High-reliability memory alloy unlocking device

Abstract

The invention discloses a high-reliability memory alloy unlocking device, and relates to the technical field of spacecraft separation unlocking devices, in particular to a high-reliability memory alloy unlocking device which comprises a lower seat body and a shell arranged on the lower seat body, a guide hole is formed in the shell, and a separation sleeve is arranged in the guide hole; a separation cavity is formed in the separation sleeve, a separation pin is movably arranged in the separation cavity, and the separation pin is connected with the shell in a sliding mode; a second unlocking device for locking the separation pin is arranged in the separation cavity, and when the separation sleeve moves to the unlocking position towards the lower seat body, the second unlocking device is unlocked; a sliding groove is formed in the lower seat body, a first unlocking device is arranged in the sliding groove, and the first unlocking device comprises a release plate and a memory alloy wire which are arranged in the sliding groove in a sliding mode; according to the two-stage unlocking mechanism with the memory alloy deformation force as drive, the memory alloy serves as driving force, influences of electromagnetic interference and the like are completely avoided, and the space application reliability is high.

Description

Technical Field

[0001] This invention relates to the technical field of spacecraft separation and unlocking devices, specifically to a high-reliability shape memory alloy unlocker. Background Technology

[0002] With the development of space network construction and commercial spaceflight, the demand for shape memory alloy unlockers has surged. Compared to traditional pyrotechnic unlocking devices, shape memory alloy unlockers offer lower unlocking impact. This effectively reduces the impact of space payload release and deployment on celestial bodies, makes it easier to correct the attitude of celestial bodies, and minimizes the impact on other payloads.

[0003] Shape memory alloys, or SMAs for short, possess properties derived from the inverse transformation of their austenite and martensite crystal structures. When shaped into a specific form at a particular temperature, the shape memory alloy returns to its original shape once the temperature reaches a preset point. Based on these deformation characteristics, they can generate power, and there are numerous successful applications in the aerospace field.

[0004] Existing patent CN111453001B discloses a shape memory alloy spring-driven connection and unlocking mechanism. This mechanism includes an upper connecting plate, a lower connecting plate, a threaded component, a lower cover plate, an upper cover plate, a locking device, a locking ball ring, four steel balls, a drive spring, a shape memory alloy spring, and a split nut. While it uses four steel balls for positioning, providing a certain degree of reliability, both the locking device and the locking ball ring are thin-walled components. Under high load conditions, they may deform, failing to tighten the split nut and causing locking failure. Furthermore, the entire device is difficult to assemble.

[0005] Other cases also primarily involve the use of release nuts, and these are mostly single-stage unlocking mechanisms. Due to the complex mechanical environment of the spacecraft during launch and orbit insertion, including shocks and vibrations, reliability is often low. Summary of the Invention

[0006] To improve the mechanical resistance and reliability of shape memory alloy unlockers, this invention aims to provide a highly reliable shape memory alloy unlocker that exhibits high reliability, high mechanical stability, small size, and high holding torque.

[0007] The present invention provides a high-reliability memory alloy unlocker, comprising a lower base and a housing disposed on the lower base. The housing has a guide hole and a release sleeve disposed in the guide hole. The release sleeve is connected to the end of the housing away from the lower base through an elastic reset structure. The release sleeve is provided with a release chamber, and a separation pin is movably disposed in the release chamber. The end of the separation pin away from the lower seat passes through the housing and extends out, and the separation pin is slidably connected to the housing. The release chamber is equipped with a second unlocking device for locking the release pin. When the release sleeve moves toward the lower seat to the unlocking position, the second unlocking device unlocks. The lower seat body is provided with a slide groove, and a first unlocking device is provided in the slide groove. The first unlocking device includes a release plate and a shape memory alloy wire that are slidably disposed in the slide groove. One end of the shape memory alloy wire is fixedly connected to the release plate, and the other end of the shape memory alloy wire passes around the wire guide wheel and is fixedly connected to the inner wall of the slide groove. An aviation plug is also connected to the shape memory alloy wire. The release plate is fixedly provided with a limiting protrusion for locking the release sleeve vertically downward. The limiting protrusion extends into the guide hole and connects with the release sleeve. When the shape memory alloy wire is energized and deformed, it pulls the release plate, and the limiting protrusion disengages from the release sleeve, thus unlocking the first unlocking device.

