Active fragment with multiple damage functions

Abstract

The invention discloses a multi-damage functional active fragment which comprises an end cover, a shell, an explosion damage front-stage active core body, an action time sequence control device and a high-temperature damage rear-stage active core body, a multi-stage damage coupling core body is designed, kinetic energy and chemical energy double damage is achieved at the front stage, and long-time high-temperature hot corrosion damage is achieved at the rear stage. And the action time sequence control device is connected with the front stage and the rear stage and is used for controlling energy output structures and action time sequences of the front stage and the rear stage, so that the damage power is maximized. The problems of single penetration damage of a traditional metal fragment kinetic energy machine, short-time damage of an existing active fragment due to secondary detonation and the like are solved, meanwhile, the fragment structure is convenient for engineering application, and the fragment structure can be used as a prefabricated fragment to be used for an explosion-killing warhead, so that the development of the multi-effect damage capability of the explosion-killing warhead is further promoted.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of prefabricated fragments, and particularly relates to a multi-damage function active fragment. BACKGROUND

[0002] The fragment is one of the main damage elements of a missile warhead. The fragment is mainly formed into a high-speed killing fragment driven by explosion energy after explosion of high-energy explosive filled in the warhead, and the target is effectively damaged by kinetic energy. The traditional fragment is usually made of metal materials (such as steel, tungsten, tungsten alloy, etc.) with stable chemical properties, high density and high strength, which often causes the effect of “hitting but not destroying” to the target, greatly reducing the damage capability of the missile warhead.

[0003] With the rapid development of target protection technology, the killing fragment faces severe technical challenges. First, the target protection capability is strong, the protection layer is thick, and the protection structure is complex, which reduces the penetration capability of the fragment by effectively buffering the kinetic energy of the fragment, and prevents the fragment from penetrating the target. Second, the battlefield target is complex, and the target cannot lose combat capability only by the penetration of the fragment, and cannot be “destroyed by one hit”. The above two deficiencies limit the play of the high-efficiency terminal damage power of the traditional metal fragment and the multipurpose application.

[0004] Active material is a new type of high-energy density energetic material, which has the typical characteristics of “metal-like mechanical strength, explosive-like chemical energy, inert impact-like insensitivity, quasi-millisecond activation delay”, and can realize the time sequence combined damage of “first penetration and then explosion” to the target. Due to the fast chemical reaction rate of “explosion after penetration”, the energy is released quickly, which can quickly generate shock wave overpressure and high-temperature fireball in a small closed space, but the shock wave positive pressure action time and fireball duration are short, and the fireball explosion temperature is low, which cannot cause fatal damage to the target behind the target and electronic equipment. Therefore, how to improve the existing active fragment structure to realize the coupling relationship between the effective damage action time persistence, high explosion temperature and target damage effect, so as to improve the high-efficiency multi-damage capability of the fragment, is a problem to be solved.

[0005] Patent document CN116294867A discloses an impact initiation enhanced active fragment, specifically a hot spot distribution network structure is arranged in the fragment, and the hot spot in the conductive network structure is activated by collision, so that the active fragment generates explosion effect under the simultaneous activation of collision and hot spot, and solves the problem that the active material in the fragment is not excited or not completely excited under the condition of insufficient collision kinetic energy or poor collision attitude. However, the invention only solves the problem of active fragment activation threshold, and still has problems such as short target damage action duration and low explosion temperature. SUMMARY

[0006] The present application aims at the deficiencies of the prior art, and provides a multi-damage functional active fragment, which makes up for the power deficiency problems of the single damage of kinetic energy mechanical penetration of traditional metal fragments and the short-time damage of secondary explosion of existing active fragments.

[0007] In order to achieve the above-mentioned purpose, the present application provides a multi-damage functional active fragment, which comprises an end cover, a shell, an explosion damage front-stage active core, an action time sequence control device and a high-temperature damage rear-stage active core. The explosion damage front-stage active core, the action time sequence control device and the high-temperature damage rear-stage active core are sequentially coaxially filled in the shell without gaps; the high-temperature damage rear-stage active core is filled in the bottom end of the shell. The end cover is installed on the opening end surface of the shell; the explosion damage front-stage active core is tightly attached to the bottom of the end cover.

[0008] Further, the thickness of the end cover along the axial direction is 0.08-0.12 times the diameter of the fragment.

