A memory metal pin puller

Abstract

The present invention relates to a memory metal pin puller, which belongs to the field of on-orbit unlocking technology for spacecraft, and comprises: an insulating bushing, a drive shaft, a drive spring, a return spring, a PCB board, a sleeve, a cylindrical roller, and a memory metal wire; the drive shaft is slidably connected to the insulating bushing, and the drive spring and the return spring are respectively sleeved on the drive shaft; the PCB board is arranged near the first end of the drive shaft; the second end of the drive shaft is arranged away from the first end; the sleeve is slidably connected to the second end of the drive shaft; the sleeve is provided with a limiting groove, and the cylindrical roller is arranged between the drive shaft and the sleeve; a wire threading groove is provided on the outer side of the insulating bushing, and the memory metal wire passes through the wire threading groove and is connected to the PCB board. The present invention adopts a two-stage unlocking method, which improves the pin pulling stroke and load-bearing capacity, and is particularly suitable for working conditions with large strokes and large loads. Resetting can also be driven by the return spring. In addition, the memory metal wire can also be pre-tightened by the return spring, thereby improving the performance and service life of the device.

Description

Technical Field

[0001] The invention belongs to the technical field of on-orbit unlocking of spacecraft, and in particular relates to a memory metal pin puller. Background Art

[0002] In the design and manufacturing process of spacecraft, connection and release mechanisms are crucial components. Some locking mechanisms are responsible for in-orbit unlocking to meet the specific functional requirements of the spacecraft. Therefore, these locking mechanisms need to ensure that the spacecraft can be safely and reliably connected or separated during various stages of launch, operation, and recovery. Traditional unlocking devices often rely on pyrotechnics for unlocking. As an efficient and reliable connection and release device, pyrotechnic unlocking devices also have certain limitations, such as large size, large unlocking impact, high price, and strict transportation restrictions. With the development of commercial aerospace technology, low-cost, low-impact, simple, efficient, and reusable non-pyrotechnic pin pullers have become an ideal supplementary product. Among non-pyrotechnic pin pullers, memory metal pin pullers are the key development direction.

[0003] The existing memory metal pin pullers mainly use two schemes: one-level unlocking and two-level unlocking. In the one-level unlocking scheme, the pin is directly pulled by contracting the memory wire (Shape Memory Alloy, SMA) to achieve unlocking; in the two-level unlocking scheme, the memory wire is first used to pull the first-level pin (such as a pin, roller, ball, etc.) to achieve the first-level unlocking, and then the spring drives the second-level pin to achieve the second-level unlocking. For example, the patent "CN109623726A, a memory metal pin puller" adopts a one-level pin pulling scheme, which directly pulls the pin to unlock by electrifying and contracting the memory wire. Furthermore, for usage scenarios that require a large stroke, the patent "CN217861082U, a large-stroke pin puller" is designed with a secondary pin part, which is placed separately outside the primary pin. After the primary pin is unlocked, the secondary pin is unlocked under the action of the spring. For example, the patent "CN118143611A, memory metal pin pulling device" also adopts a two-level unlocking method, in which the first-level pin is a cylindrical pin, the cylindrical pin is vertically inserted on the second-level cylindrical pin, and the memory metal wire is bound to the first-level pin. After power is turned on, the memory metal wire contracts to unlock the first-level pin, and the second-level pin is unlocked under the action of the spring.

