A lightweight impact-attenuating device suitable for use with an oversized load-bearing explosive bolt

Abstract

The application relates to a light-weight capture and impact-reducing device suitable for an ultra-large bearing explosive bolt, which solves the problem of strong impact during capture and belongs to the technical field of spacecraft structures. The light-weight capture and impact-reducing device adopts a multi-configuration lattice structure and a special-shaped rubber pad, combines the viscoelastic deformation characteristics of rubber and the plastic energy-absorbing characteristics of a negative Poisson's ratio lattice energy-absorbing material, and realizes the capture and buffer impact reduction of a high-speed separated bolt body. The device has the advantages of good buffer effect, strong installation adaptability, light structure weight and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of spacecraft structures and relates to a lightweight capture shock-reducing device suitable for super-large load-bearing explosive bolts. BACKGROUND

[0002] An explosive bolt is one of commonly used separation devices in a spacecraft, which uses tensile and shearing mechanical effects of loaded explosives to make a designated part break to complete unlocking. After the explosive bolt is initiated and separated, the docking bolt body will fly at a high speed to the catcher, thereby generating a large impact and vibration response, and even directly penetrating the catcher shell to cause damage to nearby structural equipment, so measures still need to be taken to control the capture risk and influence after the explosive bolt is initiated and separated. SUMMARY

[0003] The application aims to solve the technical problem of overcoming the shortcomings of the prior art and solving the problem of strong impact during capture caused by high-speed movement of a structural part when a super-large load-bearing explosive bolt is separated.

[0004] The application aims to solve the technical problem of overcoming the shortcomings of the prior art and solving the problem of strong impact during capture caused by high-speed movement of a structural part when a super-large load-bearing explosive bolt is separated.

[0005] The application aims to solve the technical problem of overcoming the shortcomings of the prior art and solving the problem of strong impact during capture caused by high-speed movement of a structural part when a super-large load-bearing explosive bolt is separated.

[0006] The connecting structure a and the connecting structure b are connected through the explosive bolt c, the flange nut and the bolt cone cap.

[0007] One end of the stud bolt is connected with the connecting structure a, and the other end passes through the special-shaped buffer pad I, the base, the special-shaped buffer pad II, the special-shaped buffer pad III, the double-hole gasket and is connected with the mounting nut.

[0008] The base is connected with the shell, the negative Poisson's ratio lattice structure is installed inside the shell, the negative Poisson's ratio lattice structure is used for energy absorption and buffering of the bolt rod flying out after the explosive bolt is separated, and the part of the negative Poisson's ratio lattice structure close to the base is inserted into the base.

[0009] The bushing is installed from the bottom of the base and is a thin-walled cylinder structure, the upper part has four inwardly curved claws, and the bottom flange is installed between the base and the special-shaped buffer pad.

[0010] Compared with the prior art, the application has the following beneficial effects:

[0011] (1) The application has strong installation adaptability: the interface is simple and suitable for various types of installation boundaries; and it is suitable for various large load-bearing explosive bolts.

[0012] (2) The invention has good buffering performance: the heterogeneous buffer pad and the negative Poisson's ratio lattice device are connected in series and parallel, the impact path is blocked and the energy is matched, so that the high-speed bolt body is captured and the impact is reduced.

[0013] (3) The invention has simple structure and light weight: the low-density light impact-reducing material is used, and the structure is simple and compact.

[0014] (4) The invention uses the compression and rebound characteristics of rubber material to form a non-rigid contact between the device and the mounting surface, and realizes the impact reduction effect by the viscoelastic deformation of rubber during the bolt body capturing process, and fills the space by the rebound of rubber after capturing, so as to realize the fixation of the device.

[0015] (5) The invention uses the negative Poisson's ratio lattice structure and the heterogeneous rubber pad, and realizes the capture and buffering impact reduction of the high-speed bolt body through the impact path blocking and energy absorption matching design.

[0016] (6) The invention integrates the existing explosive bolt box and the capture and buffering device, reduces the redundant weight of the structure, and increases the rocket carrying capacity. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a structure principle diagram of the capture and impact reduction device.

[0018] Figure 2 It is a structure principle diagram of the base.

[0019] Figure 3 It is a structure principle diagram of the shell.

[0020] Figure 4 It is a structure principle diagram of the bushing.

[0021] Figure 5 It is a structure principle diagram of the heterogeneous buffer pad I.

[0022] Figure 6 It is a structure principle diagram of the heterogeneous buffer pad II.

[0023] Figure 7 It is a structure principle diagram of the heterogeneous buffer pad III.

[0024] Figure 8 It is a structure principle diagram of the negative Poisson's ratio lattice.

[0025] Figure 9 It is a structure principle diagram of the flange nut.

