepper motor 12, and is connected to the base 18 through the connecting rod 3 17; the stepper motor 12 rotates to control the worm 6 and the worm wheel 7 to mesh and transmit, the worm wheel 7 rotates to drive the connecting rod 1 8 to rotate, the connecting rod 1 8 rotates to drive the connecting rod 2 9 to swing, and the connecting rod 2 9 drives the connecting rod 3 17 to move back and forth, so that the four-bar mechanism composed of the connecting rod 5, the connecting rod 1 8, the connecting rod 2 9 and the connecting rod 3 17 can achieve a certain range of back and forth reciprocating motion, and the locking head 10 can swing up and down within a certain range, so as to achieve an adjustable and correct locking position within a certain range.

[0031] Figure 3 It is a schematic diagram of the reverse structure of the locking mechanism in the embodiment of the present invention. The electromagnet 16 is mounted on the base 18, and the magnet 15 is mounted on the locking head 10. When the electromagnet 16 is energized, the magnet 15 is attracted, and the spring 11 is compressed so that the locking head 10 and the filling connecting shaft 2 are out of contact. When the electromagnet 16 stops energizing, the spring 11 is released, so that the spring 11 returns to its original length and contacts the filling connecting shaft 2 to achieve locking.

[0032] Figure 4 The front end of the filling connection shaft 2 is provided with a chamfer 21, which is convenient for inserting into the hole above the bracket 1. The filling connection shaft 2 enters the docking channel, and the locking head 10 is first squeezed during the downward docking process, so that the spring 11 is compressed.

[0033] Figure 5 It is a schematic diagram of the structure of the locking mechanism used in the embodiment of the present invention. When the filling connection shaft 2 continues to move downward and the locking head 10 contacts the groove area of ​​the filling connection shaft 2, the spring 11 is extended, and the filling connection shaft stops moving downward, so that the four locking heads 10 are vertically attached to the annular groove 20 to achieve locking.

[0034] Figure 6 It is a schematic diagram of the structure of the electromagnet after power is supplied to the embodiment of the present invention. In order to reduce the wear of the locking head 10 and increase the stability of the plugging and unplugging process, the electromagnet 16 is powered on after the oil delivery is completed, and the magnet installed on the locking head 10 is attracted to compress the spring 11, and the locking is released to avoid the contact between the locking head 10 and the filling connecting shaft 2. After the filling connecting shaft 2 is pulled out, the power supply to the electromagnet 16 is stopped, and the attraction disappears and the spring 11 returns to its original length. In addition, a wear-resistant layer is plated on the surface of the locking head 10 to extend the service life.

[0035] Figure 7 It is a schematic diagram of the structure of adjusting the locking position downward in an embodiment of the present invention.

[0036] Figure 8 It is a schematic diagram of the structure of adjusting the locking position upward according to an embodiment of the present invention.

[0037] Fig. 9 This is a schematic diagram of the angle changing edge of the present invention. Because there may be disturbances during the actual filling process, which may cause individual locking heads 10 to separate from the annular groove 20 or be staggered in position, in order to overcome this problem, angle changing edges 22 are provided at the upper and lower ends of the annular groove (the arc of the upper and lower parts is larger, and the arc of the middle part is smaller), so that the locking head 10 is not easy to be ejected. Even if there is a little disturbance, it will return to the annular groove 20 between the upper and lower angle changing edges 22 after shaking. The upper and lower angle changing edges 22 play a limiting role.

[0038] Fig.10 It is a schematic diagram of stress analysis of the filling mechanism of the embodiment of the present invention. In the stress analysis, the material of the filling connection shaft 2 is 6061 composite aluminum alloy, the fixed position is the end of the filling connection shaft 2, and the groove of the filling connection shaft 2 has a force of 10N in four directions. The results show that the stress distribution is concentrated in the annular groove 20 area of ​​the filling connection shaft, which is the contact area between the locking head 11 and the filling connection shaft 2, and can achieve a good locking function; the stress in this contact area is less than the yield stress of the material, which can effectively prevent fatigue fracture in the groove area.

