An electromagnetic rail launch device track with improved current density distribution

Abstract

The present invention belongs to the field of electromagnetic launch technology, and specifically relates to an electromagnetic rail launcher track with improved current density distribution. The present invention discloses that by performing finite element simulations of different sizes and materials on the concave track inner surface, square track outer surface A, square track outer surface B, concave track outer surface, square track filling, track skeleton, and convex track filling of the electromagnetic rail launcher track, the current density of the electromagnetic rail launcher track is improved, and the heating of the armature-rail contact surface by the Joule heat source is suppressed, thereby reducing the impact of temperature rise on the mechanical properties of the inner track material and minimizing damage to the track. The present invention uses a material on the inner track surface that is resistant to current-carrying sliding friction and arc erosion between the armature and the track, resists softening, and has low electrical conductivity, and uses a material on the outer track surface with high thermal conductivity and moderate electrical conductivity. This improves the distribution of Joule heat generated therein and increases the life of the track.

Description

Technical Field

[0001] The present invention belongs to the technical field of electromagnetic launch, and in particular relates to an electromagnetic rail launch device track with improved current density distribution. Background Art

[0002] To improve the ability to launch objects, researchers are constantly pursuing higher speeds and kinetic energy. Electromagnetic rail launchers (ELLs) are attracting increasing attention from researchers seeking to destroy armored targets like tanks, develop new launchers capable of accelerating satellites, space shuttles, and other spacecraft to first, second, and even third cosmic velocities, and accelerate small projectiles to several thousand meters per second for high-speed collision experiments. Among kinetic energy weapons, ELLs offer the fastest flight speeds, the greatest destructive power, and the most promising future applications.

[0003] During launch, the rails are subject to the high-speed sliding electrical contact of the armature, and are exposed to the harsh working environment of high current, high temperature, and strong magnetic field. This can lead to surface gouging, transition, arc erosion, and current-carrying friction wear. These phenomena can shorten their service life, affect the in-bore posture of the integrated launch assembly, reduce safety, increase maintenance difficulties, and significantly restrict their development. Therefore, the ablation problem is the primary core issue for electromagnetic rail launchers. Existing rails cannot meet both electrical and thermal conductivity requirements while also taking into account long-term service characteristics such as wear resistance and ablation resistance, making it difficult to ensure long-term stable use under extreme conditions. Due to the skin effect and proximity effect, the current density within the rails will be unevenly distributed. Uneven current density means that the distribution of Joule heat generated within the rails is also uneven. Periodic heat accumulation and thermal effects will seriously affect the performance and service life of electromagnetic rail launchers. Therefore, improving the current density distribution within the rails is of great significance. Summary of the Invention

[0004] To address the friction and wear issues associated with high-speed current-carrying electromagnetic rail launchers, this paper proposes a track structure and design method for an electromagnetic rail launcher with improved current density distribution. First, the current density distribution is improved by using appropriate materials at different locations on the track. A wear-resistant and arc-ablation-resistant alloy is used at the pivot-rail contact surface to reduce the friction and wear between the pivot rails. The mechanical properties of the track are enhanced by using a high-strength and high-ductility skeleton material. Second, by combining modeling and design software with finite element simulation software, the design of electromagnetic rail launcher tracks with improved current density distribution for various sizes is achieved.

[0005] The technical solutions of the present invention are as follows:

[0006] An electromagnetic rail launch device track with improved current density distribution, such as Figure 1As shown, it includes the concave track inner surface, the square track outer surface A, the square track outer surface B, the concave track outer surface, the square track filling, the track skeleton and the convex track filling.

[0007] The inner surface of the concave track is one of the parts of the track that directly contacts the armature, and is directly subjected to high-speed sliding electrical contact between the armature and the track during electromagnetic emission. The height of the inner surface of the concave track is the same as the height between the branches of the track skeleton, and the length should not exceed the length of the inner branches of the track skeleton. The concave shape is centered, and the depth of the concave shape is the same as the length of the convex track filling protrusion. When the contact conditions between the pivot and rail are poor, an arc will be generated on the pivot-rail contact surface, and the inner surface of the track will directly be subjected to arc erosion. In addition, due to the skin effect and the proximity effect, the current density near the pivot-rail contact surface is relatively large during the current rise phase of electromagnetic emission. The material of this part is selected according to the contact pressure between the pivot and rail and the magnitude of the excitation current during the actual electromagnetic emission process. The corresponding wear-resistant, arc-erosion-resistant, softening-resistant, and low-conductivity materials are selected.

