Underwater flexible explosive cutting rope-timing coupling structure with enhanced effect

Abstract

The application discloses a kind of underwater flexible detonating cord-cutting cord timing coupling structures with enhanced effect;The present application is based on the existing underwater cutting cord structure basis, a cylindrical flexible detonating cord structure is placed coaxially below it, the flexible detonating cord explodes a certain time before the cutting cord, the shock wave generated by its explosion can form a gas cavity underwater first without damaging the metal shaped charge, the cavity provides a better forming environment than water medium for the cutting cord explosion to collapse the shaped charge and form a shaped jet, thereby making the shaped jet of the present application have higher head speed and stronger cutting performance compared to the shaped jet formed by traditional underwater cutting cord explosion, which can effectively improve the cutting and separation capability of the cutting cord structure on underwater targets.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underwater shaped charge, in particular to an underwater flexible shaped charge-cutter time sequence coupling structure with enhanced effect. BACKGROUND

[0002] The shaped charge effect, also commonly known as "Munroe effect", is that after the explosion of the explosive, the explosion products fly outward along the normal direction of the surface of the explosive under high temperature and high pressure, and form a high-pressure, high-speed, instantaneous strong impact shaped jet at the central axis. When the inner surface of the charge groove is lined with a metal liner, the metal liner is affected by the high-temperature and high-pressure detonation products, and the chemical energy released by the explosion of the explosive is concentrated within a certain range to extrude the metal liner to form a high-speed shaped jet, which completes the damage, cutting and separation of the target structure.

[0003] The cutter structure utilizes the shaped charge effect, that is, after the explosion of the explosive, the explosion products cut the metal material under high temperature and high pressure, which can concentrate the explosion energy in a specific direction and output a shaped jet head speed of 7000m / s-10000m / s in the air, thereby improving the utilization efficiency of the explosive and enhancing the cutting damage ability of the cutter. However, research shows that the cutting ability of the cutter in water and air is different. Because the density, heat transfer speed and viscosity of water are much larger than those of air, the frictional resistance of the jet is greater when it moves at high speed in water, the energy is more dispersed, the head speed of the jet decays faster, the residual speed is lower than that in air, and the cutting ability to the target is weaker. The existing literature lacks research on the related action mechanism of the linear explosive separation structure in the water medium environment. Most of the research focuses on the theory of the linear explosive separation structure in the air, ignores the influence of the changes of water pressure and density, cannot master the key factors affecting the underwater separation performance, and is difficult to meet the requirements of underwater engineering application, which restricts the cutting ability and application range of the linear explosive separation structure in water. Therefore, it is increasingly important to match and couple different shaped charge structures to achieve the effect of underwater explosion close to air explosion to the greatest extent, and to improve the movement speed and cutting performance of the shaped jet in water medium. SUMMARY

[0004] Therefore, the present application provides an underwater flexible shaped charge-cutter time sequence coupling structure with enhanced effect, which adds a flexible shaped charge to the traditional cutter structure and controls the initiation time sequence, so as to obtain an underwater flexible shaped charge-cutter time sequence coupling structure with simple structure and capable of providing a cavity condition for shaped jet formation due to different initiation time sequences. The purpose of providing an air domain forming environment for shaped jet formation is achieved, and the cutting, separation and destruction of the underwater target are realized.