[0009] Further, the thickness of the shell is 0.075-0.1 times the diameter of the fragment.

[0010] Further, the shell is engraved with V-shaped grooves, the V-shaped grooves are opened inward, are uniformly distributed along the circumference, and the V-shaped grooves start from the opening end surface of the shell and end at the contact surface position of the explosion damage front-stage core and the action time sequence control device.

[0011] Further, the explosion damage front-stage active core adopts fluoropolymer-based active material.

[0012] Further, the high-temperature damage rear-stage active core adopts a mixture of aluminum thermite and fluoropolymer-based active material, and the mass percentage of the fluoropolymer-based active material is not higher than 10%.

[0013] Further, the action time sequence control device comprises a heat transfer device and an ignition rod.

[0014] Further, the heat transfer device is a cylindrical porous structure.

[0015] Further, the ignition rod is placed in the inner hole of the heat transfer device, and the length and the burning speed of the ignition rod control the action time sequence of the explosion damage front-stage active core and the high-temperature damage rear-stage active core.

[0016] The present application has the following beneficial effects: (1) The application designs a two-stage series multi-damage function active fragment structure, combines with the penetration enhancer design, takes into account mechanical penetration and chemical reaction energy release, realizes multi-mode synergistic damage of mechanical penetration damage, chemical energy explosion and high-temperature thermal erosion, greatly breaks through the limitations of traditional single kinetic energy damage of metal fragments, significantly improves the damage power and diversity of damage mechanism to the target, and at the same time solves the problems of single energy output structure and short secondary explosion damage duration of the existing active fragment, and improves the comprehensive damage effect.

[0017] (2) The multi-damage function active fragment structure of the application can accurately coordinate the energy release of the front and rear active cores through the action time sequence control device, realize the continuity and long duration of the damage process, ensure that the fragments play the optimal effect in different damage stages, and improve the killing coverage and continuous effect.

[0018] (3) The application has wide material sources, low cost, simple and easy-to-operate preparation process, and is convenient for industrialized production and engineering application, and can be used as a prefabricated fragment for a blast combat unit, and promotes the practicalization process of multi-effect damage technology. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a schematic diagram of the multi-damage function active fragment structure of the application; Figure 2 is a schematic diagram of the multi-damage function active fragment structure of the application; Figure 3 is a schematic diagram of the shell structure of the application; Figure 4 is a schematic diagram of the internal combination structure of the action time sequence control device of the application; Figure 5 is a schematic diagram of the multi-damage function active fragment structure of the application; Figure 6 is a schematic diagram of the shell structure of the application; Figure 7 is an active fragment action time sequence process diagram of the application; Figure 8a is an explosion damage front active core action process diagram of the application; Figure 8b is a high-temperature damage rear active core action process diagram of the application.

[0020] wherein 1 is an end cover, 2 is a shell, 3 is an explosion damage front active core, 4 is an action time sequence control device, 5 is a high-temperature damage rear active core, 6 is a heat transfer device, and 7 is an ignition rod. DETAILED DESCRIPTION

[0021] To clearly illustrate the technical features of the application, the following specific embodiments are used to describe the application.

[0022] The present application provides a multi-damage function active fragment, such as Figures 1-3 As shown, including end cap 1, shell 2, internal active core, action timing control device 4, internal active core includes explosive damage front active core 3, and high temperature damage after active core 5.

[0023] Explosive damage front active core 3, action timing control device 4 and high temperature damage after active core 5 are sequentially coaxially filled in the inside of shell 2; high temperature damage after active core 5 is filled in the inside of shell 2 bottom, and is tightly attached to the inside of shell 2 bottom.

[0024] End cap 1 is installed in the opening end face of shell 2, end cap 1 is a circular flat end cap with annular boss, the diameter of annular boss linearly changes, converges to the minimum diameter at the flat position, the outer envelope size of end cap 1 is consistent with the inner envelope size of the opening end face of shell 2, which is used for sealing shell 2; the bottom of end cap 1 is tightly attached to explosive damage front active core 3; End cap 1 adopts high density and high strength material, such as tungsten alloy or steel, amorphous alloy or high entropy alloy material, preferably 45# steel, stainless steel; The thickness of end cap 1 along the axial direction is 0.08-0.12 times the diameter of the active fragment, which can effectively weaken the stress wave peak value generated by impact under the premise of meeting certain penetration ability, and can ensure that the peak value is higher than the impact activation threshold of fluoropolymer-based active material; End cap 1 provides sufficient penetration ability for the internal active core and weakens the stress wave peak value generated by impact, preventing explosive damage front active core 3 from activating reaction in advance before the target.