[0004] Existing single-stage unlocking solutions all feature relatively simple pin puller structures, offering high speed, low impact, and a compact design. However, due to the small contraction displacement of the memory wire, the pin puller's travel is also limited, resulting in low load capacity and inability to achieve self-locking, making it difficult to implement in high-load mechanisms. Secondary unlocking solutions utilize a two-stage drive, which has the advantage of increasing the pin puller's travel and enabling self-locking. However, these solutions also have significant disadvantages. Some solutions utilize two sets of unlocking mechanisms, resulting in a large overall size and inconvenient installation. Furthermore, with repeated power-on, the length of the memory wire increases, causing the previously taut memory wire to become loose, making it difficult to maintain tension. This loosened memory wire's puller travel is insufficient, resulting in incomplete unlocking of the primary pin and subsequent jamming of the secondary pin. Consequently, the number of uses of these pin pullers is severely limited by the number of times the memory wire is powered. A new memory metal pin puller structure is needed, particularly for applications with larger travels and loads. Summary of the Invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a memory metal pin puller. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0006] The present invention provides a memory metal pin puller, comprising: an insulating bushing, a drive shaft, a drive spring, a return spring, a PCB board, a sliding sleeve, a cylindrical roller and a memory metal wire; the drive shaft is slidably connected to the insulating bushing, and the drive spring and the return spring are respectively sleeved on the drive shaft; the PCB board is arranged close to the first end of the drive shaft; the second end of the drive shaft is arranged away from its first end; the sliding sleeve is slidably connected to the second end of the drive shaft; the sliding sleeve is provided with a limiting groove, and the cylindrical roller is arranged between the drive shaft and the sliding sleeve; a wire threading groove is provided on the outer side of the insulating bushing, and the memory metal wire passes through the wire threading groove and is connected to the PCB board; wherein, when unlocking, the memory metal wire is energized to drive the sliding sleeve to move, so that the cylindrical roller is free from the constraint of the sliding sleeve, and the cylindrical roller cooperates with the limiting groove; the drive spring drives the drive shaft to move and compresses the return spring; when resetting, the return spring pushes the sliding sleeve to move, so that the cylindrical roller is free from the cooperation with the limiting groove.

[0007] In one embodiment of the present invention, at least two roller grooves are provided on the driving shaft, one cylindrical roller is provided in each roller groove, and all the cylindrical rollers are symmetrically arranged.

[0008] In one embodiment of the present invention, a drive sleeve is provided in the insulating sleeve, and the drive sleeve is coaxially sleeved outside the drive shaft, and separates the insulating sleeve into a first cavity and a second cavity, wherein the drive spring is provided in the first cavity, and the return spring is provided in the second cavity.

[0009] In one embodiment of the present invention, a vibration isolation pad is provided on one side of the drive sleeve close to the first cavity, and a limiting step is provided in the middle of the drive shaft; when unlocked, the limiting step contacts the vibration isolation pad.

[0010] In one embodiment of the present invention, an insulating outer sleeve is provided outside the insulating bushing, and the memory metal wire is located between the insulating bushing and the insulating outer sleeve.

[0011] In one embodiment of the present invention, an outer shell is provided outside the insulating outer sleeve, and the outer shell includes: a flange, a rear sleeve and a rear cover connected in sequence, and the rear cover is located on a side close to the second end of the drive shaft.

[0012] In one embodiment of the present invention, a slider is slidably connected in the second cavity of the insulating bushing, and the sliding sleeve is detachably connected to the slider; wherein, several groups of first steel column needles are arranged in the slider, and the memory metal wire passes through the wire threading groove after passing through several groups of first steel column needles and the surface of the slider.

[0013] In one embodiment of the present invention, an insulating gasket is provided between the back cover and the slider.

[0014] In one embodiment of the present invention, several groups of second steel column needles are provided on one side of the insulating bushing close to the first end of the drive shaft, and the memory metal wire passes around several groups of first steel column needles and the surface of the slider, passes through the wire threading groove, and is wound around several groups of second steel column needles.

[0015] In one embodiment of the present invention, a pin head is provided at the first end of the drive shaft, and a threaded hole is provided at the pin head and the second end of the drive shaft; a through hole is provided in the middle of the rear cover, and the through hole is coaxially arranged with the threaded hole.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The memory metal pin puller of the present invention utilizes a two-stage unlocking method. First, the memory wire is electrically contracted to drive the cylindrical roller to achieve primary unlocking. Second, the drive spring drives the drive shaft to move to achieve secondary unlocking. This improves both the pin pulling stroke and load-bearing capacity, making it particularly suitable for use in applications involving long strokes and heavy loads. During resetting, the pin puller can also be driven by a return spring. The cooperation of the drive spring and return spring ensures smooth operation, enabling self-locking and resetting, thereby improving operational efficiency. Furthermore, the return spring can pre-tighten the memory wire, preventing the memory wire from becoming loose after repeated energization, resulting in insufficient pin pulling stroke. This increases the number of uses for the pin puller and enhances its performance and service life.