[0005] The underwater soft explosive cord-cutting cord timing coupling structure of the present invention includes: a high-velocity explosive detonation mechanism 1, a high-velocity explosive casing 2, a high-velocity explosive 3, a metal shaped charge liner 4, and a soft explosive cord 5. The high-velocity explosive casing 2, the high-velocity explosive 3, and the metal shaped charge liner 4 together form the cutting cord structure. The high-explosive shell 2 consists of a circular arc top, two flat sidewalls, and a bottom plate with an opening in the middle. The outer radius of the circular arc top is R2, and the inner radius is R1, satisfying 11cm≤R1≤R2≤19cm. The two arcs of the circular arc top are not concentric. The height of the highest point of the circular arc top from the horizontal plane is H, satisfying 12.5cm≤H≤18cm. The thickness of the bottom plate is D2, and the opening width is T1. The distance between the inner sidewalls of the two flat plates is T3, satisfying 0.25cm≤D2≤0.45cm, 17.6cm≤T1≤25.12cm, and 27.7cm≤T3≤35.22cm. The two flat sidewalls are symmetrically distributed on both sides of the circular arc top. The thickness of the circular arc top and the two sidewalls is D1, satisfying 0.1cm≤D1≤0.3cm. The angle between the left flat sidewall and the horizontal plane is θ3, satisfying 6 0°≤θ3≤65°, the openings on both sides of the bottom plate with the central opening are sloping, tightly fitting the bottom of the metal shaped charge liner 4; the high-velocity explosive casing 2 is used to fix the high-velocity explosive detonation mechanism 1, and at the same time cooperates with the metal shaped charge liner 4 to form a sealed space to accommodate the high-velocity explosive 3, thereby improving the energy utilization rate of the explosive; the metal shaped charge liner 4 is ridge-shaped, with one outer face of the ridge making an angle θ2 with the vertical direction, and one inner face making an angle θ1 with the vertical direction. The values ​​of θ1 and θ2 are both in the range of 20°-55° and satisfy θ2>θ1. The bottom width of the outer side of the ridge is T2, satisfying 20.00cm≤T2≤27.52cm. The top width of the ridge-shaped metal shaped charge liner is h, satisfying 0.1cm≤h≤0.2cm. The bottom width of the ridge-shaped metal shaped charge liner is w, satisfying that it serves as the hypotenuse and D2, A right-angled triangle is formed; high-velocity explosive 3 is filled in the sealed space formed by the high-velocity explosive casing 2 and the metal shaped charge liner 4. The high-velocity explosive 3 is used to crush the metal shaped charge liner 4 after detonation to form a stable, high-speed metal jet; the soft detonating cord 5 is cylindrical with a charge radius R3, satisfying 0.1cm≤R3≤0.3cm, and is placed directly below the cutting cord structure. Its central axis is located on the same vertical plane as the central axis of the arc top of the high-velocity explosive casing 2 and the top axis of the metal shaped charge liner 4. The vertical distance from the horizontal plane is M, satisfying 26.6R3≤M≤60R3;

[0006] The high-velocity explosive detonation mechanism 1 is installed on the central axis of the arc-shaped top of the high-velocity explosive casing 2 and is used to detonate the high-velocity explosive 3. The high-velocity explosive 3 is detonated at a single point by the high-velocity explosive detonation mechanism 1 5t later than the flexible detonating cord, where t is the time it takes for the diameter of the bubble generated by the explosion of the flexible detonating cord 5 to expand to cover the metal jet forming stage generated by the cutting cord.

[0007] The high-blast-speed explosive 3 adopts high-blast-speed high-energy explosive, and the stable blast speed of the explosive is not less than 8000 m / s.

[0008] The metal liner 4 is made of metal material such as red copper or lead.

[0009] The flexible detonating cord 5 is made of lead or aluminum alloy material, and the inside is filled with high-energy explosive with a stable blast speed not less than 7000 m / s. The charge amount and distance M of the flexible detonating cord 5 should ensure that the shock wave formed after underwater initiation of the flexible detonating cord 5 does not cause strain failure damage to the metal liner, that is, the metal liner 4 does not break when the shock wave and blast products after blasting of the flexible detonating cord 5 act on the cutting cord structure, so that a stable metal jet is formed, and the bubbles generated can cover the space required for the formation of the shaped charge jet, so that the shaped charge jet has an air domain forming environment, and the jet cutting and separation capability is enhanced.

[0010] The high-blast-speed explosive shell 2 is made of lead, copper, tungsten or aluminum alloy, tungsten copper alloy and the like.

