Armature and electromagnetic coil emitter

Abstract

The invention provides an armature and an electromagnetic coil emitter, aims at the structural design of the armature of the electromagnetic coil emitter, and relates to the technical field of electromagnetic emission. The armature comprises a head part, a middle part and a tail part which are connected in sequence; the middle portion comprises a spiral structure used for forming circumferential rotating force, and the spiral structure is composed of one or more spiral lines. The advantages of an induction type coil emitter and a magnetic resistance type coil emitter are combined, the tail cylinder achieves axial acceleration according to the principle of the magnetic resistance type coil emitter, the middle spiral structure mainly enables a projectile to achieve circumferential rotation according to the principle of the induction type coil emitter, the same driving coil can achieve the acceleration effect on the tail, and the magnetic resistance type coil emitter achieves axial acceleration. And the spiral structure is rotated. Possible unstable phenomena such as rolling and yawing in the flight process are reduced, and then the accuracy and stability of flight are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic emission, and in particular to an armature and electromagnetic coil emitter. Background Art

[0002] As a type of electromagnetic coil launcher, the reluctance coil launcher operates on the principle of minimum magnetic resistance, accelerating the projectile by exploiting the change in magnetic resistance of the magnetic circuit formed by the drive coil and the armature. Magnetic flux tends to follow the path of minimum magnetic resistance. The magnetic permeability of a ferromagnetic armature is much higher than that of air. Therefore, when the armature is placed inside the drive coil, it will move in the direction of minimum magnetic resistance within the magnetic circuit formed by the armature and air.

[0003] The biggest difference between a reluctance coil launcher and an induction coil launcher is that the armature is made of ferromagnetic material, making it more efficient when firing small-caliber rounds than the hollow induction coil launcher. Reluctance coil launchers are currently the most prevalent form of electromagnetic firearm in non-lethal weapons. They can be used as non-lethal kinetic energy weapons in counter-terrorism and riot control operations, and therefore have attracted particular attention.

[0004] The accuracy of a launcher's firing is a key metric for evaluating its performance. The armature is subject to aerodynamic forces while in flight, which can easily create a tumbling torque, leading to tumbling and instability. Therefore, stable armature flight during the exterior ballistic phase is a prerequisite for improving firing accuracy. Currently, there are various methods for improving armature flight stability. For example, guns use rifled barrels to impart high-speed rotation to the projectile, achieving flight stability. Mortar shells utilize a forward-shifted center of gravity design, ensuring stable flight after smoothbore firing through the combined effects of gravity and aerodynamic forces. Guided artillery shells use a built-in inertial navigation system or GPS for dynamic correction during flight to ensure that trajectory deviation remains within the target range.

[0005] Because electromagnetic coil launchers primarily accelerate their armatures through electromagnetic force, the armatures are typically made of high-permeability materials. This makes them unsuitable for methods like using rifling to spin the armature or using built-in dynamic correction systems to adjust flight stability. Currently, most research in the electromagnetic coil launcher field focuses on launcher structure design and control, with little attention paid to improving the flight stability of electromagnetic coil launcher armatures. Summary of the Invention

[0006] The object of the present invention is to provide an armature and an electromagnetic coil launcher, which are used to solve the problem of how to improve the flight stability of the armature of the electromagnetic coil launcher, etc., so as to make the flight posture of the armature more stable, thereby improving the flight stability of the armature in the outer trajectory.

[0007] In order to achieve the above objectives, in a first aspect, the present invention provides an armature comprising a head portion, a middle portion and a tail portion connected in sequence; the middle portion comprises a spiral structure for generating a circumferential rotational force, and the spiral structure is composed of one or more spiral lines.

