Track of electromagnetic track launching device for improving current density distribution

Abstract

The invention belongs to the technical field of electromagnetic launching, and particularly relates to an electromagnetic track launching device track for improving current density distribution. Finite element simulation of different sizes and materials is carried out on a concave rail inner side surface, a square rail outer side surface A, a square rail outer side surface B, a concave rail outer side surface, a square rail filler, a rail framework and a convex rail filler of an electromagnetic rail launching device rail; the improvement of the rail current density of the electromagnetic rail launching device is realized, and the heating of a Joule heat source on a pivot rail contact surface is inhibited, so that the influence of temperature rise on the mechanical property of a rail inner side material is reduced, and the rail damage is reduced. The inner side surface of the rail is made of a material which is resistant to current-carrying sliding friction and arc ablation between the armature and the rail, resistant to softening and low in conductivity, the outer side surface of the rail is made of a material with high thermal conductivity and moderate conductivity, distribution of Joule heat generated in the rail is improved, and the service life of the rail is prolonged.

Description

Technical Field

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

[0002] In order to improve the ability to launch objects, people are always pursuing higher speeds and kinetic energy. In order to destroy armored targets such as tanks, to accelerate satellites, space shuttles and other spacecraft to the first, second and even third cosmic speeds, and to accelerate small-mass projectiles to several thousand meters per second for high-speed collision scientific experiments, electromagnetic orbital launchers have attracted the attention of more and more scientific researchers. Among kinetic weapons, electromagnetic launchers have the fastest flight speed, the greatest killing power, and the most ideal prospects for use.

[0003] During launch, the rail is subjected to high-speed sliding electrical contact of the armature, and is in a harsh working environment of high current, high temperature, and strong magnetic field. Surface planing, transition, arc erosion, and current-carrying friction wear will occur, which can reduce its service life, affect the posture of the integrated launch assembly in the bore, reduce safety, and increase the difficulty of maintenance, which greatly restricts its development. Therefore, the ablation problem is the primary core problem of the electromagnetic rail launch device. The existing rails cannot meet the electrical conductivity and thermal conductivity, and take into account the long-term service characteristics such as wear resistance and ablation resistance, and it is difficult to solve the problem of long-term stable use under extreme conditions. Due to the skin effect and proximity effect, the current density in the rail will be unevenly distributed. The uneven current density means that the distribution of the Joule heat generated inside the rail is also uneven, and the periodic heat accumulation and thermal effects will seriously affect the performance and service life of the electromagnetic rail launch device. Therefore, it is of great significance to improve the current density distribution in the rail. Summary of the invention

[0004] In view of the high-speed current-carrying friction and wear problem of the current electromagnetic rail launcher, the present invention 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 corresponding materials at different positions of the track, and the current-carrying friction and wear between the pivot rails is reduced by using wear-resistant and arc-ablation-resistant alloys at the contact surface of the pivot rails. The mechanical properties of the track are enhanced by using high-elongation and high-strength skeleton materials. Secondly, with the help of modeling design software and finite element simulation software, the design of electromagnetic rail launcher tracks of various sizes with improved current density distribution is realized.

[0005] The technical solution of the present invention is as follows:

[0006] An electromagnetic rail launcher track with improved current density distribution, such as Figure 1As shown, it includes 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.

[0007] The inner surface of the concave track is one of the parts of the track that directly contacts the armature, and directly bears the high-speed sliding electrical contact between the armature and the track during the electromagnetic launch process. 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 branch 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 armature and the rail are poor, an arc will be generated on the contact surface of the armature and the inner surface of the track is directly subjected to arc erosion. In addition, due to the skin effect and the proximity effect, the current density near the contact surface of the armature and the rail is relatively large during the current rising phase of the electromagnetic launch. This part of the material is selected according to the contact pressure between the armature and the rail during the actual electromagnetic launch process and the size of the excitation current. The corresponding wear-resistant, arc-erosion-resistant, softening-resistant, and low-conductivity materials are selected.

[0008] The outer surface A of the square track is the part where the outer side of the track is diffusely connected with the inner surface of the concave track, the track frame and the convex track filling. The length of the outer surface A of the square track is equal to the length of the inner surface of the concave track and the convex track after filling and assembly. During the current rising phase of electromagnetic emission, the current density in the outer surface A of the square track is relatively large. The material of this part is selected according to the waveform of the excitation current in the actual electromagnetic emission process. The material has good thermal conductivity and moderate electrical conductivity.