[0011] The underwater flexible detonating cord-cutting cord time sequence coupling structure with enhanced effect provided by the application controls the initiation time sequence of the cutting cord and the flexible detonating cord, that is, sets the initiation interval time t, so that the flexible detonating cord is initiated t time earlier than the cutting cord, the flexible detonating cord generates a bubble cavity first underwater, provides a better forming environment for the underwater formation of the shaped charge jet, and enhances the head speed of the underwater shaped charge jet and the damage to the target. Under the premise of pre-initiation of the flexible detonating cord, the shock wave generated by pre-blasting of the flexible detonating cord does not cause damage to the metal liner, and the flexible detonating cord can form a pulsating bubble first underwater, which provides a better forming environment for the high-blast-speed explosive in the cutting cord to blast and crush the metal liner to form a shaped charge jet. The problem that the underwater movement frictional resistance of the jet is larger and the energy consumption is faster due to the large difference between the density, heat transfer speed and viscosity of water and air is avoided. When the bubble generated by blasting of the flexible detonating cord can cover the space required for the formation of the metal jet, the high-blast-speed explosive in the cutting cord is ignited by the initiation mechanism, the metal liner is crushed to form a shaped charge jet, the shaped charge jet is formed and lengthened in the bubble cavity, and tends to be stable. This process is similar to air domain formation, and finally the efficient cutting and separation of the underwater target is completed.

[0012] The application has the following beneficial effects:

[0013] Compared with traditional underwater single cutting cable structures, the gas cavity formed by the underwater soft explosive cable-cutting cable time-coupling structure of the present invention with enhanced effect can effectively improve the forming effect of metal shaped charge jet, promote the elongation of metal shaped charge jet, reduce the attenuation of jet head velocity, increase the remaining velocity of metal shaped charge jet to reach the target, and improve cutting and separation capability.

[0014] This invention has a reasonable structure and simple layout, and is highly economical and reliable. It is an underwater cutting device that uses the coupling of a cutting lock and a flexible explosive cable to form a cutting enhancement effect, and has a wider range of applications. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the underwater flexible explosive cable-cutting cable timing coupling structure with enhanced effect according to the present invention;

[0016] Figure 2 This is a three-dimensional view of the underwater flexible explosive cable-cutting cable timing coupling structure with enhanced effect of the present invention;

[0017] Figure 3 This is a diagram showing the enhanced underwater flexible explosive cable-cutting cable timing coupling structure and dimensions of the present invention;

[0018] Figure 4 The curves show the changes in the metal jet velocity generated by the underwater soft explosive cable-cutting cable time-coupling structure with enhanced effect of the present invention at a distance M = 40R3 between the soft explosive cable and the cutting cable, compared with the single cutting cable structure.

[0019] Among them, 1-high-explosive detonation mechanism, 2-high-explosive shell, 3-high-explosive explosive, 4-metal shaped charge liner, 5-soft detonating cord. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] To address the poor jet formation issues inherent in existing underwater cutting devices due to the aquatic environment, this invention employs a method of coaxially placing a flexible detonating cable beneath the traditional cutting cable structure. By controlling the detonation time, a cavity environment is provided for underwater jet formation. This invention features a rational structure, simple installation, and improved underwater cutting and separation capabilities of the cutting cable.

[0022] Figure 1 This is a schematic diagram of the underwater flexible explosive cable-cutting cable timing coupling structure with enhanced effect according to the present invention. Figure 2 This is a three-dimensional view of the underwater soft explosive cable-cutting cable timing coupling structure with enhanced effect according to the present invention.

[0023] like Figure 1As shown, the present application provides a kind of underwater flexible detonating cord-cutting cord timing coupling structure with enhanced effect, comprising: high explosive initiation mechanism 1, high explosive shell 2, high explosive 3, metal shaped charge 4, flexible detonating cord 5.

[0024] As Figure 3 As shown, high explosive shell 2 is composed of a circular arc top, two flat side walls and a bottom plate with an opening in the middle, high explosive initiation mechanism 1 is installed on the central axis of the circular arc top of high explosive shell 2, and the outer surface is closely attached to the inner surface of the shell; one end of the initiation mechanism 1 is closely attached to the plane of high explosive charge 3, which is used to initiate high explosive charge 3; high explosive 3 is filled in the closed space formed by high explosive shell 2 and metal shaped charge 4; flexible detonating cord 5 is cylindrical, placed directly below the cutting cord structure, with its central axis on the same vertical plane as the central axis of the circular arc top of high explosive shell 2 and the axis of the top of metal shaped charge 4, with a vertical distance of M from the horizontal plane.