[0008] According to an armature provided by the present invention, the head is a cone or a hemisphere, the tail is a cylinder, and the middle part also includes a connecting rod and an insulating tube. The connecting rod is arranged in the insulating tube, and the two ends of the insulating tube are fixedly connected to the head and the tail respectively. A spiral groove is provided on the outer surface of the insulating tube, and the spiral wire is wound in the spiral groove and is encapsulated and reinforced to fix the spiral wire. According to an armature provided by the present invention, one end of the connecting rod is fixedly connected to the bottom surface of the head, and the other end is fixedly connected to the bottom surface of the tail; one end of the spiral wire is fixedly connected to one end of the connecting rod, and the other end of the spiral wire is fixedly connected to the other end of the connecting rod; the spiral wire extends from the side surface of one end of the connecting rod through the outer surface of the insulating tube to the side surface of the other end of the connecting rod. According to the armature provided by the present invention, the insulating cylinder is made of insulating material. According to an armature provided by the present invention, the connecting rod is a cylinder, the insulating tube is a hollow cylinder, and the insulating tube surrounds the connecting rod. According to an armature provided by the present invention, the inner diameter of the insulating tube is greater than or equal to the outer diameter of the connecting rod, the outer diameter of the insulating tube is less than or equal to the bottom diameter of the head and the diameter of the tail, and the outer diameter of the spiral structure is less than or equal to the bottom diameter of the head and the diameter of the tail. According to an armature provided by the present invention, the connecting rod and the spiral structure are both made of conductive materials. According to an armature provided by the present invention, the pitch of the helical structure is greater than or equal to the diameter of the helical wire.

[0009] According to an armature provided by the present invention, in a spiral structure, the direction of the spiral line is left-handed or right-handed, and the number of spiral turns of the spiral line is greater than or equal to 0.5.

[0010] In a second aspect, the present invention provides an electromagnetic coil transmitter, comprising a drive coil and the armature according to the first aspect.

[0011] Compared with the prior art, the present invention has at least the following technical effects: The present invention provides an armature and electromagnetic coil launcher that improve the armature's flight stability during launch. The central portion of the armature features a spiral structure that allows for gradual rotation during launch, imparting rotational energy to the armature and generating a gyroscopic effect. The armature's rotational axis resists any external forces attempting to alter its flight direction, tending to maintain its direction during flight. This stabilizes the armature's flight attitude and improves its flight stability in an exterior trajectory. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0013] In the attached figure: Figure 1a It is a structural schematic diagram of the armature of the present invention; Figure 1b It is a structural schematic diagram of the middle part of the armature of the present invention; Figure 1c It is a schematic diagram of the force of the armature in the electromagnetic coil transmitter of the present invention; Figure 1d Schematic diagram of the dimensions of the helical structure pitch and helical wire diameter of the present invention; Figure 2 A schematic diagram of the use of the armature of the present invention in an electromagnetic coil transmitter; Figure 3 The figure is a speed curve diagram of the axial motion of the armature of the present invention in the finite element simulation; Figure 4 This is a rotation speed curve diagram of the armature of the present invention moving around the axial direction in the finite element simulation.

[0014] Reference numerals: 1. Head; 2. Spiral structure; 3. Tail; 4. Connecting rod; 5. Insulating tube. DETAILED DESCRIPTION

[0015] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0016] The following will describe some embodiments of the present invention in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0017] See also Figure 1a and Figure 1bThe embodiment of the present invention provides an armature, comprising a head 1, a middle part and a tail 3 connected in sequence; the head 1 is a cone or a hemisphere, used to improve the attack specific kinetic energy; the middle part includes a spiral structure 2, which is composed of one or more spiral lines, that is, the number of spiral lines Ns ≥ 1, used to generate a circumferential rotation force; the tail 3 is a cylinder, used to generate an axial acceleration thrust. Figure 1a and Figure 1b FIG. 2 shows a helical structure 2 consisting of three helical lines.

[0018] It should be noted that the present invention combines the advantages of the induction coil launcher and the magnetoresistive coil launcher. The tail cylinder realizes axial acceleration according to the principle of the magnetoresistive coil launcher, while the middle spiral structure mainly realizes circumferential rotation of the projectile according to the principle of the induction coil launcher. Figure 1c As shown, the same drive coil can both accelerate the tail 3 (axial force) and rotate the helical structure 2 (radial force). Therefore, increasing the number of drive coils allows for a gradual increase in both launch and rotational speeds. This allows the armature to simultaneously accelerate axially within the launcher while generating a torque around the armature axis to rotate it. This enhanced rotational stability results in a more stable forward path for the armature during flight, reducing potential instabilities such as roll and yaw during flight, thereby improving flight accuracy and stability.