[0026] Figure 10 It is a structure principle diagram of the bolt cone cap.

[0027] Figure 11 It is a structure principle diagram of the double-headed stud.

[0028] Figure 12 It is a double-hole gasket structure schematic diagram.

[0029] The figure mark: base-1, shell-2, bush-3, profiled cushion I-4, profiled cushion II-5, profiled cushion III-6, negative Poisson's ratio lattice structure-7, double-hole gasket-8, bolt cone cap-9, stud bolt-10, flange nut-11, mounting nut-12, connecting structure a-13, connecting structure b-14, explosive bolt c-15. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0031] A lightweight capture and impact reduction device suitable for explosive bolts with a bearing capacity greater than 150kN, adopts multi-configuration lattice structure and profiled rubber cushion, combines the viscoelastic deformation characteristics of rubber and the plastic energy absorption characteristics of negative Poisson's ratio lattice energy absorption material, realizes the capture and impact reduction of high-speed separated bolt body. The device has the advantages of good buffering effect, strong installation adaptability, light structure weight, etc.

[0032] A lightweight capture and impact reduction device suitable for explosive bolts with a bearing capacity greater than 150kN, comprising a base 1, a shell 2, a bush 3, a profiled cushion I 4, a profiled cushion II 5, a profiled cushion III 6, a negative Poisson's ratio lattice structure 7, a double-hole gasket 8, a bolt cone cap 9, a stud bolt 10, a flange nut 11, a mounting nut 12, as shown in Figure 1 .

[0033] The impact reduction device is installed on the side of the separated bolt body flying out after the explosive bolt c15 is ignited and separated, one end of the stud bolt 10 is connected with the connecting structure a13, the other end passes through the profiled cushion I 4, the base 1, the profiled cushion II 5, the profiled cushion III 6, the double-hole gasket 8, and is connected with the nut 12. The nut 12 is prevented from loosening by a fuse. There are multiple layers of profiled cushions between the base 1 and the gasket 8, including multiple layers of profiled cushion III 6 and one layer of profiled cushion II 5, and there is one layer of profiled cushion I 4 between the base 1 and the connecting structure a13, which are respectively used for buffering and shock absorption between the device and the connecting structure a13 during the bolt body capture process, as shown in Figure 2 , 5 , 6, 7. The stud bolt 10 is designed with two steps at the upper and lower positions for positioning between the thread connection interfaces at both ends, while controlling the compression amount of the profiled cushion, as shown in Figure 11 .

[0034] The base 1 and the housing 2 are connected by threads and secured with set screws. A negative Poisson's ratio lattice structure 7 is installed inside the housing 2 to absorb and buffer the energy of the propellant bolts ejected after separation. A smaller diameter stepped portion of the negative Poisson's ratio lattice structure 7, near the base 1, is inserted into the base 1 for radial positioning. The entire structure is tightened by the threaded connection between the base 1 and the housing 2. Figure 2 , 3 As shown in Figure 8. Bushing 3 is a thin-walled cylindrical structure with four inwardly curved spring claws at the top, as shown in Figure 8. Figure 4 As shown, the bottom flange is installed between the base 1 and the irregular buffer pad 4. It is positioned by the annular step at the bottom of the base 1 and is used to capture and collect the bolt body after separation, preventing the bolt body from returning to the connection hole when it moves freely, which would cause the spacecraft to lose attitude control during separation.

[0035] Connection structure a13 and connection structure b14 are connected by explosion bolt c15, flange nut 11, and bolt cone nut 9. Flange nut 11 and bolt cone nut 9 form a double-nut anti-loosening system. Flange nut 11 is designed with a bottom flange to increase the clamping area. After installation, bolt cone nut 9 is flush with the end face of the explosion bolt, increasing the positive pressure area when the bolt impacts the lattice structure 7. Simultaneously, bolt cone nut 9 provides a circular cross-section top for the separated bolt-nut assembly, ensuring uniform force distribution when the assembly passes through the spring claw of bushing 3, preventing the bolt-nut assembly from tilting and impacting the base 1 or the side wall of housing 2. Figure 9 , 10 As shown.

[0036] The number and distribution of connection holes on the flange face of base 1 can be selected according to the installation boundary of connection structure a, and different numbers of double-ended studs 10 can be used to install the impact capture device. At the same time, it can be adapted to the design of irregular buffer pads I 4, II 5, and III 6.