[0025] Shell 2 is made of LY12 hard aluminum, so that the energy released by the explosion of the explosive can fully act on the metal shaped charge, increasing the velocity of the shaped jet and enhancing the damage and damage to the target. The outer side of the top circular arc end of the shell 2 has a radius R1 of 16.989 cm, and the inner side has a radius R2 of 15.053 cm, with the two arcs being eccentric; the thickness of the circular arc and the two sides is D1=0.240 cm, the thickness of the bottom plate of the shell is D2=0.340 cm, the opening width of the bottom plate is T1=17.6 cm, the distance between the inner side walls of the two end plates is T3=27.7 cm, the angle between the left side plate side wall and the horizontal plane is θ3=64.056°, and the height of the highest point of the circular arc top from the horizontal plane is H=16.781 cm.

[0026] The material of the metal shaped charge 4 is metal lead. The metal shaped charge 4 is in the shape of a roof, with an inner and outer side distance h of 0.120 cm at the top end of the roof-shaped metal shaped charge, a width w of 0.297 cm at the bottom end of the roof-shaped metal shaped charge, and a width T2 of 20.000 cm at the bottom end of the outer side of the roof. The small cone angle of the shaped charge is θ1=45°, and the large cone angle is θ2=51.224°.

[0027] High explosive 3 is formed by mature and reliable technology, using TNT explosive with a detonation velocity of 8700 m / s and a charge density of 1.82 g / cm 3 .

[0028] Flexible detonating cord 5 is cylindrical, with its central axis on the same vertical plane as the central axis of the circular arc top of high explosive shell 2 and the axis of the top of metal shaped charge 4, with a radius R3 of 0.15 cm, placed directly below the cutting cord structure at M=6 cm, using RDX explosive with a detonation velocity of 7420 m / s and a density of 1.67 g / cm 3.

[0029] The working process of the underwater flexible explosive cord-cutting cord timing coupling structure with the enhanced effect is as follows: the flexible explosive cord is first detonated at a certain blast height away from the target, and after the cavity generated by the flexible explosive cord can cover the space required for the formation of the jet, that is, after time t, the cutting cord is detonated through the detonation mechanism, so that the jet generated by the cutting cord can be stretched and formed in the underwater cavity, the resistance is reduced, and then the residual velocity is increased, so as to improve the cutting and separating capacity of the jet. The above structure is used for numerical simulation of a single cutting cord and a cutting cord-flexible explosive cord coupling structure, a 2D finite element model is used to calculate the jet velocity, the time interval t between the detonation of the flexible explosive cord and the cutting cord is 700 μs, a measuring point is arranged every 1 cm on the jet forming path, and the jet velocity curves under two working conditions are as shown in Figure 4 It can be found that for the cutting cord-flexible explosive cord coupling structure, the residual velocity of the shaped jet generated after passing through the bubble is 1320 m / s, and for the single cutting cord structure, the residual velocity of the shaped jet generated at the same position is 1120 m / s, which is 200 m / s lower than that of the jet generated by the present application. The jet head velocity of the underwater cutting of the present application is increased by 17.86%, the cutting and separating capacity of the shaped jet under water is improved, and then stronger damage to the target is formed.