[0018] The present invention optimizes the winding method of the memory metal wire, integrates the PCB board, and has a compact overall structure. The memory metal wire is wound around the slider from the outside, passes through the wire threading groove provided on the insulating bushing, and is finally connected to the PCB board. The wire winding is convenient, simple and easy to operate, and easy to maintain. The memory metal wire can be directly sleeved on the outside of the insulating sleeve for assembly, which reduces the process difficulty and improves the assembly efficiency, and solves the problems of complex wire winding method and inconvenient wire winding operation in the existing pin puller.

[0019] The present invention also pre-embeds steel column needles in the insulating bushing and the slider respectively. The memory metal wire contacts the steel column needles during the wire winding process, reducing the problem of contact friction between the memory metal wire and the edge of the part, increasing the service life of the memory metal wire, and reducing the risk of friction breakage of the memory metal wire.

[0020] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a structural diagram of a memory metal pin puller provided by an embodiment of the present invention;

[0022] Figure 2 2 is a cross-sectional view of the structure of the memory metal pin puller provided by an embodiment of the present invention (locked state);

[0023] Figure 3 2 is a cross-sectional view of the structure of the memory metal pin puller provided by an embodiment of the present invention (unlocked state);

[0024] Figure 4 1 is a schematic structural diagram of a drive shaft provided by an embodiment of the present invention;

[0025] Figure 51 is a schematic diagram of the winding of the memory metal wire provided by an embodiment of the present invention (first end);

[0026] Figure 6 3 is a schematic diagram of the winding of the memory metal wire provided by an embodiment of the present invention (second end).

[0027] Icons: 1-insulating bushing; 101-wire threading groove; 102-second steel column needle; 2-driving shaft; 201-pin head; 202-roller groove; 203-limiting step; 3-driving spring; 4-return spring; 5-PCB board; 501-solder point; 6-sleeve; 601-limiting groove; 7-cylindrical roller; 8-memory wire; 9-driving bushing; 10-vibration isolation pad; 11-insulating outer sleeve; 12-outer shell; 121-flange; 122-rear sleeve; 123-rear cover; 13-slider; 131-first steel column needle; 14-insulating gasket; 15-limiting screw; 16-coil. DETAILED DESCRIPTION

[0028] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, a memory metal pin puller proposed in accordance with the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] The aforementioned and other technical contents, features, and effects of the present invention are clearly presented in the following detailed description of the specific embodiments in conjunction with the accompanying drawings. Through the description of the specific embodiments, a deeper and more specific understanding of the technical means and effects adopted by the present invention to achieve the intended purpose can be obtained. However, the accompanying drawings are provided for reference and illustration purposes only and are not intended to limit the technical solutions of the present invention.

[0030] Example 1

[0031] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 5 and Figure 6 As shown, Figure 1 This is a structural diagram of a memory metal pin puller provided by an embodiment of the present invention; Figure 2 2 is a cross-sectional view of the structure of the memory metal pin puller provided by an embodiment of the present invention (locked state); Figure 3 2 is a cross-sectional view of the structure of the memory metal pin puller provided by an embodiment of the present invention (unlocked state); Figure 5 1 is a schematic diagram of the winding of the memory metal wire provided by an embodiment of the present invention (first end); Figure 6 3 is a schematic diagram of the winding of the memory metal wire provided by an embodiment of the present invention (second end).

[0032] This embodiment provides a memory metal pin puller, comprising: an insulating bushing 1, a drive shaft 2, a drive spring 3, a return spring 4, a PCB board 5 (Printed Circuit Board), a sleeve 6, a cylindrical roller 7 and a memory metal wire 8; wherein, the drive shaft 2 is slidingly connected to the insulating bushing 1, and the drive spring 3 and the return spring 4 are respectively sleeved on the drive shaft 2; the PCB board 5 is arranged close to the first end of the drive shaft 2; the second end of the drive shaft 2 is arranged away from its first end; the sleeve 6 is slidingly connected to the second end of the drive shaft 2; the sleeve 6 is provided with a limiting groove 601, and the cylindrical roller 7 is arranged between the drive shaft 2 and the sleeve 6; a wire threading groove 101 is provided on the outside of the insulating bushing 1, and the memory metal wire 8 passes through the wire threading groove 101 and is connected to the PCB board 5.