[0008] Preferably, the elastic reset structure includes a release sleeve reset spring, a limiting ring is provided on the release sleeve, the release sleeve reset spring is sleeved on the release sleeve, one end of the release sleeve reset spring abuts against the limiting ring, and the other end of the release sleeve reset spring abuts against the end of the housing away from the lower seat.

[0009] Preferably, there are two memory alloy wires and two guide wheels. The guide wheels are rotatably connected to the lower body via pins. One end of each of the two memory alloy wires is connected to the same end of the release plate, and the other end is fixedly connected to the corresponding inner wall of the slide groove. The two guide wheels are located on the same side of the housing, and both memory alloy wires are connected to the aviation socket.

[0010] Preferably, a reset device is also provided on the lower seat body. The reset device includes a reset rod and a release plate reset spring. One end of the release plate connected to the shape memory alloy wire is connected to the lower seat body through the release plate reset spring. When the first unlocking device unlocks, the release plate reset spring is in a compressed state; The reset rod is fixedly connected to the end of the release plate away from the shape memory alloy wire, and the end of the reset rod away from the release plate extends out from the lower body.

[0011] Preferably, the housing is further provided with an annular spring cover plate for preventing the release sleeve from coming out of the guide hole. The spring cover plate is provided at one end of the guide hole near the lower seat body, and the inner diameter of the spring cover plate is smaller than the outer diameter of the release sleeve.

[0012] Preferably, an annular seat cover plate is also fixedly provided on the lower seat body, and the shell is fixedly connected to the seat cover plate.

[0013] Preferably, the second unlocking device includes a rack and a transmission gear located in the release chamber. The rack is vertically arranged and fixedly connected to the release sleeve. The transmission gear is connected to the housing through a gear fixing seat and is mounted on the gear fixing seat through a pin. The transmission gear is meshed with the rack. An eccentric wheel is fixed and eccentrically connected to the transmission gear. The eccentric wheel is located on one side of the separating pin. A limiting groove is provided on the circumferential surface of the separating pin, and the limiting groove is correspondingly provided to the eccentric wheel. As the transmission gear rotates, the eccentric wheel extends into the limiting groove; As the release sleeve moves toward the lower seat, the rack drives the transmission gear to rotate, and the eccentric wheel disengages from the limiting groove, releasing the second unlocking device from locking the release pin.

[0014] Preferably, there are two second unlocking devices, which are symmetrically arranged on both sides of the separating pin; The eccentric wheels of the two unlocking devices move synchronously.

[0015] Preferably, the release sleeve is also provided with a vertical stepped through hole, and a release pin is provided in the stepped hole. One end of the release pin extends out of the stepped hole and is positioned towards the vertically downward end of the release pin. The other end of the release pin is limited and engaged in the stepped through hole. A set screw is threaded to the end of the stepped through hole away from the release pin. A release pin spring located in the stepped hole is provided between the set screw and the release pin.

[0016] This invention is a two-stage unlocking mechanism that uses the deformation force of a shape memory alloy as the driving force. The shape memory alloy, as the driving force, is completely unaffected by electromagnetic interference, resulting in high reliability for space applications. All materials used are corrosion-resistant and wear-resistant, exhibiting excellent environmental adaptability.

[0017] The components in this invention have good machinability, are easy to manufacture, have low cost, and controllable processing cycle. In addition, the first-level unlocking mechanism has self-locking characteristics, and the mechanism can reliably maintain the lock even under high-level vibration and impact environments, without causing false locking.

[0018] In this invention, the shape memory alloy wire, after being energized, pulls the release plate to work and unlocks the release sleeve. The release sleeve moves under the action of the release sleeve reset spring, which drives the rack to move downward. The rack drives the transmission gear to rotate, thereby driving the eccentric wheel to rotate and releasing the restriction on the release pin. The release pin is separated and unlocked under the action of the load unfolding torque and the release pin spring. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention.