[0008] The square track outer surface A is the portion of the track that connects the outer side of the track to the inner surface of the concave track, the track frame, and the convex track filling diffusion connection. The length of the square track outer surface A is equal to the length of the concave track inner surface and the convex track after filling. During the current rise phase of electromagnetic transmission, the current density within the square track outer surface A is relatively high. The material for this portion should be selected based on the excitation current waveform during actual electromagnetic transmission, with good thermal conductivity and moderate electrical conductivity.

[0009] The square track outer surface B is the portion of the track that connects the outer surface of the concave track and the track frame. The length of the square track outer surface B is the same as the length of the outer branch of the track frame and the length of the outer surface of the concave track. During the current rise phase of electromagnetic emission, the current density within the square track outer surface A is relatively high. The material for this portion should be selected based on the excitation current waveform during actual electromagnetic emission, with good thermal conductivity and moderate electrical conductivity.

[0010] The concave outer surface of the track is the portion of the track that connects to the square track filling and the track frame. Its length is equal to the length of the outer branch of the track frame and the length of the outer surface B of the square track. During electromagnetic launch, it primarily reduces current density concentration and, in conjunction with insulation, maintains the structural stability of the electromagnetic launch device. The material used for the outer surface of the track is selected to have good thermal conductivity and moderate electrical conductivity.

[0011] The square track filler is the portion of the track that distributes the track current. It perfectly matches the outer surface of the concave track and is diffusely connected to the outer surface of the concave track and the track frame. The square track filler is made of a high-conductivity material to suppress the skin effect, increase the diffusion depth of the time-varying electromagnetic field, improve the current density distribution, and suppress Joule heating at the armature-track interface. This, in turn, prevents the deterioration of the material's mechanical properties due to temperature rise at the armature-track interface, thereby reducing wear on the armature and track.

[0012] The track skeleton has the excellent properties of high ductility and high strength, and is used to support and connect the inner surface of the concave track, the outer surface A of the square track, the outer surface B of the square track, the outer surface of the concave track, the square track filling, and the convex track filling. The inner and outer branches of the track skeleton have different lengths, wherein the outer branch of the track skeleton is the same length as the outer surface of the concave track, and the inner branch of the track skeleton is the same length as the inner surface of the concave track and the convex track filling after assembly. The distance between the branches of the track skeleton is consistent with the height of the inner surface of the concave track, the outer surface of the concave track, and the convex track filling. Considering the asymmetry of the current distribution inside and outside, the structure of the track skeleton is asymmetric inside and outside. The outer surface of the track, the track filling, and the outer filling of the track improve the strength of the track, withstand the extreme electromagnetic force and heat distribution during electromagnetic transmission, limit deformation, and maintain the stability of the track structure size. The track skeleton is selected from a material with moderate electrical conductivity and the properties of high ductility and strength.

[0013] The convex track filler is the part inside the track that shares the track current. The convex track filler is complementary to the shape of the inner surface of the concave track. The height of the convex track filler protrusion is the same as the depth of the groove on the inner surface of the concave track. After assembly, a rectangular parallelepiped can be formed. The convex track filler is diffusely connected to the inner surface of the concave track and the track skeleton. The convex track filler is made of a material with high electrical conductivity to suppress the skin effect, increase the diffusion depth of the time-varying electromagnetic field, improve the current density distribution, and suppress the Joule heat generated on the contact surface between the armature and the track, thereby suppressing the deterioration of the mechanical properties of the material at the armature-rail contact surface due to temperature rise, and reducing wear on the armature and the track.

[0014] Diffusion bonding technology achieves precise and reliable connections between the concave track inner surface, square track outer surface A, square track outer surface B, concave track outer surface, square track filling, track frame, and convex track filling. The workpieces to be joined are placed in a vacuum or protective atmosphere and heated to an appropriate temperature. Pressure is then applied to the workpieces through the mold, causing microscopic plastic deformation of the uneven contact surfaces of the workpieces to increase the contact area and achieve close contact. Heat preservation and atomic diffusion then form a strong metallurgical bond.