[0037] The height and diameter of the negative Poisson's ratio lattice structure 7 can be adjusted to suit the mass, separation speed, and impact reduction requirements of different explosive bolts. For explosive bolts with a load capacity of 30t, a negative Poisson's ratio lattice structure with a height of not less than 45mm and a diameter of not less than 37mm is selected; for explosive bolts with a load capacity of 20t, a negative Poisson's ratio lattice structure with a height of not less than 30mm and a diameter of not less than 37mm is selected; and for explosive bolts with a load capacity of 15t, a negative Poisson's ratio lattice structure with a height of not less than 7.5mm and a diameter of not less than 26mm is selected.

[0038] After the explosive bolt C is ignited and separated, the combination of the explosive bolt separation bolt body, the flange nut 11 and the bolt cone cap 9 is ejected under the explosion energy of the explosive agent, impacts the negative Poisson's ratio lattice structure 7, so that the lattice structure is plastically deformed, and at the same time drives the base 1 and the shell 2 combination to move, extrudes the special-shaped buffer pad 5, 6. The plastic energy absorption characteristics of the negative Poisson's ratio lattice energy absorption material and the viscoelastic deformation characteristics of the rubber are used to realize the buffer capture of the high-speed bolt body. After the special-shaped rubber pad 5, 6 is extruded to the limit, the elastic potential energy is released, the base 1 and the shell 2 combination are rebounded, the special-shaped rubber pad 4 is extruded, the impact response generated by the bolt body capture is gradually consumed in the deformation process between the rubber pads, the short-time large response is converted into continuous small response in a longer period of time, and the impact reduction effect is realized.

[0039] More specifically:

[0040] The base 1, the bolt cone cap 9 and the stud 10 are made of 1Cr17Ni2 steel. The threads on both sides of the stud 10 are of different lengths, which are used to distinguish the installation direction, and a step is arranged at the root of the thread for tightening limiting, so as to avoid pre-compressing the special-shaped rubber pad II 5 and the special-shaped rubber pad III 6 during installation, and losing the deformation stroke. The non-threaded light rod has six deformation sections, which is used for tool clamping when torque is applied, and the height of the light rod section is selected according to the number of special-shaped buffer pads.

[0041] The shell 2 is made of 2A14 aluminum alloy.

[0042] The special-shaped buffer pad I 4, the special-shaped buffer pad II 5 and the special-shaped buffer pad III 6 are made of silicone rubber, and the thickness is 6mm. For the layer number of the special-shaped buffer pad III 6, 4 layers are selected for the explosive bolt with a bearing capacity of 30t; 3 layers are selected for the explosive bolt with a bearing capacity of 20t; and 2 layers are selected for the explosive bolt with a bearing capacity of 15t.

[0043] The bushing 3 is made of Ph13-8Mo precipitation hardened stainless steel, and the whole bushing 3 is a thin-walled cylinder structure. The upper half part has four inwardly bent claws for realizing the capture of the separated bolt body, and the bottom end has an outwardly bent flange for installation and fixation.

[0044] The negative Poisson's ratio lattice structure 7 is made of AlSi10Mg metal powder by 3D printing additive manufacturing. The printing wall thickness is 0.5mm, and the wall thickness error is not more than ±10% of the designed wall thickness.

[0045] The double-hole gasket 8 is made of 1Cr18Ni9Ti stainless steel, as shown in Figure 12 .

[0046] The flange nut 11 is made of 30CrMnSiA steel.

[0047] The installation process of the impact reduction and capture device of the application is performed according to the following steps:

[0048] 1) using flange nut 11, bolt cone cap 9, explosive bolt c15 to connect connecting structure a13 and connecting structure b14, and apply a specified torque on flange nut 11 and bolt cone cap 9;

[0049] 2) install stud 10 on connecting structure a13 and apply a specified torque;

[0050] 3) install profiled cushion pad II 5 and profiled cushion pad III 6 on base 1, and ensure that the mounting hole positions are aligned;

[0051] 4) place negative Poisson's ratio lattice 7 on base 1, with the end of the negative Poisson's ratio lattice 7 having a step inserted into base 1;

[0052] 5) tighten the threads between shell 2 and base 1 and apply a specified torque, and before screwing, apply silicone rubber to the threads to achieve the anti-loose of shell 2 and base 1;

[0053] 6) load bushing 3 from the bottom of base 1;

[0054] 7) cover the combination of steps 3)-6) and profiled cushion pad I 4 into the stud of step 2);

[0055] 8) install double-hole gasket 8 and mounting nut 12 according to the position shown in Figure 1 , and after applying a specified torque, secure it.

[0056] The contents not described in detail in the specification of the present application are known to those skilled in the art.

[0057] Although the present application has been disclosed with the above preferred embodiments, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the present application using the methods and technical contents disclosed above without departing from the spirit and scope of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, which does not deviate from the technical solutions of the present application, belongs to the protection scope of the technical solutions of the present application.