[0020] Figure 2 for Figure 1 AA sectional view.

[0021] Figure 3 for Figure 1 BB cross-sectional view.

[0022] Figure 4 This is a schematic diagram showing the positions of the eccentric wheel and the release pin.

[0023] Reference numerals: 1-Separation pin, 2-House, 3-Disengagement sleeve, 4-Release plate, 5-Cover plate, 6-Reset rod, 7-Lower seat body, 8-Wire guide wheel, 9-Memory alloy wire, 10-Release plate reset spring, 11-Disengagement sleeve reset spring, 12-Disengagement pin, 13-Separation pin spring, 14-Seat body cover plate, 15-Reset side plate, 16-Adjusting screw, 17-Aviation plug, 19-Eccentric wheel, 20-Transmission gear, 21-Rack, 23-Gear fixing seat, 24-Setting screw. Detailed Implementation

[0024] The present invention will be described below with reference to the accompanying drawings.

[0025] See Figure 1 and Figure 2 As shown, the present invention provides a high-reliability memory alloy unlocker, including a lower base 7 and a housing 2 disposed on the lower base 7. The housing 2 is provided with a guide hole, and a release sleeve 3 is disposed in the guide hole. The release sleeve 3 is connected to the end of the housing 2 away from the lower base 7 through an elastic reset structure. The release sleeve 3 is provided with a release chamber, and a separation pin 1 is movably disposed in the release chamber. The end of the separation pin 1 away from the lower seat 7 passes through the housing 2 and extends out. The separation pin 1 is slidably connected to the housing 2. The release chamber is provided with a second unlocking device for locking the release pin 1. When the release sleeve 3 moves toward the lower seat 7 to the unlocking position, the second unlocking device unlocks. The lower seat 7 is provided with a sliding groove, and a first unlocking device is provided in the sliding groove. The first unlocking device includes a release plate 4 and a shape memory alloy wire 9 slidably disposed in the sliding groove. One end of the shape memory alloy wire 9 is fixedly connected to the release plate 4, and the other end of the shape memory alloy wire 9 passes around the wire pulley 8 and is fixedly connected to the inner wall of the sliding groove. An aviation plug 17 is also connected to the shape memory alloy wire 9. The release plate 4 is fixedly provided with a limiting protrusion for locking the release sleeve 3 vertically downward. The limiting protrusion extends into the guide hole and connects with the release sleeve 3. When the shape memory alloy wire 9 is energized and deformed, it pulls the release plate 4, and the limiting protrusion disengages from the release sleeve 3, thus unlocking the first unlocking device.

[0026] In one embodiment, the elastic reset structure includes a release sleeve reset spring 11. A limiting ring is provided on the release sleeve 3, and the release sleeve reset spring 11 is sleeved on the release sleeve 3. One end of the release sleeve reset spring 11 abuts against the limiting ring, and the other end of the release sleeve reset spring 11 abuts against the end of the housing 2 away from the lower seat 7.

[0027] In one embodiment, there are two memory alloy wires 9 and two guide wheels 8. The guide wheels 8 are rotatably connected to the lower body 7 via pins. One end of each of the two memory alloy wires 9 is connected to the same end of the release plate 4, and the other end is fixedly connected to the inner wall of the corresponding groove. The two guide wheels 8 are located on the same side of the housing 2, and the two memory alloy wires 9 are connected to the aviation socket.

[0028] In one embodiment, a reset device is also provided on the lower seat 7. The reset device includes a reset rod 6 and a release plate reset spring. One end of the release plate 4 connected to the shape memory alloy wire 9 is connected to the lower seat 7 through the release plate reset spring. When the first unlocking device unlocks, the release plate return spring is in a compressed state; The reset rod 6 is fixedly connected to the end of the release plate 4 away from the shape memory alloy wire 9. The end of the reset rod 6 away from the release plate 4 extends out from the lower seat 7. In use, a reset side plate 15 is fixedly connected to the lower seat 7 on the side of the release plate 4 away from the shape memory alloy wire 9. An adjusting screw 16 is threaded onto the reset side plate 15 and extends out through the reset side plate 15. One end of the adjusting screw 16 is axially fixedly connected to the reset rod 6. Rotating the adjusting screw 16 moves the reset rod 6.