[0033] For example, the first end of the drive shaft 2 is provided with a pin head 201, and the pin head 201 can be extended or retracted. Specifically, in the locked state, the pin head 201 is extended and maintained in the locked state; when unlocked, the pin head 201 is retracted. Furthermore, one end of the pin head 201 of the drive shaft 2 and the second end thereof are both provided with threaded holes, which are used to connect the reset tooling through the threaded holes to achieve reset. Taking reset through one end of the pin head 201 of the drive shaft 2 as an example, when resetting, the threaded end of the reset tooling is screwed into the threaded hole at one end of the pin head 201, and the pin head 201 is pulled out, thereby pulling the drive shaft 2, and at the same time, the return spring 4 releases elastic energy to push the sleeve 6 to move to achieve reset.

[0034] In the locked state, the drive spring 3 is compressed, and the cylindrical roller 7, under the combined action of the sleeve 6 and the return spring 4, maintains equilibrium between the drive shaft 2 and the sleeve 6. That is, the cylindrical roller 7 is constrained between the drive shaft 2 and the sleeve 6, so that the cylindrical roller 7 is constrained in both the radial and axial directions in the absence of external forces. The axial direction is defined as the direction from the first end of the drive shaft 2 to the second end thereof, and the radial direction is defined as the diameter of the drive shaft 2. The pin 201 of the drive shaft 2 is extended and maintained in the locked state.

[0035] When unlocking, the memory wire 8 is energized. Since the memory wire 8 contracts after being heated, it drives the sleeve 6 to move, so that the cylindrical roller 7 is freed from the constraint of the sleeve 6. Under the push of the drive shaft 2, the cylindrical roller 7 rolls into the limiting groove 601 of the sleeve 6 and cooperates with the limiting groove 601. That is, at this time, the cylindrical roller 7 is freed from the constraint in the radial direction. At the same time, the constraint in the axial direction of the drive shaft 2 is also released, and the elastic energy of the drive spring 3 is released. The drive shaft 2 is driven to move through the drive spring 3, compressing the return spring 4, and completing the unlocking of the pin head 201.

[0036] During resetting, the pin head 201 can be pulled out through the resetting tool, the elastic energy of the return spring 4 is released, and the sleeve 6 is pushed to move by the return spring 4. At this time, the cylindrical roller 7 is disengaged from the limit groove 601, and the cylindrical roller 7 also falls back into the roller groove 202 of the drive shaft 2. The memory metal wire 8 is re-pretightened, and the memory metal pin puller of this embodiment is restored to the locked state.

[0037] It is understandable that this embodiment does not limit the structure of the reset tooling. For example, bolts or screws may be connected to the threaded holes of the drive shaft 2 to achieve the effect of pulling or pushing the drive shaft 2 to achieve reset.

[0038] Notably, the memory metal pin puller of this embodiment utilizes cylindrical rollers 7 to constrain the first-stage unlocking, memory wire 8 to drive the first-stage unlocking, and drive spring 3 to achieve the second-stage unlocking. This increases the pin pulling stroke and driving force, and also enables self-locking of the pin head 201 after pin pulling. It also offers advantages such as fast pin pulling speed, high reliability, and a high repeatability, making it suitable for use under long strokes and heavy loads. Furthermore, the return spring 4 preloads the memory wire 8, ensuring that it remains tensioned in real time. This eliminates the need for multiple power cycles and eliminates the need for multiple pre-training sessions, reducing operational requirements. This solves the problem of insufficient pin pulling stroke due to a relaxed state, which can lead to the secondary pin becoming stuck due to inadequate unlocking of the primary pin. Specifically, after preloading and secondary unlocking, the pin pulling stroke of this embodiment can reach 5 mm, and its load capacity can range from 400 N to 600 N. Furthermore, the load capacity of the pin puller can be increased by replacing the drive spring 3 with a higher load capacity, meeting both stroke and load requirements.

