A buffer device for explosive bolts

Abstract

The application provides a buffer device for explosive bolts, which comprises a box, a first through hole is formed in the bottom wall of the box, a floating nut is made of high-strength steel, abuts against the inner side of the bottom wall of the box, and is provided with a threaded hole suitable for connecting with the explosive bolt, the threaded hole is aligned with the first through hole, the diameter of the first through hole is larger than that of the threaded hole, a top block is made of light metal, the top block is clamped with the inner cavity of the box, so as to prevent the top block from rotating around the axis of the first through hole, the top block and the box are slidably connected in the axial direction of the first through hole, a groove is formed in the bottom surface of the top block, the groove is clamped with the floating nut, so as to prevent the floating nut from rotating around the axis of the threaded hole, a floating gap is arranged between the side walls of the floating nut and the groove, and a buffer is arranged between the top surface of the top block and the top wall of the box. The device overcomes the defect that the buffer device in the prior art has a large quality.

Description

Technical Field

[0001] This invention relates to the field of spacecraft separation technology, and more specifically to a buffer device for explosive bolts. Background Technology

[0002] In the aerospace field, rocket launches involve numerous separation maneuvers, such as rocket-satellite separation, stage separation, fairing jettison separation, tail cone separation, mouthpiece separation, and nose cone separation. Rocket-satellite separation, as the final maneuver in a rocket launch, plays a crucial role in determining the success or failure of the launch. Explosive bolts, due to their advantages of quick and reliable connection and unlocking, simple structure, and small space occupation, are widely used as connection and separation devices in spacecraft. However, explosive bolts have the drawback of significant impact, and the precision optical equipment and electronic components on satellites are highly sensitive to impact. To mitigate the impact, a buffer device is required on the satellite side. However, this buffer device, as part of the satellite's on-orbit mass, occupies part of the rocket's payload, necessitating consideration of how to develop a lightweight buffer device. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defect of the excessive mass of the buffer device in the prior art.

[0004] To solve the above-mentioned technical problems, this application provides a buffer device for explosive bolts, comprising:

[0005] The box body has a through hole on the bottom wall;

[0006] The movable nut, made of high-strength steel, abuts against the inner side of the bottom wall of the housing and is provided with a threaded hole suitable for connection with the explosion bolt; the threaded hole is aligned with the first through hole; the diameter of the first through hole is larger than the diameter of the threaded hole.

[0007] The top block is made of lightweight metal; the top block is engaged with the inner cavity of the housing to prevent the top block from rotating around the axis of the first through hole; the top block and the housing form a sliding connection in the axial direction of the first through hole; a groove is provided on the bottom surface of the top block; the groove is engaged with the floating nut to prevent the floating nut from rotating around the axis of the threaded hole; a floating clearance is provided between the side walls of the floating nut and the groove.

[0008] The buffer is located between the top surface of the top block and the top wall of the box.

[0009] Furthermore, the top wall of the enclosure extends outward to form a connecting plate, and the connecting plate is provided with a second through hole suitable for bolt connection.

[0010] Furthermore, the side wall of the housing is provided with an opening; the sliding nut, top block and buffer are adapted to be inserted into the inner cavity of the housing through the opening.

[0011] Furthermore, the side walls of the box located on both sides of the opening are integrally formed with the top and bottom walls of the box, thereby forming a supporting connection between the top and bottom walls of the box.

[0012] Furthermore, a baffle is provided at the opening, which is detachably connected to the box body, and the baffle seals the inner cavity of the box.

[0013] Furthermore, a stop block is provided at the top of each of the two opposite sidewalls of the groove, with one side of the stop block flush with the inner wall of the groove; and the height from the bottom of the groove to the top of the stop block is the same as the height of the floating nut.

[0014] Furthermore, the stop block is arranged along the direction of insertion of the top block from the opening, and a locking block is provided on the side wall of the housing located on both sides of the opening. The movable nut is square, and a locking relationship with a movable gap is formed between the locking block and the adjacent side of the movable nut.

[0015] Furthermore, a boss is provided on the top surface of the top block, the boss is located on the back side of the groove, and the bottom surface of the boss is larger than the bottom surface of the groove; the buffer is provided with a receiving groove that matches the contour of the boss.

[0016] Furthermore, a first receiving hole is provided on the bottom surface of the groove, and the first receiving hole is aligned with the threaded hole.