[0029] In one embodiment, the housing 2 is further provided with an annular spring cover plate 5 for preventing the release sleeve 3 from dislodging from the guide hole. The spring cover plate 5 is provided to block the end of the guide hole near the lower seat body 7, and the inner diameter of the spring cover plate 5 is smaller than the outer diameter of the release sleeve 3.

[0030] In one embodiment, an annular seat cover plate 14 is also fixedly provided on the lower seat 7, and the housing 2 is fixedly connected to the seat cover plate 14.

[0031] In one embodiment, the second unlocking device includes a rack 21 and a transmission gear 20 located in the release chamber. The rack 21 is vertically arranged and fixedly connected to the release sleeve 3. The transmission gear 20 is connected to the housing 2 through a gear fixing seat 23. The transmission gear 20 is mounted on the gear fixing seat 23 through a pin. The transmission gear 20 is meshed with the rack 21. An eccentric wheel 19 is fixed and eccentrically connected to the transmission gear 20. The eccentric wheel 19 is located on one side of the separating pin 1. A limiting groove is provided on the circumferential surface of the separating pin 1, and the limiting groove is correspondingly provided to the eccentric wheel 19. When the transmission gear 20 rotates, part of the eccentric wheel 19 extends into the limiting groove; When the release sleeve 3 moves toward the lower seat 7, the rack 21 drives the transmission gear 20 to rotate, and the eccentric wheel 19 disengages from the limiting groove, releasing the second unlocking device from locking the release pin 1.

[0032] In one embodiment, two second unlocking devices are provided, and the two unlocking devices are symmetrically arranged on both sides of the separating pin 1; The eccentric wheels 19 of the two unlocking devices operate synchronously.

[0033] In one embodiment, the release sleeve 3 is also provided with a vertically stepped through hole, and a release pin 12 is provided in the stepped hole. One end of the release pin 12 extends out of the stepped hole and is set towards the vertically downward end of the release pin 1. The other end of the release pin 12 is limited and engaged in the stepped through hole. A set screw 24 is threadedly connected to the end of the stepped through hole away from the release pin 1. A release pin spring 13 is provided between the set screw 24 and the release pin and is located in the stepped hole. When the release pin 1 presses down on the release pin 12, the release pin spring 13 is compressed. When the release pin 1 separates from the release pin 12, the release pin spring 13 resets and pushes the release pin 12 vertically upward to the step hole limit position.

[0034] like Figure 2 As shown, the shape memory alloy wire 9 is energized and deformed through the aviation plug 17, pulling the release plate 4 to the left. Since the limiting protrusion on the release plate 4 limits the release sleeve 3 vertically downward, after the release plate 4 moves to the position, the limiting protrusion releases the limitation on the release sleeve 3. Under the action of the release sleeve 3 return spring, the release sleeve 3 moves vertically downward. The movement of the release sleeve 3 drives the rack 21 to move downward together. The rack 21 meshes with the transmission gear 20, causing the transmission gear 20 to rotate. The rotation of the transmission gear 20 drives the eccentric wheel 19 to disengage from the limiting groove, releasing the restriction on the separation pin 1. Under the action of the load unfolding torque and the return action of the separation pin spring 13, the separation pin 1 is separated and unlocked, and the separation pin 1 is disengaged from the mechanism, completing the function.