[0039] In addition, the memory metal pin puller of this embodiment, combined with the low energy consumption characteristics of the memory metal wire 8 and the precise control through the PCB board 5, has the advantages of strong adaptability and easy maintenance, and has significant practical value and economic benefits.

[0040] like Figure 4 As shown, Figure 4 It is a schematic structural diagram of a drive shaft provided by an embodiment of the present invention.

[0041] In an optional embodiment, at least two roller grooves 202 are provided on the driving shaft 2 , a cylindrical roller 7 is provided in each roller groove 202 , and all cylindrical rollers 7 are symmetrically arranged.

[0042] For example, taking two roller grooves 202 as an example, the two roller grooves 202 are symmetrically arranged, and the two cylindrical rollers 7 are also symmetrically arranged in the two roller grooves 202, so that the bearing force on the drive shaft 2 is evenly distributed.

[0043] For example, the cylindrical rollers 7 of this embodiment may be replaced by round balls.

[0044] Please see again Figure 2 and Figure 3 In an optional embodiment, a drive sleeve 9 is provided in the insulating bushing 1. The drive sleeve 9 is coaxially sleeved outside the drive shaft 2 and separates the insulating bushing 1 into a first cavity and a second cavity.

[0045] Exemplarily, the cavity near the first end of the drive shaft 2 is the first cavity, and the drive spring 3 is arranged in the first cavity; the cavity near the second end of the drive shaft 2 is the second cavity, and the return spring 4 is arranged in the second cavity.

[0046] For example, the drive sleeve 9 and the drive shaft 2 may be interference fit to achieve sealing and prevent foreign matter from entering the cavity.

[0047] like Figures 2 to 4 As shown, Figure 4 It is a schematic structural diagram of a drive shaft provided by an embodiment of the present invention.

[0048] Furthermore, a limiting step 203 is provided in the middle of the drive shaft 2 , and a vibration isolation pad 10 is provided on the side of the drive sleeve 9 close to the first cavity; when unlocked, the limiting step 203 contacts the vibration isolation pad 10 .

[0049] Illustratively, when unlocking, the driving shaft 2 is driven to move by the driving spring 3, and the limiting step 203 impacts the vibration isolation pad 10 to reduce the impact force during unlocking.

[0050] Furthermore, the vibration isolation pad 10 may be made of rubber or silicone cushioning material.

[0051] In an optional embodiment, an insulating outer sleeve 11 is provided outside the insulating bushing 1 , and the memory metal wire 8 is located between the insulating bushing 1 and the insulating outer sleeve 11 .

[0052] For example, the insulating bushing 1, insulating outer sleeve 11, and slider 13 can all be made of non-metallic materials, such as polyimide. Polyimide, as an engineering plastic, has high-temperature resistance and high strength. Alternatively, the insulating bushing 1 and slider 13 can be made of metal. To ensure insulation, the outer surfaces of the insulating bushing 1 and slider 13 can be treated with an insulating coating.

[0053] It is worth noting that both the insulating bushing 1 and the insulating outer sleeve 11 are made of insulating materials. In addition, insulation can be achieved through an insulating plating process or an insulating coating process. The insulating plating process can form an insulating coating on the material surface through chemical treatment, and the insulating coating process can use polyurethane insulating coating or ceramic insulating coating to achieve an insulating effect. Since the memory metal wire 8 needs to directly contact the insulating bushing 1 and the insulating outer sleeve 11, the use of insulating materials or insulating processes can achieve good external insulation, improving the operating safety and stability of the memory metal wire 8. In other words, the use of the insulating bushing 1 and the insulating outer sleeve 11 effectively isolates electrical and mechanical components, enhancing safety.

[0054] In an optional embodiment, an outer shell 12 is provided outside the insulating outer sleeve 11 , and the outer shell 12 includes: a flange 121 , a rear sleeve 122 and a rear cover 123 connected in sequence, and the rear cover 123 is located on a side close to the second end of the drive shaft 2 .

[0055] In an optional embodiment, a slider 13 is slidably connected to the second cavity of the insulating bushing 1 , and the sliding sleeve 6 is detachably connected to the slider 13 .

[0056] For example, the sliding sleeve 6 and the slider 13 may be connected as one body by fastening screws.