[0017] Furthermore, the first receiving hole is a through hole, and a second receiving hole is provided on the buffer.

[0018] By adopting the above technical solution, the present invention has the following technical effects:

[0019] The buffer device for explosive bolts provided by this invention transmits impact force through two components: a floating nut and a top block. Therefore, the floating nut can be made of high-strength steel to ensure the connection strength of the bolt and avoid connection failures such as stripping, especially preventing thread stripping caused by the strong impact after an explosion, which would lead to force transmission failure. The top block, compared to the floating nut, has a larger volume; therefore, it can be made of lightweight metal to ensure sufficient force transmission strength while reducing the overall weight of the device. Furthermore, the separate design of the floating nut and top block allows for a floating gap between their side walls, enabling the floating nut to move laterally relative to the top block rather than being completely fixed. In existing buffer devices, the nut connected to the explosive bolt forms a strong mutual restraint with adjacent components outside the buffering direction, ensuring smooth buffering action. However, this restricts the position of the threaded hole within the entire device. Sometimes, due to manufacturing tolerances, the connecting holes between the star-and-arrow separation components are aligned but not fully centered, causing misalignment between the bolt and nut, preventing proper connection. This device features a floating clearance and a first through-hole diameter larger than the threaded hole diameter. This allows the floating nut to move during bolt insertion, ensuring complete alignment between the first through-hole and the threaded hole and guaranteeing a smooth connection. Furthermore, the buffer is made of dense foam, reducing the impact from 3500g to 2000g during cushioning, achieving a superior buffering effect. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic cross-sectional view of the structure of an embodiment of the present invention;

[0022] Figure 2 for Figure 1 Sectional view at point A-A;

[0023] Figure 3 This is a schematic perspective view of the connector structure according to an embodiment of the present invention;

[0024] Figure 4 This is a schematic perspective view of the structure of the floating nut according to an embodiment of the present invention;

[0025] Figure 5 This is a schematic perspective view of the top block of an embodiment of the present invention, viewed from an obliquely upward angle.

[0026] Figure 6 This is a schematic perspective view of the top block of an embodiment of the present invention, viewed from a slightly lower angle.

[0027] Figure 7 This is a schematic perspective view of the structure of the buffer pad according to an embodiment of the present invention.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1 - Box body, 2 - First buffer pad, 3 - Buffer component, 4 - Second buffer pad, 5 - Top block, 6 - Floating nut, 7 - Separation plate, 8 - Explosion bolt, 9 - Baffle, 10 - Floating clearance, 11 - Baffle connection hole, 12 - Locking block, 13 - First through hole, 14 - Opening, 15 - Box body, 16 - Threaded hole, 17 - Side end face, 18 - Top block body, 19 - First receiving hole, 20 - First side stop, 21 - Boss, 22 - Second side stop, 23 - Groove, 24 - Receiving groove, 25 - Second receiving hole, 26 - Connecting plate. Detailed Implementation

[0030] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be noted in the description of this invention that the coordinate system used in describing orientation is based on... Figure 1 The orientation is determined by the posture in the figure, and the naming of the observation angle of the corresponding view is also based on this. Therefore, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figure. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0034] This embodiment provides a buffer device for explosive bolts.

[0035] In one implementation, such as Figures 1 to 7 As shown, it includes: a housing 1, a sliding nut 6, a top block 5, and a buffer 3. A through hole 13 is formed in the bottom wall of the housing 1. The sliding nut 6 is made of high-strength steel with a tensile strength of at least 800 MPa to meet the strength requirements for a nut. The sliding nut 6 abuts against the inner side of the bottom wall of the housing 1 and has a threaded hole 16 suitable for connection with an explosion bolt 8. The threaded hole 16 is aligned with the first through hole 13; and the diameter of the first through hole 13 is larger than the diameter of the threaded hole 16. The top block 5 is made of a lightweight metal, such as aluminum, titanium, or their corresponding alloys, thus combining relatively high strength with lightweight advantages. Considering cost, the top block 5 is preferably made of aluminum alloy and machined. The top block 5 engages with the inner cavity of the housing 1, thereby preventing the top block 5 from rotating around the axis of the first through hole 13. The top block 5 and the housing 1 form a sliding connection in the axial direction of the first through hole 13. A groove 23 is provided on the bottom surface of the top block 5. The groove 23 engages with the movable nut 6, thereby preventing the movable nut 6 from rotating around the axis of the threaded hole 16. A clearance 10 is provided between the side walls of the movable nut 6 and the groove 23. A buffer 3 is disposed between the top surface of the top block 5 and the top wall of the housing 1. The buffer 3 can be made of elastic materials such as rubber or PVC foam and can be machined.