[0019] Specifically, if Figure 1b As shown, the middle portion also includes a connecting rod 4 and an insulating tube 5. The connecting rod 4 is located within the insulating tube 5, with its ends fixedly connected to the head 1 and tail 3, respectively. The outer surface of the insulating tube 5 is provided with a spiral groove, within which the spiral wire is wound and encapsulated and reinforced to secure the wire. One end of the connecting rod 4 is fixedly connected to the bottom surface of the head 1, and the other end is fixedly connected to the bottom surface of the tail 3. One end of the spiral wire is fixedly connected to one end of the connecting rod 4, and the other end of the spiral wire is fixedly connected to the other end of the connecting rod 4. The spiral wire extends from the side surface of one end of the connecting rod 4 through the outer surface of the insulating tube 5 to the side surface of the other end of the connecting rod 4.

[0020] Specifically, the insulating tube 5 is made of insulating material, and the insulating tube 5 can fix and support the spiral structure 2 .

[0021] Furthermore, the connecting rod 4 is cylindrical, and the insulating tube 5 is a hollow cylinder, surrounding the connecting rod. The inner diameter of the insulating tube 5 is greater than or equal to the outer diameter of the connecting rod 4, and the outer diameter of the insulating tube 5 is less than or equal to the bottom diameter of the head 1 and the diameter of the tail 3. The outer diameter of the spiral structure is less than or equal to the bottom diameter of the head 1 and the diameter of the tail 3.

[0022] Specifically, the connecting rod 4 and the spiral structure 2 are both made of conductive materials, such as aluminum or copper. In the spiral structure 2, the direction of the spiral is left-handed or right-handed, and the number of spiral turns n0 of the spiral is ≥0.5.

[0023] like Figure 1d As shown, the pitch p of the helical structure 2 is greater than or equal to the diameter d of the helical line. For example, the pitch p is one time or more than the diameter d of the helical line.

[0024] It should be noted that the present invention improves the armature of the electromagnetic coil launcher by adding a spiral structure to the armature, enabling spontaneous rotation through the mechanical structure. This allows the armature to undergo axial acceleration within the launcher while simultaneously generating a torque around the armature axis to cause the armature to rotate, thus avoiding the need for a complex electromagnetic control system. By gradually accelerating the armature during the launch process, the armature can achieve an efficient and stable rotational speed. This enhanced rotational stability further stabilizes the armature's forward path during flight, reducing potential instabilities such as roll and yaw during flight, thereby improving flight accuracy and stability.

[0025] When the electromagnetic coil transmitter is working, the driving coil is fed by the pulse capacitor to generate a pulse current, forming a transient magnetic field inside the driving coil. The transient magnetic field magnetizes the armature, causing the armature to be subjected to axial tension and undergo axial accelerated motion inside the transmitting tube.

[0026] The helical structure generates an asymmetric electromagnetic force distribution in the magnetic field gradient, which creates a torque around the centerline of the armature, driving the armature to rotate. To achieve higher speeds, multi-stage drive coils are usually used to gradually accelerate the armature movement.

[0027] Another embodiment of the present invention provides an electromagnetic coil transmitter, the basic structure of which primarily comprises a drive coil, the armature of the aforementioned embodiment, a capacitor, and other components. The electromagnetic coil transmitter utilizes the changes in magnetic resistance of the magnetic circuit formed by the drive coil and armature to propel the armature into accelerated motion. Because a high magnetic field intensity is generated in the drive coil, the ferromagnetic armature tends to move toward the position of minimum magnetic resistance. This creates an axial tension on the armature, allowing for axial acceleration.