[0015] A method for designing an electromagnetic railgun track to improve current density distribution: For an electromagnetic railgun launcher with specific size requirements, SolidWorks or other modeling and design software is used to design and draw the launcher. COMSOL Multiphysics or other finite element simulation software is used to simulate the physical field of the electromagnetic launch process. First, the launcher is drawn in the modeling and design software and imported into the finite element simulation software. An air domain is added around the launcher, and material properties are set for the air domain, the inner and outer surface of the track, the track fill, and the track frame.

[0016] Then, set up the physical field, such as Figure 2 As shown. The Magnetic Field Interface is selected as the physical field interface to calculate the magnetic field distribution and induced current distribution inside and around the armature and track during the electromagnetic launch process. The Coil Node simulates the skin effect and proximity effect in the armature and track during the electromagnetic launch process. The single coil model is selected as the wire model of the Coil Node. The coil excitation is set to voltage. The global equation is used to solve the real-time excitation voltage of the coil according to the excitation current applied by the electromagnetic launch, and the input and output boundaries of the coil are set. Considering the symmetry of the electromagnetic launch device, one-fourth of the electromagnetic launch device model is simulated to reduce the amount of calculation. The symmetry plane boundary condition is added and set in the Magnetic Field Interface. The symmetry type of the magnetic flux density of symmetry plane 1 is symmetric, and the symmetry type of the magnetic flux density of symmetry plane 2 is antisymmetric.

[0017] Finally, a three-dimensional current density cloud map at different times is obtained. According to the cloud map, the sizes and materials of the inner surface of the concave track, the outer surface A of the square track, the outer surface B of the square track, the outer surface of the concave track, the square track filling, the track skeleton and the convex track filling are adjusted to obtain a track structure with improved current density.

[0018] Working principle:

[0019] The working principle diagram of the electromagnetic rail launch device is as follows Figure 3 As shown. The track is the core component of the electromagnetic rail launcher. It not only conducts current but also guides the movement of the armature and projectile. The guide rail must be a good conductor, resistant to ablation and wear, have good mechanical strength and rigidity, and be able to generate a strong enough magnetic induction intensity between the guide rails to drive the armature to a speed of the order of km / s. Figure 4 As shown, they are typically embedded within an insulating barrel made of high-strength composite materials or between wall panels, forming the launch barrel. During operation, the electromagnetic rail launcher forms a circuit through the power supply, rails, and armature. Pulsed currents in opposite directions flow through the two rails, generating a magnetic field perpendicular to the paper and inward in the area enclosed by the rails and armature. The magnetic field generated near the armature by the excitation current I flowing through the rails is:

[0020]

[0021] B=∫dB (2)

[0022] Where μ0 is the magnetic permeability in a vacuum, and r is the vector pointing from the current source to the field point. Under the action of the current I and the magnetic field B, the armature is subjected to the electromagnetic thrust F:

[0023] dF=Idl×B (3)

[0024] F=∫dF (4)

[0025] The armature will overcome resistance and accelerate under the action of electromagnetic thrust F. The motion process can be described by the following formula:

[0026] Ff=ma (5)

[0027] v=∫adt (6)

[0028] s=∫vdt (7)

[0029] Among them, f is the resistance that needs to be overcome during the movement of the armature, m is the mass of the armature, a is the acceleration of the armature, v is the velocity of the armature, and s is the displacement of the armature.

[0030] The track is a conductor. When a pulsed excitation current I flows through the conductor, I can be decomposed into high-frequency components through Fourier transformation. When alternating current flows through the conductor, the current density inside the conductor is unevenly distributed. The actual current inside the conductor is small, and the current is concentrated in a thin layer on the surface of the conductor. The closer to the surface of the conductor, the greater the current density. This phenomenon is called the skin effect. The higher the frequency, the more obvious the skin effect. In the eddy current field, the relationship between the current penetration depth in the conductor and the frequency is:

[0031]

[0032] Where μ is the magnetic permeability of the conductor, σ is the electrical conductivity of the conductor, and f is the excitation current frequency. When the armature moves inside the track, the track has two sections: energized and unenergized. Current diffuses inside the track in the contact area, forming a distribution along the track surface from the track contact interface to the breech. This concentration of current on the surface is known as the velocity skin effect.