[0036] In use, the explosive bolt 8 is first passed through the separation plate 7, then through the first through hole 13 of the housing 1, and finally connected to the floating nut 6. The floating nut 6 is engaged with the top block 5 and prevented from spinning by the housing body 15, thus preventing any follow-up movement when the explosive bolt 8 is rotated, ensuring smooth connection. When separating, the explosive bolt 8 explodes, and the bolt head, under the impact force, drives the floating nut 6 towards the inside of the housing 1. After the floating nut 6 reaches the groove 23 of the top block 5, it transmits the impact force to the top block 5. During its movement, the top block 5 compresses the buffer 3, thus providing a cushioning effect.

[0037] Because this device transmits impact force through two components, the floating nut 6 and the top block 5, the floating nut 6 can be made of high-strength steel to ensure the connection strength of the bolt and avoid connection failures such as stripping. In particular, it can prevent the threads from stripping due to the strong impact after the explosion, which would lead to force transmission failure. The top block 5, compared to the floating nut 6, has a larger volume, so it can be made of lightweight metal to ensure sufficient force transmission strength while reducing the overall weight of the device. Furthermore, due to the separate design of the floating nut 6 and the top block 5, a floating gap 10 can be set between their side walls, allowing the floating nut 6 to move laterally relative to the top block 5, rather than being completely fixed. In existing buffer devices, the nut connected to the explosive bolt 8 forms a strong mutual restraint with adjacent components outside the buffering direction, ensuring smooth buffering action. However, this restricts the position of the threaded hole within the entire device. Sometimes, due to manufacturing tolerances, the connecting holes between the star-rocket separation components are aligned but not fully centered, causing the bolt and nut to misalign and fail to connect properly. This device features a movable clearance 10 and a first through hole 13 with a diameter larger than the threaded hole 16. This allows the movable nut 6 to move itself when the explosive bolt 8 is screwed in, ensuring complete alignment between the first through hole 13 and the threaded hole 16 and guaranteeing smooth connection. Furthermore, the buffer 3 is made of dense foam, which reduces the impact from 3500g to 2000g during buffering, achieving a better cushioning effect.

[0038] Based on the above embodiments, in a preferred embodiment, such as Figure 3 As shown, the top wall of the housing 1 extends outward to form a connecting plate 26. The connecting plate 26 is provided with a second through hole suitable for bolt connection, thereby enabling connection with a satellite. This design of the connecting plate 26 utilizes the height of the housing 1 itself, providing ample operating space for bolt connection with the satellite, and offering greater operational convenience compared to connecting via the bottom plate of the housing 1.

[0039] Based on the above embodiments, in a preferred embodiment, such as Figure 3 As shown, the side wall of the housing 1 has an opening 14; the sliding nut 6, the top block 5, and the buffer 3 are adapted to be inserted into the inner cavity of the housing 1 through the opening 14, so that these buffer-related parts can be installed or removed from the side of the housing 1. This side-mounted buffer part is more conducive to the maintenance of the buffer parts than the top or bottom-mounted method. In particular, after the satellite and rocket are assembled, it can avoid the need to disassemble the rocket body or satellite before the buffer device can be inspected or repaired. For example, if the threaded pair is stripped, the sliding nut 6 can be easily replaced, or the elasticity of the buffer 3 can be checked before launch, thus ensuring the smooth separation of the satellite and rocket.

[0040] However, the side-mounted buffer component may not completely fill the inner cavity of the housing 1. In this case, it can be addressed as follows: Figure 1 As shown, a first buffer pad 2 with elasticity can be appropriately added to fill the gap, thereby fully utilizing the buffering capacity. Similarly, a second buffer pad 4 can be set between the floating nut 6 and the top block 5.