[0057] Exemplarily, an insulating gasket 14 is provided between the rear cover 123 and the slider 13 , and the insulating gasket 14 further achieves insulation at the contact position with the memory metal wire 8 .

[0058] Exemplarily, a through hole is provided in the middle of the rear cover 123, and the through hole is coaxially arranged with the threaded hole of the drive shaft 2. When resetting, the threaded end of the reset tool is passed through the through hole in the middle of the rear cover 123 and threadedly connected to the threaded hole of the drive shaft 2, thereby pushing the drive shaft 2 to move to achieve reset. Resetting through this end does not require removing the pin head 201, and reset is convenient and simple to operate.

[0059] Please see again Figures 2 to 4 In an optional embodiment, the memory metal pin puller of this embodiment is also provided with a limit screw 15. After the limit screw 15 passes through the rear sleeve 122 and the insulating outer sleeve 11, it is connected to the insulating bushing 1 to limit the insulating bushing 1 in the axial direction.

[0060] In an optional embodiment, the memory metal pin puller of this embodiment is also provided with a coil 16, which is arranged on the rear sleeve 122 and located on the opposite side of the limit screw 15. The PCB board 5 is connected to the external circuit line through the coil 16 to control the power supply of the memory metal wire 8.

[0061] Existing memory metal pin pullers also generally have problems with complex wire winding methods and inconvenient wire winding operations. In addition, there is a certain amount of friction between the memory metal wire and the contact point, and after a certain number of operations, there is a risk of the memory metal wire breaking due to friction.

[0062] In view of this, the present embodiment optimizes the winding method of the memory metal wire 8 , which not only reduces the process difficulty but also increases the service life of the memory metal wire 8 .

[0063] Please see again Figure 5 and Figure 6 In this embodiment, several groups of first steel column needles 131 are provided in the slider 13, and the memory metal wire 8 passes around the several groups of first steel column needles 131 and the surface of the slider 13, and then passes through the wire threading groove 101; several groups of second steel column needles 102 are provided on one side of the insulating bushing 1 close to the first end of the drive shaft 2, and the memory metal wire 8 passes around the several groups of first steel column needles 131 and the surface of the slider 13, and then passes through the wire threading groove 101 and is wound around the several groups of second steel column needles 102.

[0064] Exemplarily, wire threading slots 101 are symmetrically provided on both sides of the insulating bushing 1 , wherein two wire threading slots 101 are spaced apart on each side, and at least one memory metal wire 8 can pass through each wire threading slot 101 .

[0065] Exemplarily, the memory metal wire 8 is wound in a ferrule manner, with two second steel column needles 102 spaced apart in the axial direction, and four first steel column needles 131 evenly arranged at the turning positions of the memory metal wire 8, so that the memory metal wire 8 does not directly contact the edge of the part, reducing the risk of the memory metal wire 8 breaking due to friction.

[0066] Exemplarily, the four first steel column needles 131 are arranged parallel to each other, and their axial directions are perpendicular to the extending direction of the wire threading groove 101 , and their axial directions are also parallel to the surface of the slider 13 .

[0067] Furthermore, the memory metal wire 8 is wound around the two second steel column needles 102 and passes through the wire threading slot 101. The memory metal wire 8 extends along the wire threading slot 101, is wound around the first steel column needle 131 at the turning position, and then continues to be wound around another group of first steel column needles 131 after bypassing the surface of the slider 13. After bypassing the first steel column needle 131, the memory metal wire 8 continues to extend along the wire threading slot 101 on the other side of the insulating bushing 1, and finally, the two ends of the memory metal wire 8 are respectively welded to the two welding points 501 of the PCB board 5.

[0068] It is worth noting that the memory metal pin puller of this embodiment optimizes the winding method of the memory metal wire 8, and the PCB board 5 is built-in. The overall structure is compact. The memory metal wire 8 passes around the slider 13 from the outside, passes through the wire threading groove 101 set on the insulating bushing 1, and is finally connected to the PCB board 5. The winding is convenient, simple and easy to operate, and easy to maintain. The memory metal wire 8 can be directly put on the outside of the insulating bushing 1 for assembly, which reduces the process difficulty, improves the assembly efficiency, and solves the problems of complex winding methods and inconvenient winding operations in existing pin pullers.