[0033] When alternating current flows in opposite directions between two conductors, the alternating magnetic fields generated by each conductor induce eddy currents in the adjacent conductor. These induced eddy currents are superimposed on the original operating current, causing the actual current in the conductors to concentrate on the adjacent side. This phenomenon is known as the proximity effect.

[0034] The working process of the electromagnetic rail launcher is:

[0035] (1) At the start of launch, the excitation within the electromagnetic rail launcher is relatively small. The electromagnetic thrust generated by the excitation is insufficient to overcome the static friction generated by the preload and electromagnetic pressure between the armature and rail to drive the armature to move. At this time, the armature is stationary. When the current is large enough, sufficient electromagnetic thrust is generated within the armature, and the armature begins to accelerate. The acceleration of the armature depends on the electromagnetic thrust, friction, and air resistance it experiences, and is also affected by the state of the armature-rail contact surface.

[0036] (2) As the excitation current rises, the acceleration of the armature gradually increases and continues to accelerate. When the excitation current does not change much, the acceleration of the armature is relatively stable and the armature is almost in a state of uniform acceleration.

[0037] (3) The armature of an electromagnetic rail launcher generally leaves the barrel after the excitation current has decreased for a period of time. This helps improve the launcher efficiency of the electromagnetic rail launcher and reduce the ablation damage of the armature at the muzzle. During the current decrease process, the acceleration of the armature also gradually decreases. If the armature leaves the barrel relatively late, the armature may have a brief moment when the acceleration decreases to zero or even a negative value. This means that there is a period of time when the armature decelerates slightly before leaving the muzzle.

[0038] (4) When the armature leaves the muzzle, the remaining energy in the electromagnetic rail launcher is released in the form of muzzle arc.

[0039] During launch, high pulse transient currents concentrate on the inner surface of the rail due to the skin effect and proximity effect. This concentrated current generates significant Joule heating, which, combined with Joule heating from the contact resistance and frictional heat between the armature and rail surfaces, results in localized high temperatures at the contact surface. This high temperature can affect the mechanical properties of the material, exacerbating ablation and wear, and causing severe damage to the rail surface.

[0040] The present invention can make the excitation current more evenly distributed in the guide rail, reduce the degree of current concentration on the inner side of the track due to proximity effect and skin effect, inhibit the heating of the pivot-rail contact surface by the Joule heat source, thereby reducing the impact of temperature rise on the mechanical properties of the inner side material of the track, reducing damage to the track, and extending the track life.

[0041] Beneficial effects of the present invention:

[0042] 1. The present invention discloses that by performing finite element simulations of different sizes and materials on the concave track inner surface, square track outer surface A, square track outer surface B, concave track outer surface, square track filling, track skeleton, and convex track filling of the electromagnetic track launcher track, the track current density of the electromagnetic track launcher track is improved, the heating of the pivot-rail contact surface by the Joule heat source is suppressed, the effect of temperature rise on the mechanical properties of the inner track material is reduced, and damage to the track is reduced.

[0043] 2. The present invention discloses that the inner surface of the track is made of a material that can withstand the current-carrying sliding friction and arc erosion between the armature and the track, is resistant to softening and has low conductivity, the outer surface of the track is made of a material with high thermal conductivity and moderate electrical conductivity, the track filling is made of a material with high electrical conductivity, and the track skeleton is made of a material with high ductility and strength. This ensures that the track can withstand current-carrying friction, wear and arc erosion, while improving the distribution of Joule heat generated therein and increasing the service life of the track.

[0044] 3. The present invention discloses that the rail skeleton adopts high-strength and high-ductility materials, and the inner surface of the rail, the outer surface of the rail, the rail filling and the rail skeleton are reliably connected through welding methods such as diffusion bonding, thereby improving the yield strength of the rail, improving its stress distribution, reducing the strain of the rail, and improving the stability of the rail. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the overall structure of the three-dimensional structure of the present invention.

[0046] Figure 2 Schematic diagram of the simulation model of the electromagnetic rail launcher.

[0047] Figure 3 This is a schematic diagram of the working principle of the electromagnetic rail launch device.

[0048] Figure 4 This is a cross-sectional view of the launch barrel.