[0030] To sum up, the above is only a preferred example of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A time-series coupling structure for underwater flexible explosive cable-cutting cable with enhanced effect, characterized in that: The high-velocity explosive detonation mechanism (1), the high-velocity explosive casing (2), the high-velocity explosive (3), the metal shaped charge liner (4), and the soft detonating cord (5) together form a cutting cord structure; wherein, the high-velocity explosive casing (2) consists of a circular arc top, two flat sidewalls, and a bottom plate with an opening in the middle. The outer radius of the circular arc top is R2, and the inner radius is R1, satisfying 11cm≤R1≤R2≤19cm. The two arcs at the top of the structure are not concentric. The height of the highest point of the top from the horizontal plane is H, satisfying 12.5cm ≤ H ≤ 18cm. The thickness of the base plate is D2, the opening width is T1, and the distance between the inner sidewalls of the two end plates is T3, satisfying 0.25cm ≤ D2 ≤ 0.45cm, 17.6cm ≤ T1 ≤ 25.12cm, and 27.7cm ≤ T3 ≤ 35.22cm. The two end plate sidewalls are symmetrically distributed on both sides of the top of the structure, and the thickness of the top and the end sidewalls is D1. The following conditions must be met: 0.1cm≤D1≤0.3cm; the angle between the left flat plate sidewall and the horizontal plane is θ3, which must be met: 60°≤θ3≤65°; the openings on both sides of the bottom plate with the middle opening are sloping and fit tightly against the bottom of the metal shaped charge liner (4); the high-velocity explosive casing (2) is used to fix the high-velocity explosive detonation mechanism (1), and at the same time, it cooperates with the metal shaped charge liner (4) to form a sealed space to accommodate the high-velocity explosive (3), thereby improving the energy utilization rate of the explosive; the metal shaped charge liner ( 4) The roof is ridge-shaped. The angle between one outer face of the ridge and the vertical direction is θ2, and the angle between one inner face and the vertical direction is θ1. Both θ1 and θ2 range from 20° to 55° and satisfy θ2 > θ1. The width of the bottom edge of the outer side of the ridge is T2, satisfying 20.00cm ≤ T2 ≤ 27.52cm. The width of the top edge of the ridge-shaped metal shaped charge is h, satisfying 0.1cm ≤ h ≤ 0.2cm. The width of the bottom edge of the ridge-shaped metal shaped charge is w, satisfying the condition of serving as the hypotenuse and intersecting with D2. A right triangle is formed; the high-velocity explosive (3) is filled in the closed space formed by the high-velocity explosive shell (2) and the metal shaped charge liner (4). The high-velocity explosive (3) is used to crush the metal shaped charge liner (4) after detonation to form a stable, high-speed metal jet; the soft explosive cord (5) is cylindrical with a charge radius R3, satisfying 0.1cm≤R3≤0.3cm. It is placed directly below the cutting cord structure. Its central axis is located on the same vertical plane as the central axis of the arc top of the high-velocity explosive shell (2) and the top axis of the metal shaped charge liner (4). The vertical distance from the horizontal plane is M, satisfying 26.6R3≤M≤60R3; The high-velocity explosive detonation mechanism (1) is installed on the central axis of the arc top of the high-velocity explosive shell (2) and is used to detonate the high-velocity explosive (3). The high-velocity explosive (3) is detonated at a single point by the high-velocity explosive initiation mechanism (1) after the soft detonating cord (5) for a time t. t is the time it takes for the diameter of the bubble generated by the explosion of the soft detonating cord (5) to expand to cover the distance range of the metal jet forming stage generated by the cutting cord.

2. The underwater flexible explosive cable-cutting cable timing coupling structure with enhanced effect according to claim 1, characterized in that: The high-velocity explosive (3) is a high-velocity, high-energy explosive with a stable detonation velocity of not less than 8000 m / s.

3. The underwater flexible explosive cable-cutting cable timing coupling structure with enhancement effect according to claim 1, characterized in that: The metal shaped charge liner (4) is made of copper or lead, and its structural shape should be chosen to ensure that it can form a stable and high-speed rod jet.

4. The underwater flexible explosive cable-cutting cable timing coupling structure with enhanced effect according to claim 1, characterized in that: The outer shell of the soft detonating cord (5) is made of lead or aluminum alloy and is filled with high-energy explosive with a stable detonation velocity of not less than 7000 m / s.

5. The underwater flexible explosive cable-cutting cable timing coupling structure with enhanced effect according to claim 4, characterized in that: The charge amount and distance M of the soft explosive cord (5) should ensure that the shock wave formed after its underwater detonation does not cause strain failure damage to the metal shaped charge liner (4). That is, when the shock wave and detonation products act on the cutting cord structure after the soft explosive cord blasts, the metal shaped charge liner does not break, and a stable metal jet can be formed. Moreover, the generated bubbles can cover the space required for the formation of the shaped charge jet, so that the shaped charge jet has an air domain formation environment and enhances the jet penetration capability.

6. The underwater flexible explosive cable-cutting cable timing coupling structure with enhanced effect according to claim 1, characterized in that: The high-explosive shell (2) is made of lead, copper, tungsten or aluminum alloy, or tungsten-copper alloy.

Images