[0069] In addition, the memory metal pin puller of this embodiment also pre-buries steel column needles in the insulating bushing 1 and the slider 13, namely the second steel column needle 102 and the first steel column needle 131. The memory metal wire 8 contacts the steel column needles during the wire winding process, which reduces the contact friction between the memory metal wire 8 and the edge of the part, avoids the problem of high-temperature melting of the memory metal wire 8 when power is turned on after it contacts non-metallic parts, improves the service life of the memory metal wire 8, and reduces the risk of friction breakage of the memory metal wire 8.

[0070] Generally speaking, the memory metal pin puller of this embodiment improves the winding method of the memory wire 8, increasing the assembly efficiency of the pin puller and reducing the defect rate. Compared with the existing wire winding method, the PCB board 5 and the memory wire 8 are directly sheathed on the outside of the insulating bushing 1 after welding, eliminating the coupling problem between the memory wire 8 and the insulating bushing 1 during the wire winding process, simplifying the assembly process, and achieving the effective coordinated assembly of the insulating bushing 1, the PCB board 5, and the memory wire 8. Furthermore, the PCB board 5 is placed inside the pin puller and connected to the power supply via wires, resulting in a simpler product appearance and preventing short circuits or damage to the PCB board 5 caused by improper operation.

[0071] For easier understanding, please refer to Figure 2 and Figure 3 As shown in FIG, the left and right directions are represented, where the left-to-right direction is from the first end of the drive shaft 2 to the second end thereof, i.e., along the axial direction. When the pin puller is unlocked, the drive shaft 2 moves to the right, and the PCB board 5 is placed on the left side, and the movement of the sliding sleeve 6 is not affected.

[0072] The working principle of this embodiment's memory metal pin puller is that memory wire 8 passes through slider 13 and insulating sleeve 1, connecting to PCB 5. When energized, memory wire 8 contracts, pulling slider 13 and sleeve 6 to the left. The radial constraint of cylindrical roller 7 is released, and the compressed drive spring 3 pushes drive shaft 2 to the right. Under pressure from drive shaft 2, cylindrical roller 7 rolls into the groove of sleeve 6, allowing drive shaft 2 to smoothly move rightward. The energy of drive spring 3 is released, and return spring 4 is compressed. After the drive shaft 2 reaches its full right position, it impacts with vibration isolation pad 10, reducing the impact force during unlocking.

[0073] After unlocking, the drive shaft 2 is locked, and the drive spring 3 continuously pushes the drive shaft 2 to the right, causing the pin 201 to self-lock. To reset, simply screw the screw into the threaded hole and pull the drive shaft 2 to the left. The return spring 4 pushes the sleeve 6 to the right, causing the cylindrical roller 7 to fall back into the roller groove 202 of the drive shaft 2, thus resetting. Alternatively, the central through-hole of the rear cover 123 is connected to the threaded hole at the rear end of the drive shaft 2, and the drive shaft 2 can be pushed to the left to reset.

[0074] The memory metal pin puller of the present invention utilizes a two-stage unlocking method. First, the memory wire is electrically contracted to drive the cylindrical roller to achieve primary unlocking. Second, the drive spring drives the drive shaft to move to achieve secondary unlocking. This improves both the pin pulling stroke and load-bearing capacity, making it particularly suitable for use in applications involving long strokes and heavy loads. During resetting, the pin puller can also be driven by a return spring. The cooperation of the drive spring and return spring ensures smooth operation, enabling self-locking and resetting, thereby improving operational efficiency. Furthermore, the return spring can pre-tighten the memory wire, preventing the memory wire from becoming loose after repeated energization, resulting in insufficient pin pulling stroke. This increases the number of uses for the pin puller and enhances its performance and service life.

[0075] It should be noted that, in this document, relational terms such as first and second are used solely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements but also other elements not explicitly listed. Without further limitation, an element defined by the phrase "comprising a..." does not preclude the presence of additional identical elements in the article or device comprising the element. Terms such as "connected" or "connected" are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. References to orientations or positional relationships, such as "upper," "lower," "left," and "right," are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate description and simplify the description of the present invention. They do not indicate or imply that the device or element referred to must have, be constructed, or operate in a specific orientation, and are therefore not to be construed as limiting the present invention.