[0009] The outer surface B of the square track is the part where the outer side of the track is diffusely connected to the outer surface of the concave track and the track frame. The length of the outer surface B of the square track 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 rising phase of electromagnetic emission, the current density in the outer surface A of the square track is relatively large. The material of this part is selected according to the waveform of the excitation current in the actual electromagnetic emission process. The corresponding material with good thermal conductivity and moderate electrical conductivity is selected.

[0010] The outer surface of the concave track is the part of the track outside that is filled with the square track and diffusely connected to the track frame. The length of the outer surface of the concave track is equal to the length of the branch outside the track frame and the length of the outer surface B of the square track. During the electromagnetic launch process, it mainly plays a role in reducing the concentration of current density and cooperating with insulation to maintain the structural stability of the electromagnetic launch device. The material of the outer surface of the track is selected from materials with good thermal conductivity and moderate electrical conductivity.

[0011] The square track filling is the part of the track that shares the track current. The square track filling is completely matched with the outer surface of the concave track, and is diffusely connected with the outer surface of the concave track and the track skeleton. The square track filling is made of materials with high 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 caused by the temperature rise at the contact surface of the armature and the track, and reducing the wear of the armature and the track.

[0012] The track skeleton has 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 lengths of the inner and outer branches of the track skeleton are different, 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 emission, limit the deformation, and maintain the stability of the track structure size. The track skeleton selects a material with moderate conductivity and high ductility and strength.

[0013] The convex track filling is the part inside the track that shares the track current. The convex track filling is complementary to the shape of the inner surface of the concave track. The height of the convex track filling protrusion is the same as the depth of the groove on the inner surface of the concave track, and a rectangular parallelepiped can be formed after assembly. The convex track filling is diffusely connected to the inner surface of the concave track and the track skeleton. The convex track filling is made of materials 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 the wear of the armature and the track.

[0014] 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 are precisely and reliably connected through diffusion bonding technology. The workpieces to be connected are placed in a vacuum or protective atmosphere, heated to an appropriate temperature, 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 atomic mutual diffusion.

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

[0016] Then, set up the physical field, such as Figure 2 As shown. The physical field interface selects the magnetic 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 wire model of the coil node uses a single coil model, the coil excitation is set to voltage, and the real-time excitation voltage of the coil is solved according to the excitation current applied by the electromagnetic launch through the global equation, and the input boundary and output boundary 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, and the symmetry plane boundary conditions are 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, and the dimensions 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 according to the cloud map to obtain a track structure with improved current density.

[0018] Working principle:

[0019] The working principle diagram of the electromagnetic rail launcher is as follows Figure 3 As shown. The track is the core component of the electromagnetic track 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, with good mechanical strength and rigidity, and be able to generate a magnetic induction intensity of sufficient strength between the guide rails to drive the armature to a speed of the order of km / s. Figure 4 As shown, they are usually embedded in an insulating barrel of high-strength composite materials or between wall panels to form a launch tube. During the operation of the electromagnetic rail launcher, the current passes through the power supply, rail and armature to form a loop. The two rails are passed with pulse currents in opposite directions, and a magnetic field perpendicular to the paper surface and inward is generated in the area surrounded by the rail and the armature. The magnetic field generated by the excitation current I flowing through the rail near the armature is:

[0020]

[0021] B = ∫dB (2)

[0022] Where μ0 is the magnetic permeability in 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 passes through the conductor, I can be decomposed into high-frequency components through Fourier transformation. When alternating current passes 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 parts, one powered and one not powered. There is current diffusion inside the track in the contact area, forming a current distribution along the track surface from the track contact interface to the breech. That is, the current is concentrated on the surface, which is called the velocity skin effect.

[0033] When alternating current flows in opposite directions in two conductors, the alternating magnetic fields generated by the two conductors generate eddy currents on the other adjacent conductor. The induced eddy currents are superimposed on the original working current, causing the actual current of the conductor to be concentrated and distributed on the adjacent side of the conductor. This phenomenon is called the proximity effect.

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

[0035] (1) At the start of the launch, the excitation in the electromagnetic rail launcher is relatively small, and the electromagnetic thrust generated by the excitation is insufficient to overcome the static friction generated by the preload force and electromagnetic pressure between the armature 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 in the armature, and the armature begins to accelerate. The acceleration of the armature depends on the electromagnetic thrust, friction, and air resistance of the armature, and is affected by the state of the contact surface between the armature rail.

