Analysis And Research Based On Multistage Tubular Coil Impact Loading Device

As powder metallurgy products account for a large proportion of mechanical parts,many powder metallurgy technologies have emerged continuously,such as the high-speed press technology and electromagnetic forming technology of explosion sintering technology,but these modern high-energy powder press technology has the impact loading mechanism and tradition.The powder press technology is very different,and it has attracted many people's attention.In the process of powder compaction,although the loading device for impact implosion of metal powder can compact powder,the problem of large energy utilization efficiency of the punches leads to insufficient loading speed and can't obtain higher density powder products.Therefore,it is necessary to It is particularly important to design a more efficient loading device.At present,in the design of the powder compacting device,the finite element simulation technology becomes an important means for optimizing the mechanical device because of its fast and efficient advantages.In this paper,a high-rate powder press technology and electromagnetic propulsion technology are combined to design an impact loading device based on multi-level tubular coils.With the aim of improving axial impact force and suppressing speed,a simulation model of the loading device is established using finite element simulation software.The theoretical analysis of the magnetic field generated by the current-carrying tubular coil,the influence of various parameters on the electromagnetic force of the loading device is studied,and the structure of the axial coil impact loading device of the tubular coil is optimized.It provides a new idea for the design of metal powder impact pressing device.Firstly,this paper proposes an electromagnetism impact press forming device based on tubular coils,establishes a numerical model of the tubular coil axial loading device,uses ANSYS finite element software to study the influence of structural parameters on the electromagnetic impact force,and obtains related Displacement-electromagnetic force characteristic curve,use MATLAB to analyze the loading speed.The relative position,length and thickness of the magnetic shut-off ring are directly related to the size of the axial electromagnetic force;when the optimal ratio of the height to the diameter of the coil is 2.12,the loading speed of the core of the loading device is the maximum;and the differential ratio of the core coil is-0.27.The resulting axial electromagnetic impact force is greatest and the core quality is relatively small.Secondly,the structural parameters of the tubular coil axial impact loading device are optimized,a finite element simulation model is established,and the influence of the size and the load current on the electromagnetic force and velocity of the loading device are discussed.The size of the electromagnetic force generated by the tubular coil axial impact loading device increases as the size increases,eventually reaching the maximum value due to the current-loading current unchanged;the electromagnetic force generated by the tubular coil axial impact loading device increases with the penetration current density.Increase,due to the influence of magnetic saturation to reach the maximum;the tubular coil axial impact loading device designed to a single-stage form,access to DC power 500 A DC current,can produce 23 m / s loading speed.Then,due to the high initial velocity required for the powder impact compression process,it is difficult to obtain a high speed with a single-stage tubular coil axial impact loading device,and the loading distance is relatively short.Therefore,a multi-stage tubular coil impact loading device is designed.The structure and working principle of the gun are similar.Ansoft Maxwell electromagnetic simulation software is used to establish a coil-driven finite element model.Firstly,the effects of single-stage coils and multi-stage coils on the electromagnetic force are compared and analyzed.Then,the cross-sectional shape of the coils on different positions is discussed.The influence of the electromagnetic force,and finally studied the law of the influence of the coil series on the electromagnetic force.The tubular coil axial impact loading device shall be accelerated in the form of a multi-stage tubular coil drive,and a magnetic break ring is provided inside the drive coil to not only extend the acceleration stroke,increase the loading efficiency,but also change the flow path of the magnetic flux lines and increase the iron core.The electromagnetic force and the loading speed;the coil of the axial coil impact loading device of the tubular coil adopts a tubular coil with a square cross-section shape,which can generate a large electromagnetic force on the moving iron core to accelerate it to a greater loading speed.Then,the effects of structural parameters,such as the distance between the stages,the thickness of the shell,the distance between the ring gaps,the angle and length of the off-loop magnetic ring on the electromagnetic force of the device,are discussed.The method of orthogonal test and simulation is applied to the structural parameters optimization.The coupling effect between the two coils affects the efficiency of electromagnetic induction.When the stage spacing is 1.22 times the length of the iron core,the coupling effect tends to zero,and increasing the spacing will lead to an increase in the size of the device;obtaining the spacing of the stages and the thickness of the shell The best ratio,when the thickness of the shell is 0.3 times the stage spacing,the electromagnetic force of the iron core is the largest,which provides guidance for the specific structural design;the magnetic cutting ring is useful,the position of the magnetic cutting ring is clearly defined,and the two-stage coil Adding a magnetic break ring in the interval has little effect on the axial electromagnetic force generated by the iron core,so it does not need to be added,and adding a magnetic break ring on the inner side of the tubular coil can significantly improve the magnetic circuit.When the length of the magnetic break ring is the same as the height of the coil,the maximum electromagnetic force is generated.It provides the basis for structural design of a multi-stage tubular coil impact loading device.Finally,six-axis tubular coil axial impact loading device structure was designed to construct a device system.The influence of electrical parameters such as current,voltage and coil resistance on its electromagnetic force was studied,and the electromagnetic force and loading speed generated by the loading device were calculated.Increasing the voltage or current and reducing the resistance of the coil can obtain greater electromagnetic force and loading speed.When electromagnetic saturation occurs,it is meaningless to further increase the voltage or current and reduce the resistance of the coil;multi-stage tubular coil loading device is designed in six stages with an accelerating distance of 1.1m.A current of 500 A can be used to obtain a loading speed of 48 m/s.