Claims

1. A lightweight impact-reducing device suitable for ultra-large load-bearing explosive bolts, characterized in that, Includes base (1), housing (2), bushing (3), irregular buffer pad I (4), irregular buffer pad II (5), irregular buffer pad III (6), negative Poisson ratio lattice structure (7), double hole gasket (8), bolt cone nut (9), double-ended stud (10), flange nut (11), and mounting nut (12); Connection structure a (13) and connection structure b (14) are connected by explosion bolt c (15), flange nut (11) and bolt cone nut (9); One end of the double-ended stud (10) is connected to the connecting structure a (13), and the other end passes through the irregular buffer pad I (4), the base (1), the irregular buffer pad II (5), the irregular buffer pad III (6), and the double-hole washer (8) and is connected to the mounting nut (12); The base (1) is connected to the shell (2). The shell (2) is equipped with a negative Poisson's ratio lattice structure (7). The negative Poisson's ratio lattice structure (7) is used to absorb energy and buffer the screw that flies out after the explosive bolt is separated. The part of the negative Poisson's ratio lattice structure (7) near the base (1) is inserted into the base (1). The bushing (3) is inserted from the bottom of the base (1). It is a thin-walled cylindrical structure with four inwardly curved spring claws on the upper part and the bottom flange is installed between the base (1) and the irregular buffer pad I (4). The load-bearing capacity of the explosion bolt is greater than 150kN.

2. The lightweight capture and impact reduction device according to claim 1, characterized in that, Different-shaped buffer pad Ⅲ (6) is set in multiple layers according to the buffering needs.

3. The lightweight capture and impact reduction device according to claim 1, characterized in that, The irregularly shaped buffer pads III (6) and II (5) are both located between the base (1) and the pad (8); the irregularly shaped buffer pad I (4) is located between the base (1) and the connecting structure a (13).

4. The lightweight capture and impact reduction device according to claim 1, characterized in that, The double-ended stud (10) has two steps at the top and bottom for positioning between the threaded connection interfaces at both ends, and at the same time controls the compression of the irregular buffer pad I (4), irregular buffer pad II (5), and irregular buffer pad III (6).

5. The lightweight capture and impact reduction device according to claim 1, characterized in that, The spring claw of the bushing (3) can prevent the bolt body from returning to the bushing (3) when it moves freely.

6. The lightweight capture and impact reduction device according to claim 1, characterized in that, The flange nut (11) and the bolt cone nut (9) form a double nut anti-loosening mechanism. The bottom flange of the flange nut (11) is used to increase the clamping area. After installation, the bolt cone nut (9) is flush with the end face of the bolt of the explosive bolt, which increases the positive pressure area when the bolt impacts the lattice structure (7). At the same time, the bolt cone nut (9) provides a circular cross-section top for the bolt-nut assembly of the explosive bolt after separation, so that the assembly can be evenly stressed when passing through the spring claw of the bushing (3), and avoid the bolt-nut assembly of the explosive bolt from tilting.

7. The lightweight capture and impact reduction device according to claim 1, characterized in that, The irregularly shaped buffer pads I (4), II (5), and III (6) are all made of silicone rubber.

8. The lightweight capture and impact reduction device according to claim 1, characterized in that, The negative Poisson's ratio lattice structure (7) is formed by 3D printing additive manufacturing of AlSi10Mg metal powder.

9. The lightweight capture and impact reduction device according to claim 1, characterized in that, The bushing (3) is made of Ph13-8Mo precipitation hardening stainless steel. The bushing (3) is a thin-walled cylindrical structure with four inwardly curved spring claws in the upper part.

10. The lightweight capture and impact reduction device according to claim 1, characterized in that, The capture process is as follows: After the explosive bolt c (15) is ignited and separated, the combination of the explosive bolt body, flange nut (11) and bolt cone cap (9) is ejected under the explosive energy of the pyrotechnic agent and impacts the negative Poisson's ratio lattice structure (7), causing the negative Poisson's ratio lattice structure (7) to undergo plastic deformation. At the same time, it drives the combination of the base (1) and the shell (2) to move and squeeze the irregular buffer pad II (5) and irregular buffer pad III (6). Utilizing the plastic energy absorption characteristics of the energy-absorbing material of the negative Poisson's ratio lattice structure (7) and the viscoelastic deformation characteristics of the irregular buffer pad II (5) and irregular buffer pad III (6), the high-speed bolt body is buffered and captured. After the irregular buffer pad II (5) and irregular buffer pad III (6) are squeezed to the limit, the elastic potential energy is released, which pushes the combination of the base (1) and the shell (2) to rebound and squeeze the irregular buffer pad I (4), so that the impact response generated by the bolt body capture is gradually consumed and the capture is completed.

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