[0025] The material of shell 2 is selected to be the same as the material of end cap; Shell 2 is a cylindrical thin-walled structure, the geometric shape of which is determined by the thickness, diameter and height parameters; The thickness of shell 2 is 0.075-0.1 times the diameter of the fragment, which can ensure the integrity of the internal core when penetrating the first layer of target, and can ensure that the energy consumed by the shell rupture during the post-explosion reaction process is less; Shell 2 is used to assemble front and rear active cores and action timing control device 4, which improves the strength of active fragment, improves the kinetic energy penetration ability, protects the effective residual mass of active fragment into the target, and provides certain penetration ability for the core.

[0026] Explosive damage front active core 3 is cylindrical and is filled in the structure inside of shell 2; The outer envelope size of explosive damage front active core 3 is consistent with the inner cavity size of shell 2 structure; Explosive damage front active core 3 is made of fluoropolymer-based active material, which has impact activation characteristics; Key parameters such as the outer envelope size, material formula, activation threshold, theoretical energy content, etc. of the active core 3 before explosion damage should be determined in combination with the target damage requirements.

[0027] like Figure 4 As shown, the action sequence control device 4 is cylindrical, with its outer envelope dimensions consistent with the internal dimensions of the shell 2 structure. It is installed between the front-stage active core 3 for explosion damage and the rear-stage active core 5 for high-temperature damage. It is used to control the action sequence of the front-stage active core 3 and the rear-stage active core 5, that is, to control the start time of the high-temperature damage of the rear-stage active core 5. On the other hand, when the density or length of the front and rear-stage cores are adjusted, the position and length of the action sequence control device can be used to effectively adjust the overall center of mass of the active fragments, thereby ensuring flight stability. The action timing control device 4 includes a heat transfer device 6 and an ignition rod 7; The heat transfer device 6 is a cylindrical porous structure, made of a metal material with good thermal conductivity such as copper, aluminum, etc., and has good thermal conductivity; An ignition rod 7 having the same diameter and height as the hole is placed in the hole of the heat transfer device 6. The ignition rod 7 is made of flammable metal such as magnesium, or a cylindrical propellant, which has good ignition performance, uniform combustion and stable speed; The length and burning speed of the ignition rod 7 are used to control the action time of the front and rear cores, thereby adjusting the energy output structure and action sequence of the front and rear cores to maximize the multi-destructive power. Parameters such as the internal hole diameter and distribution number of the action timing control device 4 should be determined in combination with the damage requirements for the target.

[0028] The high-temperature damage rear-stage active core 5 is cylindrical, and its outer envelope size is consistent with the inner cavity size of the shell 2 structure, and is installed at the bottom end of the shell 2 structure; The high-temperature damage post-stage active core 5 is made of a mixture of thermite and fluoropolymer-based active materials, wherein the fluoropolymer material is mainly used as a binder for forming the high-temperature damage post-stage active core, and the mass percentage of the fluoropolymer material is not higher than 10%; Key parameters such as the outer envelope size, material formulation, activation threshold, and theoretical energy content of the high-temperature damage post-stage active core 5 should be determined in combination with the target damage requirements. Example 1

[0029] When penetrating a thick target plate, in order to ensure the quality of the active core remaining behind the target, thicker end caps 1 and shells 2 are required.

[0030] A multi-damage function active fragment, the outer end diameter of the end cap 1 is 40mm, the inner end diameter is 32mm, the total thickness is 4.8mm, the thickness of the region with linearly changing diameter is 2mm, and it is tightly fitted in the internal structure size of the shell 2. The material is selected from 45 steel, the density is 7.85g / cm 3 , the elastic modulus is 200GPa, the yield strength is 496MPa, and the tensile strength is 600MPa.