[0049] In the figure: 1 inner surface of the concave track; 2 outer surface A of the square track; 3 outer surface B of the square track; 4 outer surface of the concave track; 5 square track filling; 6 track skeleton; 7 convex track filling. DETAILED DESCRIPTION

[0050] The specific embodiments of the present invention are described in detail below in conjunction with the technical solutions and accompanying drawings:

[0051] Example 1:

[0052] An electromagnetic rail launch device track with improved current density distribution, such as Figure 1As shown, it includes a concave track inner surface 1, a square track outer surface A2, a square track outer surface B3, a concave track outer surface 4, a square track filling 5, a track skeleton 6 and a convex track filling 7.

[0053] The concave track inner surface 1 is one of the parts of the track that directly contacts the armature and is directly subjected to high-speed sliding electrical contact between the armature and the track during electromagnetic transmission. The height of the concave track inner surface 1 is the same as the height between the branches of the track frame 6, and its length should not exceed the length of the inner branches of the track frame 6. The concave shape is centered, and the depth of the concave shape is the same as the length of the protrusion of the convex track filler 7. When the contact conditions between the pivot and rail are poor, an arc will be generated on the pivot-rail contact surface, and the track inner surface will be directly subjected to arc erosion. In addition, due to the skin effect and proximity effect, the current density near the pivot-rail contact surface is relatively high during the current rise phase of electromagnetic transmission. The material of this part is selected according to the contact pressure between the pivot and rail and the magnitude of the excitation current during actual electromagnetic transmission. The corresponding material with wear resistance, arc erosion resistance, softening resistance, and low electrical conductivity is selected.

[0054] The square track outer surface A2 is the portion of the track that connects the outer side of the track with the concave track inner surface 1, the track frame 6, and the convex track filler 7. The length of the square track outer surface A2 is equal to the length of the concave track inner surface 1 and the convex track filler 7 after assembly. During the current rise phase of electromagnetic emission, the current density within the square track outer surface A2 is relatively high. The material for this portion should be selected based on the waveform of the excitation current during actual electromagnetic emission, with good thermal conductivity and moderate electrical conductivity.

[0055] The square track outer surface B3 is the portion of the track that diffusely connects to the concave track outer surface 4 and the track frame 6. The length of the square track outer surface B3 is the same as the length of the outer branch of the track frame 6 and the length of the concave track outer surface 4. During the current rise phase of electromagnetic emission, the current density within the square track outer surface A2 is relatively high. The material for this portion should be selected based on the excitation current waveform during actual electromagnetic emission, with good thermal conductivity and moderate electrical conductivity.

[0056] The concave track outer surface 4 is the portion of the track that is diffusely connected to the square track infill 5 and track frame 6. The length of the concave track outer surface 4 is equal to the length of the branch outside the track frame 6 and the length of the square track outer surface B3. During electromagnetic transmission, it primarily serves to reduce current density concentration and, in conjunction with the insulation, maintain the structural stability of the electromagnetic transmission device. The material used for the track outer surface is selected to have good thermal conductivity and moderate electrical conductivity.

[0057] The square track filler 5 distributes the track current within the track. It fully matches the concave track outer surface 4 and forms a diffusion connection with the concave track outer surface 4 and the track frame 6. The square track filler 5 is made of a material with high electrical conductivity to suppress the skin effect, increase the diffusion depth of the time-varying electromagnetic field, improve the current density distribution, and suppress Joule heating at the armature-track interface. This, in turn, prevents deterioration in the mechanical properties of the material at the armature-track interface due to temperature rise, thereby reducing wear on the armature and track.

[0058] The track skeleton 6, characterized by its superior ductility and strength, supports and connects the concave track inner surface 1, the square track outer surface A2, the square track outer surface B3, the concave track outer surface 4, the square track filler 5, and the convex track filler 7. The inner and outer branches of the track skeleton 6 have different lengths: the outer branch is the same length as the concave track outer surface, while the inner branch is the same length as the concave track inner surface 1 and the convex track filler 7 after assembly. The distance between the branches corresponds to the height of the concave track inner surface 1, the concave track outer surface 4, and the convex track filler 7. The track skeleton 6 has an asymmetric structure, both inside and outside, to account for the asymmetric current distribution. The outer surface, the filler, and the outer filler enhance track strength, withstand the extreme electromagnetic forces and heat distribution during electromagnetic transmission, limit deformation, and maintain the dimensional stability of the track structure. The track skeleton 6 is constructed from a material with moderate electrical conductivity and high ductility and strength.