[0041] Based on the above embodiments, in a preferred embodiment, such as Figure 2 and 3 As shown, the side walls of the housing 1 located on both sides of the opening 14 are integrally formed with the top and bottom walls of the housing 1, thus forming a supporting connection between the top and bottom walls of the housing 1. The side walls of the housing 1 serve as connecting components between its top and bottom walls. Compared to a split structure assembled and connected, such as using plates and bolts to form the housing body 15, the integrally formed side walls provide a continuous and uninterrupted connection between the two walls, resulting in higher connection strength. This ensures the reliability of the connection between the satellite and the rocket body at both ends of the buffer device, and also maintains the integrity of the housing 1 after being subjected to the explosive impact of the explosive bolts 8, preventing debris from entering the orbital space and causing contamination. Alternatively, with the same connection strength, the higher strength of the integral structure can reduce the overall weight and volume of the device.

[0042] Based on the above embodiments, in a preferred embodiment, such as Figure 1 As shown, a baffle 9 is provided at the opening 14. The baffle 9 is detachably connected to the box 1 via bolts and baffle connection holes 11, and the baffle 9 seals the inner cavity of the box 1. Because the explosive bolt 8 will generate a strong impact after the explosion, it may cause partial breakage of the buffer 3. However, after the baffle 9 seals the inner cavity of the box 1, the box 1 can perform its collection function and prevent debris from entering the track space.

[0043] Based on the above embodiments, in a preferred embodiment, such as Figure 5 and 6As shown, a stop block, namely a first side stop block 20 and a second side stop block 22, is provided at the top of the two opposite side walls of the groove 23. The side of the stop block is flush with the inner wall of the groove 23. The height from the bottom surface of the groove 23 to the top of the stop block is the same as the height of the movable nut 6. Since the groove 23 serves to lock and limit the movable nut 6, the mating surface between the groove 23 and the movable nut 6, i.e., the side end face 17 of the groove 23 and the movable nut 6, needs to be relatively large to ensure the stability of the lock. Although the top block 5 could be made of a thicker plate to create a deeper groove 23 to achieve this purpose, this would result in a larger self-weight of the top block 5. By using the first side stop block 20 and the second side stop block 22, the lock block completes the engagement with the movable nut 6, so that the groove 23 does not need to be too deep. This allows the top block 5 to use a thinner top block body 18, reducing the self-weight of the top block 5. In addition, this also provides the feasibility for setting the locking block 12 mentioned below.

[0044] Based on the above embodiments, in a preferred embodiment, such as Figure 2 and 3 As shown, the stop block is arranged along the direction in which the top block 5 is inserted from the opening 14. A locking block 12 is provided on the side walls of the housing 1 located on both sides of the opening 14. The movable nut 6 is square, and a locking relationship is formed between the locking block 12 and the adjacent side of the movable nut 6. This locking relationship should also have a movable clearance 10 to ensure the aforementioned nut movable ability. After the stop block is arranged along the direction in which the top block 5 is inserted from the opening 14, a certain gap can appear in the movable nut 6. By setting the locking block 12 within this space, the movable nut 6 can directly engage and limit the movement of the housing 1, thereby reducing the torque transmitted through the top block 5 during the pre-tightening bolt process. This torque creates a compressive force between the top block 5 and the housing 1. However, as mentioned above, to reduce the weight of the top block 5, the main body 18 of the top block is made of a thinner plate. Since friction is inversely proportional to the contact area, under the same compressive force, the thinner main body 18 will generate greater friction between the top block and the housing 1. This increases friction during the sliding process of the top block 5 under impact, causing the impact force to act more directly on the housing 1, rather than being buffered through the buffer 3. After the compressive force between the top block 5 and the housing 1 is distributed by the locking block 12, the frictional force on the housing 1 during the buffer sliding process can be reduced, thereby improving the overall buffering effect.

[0045] Based on the above embodiments, in a preferred embodiment, such as Figure 5As shown, a boss 21 is provided on the top surface of the top block 5. The boss 21 is located on the back side of the groove 23, and the bottom surface of the boss 21 is larger than the bottom surface of the groove 23. In order to achieve a proper fit with the top block 5, the buffer 3 is provided with a receiving groove 24 that matches the contour of the boss 21, so that the two form the largest possible contact surface. The above arrangement can minimize the weight of the top block 5 while ensuring the structural strength of the top block 5. Because the presence of the groove 23 weakens the wall thickness of the relevant parts of the top block body 18, it causes a decrease in strength and may break unexpectedly under strong impact, thus affecting the normal operation of the buffering process. By providing a boss 21 with a larger bottom surface on the back side of the groove 23, the wall thickness weakened by the sinking of the groove 23 can be strengthened without excessively increasing the weight of the top block 5.