[0039] It should be noted that the above content only illustrates the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. For ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made. For example, the bracket can be changed into a cylindrical structure, and four docking locking mechanisms 3 can be fixed. These improvements and modifications all fall within the protection scope of the claims of the present invention.

Claims

1. A fuel filling docking locking mechanism with adjustable stiffness, characterized in that: The invention comprises a bracket (1), a filling connection shaft (2), and a locking mechanism (3); the bracket (1) is a square structure; the number of the locking mechanisms (3) is four and they are fixed on the four side walls of the bracket (1), respectively; the filling connection shaft (2) is vertically inserted into the bracket (1) and is located in the middle of the four locking mechanisms (3); the locking mechanism (3) comprises a stepping motor (12), a worm (6), a worm wheel (7), an elastic clamping mechanism, a connecting rod (5) and a four-bar mechanism; the stepping motor (12) is fixed on the inner wall of the bracket (1); the stepping motor (12) is connected to the worm (6) via a coupling (19); the worm (6) and the worm wheel (7) are meshed for transmission; the elastic clamping mechanism is a connecting rod (5) and a four-bar mechanism; The clamping mechanism comprises a base (18), a spring (11) and a locking head (10), the two ends of the spring (11) being respectively connected to the base (18) and the locking head (10), the four-bar mechanism being connected to the worm gear (7), one end of the four-bar mechanism being sleeved on a coupling (19) through a connecting rod (5), and the other end being connected to the base (18), the locking head (10) being a free end, an electromagnet (15) being provided on the base (18), a magnet (16) being provided inside the locking head (10), the front end of the locking head (10) being arc-shaped, the middle part of the filling connection shaft (2) being provided with an annular groove (20), the front end of the locking head (10) and the annular groove (20) having the same arc.

2. A fuel filling docking locking mechanism with adjustable stiffness according to claim 1, characterized in that: The stepper motor (12) is fixed to the inner wall of the bracket (1) via a motor bracket (4).

3. The fuel filling docking locking mechanism with adjustable stiffness according to claim 1, characterized in that: The four-bar mechanism comprises a connecting rod 1 (8), a connecting rod 2 (9), a connecting rod 3 (17), and a connecting rod 4 (13); the connecting rod (5) is a T-shaped structure; one end of the connecting rod (5) is sleeved on a coupling (19), the other end is connected to a worm gear (7), and the third end is connected to the connecting rod 4 (13); the connecting rod 1 (8) is connected to the worm gear (7), the connecting rod 1 (8), the connecting rod 2 (9), the connecting rod 3 (17), and the connecting rod 4 (13) are connected in sequence, and the base (18) is fixed on the connecting rod 3 (17).

4. A fuel filling docking locking mechanism with adjustable stiffness according to claim 1, characterized in that: The surface of the locking head (10) is provided with a wear-resistant layer.

5. The fuel filling docking locking mechanism with adjustable stiffness according to claim 1, characterized in that: The front end of the filling connection shaft (2) is provided with a chamfer (21).

6. The fuel filling docking locking mechanism with adjustable stiffness according to claim 1, characterized in that: Angle-changing edges (22) are provided at the upper and lower ends of the annular groove (20).

7. The working process of the fuel filling docking locking mechanism with adjustable stiffness according to claim 1 is characterized in that: The filling connection shaft (2) vertically enters the docking channel in the bracket (1), first squeezing the locking head (10) to compress the spring (11). When the locking head (10) contacts the annular groove (20) area of ​​the filling connection shaft (2), the spring (11) extends to achieve locking and start fuel filling. After the fuel filling is completed, the electromagnet (16) is energized to attract the magnet (15) installed on the locking head (10) to compress the spring (11) and release the lock. After the filling connection shaft (2) is pulled away, the power supply to the electromagnet (16) is stopped, the attraction disappears and the spring (11) returns to its original length. If the locking position is incorrect during the docking process, the stepper motor (12) is used to rotate the control link rod (17) to swing up and down, and the locking position is adjusted to achieve controllable manual calibration.

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