Claims

1. A high-reliability shape memory alloy unlocker, comprising a lower base and a housing disposed on the lower base, characterized in that, The housing is provided with a guide hole, and a release sleeve is provided in the guide hole. The release sleeve is connected to the end of the housing away from the lower seat through an elastic reset structure. The release sleeve is provided with a release chamber, and a separation pin is movably disposed in the release chamber. The end of the separation pin away from the lower seat passes through the housing and extends out, and the separation pin is slidably connected to the housing. The release chamber is equipped with a second unlocking device for locking the release pin. When the release sleeve moves toward the lower seat to the unlocking position, the second unlocking device unlocks. The lower seat body is provided with a slide groove, and a first unlocking device is provided in the slide groove. The first unlocking device includes a release plate and a shape memory alloy wire that are slidably disposed in the slide groove. One end of the shape memory alloy wire is fixedly connected to the release plate, and the other end of the shape memory alloy wire passes around the wire guide wheel and is fixedly connected to the inner wall of the slide groove. An aviation plug is also connected to the shape memory alloy wire. The release plate is fixedly provided with a limiting protrusion for locking the release sleeve vertically downward. The limiting protrusion extends into the guide hole and connects with the release sleeve. When the shape memory alloy wire is energized and deformed, it pulls the release plate, and the limiting protrusion disengages from the release sleeve, thus unlocking the first unlocking device.

2. The high-reliability shape memory alloy unlocker as described in claim 1, characterized in that, The elastic reset structure includes a release sleeve reset spring. A limiting ring is provided on the release sleeve, and the release sleeve reset spring is sleeved on the release sleeve. One end of the release sleeve reset spring abuts against the limiting ring, and the other end of the release sleeve reset spring abuts against the end of the housing away from the lower seat.

3. The high-reliability memory alloy unlocker as described in claim 1, characterized in that, The memory alloy wire and the wire guide wheel are both provided in pairs. The wire guide wheel is rotatably connected to the lower seat body through a pin shaft. One end of each of the two memory alloy wires is connected to the same end of the release plate, and the other end is fixedly connected to the corresponding inner wall of the slide groove. The two wire guide wheels are located on the same side of the housing, and both memory alloy wires are connected to the aviation socket.

4. The high-reliability shape memory alloy unlocker as described in claim 1, characterized in that, The lower seat is also provided with a reset device, which includes a reset rod and a release plate reset spring. One end of the release plate connected to the memory alloy wire is connected to the lower seat through the release plate reset spring. When the first unlocking device unlocks, the release plate reset spring is in a compressed state; The reset rod is fixedly connected to the end of the release plate away from the shape memory alloy wire, and the end of the reset rod away from the release plate extends out from the lower body.

5. The high-reliability shape memory alloy unlocker as described in claim 1, characterized in that, The housing is also provided with an annular spring cover plate to prevent the release sleeve from coming out of the guide hole. The spring cover plate is provided at the end of the guide hole near the lower seat body, and the inner diameter of the spring cover plate is smaller than the outer diameter of the release sleeve.

6. The high-reliability shape memory alloy unlocker as described in claim 1, characterized in that, An annular seat cover plate is also fixedly installed on the lower seat body, and the shell is fixedly connected to the seat cover plate.

7. The high-reliability shape memory alloy unlocker as described in claim 1, characterized in that, The second unlocking device includes a rack and a transmission gear located in the release chamber. The rack is vertically arranged and fixedly connected to the release sleeve. The transmission gear is connected to the housing through a gear fixing seat and is mounted on the gear fixing seat through a pin. The transmission gear is meshed with the rack. An eccentric wheel is fixed and eccentrically connected to the transmission gear. The eccentric wheel is located on one side of the separating pin. A limiting groove is provided on the circumferential surface of the separating pin, and the limiting groove is correspondingly provided to the eccentric wheel. As the transmission gear rotates, the eccentric wheel extends into the limiting groove; As the release sleeve moves toward the lower seat, the rack drives the transmission gear to rotate, and the eccentric wheel disengages from the limiting groove, releasing the second unlocking device from locking the release pin.

8. The high-reliability memory alloy unlocker as described in claim 7, characterized in that, The second unlocking device is provided in two parts, which are symmetrically arranged on both sides of the separating pin; The eccentric wheels of the two unlocking devices move synchronously.

9. A high-reliability memory alloy unlocker as described in claim 1, characterized in that, The release sleeve is also provided with a vertical stepped through hole, and a release pin is provided in the stepped hole. One end of the release pin extends out of the stepped hole and is set towards the vertically downward end of the release pin. The other end of the release pin is limited and engaged in the stepped through hole. A set screw is threaded on the end of the stepped through hole away from the release pin. A release pin spring is provided between the set screw and the release pin and is located in the stepped hole.

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