[0076] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A memory metal pin puller, characterized in that: include: Insulating bushing (1), driving shaft (2), driving spring (3), return spring (4), PCB board (5), sliding sleeve (6), cylindrical roller (7) and memory wire (8); The driving shaft (2) is slidably connected to the insulating bushing (1); the driving spring (3) and the return spring (4) are respectively sleeved on the driving shaft (2); the PCB board (5) is arranged near the first end of the driving shaft (2); The second end of the drive shaft (2) is arranged away from the first end thereof; the sliding sleeve (6) is slidably connected to the second end of the drive shaft (2); a limiting groove (601) is provided on the sliding sleeve (6), and the cylindrical roller (7) is arranged between the drive shaft (2) and the sliding sleeve (6); A wire threading slot (101) is provided on the outer side of the insulating bushing (1), and the memory metal wire (8) passes through the wire threading slot (101) and is connected to the PCB board (5); When unlocking, the memory wire (8) is energized to drive the sliding sleeve (6) to move, so that the cylindrical roller (7) is separated from the constraint of the sliding sleeve (6), the cylindrical roller (7) cooperates with the limiting groove (601), and the driving spring (3) drives the driving shaft (2) to move and compresses the return spring (4); when resetting, the return spring (4) pushes the sliding sleeve (6) to move, so that the cylindrical roller (7) is separated from the cooperation with the limiting groove (601); A drive sleeve (9) is provided in the insulating sleeve (1), the drive sleeve (9) being coaxially sleeved on the outside of the drive shaft (2) and dividing the insulating sleeve (1) into a first cavity and a second cavity, the drive spring (3) being provided in the first cavity, and the return spring (4) being provided in the second cavity; A slider (13) is slidably connected in the second cavity of the insulating bushing (1), and the sliding sleeve (6) is detachably connected to the slider (13); a plurality of groups of first steel column needles (131) are provided in the slider (13), and the memory metal wire (8) passes through the wire threading slot (101) after passing through the plurality of first steel column needles (131) and the surface of the slider (13); a plurality of groups of second steel column needles (102) are provided on one side of the insulating bushing (1) close to the first end of the drive shaft (2), and the memory metal wire (8) is directly sleeved on the outside of the insulating bushing (1) for assembly, and the memory metal wire (8) passes through the plurality of first steel column needles (131) and the surface of the slider (13) from the outside, passes through the wire threading slot (101), and is wound around the plurality of second steel column needles (102), and is finally connected to the PCB board (5).

2. The memory metal pin puller according to claim 1, characterized in that: At least two roller grooves (202) are provided on the driving shaft (2), one cylindrical roller (7) is provided in each roller groove (202), and all the cylindrical rollers (7) are symmetrically arranged.

3. The memory metal pin puller according to claim 1, characterized in that: A vibration isolation pad (10) is provided on one side of the drive sleeve (9) close to the first cavity, and a limiting step (203) is provided in the middle of the drive shaft (2); When unlocked, the limiting step (203) contacts the vibration isolation pad (10).

4. The memory metal pin puller according to claim 1, characterized in that: An insulating outer sleeve (11) is provided outside the insulating bushing (1), and the memory metal wire (8) is located between the insulating bushing (1) and the insulating outer sleeve (11).

5. The memory metal pin puller according to claim 4, characterized in that: An outer shell (12) is provided outside the insulating outer sleeve (11), and the outer shell (12) comprises a flange (121), a rear sleeve (122), and a rear cover (123) connected in sequence, and the rear cover (123) is located on a side close to the second end of the drive shaft (2).

6. The memory metal pin puller according to claim 5, characterized in that: An insulating gasket (14) is provided between the rear cover (123) and the slider (13).

7. The memory metal pin puller according to claim 5, characterized in that: The first end of the drive shaft (2) is provided with a pin head (201), and the pin head (201) and the second end of the drive shaft (2) are both provided with threaded holes; the middle portion of the rear cover (123) is provided with a through hole, and the through hole is coaxially arranged with the threaded hole.

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