[0036] (2) As the excitation current increases, 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 the electromagnetic rail launcher will generally leave the barrel after the excitation current has dropped for a period of time, which is beneficial to improving the launcher efficiency of the electromagnetic rail launcher and reducing the ablation damage of the armature at the muzzle. During the current drop process, the acceleration of the armature 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, which 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 a muzzle arc.

[0039] During the launch process, due to the skin effect and proximity effect, high pulse transient current is concentrated on the inner surface of the track. The current concentration generates a lot of Joule heat, and the Joule heat generated by the contact resistance between the armature and the track surface and the friction heat generated by the contact friction, the contact surface between the armature and the track forms a local high temperature. High temperature will affect the mechanical properties of the material, aggravate ablation and wear, and cause serious damage to the track surface.

[0040] The present invention can make the excitation current more evenly distributed in the guide rail, reduce the concentration of current 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 influence of temperature rise on the mechanical properties of the inner side material of the track, reducing damage to the track, and extending the service life of the track.

[0041] Beneficial effects of the present invention:

[0042] 1. The present invention discloses that by performing finite element simulation 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 launch device track, the track current density of the electromagnetic track launch device is improved, the heating of the pivot rail contact surface by the Joule heat source is suppressed, thereby reducing the influence of temperature rise on the mechanical properties of the inner material of the track and reducing the damage to the track.

[0043] 2. The present invention discloses that the inner surface of the track adopts 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 adopts a material with high thermal conductivity and moderate electrical conductivity, the track filling adopts a material with high electrical conductivity, and the track skeleton adopts a material with high elongation 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 reliably connects the inner surface of the rail, the outer surface of the rail, the rail filling and the rail skeleton 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 This is a 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 implementation of the present invention is described in detail below in conjunction with the technical scheme and the accompanying drawings:

[0051] Embodiment 1:

[0052] An electromagnetic rail launcher 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 directly bears the high-speed sliding electrical contact between the armature and the track during the electromagnetic launch process. The height of the concave track inner surface 1 is the same as the height between the branches of the track skeleton 6, and the length should not exceed the length of the inner branch of the track skeleton 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 condition between the armature and the rail is poor, an arc will be generated on the contact surface of the armature and the rail, and the inner surface of the track will directly bear arc erosion. In addition, due to the skin effect and the proximity effect, the current density near the armature and rail contact surface is relatively large during the current rising stage of electromagnetic launch. This part of the material is selected according to the contact pressure between the armature and the rail during the actual electromagnetic launch process and the size of the excitation current. The corresponding wear-resistant, arc-erosion-resistant, softening-resistant, and low-conductivity materials are selected.

[0054] The outer surface A2 of the square track is the part where the outer side of the track is diffusely connected with the inner surface 1 of the concave track, the track frame 6 and the convex track filling 7. The length of the outer surface A2 of the square track is equal to the length of the concave track inner surface 1 and the convex track filling 7 after assembly. During the current rising phase of electromagnetic emission, the current density in the outer surface A2 of the square track is relatively large. The material of this part is selected according to the waveform of the excitation current in the actual electromagnetic emission process. The material has good thermal conductivity and moderate electrical conductivity.

[0055] The outer surface B3 of the square track is the part where the outer side of the track is diffusely connected to the outer surface 4 of the concave track and the track frame 6. The length of the outer surface B3 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. During the current rising phase of electromagnetic emission, the current density in the outer surface A2 of the square track is relatively large. The material of this part is selected according to the waveform of the excitation current in the actual electromagnetic emission process. The material has good thermal conductivity and moderate electrical conductivity.

[0056] The concave track outer surface 4 is the part 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 B3. During the electromagnetic launch process, it mainly plays a role in reducing the concentration of current density and cooperating with insulation to maintain the structural stability of the electromagnetic launch device. The material of the track outer surface is selected from materials with good thermal conductivity and moderate electrical conductivity.

[0057] The square track filling 5 is the part of the track that shares the track current. The square track filling 5 is completely matched with the outer surface 4 of the concave track, and is diffusely connected with the outer surface 4 of the concave track and the track skeleton 6. The square track filling 5 is made of a material with high 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 caused by the temperature rise at the contact surface between the armature and the track, and reducing the wear of the armature and the track.