[0059] The convex track filler 7 is the part inside the track that shares the track current. The convex track filler 7 is complementary in shape to the concave track inner surface 1. The height of the protrusion of the convex track filler 7 is the same as the depth of the groove on the concave track inner surface 1. After assembly, they can form a rectangular parallelepiped. The convex track filler 7 is diffusely connected to the concave track inner surface 1 and the track skeleton 6. The convex track filler 7 is made of a material with high electrical conductivity to suppress the skin effect, increase the diffusion depth of the time-varying electromagnetic field, improve the current density distribution, and suppress the Joule heat generated on the contact surface between the armature and the track, thereby suppressing the deterioration of the mechanical properties of the material at the armature-rail contact surface due to temperature rise, and reducing wear on the armature and the track.

[0060] Diffusion bonding technology achieves precise and reliable connections between the concave track inner surface 1, the square track outer surface A2, the square track outer surface B3, the concave track outer surface 4, the square track filler 5, the track skeleton 6, and the convex track filler 7. The workpieces to be joined are placed in a vacuum or protective atmosphere and heated to an appropriate temperature. Pressure is then applied to the workpieces through the mold, causing microscopic plastic deformation on the uneven contact surfaces of the workpieces to increase the contact area and achieve close contact. Heat preservation and atomic diffusion then form a strong metallurgical bond.

[0061] Example 2:

[0062] The overall dimensions of the track, including its length, width, and height, are determined based on actual needs. Based on a commonly used planar electromagnetic track launcher, the present invention investigates ways to improve the current density distribution under pulsed current excitation. The present invention divides the planar electromagnetic track launcher track into seven parts: a concave track inner surface 1, a square track outer surface A2, a square track outer surface B3, a concave track outer surface 4, a square track filler 5, a track skeleton 6, and a convex track filler 7. The concave track inner surface 1 is resistant to ablation and softening, designed to withstand current-carrying sliding friction and arc erosion between the armature and the track. The square track outer surface A2, the square track outer surface B3, and the concave track outer surface 4 have moderate electrical conductivity and good heat dissipation, designed to improve current density and accelerate heat dissipation. The square track filler 5 and the convex track filler 7 have high electrical conductivity and are designed to improve current density distribution. The track skeleton 6 is highly ductile and strong, supporting and connecting the track inner surface, track outer surface, and track filler, and dissipating stress. During the application of pulse current excitation, the electromagnetic railgun launcher track with improved current density distribution can eliminate the uneven current density distribution caused by skin effect and proximity effect, thereby uniformly generating Joule heat during the launch process, while also withstanding the current-carrying friction wear and arc erosion during the launch process, thereby improving the service life of the railgun.

[0063] Specifically, such as Figure 1 As shown, the present invention discloses an electromagnetic rail launch device track with improved current density distribution. The track structure includes a concave track inner surface 1, a square track outer surface A2, a square track outer surface B3, a concave track outer surface 4, a square track filler 5, a track frame 6, and a convex track filler 7. The track inner surface, the track outer surface, the track filler, and the track frame have relatively large contact areas and are welded together by diffusion bonding, resulting in good structural stability. The track inner surface is resistant to ablation and softening, and is used to withstand current-carrying sliding friction and arc ablation between the armature and the track. The track outer surface has moderate electrical conductivity and good heat dissipation, and is used to improve current density and accelerate heat dissipation. The track filler has high electrical conductivity and is used to improve current density distribution. The track frame has high ductility and strength, and is used to support and connect the track inner surface, the track outer surface, the track inner filler, and the track outer filler, thereby dissipating stress.