[0046] Based on the above embodiments, in a preferred embodiment, such as Figure 5 and 6 As shown, a first receiving hole 19 is provided on the bottom surface of the groove 23, and the first receiving hole 19 is aligned with the threaded hole 16. After the explosion bolt 8 is screwed into the floating nut 6, it may protrude one end. Therefore, the first receiving hole 19 is provided to avoid interference between the components and ensure that the connection operation is carried out smoothly.

[0047] Based on the above embodiments, in a preferred embodiment, such as Figures 5 to 7 As shown, the first receiving hole 19 is a through hole, and the second receiving hole 25 is provided on the buffer member 3. This arrangement enhances the device's ability to accommodate the protruding part of the explosion bolt 8, thus improving its applicability.

[0048] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A buffer device for explosive bolts, characterized in that, include: The bottom wall of the box (1) has a through hole (13). The movable nut (6) is made of high-strength steel and abuts against the inner side of the bottom wall of the box (1). It is provided with a threaded hole (16) suitable for connection with the explosion bolt (8). The threaded hole (16) is aligned with the first through hole (13). The diameter of the first through hole (13) is larger than the diameter of the threaded hole (16). The top block (5) is made of lightweight metal; the top block (5) is engaged with the inner cavity of the housing (1), thereby preventing the top block (5) from rotating around the axis of the first through hole (13); the top block (5) and the housing (1) form a sliding connection in the axial direction of the first through hole (13); a groove (23) is provided on the bottom surface of the top block (5); the groove (23) is engaged with the floating nut (6), thereby preventing the floating nut (6) from rotating around the axis of the threaded hole (16); a floating gap (10) is provided between the side walls of the floating nut (6) and the groove (23). The buffer (3) is set between the top surface of the top block (5) and the top wall of the box (1); A stop block is provided at the top of each of the two opposite sidewalls of the groove (23), and the side of the stop block is flush with the inner wall of the groove (23); the height from the bottom surface of the groove (23) to the top of the stop block is equal to the height of the floating nut (6); The stop block is set along the direction in which the top block (5) is inserted from the opening (14). A locking block (12) is set on the side wall of the housing (1) on both sides of the opening (14). The movable nut (6) is square. The locking block (12) and the adjacent side of the movable nut (6) form a locking relationship with a movable gap (10). The stop block completes the cooperation with the movable nut (6), so that the groove (23) does not have to be too deep, and the top block (5) can use a thinner top block body (18), reducing the weight of the top block (5). A boss (21) is provided on the top surface of the top block (5). The boss (21) is located on the back side of the groove (23). The bottom surface of the boss (21) is larger than the bottom surface of the groove (23). A receiving groove (24) that matches the contour of the boss (21) is provided on the buffer (3). After the stop block is set along the direction of insertion of the top block (5) from the opening (14), a certain gap appears in the floating nut (6). In this space, a locking block (12) is set on the housing (1) so that the floating nut (6) and the housing (1) directly form a locking and limiting relationship, thereby reducing the torque transmitted through the top block (5) during the pre-tightening bolt process.

2. The buffer device for explosive bolts according to claim 1, characterized in that, The top wall of the box (1) extends outward to form a connecting plate (26), and the connecting plate (26) is provided with a second through hole suitable for bolt connection.

3. The buffer device for explosive bolts according to claim 2, characterized in that, The side wall of the housing (1) is provided with an opening (14); the floating nut (6), the top block (5) and the buffer (3) are adapted to be inserted into the inner cavity of the housing (1) through the opening (14).

4. The buffer device for explosive bolts according to claim 3, characterized in that, The side walls of the box (1) located on both sides of the opening (14) are integrally formed with the top and bottom walls of the box (1), thereby forming a support connection between the top and bottom walls of the box (1).

5. The buffer device for explosive bolts according to claim 3, characterized in that, A baffle (9) is provided at the opening (14). The baffle (9) is detachably connected to the box (1). The baffle (9) closes the inner cavity of the box (1).

6. The buffer device for explosive bolts according to claim 1, characterized in that, A first receiving hole (19) is provided on the bottom surface of the groove (23), and the first receiving hole (19) is aligned with the threaded hole (16).

7. The buffer device for explosive bolts according to claim 6, characterized in that, The first receiving hole (19) is a through hole, and the second receiving hole (25) is provided on the buffer (3).

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