[0058] The track skeleton 6 has excellent properties of high ductility and high strength, and is used to support and connect the inner surface 1 of the concave track, the outer surface A2 of the square track, the outer surface B3 of the square track, the outer surface 4 of the concave track, the square track filling 5 and the convex track filling 7. The lengths of the inner and outer branches of the track skeleton 6 are different, wherein the outer branch of the track skeleton is the same as the length of the outer surface of the concave track, and the inner branch of the track skeleton is the same as the length of the inner surface 1 of the concave track and the convex track filling 7 after assembly. The distance between the branches of the track skeleton is consistent with the height of the inner surface 1 of the concave track, the outer surface 4 of the concave track and the convex track filling 7. Considering the asymmetry of the current distribution inside and outside, the structure of the track skeleton 6 is asymmetric inside and outside. The outer surface of the track, the track filling and the outer filling of the track improve the track strength, withstand the extreme electromagnetic force and heat distribution during electromagnetic emission, limit the deformation, and maintain the stability of the track structure size. The track skeleton 6 selects a material with moderate conductivity and high ductility and high 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 of the concave track inner surface 1. After assembly, a rectangular parallelepiped can be formed. 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 the wear of the armature and the track.

[0060] 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 filling 5, the track skeleton 6 and the convex track filling 7 are precisely and reliably connected through diffusion bonding technology. The workpieces to be connected are placed in a vacuum or protective atmosphere, heated to an appropriate temperature, 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 atomic mutual diffusion.

[0061] Embodiment 2:

[0062] The overall size of the track is determined according to actual needs, including the length, width and height of the track. Based on the commonly used planar electromagnetic track launcher, the present invention has conducted research on improving the current density distribution under the excitation of pulse current. The present invention divides the track of the planar electromagnetic track launcher into 7 parts: the inner surface 1 of the concave track, the outer surface A2 of the square track, the outer surface B3 of the square track, the outer surface 4 of the concave track, the square track filling 5, the track skeleton 6 and the convex track filling 7. The inner surface 1 of the concave track is resistant to ablation and softening, and is used to withstand the current-carrying sliding friction and arc ablation between the armature and the track; the outer surface A2 of the square track, the outer surface B3 of the square track and the outer surface 4 of the concave track have moderate conductivity and good heat dissipation, and are used to improve the current density and accelerate heat dissipation; the square track filling 5 and the convex track filling 7 have high conductivity and are used to improve the current density distribution; the track skeleton 6 has high ductility and strength, and is used to support and connect the inner surface of the track, the outer surface of the track and the track filling, and disperse stress. During the pulse current excitation application, 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 at the same time tolerating current-carrying friction wear and arc ablation during the launch of the railgun, thereby increasing the service life of the railgun.

[0063] Specifically, Figure 1 As shown, the present invention discloses an electromagnetic track launch device track for improving current density distribution, and 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 filling 5, a track skeleton 6 and a convex track filling 7. It is characterized in that the contact area between the track inner surface, the track outer surface, the track filling and the track skeleton is relatively large, and they are welded together by diffusion connection, and the structural stability is good; the track inner surface is resistant to ablation and softening, and is used to withstand the current-carrying sliding friction and arc ablation between the armature and the track; the track outer surface has moderate conductivity and good heat dissipation, and is used to improve current density and accelerate heat dissipation; the track filling has high conductivity and is used to improve current density distribution; the track skeleton has high ductility and strength, and is used to support and connect the track inner surface, the track outer surface, the track inner filling and the track outer filling to disperse stress.

[0064] Embodiment 3:

[0065] The preferred embodiment of the present invention is a track of an electromagnetic launch device with a cross-sectional size of 6mm*14mm. The inner surface of the track is made of Cu-20% W alloy, the depth of the concave structure is 1mm, symmetrical on both sides, 3mm in height, and 2mm in length; the outer surface of the track is made of copper-chromium alloy, the cross-sectional dimensions of the outer surface of the square track are 3mm*1.5mm and 2mm*1.5mm respectively, the concave cross-sectional structure is symmetrical up and down, 3mm in height, 2mm in width, and the concave depth is 1mm; the track filling is made of TP copper material, the rectangular cross-sectional dimensions are 1mm*1mm, the convex cross-sectional dimensions are symmetrical up and down, 3mm in height, the protrusion is centered, the length and width are both 1mm, and the leftmost distance of the convex is 2mm from the rightmost; the track skeleton is made of 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 skeleton 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 branch 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 side surface A (2) of the square track is a portion where the outer side of the track is diffusely connected to the inner side surface (1) of the concave track, the track frame (6) and the convex track filling (7); the length of the outer side surface A (2) of the square track is equal to the length of the inner side surface (1) of the concave track and the convex track filling (7) after assembly; The outer surface B (3) of the square track is a portion where the outer side of the track 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 part 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 as claimed in 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 a 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 atomic mutual diffusion.

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

4. An electromagnetic rail launcher track with improved current density distribution as claimed in 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).

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