[0031] The pre-explosion damage active core 3 is cylindrical, the size is F32mm´17mm, the material is PTFE / Al, and it is prepared by dry mixing, hot pressing and vacuum sintering, the density is 2.30g / cm 3 , the theoretical energy content is 9.13MJ / kg, the activation pressure threshold is 735MPa, and it is tightly fitted in the internal cavity of the shell 2 structure.

[0032] The post-high-temperature damage active core 5 is cylindrical, the size is F32mm´11mm. The material is PTFE / Al / Fe2O3, which is prepared by dry mixing, cold pressing and vacuum sintering, the density is 3.24g / cm 3 , the density is 80%, the theoretical energy content is 3.96MJ / kg, and it is tightly fitted in the internal cavity of the shell 2 structure.

[0033] The action time sequence control device 4 includes a heat transfer device 6 and an ignition rod 7, wherein the heat transfer device 6 is cylindrical, the inside is a porous structure, and the outer envelope size is F32mm´4mm. The material is copper, the density is 8.94g / cm 3 , the thermal conductivity of copper is 400W / (m·K), and it is tightly fitted in the internal cavity of the shell 2 structure.

[0034] The internal structure of the heat transfer device 6 is three layers of small holes, the center of the innermost layer of small holes coincides with the center of the heat transfer device 6; the center of the second layer of small holes is 6mm away from the innermost layer of small holes, and is uniformly distributed on the circumference with the center of the innermost layer of small holes as the center and a radius of 6mm, and the number of distribution is 6; the center of the third layer of small holes is 12mm away from the innermost layer of small holes, and is uniformly distributed on the circumference with the center of the innermost layer of small holes as the center and a radius of 12mm, and the number of distribution is 12, and the size of all small holes in the material is F4mm´4mm.

[0035] The ignition rod 7 in the action time sequence control device 4 is cylindrical, the size is F4mm´4mm, and it is tightly fitted in the small hole of the heat transfer device 6. The material is magnesium, the density is 1.74g / cm 3 , the flash point is 500℃, and the combustion enthalpy is 688J / (kg·K).

[0036] The shell 2 has an outer diameter of 40 mm, an inner diameter of 32 mm, and a total height of 40 mm. At the opening end of the shell 2, there is a region with a linearly changing wall thickness, which closely matches the outer envelope size of the end cap. The material is consistent with that of the end cap, which is 45 steel, with a density of 7.85 g / cm 3 , an elastic modulus of 200 GPa, a yield strength of 496 MPa, and a tensile strength of 600 MPa. Example 2

[0037] When penetrating a thin target plate, in order to achieve a higher loading ratio of the active core, the thickness of the end cap 1 and the shell 2 can be reduced.

[0038] Unlike example 1, the end cap 1 has an outer diameter of 40 mm, an inner diameter of 34 mm, and a total thickness of 3.2 mm, of which the region with a linearly changing diameter has a thickness of 2 mm.

[0039] The pre-explosion damage active core 3 has a size of F34 mm´18 mm.

[0040] The outer envelope size of the action timing control device 4 is F34 mm´3 mm.

[0041] The post-high-temperature damage active core 5 has a size of F34 mm´12 mm.

[0042] The size of all the small holes in the heat transfer device 6 is F4 mm´3 mm, and the size of the ignition rod 7 is F4 mm´3 mm.

[0043] The shell 2 has an outer diameter of 40 mm, an inner diameter of 34 mm, and a total height of 40 mm. Example 3

[0044] Unlike example 1, as shown in Figure 5 and Figure 6 , a V-shaped groove is engraved in the shell 2, the V-shaped groove is open inward, and there are 32 evenly distributed V-shaped grooves along the circumference, the groove depth is half the thickness of the shell 2, the V-shaped groove angle is 20°, and the V-shaped groove starts from the opening end surface of the shell 2 and ends at the contact surface position of the pre-explosion damage active core 3 and the action timing control device 4, that is, the length of the V-shaped groove is the sum of the thickness of the end cap and the pre-explosion damage active core.

[0045] The V-shaped groove engraved in the shell 2 can not only ensure that the active fragments have a certain penetration ability, but also further reduce the energy consumed by the shell rupture during the post-explosion reaction of the target, and can also meet the requirement of forming small fragments with uniform mass distribution when the active fragments are broken, thereby causing certain damage to the target.