[0064] Example 3:

[0065] A preferred embodiment of the present invention is a track for an electromagnetic launcher with a cross-sectional dimension of 6mm by 14mm. The track's inner surface is made of a Cu-20% W alloy, with a concave structure that is 1mm deep, symmetrical, 3mm high, and 2mm long. The track's outer surface is made of a copper-chromium alloy, with square track cross-sectional dimensions of 3mm by 1.5mm and 2mm by 1.5mm, respectively. The concave cross-sectional structure is symmetrical, 3mm high, 2mm wide, and 1mm deep. The track filling is made of TP copper material, with a rectangular cross-sectional dimension of 1mm by 1mm, and a convex cross-sectional dimension of 3mm high, with a central protrusion, a length and width of 1mm, and a 2mm distance between the leftmost and rightmost sides of the convex shape. The track frame is made of a Cu-20% Ag alloy.

[0066] With the help of finite element simulation software, the track current density under pulse current excitation is simulated, the materials and dimensions of the inner surface of the track, the outer surface of the track, the track filling and the track frame are adjusted, and the temporal and spatial distribution of the track current density is observed.

Claims

1. An electromagnetic rail launcher track with improved current density distribution, characterized in that: It comprises a concave track inner surface (1), a square track outer surface A (2), a square track outer surface B (3), a concave track outer surface (4), a square track filling (5), a track frame (6) and a convex track filling (7); The height of the inner surface of the concave track (1) is the same as the height between the branches of the track frame (6), the length does not exceed the length of the inner branches of the track frame (6), the concave shape is centered, and the depth of the concave shape is the same as the length of the protrusion of the convex track filling (7); The outer surface A (2) of the square track is a portion where the outer side of the track is diffusely connected to the inner surface (1) of the concave track, the track frame (6) and the convex track filling (7); the length of the outer surface A (2) of the square track is equal to the length of the concave track inner surface (1) and the convex track filling (7) after assembly; The outer surface B (3) of the square track is a portion of the track outer side that is diffusely connected to the outer surface (4) of the concave track and the track frame (6); the length of the outer surface B (3) of the square track is the same as the length of the outer branch of the track frame (6) and the length of the outer surface (4) of the concave track; The concave track outer surface (4) is the portion of the track outer side that is diffusely connected to the square track filling (5) and the track frame (6); the length of the concave track outer surface (4) is equal to the length of the branch outside the track frame (6) and the length of the square track outer surface B (3); The track frame (6) is used to support and connect the inner surface of the concave track (1), the outer surface A (2) of the square track, the outer surface B (3) of the square track, the outer surface (4) of the concave track, the square track filling (5) and the convex track filling (7); the inner and outer branches of the track frame (6) are of different lengths, wherein the outer branch of the track frame is the same length as the outer surface of the concave track, and the inner branch of the track frame is the same length as the inner surface of the concave track (1) and the convex track filling (7) after assembly; the distance between the branches of the track frame is consistent with the height of the inner surface of the concave track (1), the outer surface of the concave track (4) and the convex track filling (7); The convex track filler (7) and the concave track inner surface (1) are complementary in shape, the height of the protrusion of the convex track filler (7) is the same as the depth of the groove of the concave track inner surface (1), and a rectangular parallelepiped is formed after assembly; the convex track filler (7) is diffusely connected to the concave track inner surface (1) and the track frame (6).

2. The electromagnetic rail launcher track with improved current density distribution according to claim 1, characterized in that: The concave track inner surface (1), the square track outer surface A (2), the square track outer surface B (3), the concave track outer surface (4), the square track filling (5), the track skeleton (6) and the convex track filling (7) are connected by diffusion bonding technology; the workpieces to be connected are placed in a vacuum or protective atmosphere, heated and pressure is applied to the workpieces to be connected through the mold, so that the microscopic uneven contact surfaces of the workpieces to be connected produce microscopic plastic deformation, increase the contact area, achieve close contact, and then form a strong metallurgical bond through heat preservation and mutual diffusion of atoms.

3. The electromagnetic rail launcher track with improved current density distribution according to claim 1 or 2, characterized in that: The structure of the track frame (6) is asymmetrical inside and outside.

4. The electromagnetic rail launcher track with improved current density distribution according to claim 1 or 2, characterized in that: The square track filling (5) is completely matched with the outer surface of the concave track (4), and is diffusely connected with the outer surface of the concave track (4) and the track skeleton (6).

5. The electromagnetic rail launcher track with improved current density distribution as claimed in claim 3, characterized in that: The square track filling (5) is completely matched with the outer surface of the concave track (4), and is diffusely connected with the outer surface of the concave track (4) and the track skeleton (6).

Images