[0046] The working principle of the multi-damage functional active fragment of the present application is as follows Figure 7And as shown in Figure 8: the fragments fly at a high initial velocity under the driving of high-energy explosive detonation. The fragment end cap 1 first contacts the target, generating a strong impact load, causing the end cap to rupture, and the shock wave is transmitted to the explosive damage front-stage active core 3 along the axial direction. The end cap structure effectively weakens the load peak transmitted to the front-stage core, avoiding its activation and deflagration reaction in front of the target, ensuring the integrity of the internal active material. After the fragment penetrates the target, the front-stage active core is activated and explodes, releasing high-temperature and high-pressure gas and accompanied by shell fragmentation, forming fragments with uniform mass distribution, causing damage to the target. The action timing control device 4 ignites the high-temperature damage rear-stage active core through the internal ignition rod 7, controls the time when it starts to react, adjusts the total energy output time of the front-stage and rear-stage cores, and maximizes the damage and power.

[0047] As shown in Figure 8, the front-stage core undergoes a violent deflagration reaction after penetrating the target, forming a high-temperature fireball and a secondary shock wave, and implementing the first stage of damage to the target. At the same time, the ignition rod 7 in the action timing control device 4 is ignited, and according to its burning speed and length, the start time of the rear-stage core is determined, realizing the adjustment of the energy output structure. When the rear-stage core starts to react, a large number of high-temperature molten metal droplets are generated, which implement the second stage of damage to the target behind the target, and finally realize the "one-hit destruction" of the target through the time sequence coupling of kinetic energy penetration, chemical deflagration and high-temperature thermal erosion.

[0048] Based on the above principles, the length-diameter ratio and loading mass of the front-stage and rear-stage active cores can be adjusted according to the target characteristics such as target plate thickness and damage requirements, as well as the active core activation threshold and energy content, to realize active fragment kinetic energy penetration, target rear chemical energy release and high-temperature, long-time thermal erosion damage.

[0049] The technical features of the present application not described herein can be realized by or using existing technology, which will not be described here. Of course, the above description is not a limitation of the present application, and the present application is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary skilled in the art within the scope of the present application should also be within the scope of protection of the present application.

Claims

1. A multi-damage function active fragment, characterized in that: It comprises an end cover (1), a shell (2), an explosion-damaged front-stage active core (3), an action timing control device (4), and a high-temperature-damaged rear-stage active core (5); The explosion damage front stage active core (3), the action timing control device (4) and the high temperature damage rear stage active core (5) are sequentially coaxially and seamlessly loaded inside the shell (2); the high temperature damage rear stage active core (5) is loaded at the bottom end inside the shell (2); The end cover (1) is mounted on the open end surface of the shell (2); the explosion-damaged front-stage active core (3) is tightly fitted to the bottom of the end cover (1).

2. The multi-damage active fragment according to claim 1, characterized in that: The thickness of the end cover (1) along the axial direction is 0.08 to 0.12 times the diameter of the fragment.

3. The multi-damage active fragment according to claim 1, characterized in that: The thickness of the shell (2) is 0.075 to 0.1 times the diameter of the fragment.

4. The multi-damage active fragment according to claim 1, characterized in that: The shell (2) is internally engraved with V-shaped grooves, which open inward and are evenly distributed along the circumference; the V-shaped grooves start from the open end face of the shell (2) and end at the contact surface position between the front-stage core (3) and the action timing control device (4) through explosion damage.

5. The multi-damage active fragment according to claim 1, characterized in that: The explosion-damaging front-stage active core (3) adopts a fluoropolymer-based active material.

6. The multi-damage active fragment according to claim 1, characterized in that: The high-temperature damaged rear-stage active core (5) is made of a mixture of thermite and fluoropolymer-based active material, wherein the mass percentage of the fluoropolymer-based active material is not higher than 10%.

7. The multi-damage active fragment according to claim 1, characterized in that: The action timing control device (4) comprises a heat transfer device (6) and an ignition rod (7).

8. The multi-damage active fragment according to claim 7, characterized in that: The heat transfer device (6) is a cylindrical porous structure.

9. The multi-damage active fragment according to claim 8, characterized in that: The ignition rod (7) is placed in the inner hole of the heat transfer device (6), and the action sequence of the explosion damaging the front-stage active core (3) and the high-temperature damaging the rear-stage active core (5) is controlled by the length of the ignition rod (7) and its burning speed.

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