[0028] The relevant electromagnetic field equations describing the motion of the armature are as follows: (1) Where, is the curl operator, which indicates the degree of rotation of the vector field; μ0 is the vacuum magnetic permeability, μ0=4π×10 ﹣7 H / m; B is the magnetic induction intensity; is the free current density; is the magnetizing current density, Equal to the curl of the magnetization intensity M; M1 and M2 are the magnetization intensities of medium 1 and medium 2 on both sides of the medium interface respectively; is the conductivity; E is the electric field intensity; A is the vector magnetic potential; is the scalar potential; v is the speed of the projectile; t is the time; is the surface density of the magnetizing current on the dielectric interface; n is the normal unit vector pointing from medium 1 to medium 2 on the dielectric interface.

[0029] The magnetic field in a moving armature is generated by the free current and the magnetizing current. The free current in the armature is considered to be composed of induced eddy currents and motional eddy currents generated by the motional electromotive force. Ignoring the influence of displacement current, the free current and magnetizing current are the only two factors that contribute. The circuit parameters directly affect the values ​​of these two factors, thus determining the form of armature acceleration.

[0030] If the influence of reverse eddy current exceeds the magnetizing current, the drive is mainly driven by induction; if the magnetizing current plays a major role, it is a so-called reluctance drive. The armature control equation expressed is: (2) The force density acting on the armature is: (3) In formula (3) include and .

[0031] Assume the armature is The position at time is , the equivalent inductance is , the current in the driving coil is , then the electromagnetic energy of the entire system satisfies: (4) in, for The energy of the inductor at a moment. Assuming that in a very small time period The movement distance of the armature under the action of electromagnetic force is ,at this time The change is not significant and can be considered as a constant. According to the principle of conservation of energy, the armature force can be obtained as: (5) in, The armature is subjected to force. is the armature mass.

[0032] The energy obtained by the armature all comes from the external circuit, and the electromagnetic force it is subjected to is only determined by the energy conversion of the drive coil, the external circuit and some basic parameters of the armature itself.

[0033] In this invention, a helical structure is added to the armature. This helical structure, under the influence of the electromagnetic force generated by the drive coil, generates an axial rotational torque, driving the armature to rotate along its axis. When a transient magnetic field is applied to the armature, the helical structure generates an asymmetric electromagnetic force distribution within the magnetic field gradient, creating a torque around the armature axis, driving the armature to rotate.

[0034] The main electromagnetic force (i.e., axial magnetic pull) exerted by the transient magnetic field still pushes the armature to accelerate along the axis of the launch tube. The helical structure converts part of the magnetic force into a torque around the axis, the magnitude of which depends on the angle of the helical structure and the intensity distribution of the magnetic field.

[0035] The armature of the present invention possesses both translational and rotational kinetic energy during flight. The helical structure design adds additional rotational kinetic energy to the armature without affecting axial acceleration, thereby improving its overall energy efficiency. The rotating armature creates a more stable airflow distribution during flight, reducing asymmetric air resistance or vibration during flight, thereby improving the armature's flight stability.

[0036] Figure 2 This is a schematic diagram of the use of the armature of the present invention under the action of the 5-level drive coil in the transmitter. Before the transmitter works, the armature is placed at the tail of the drive coil, waiting for the transmitter to work.

[0037] The transmitter first charges each capacitor to a specified voltage.

[0038] After the transmitter finishes charging the capacitor, it turns on the switches at each level in sequence according to the set switching timing to discharge, and energizes the corresponding drive coils.

[0039] When current flows through the driving coil, a magnetic field is generated around the driving coil. The magnetic field in the driving coil exerts an axial electromagnetic force on the armature in the magnetic field.

[0040] The electromagnetic force causes the armature to move axially toward the coil, attracting the armature toward the center of the coil.

[0041] The present invention adds a spiral structure in the middle of the armature, and when the armature is subjected to axial attraction, a torque rotating along the axial direction is generated, so that the armature rotates.

[0042] like Figure 3The figure shows a velocity curve of the axial motion of an armature provided by a specific embodiment of the present invention under the action of a five-stage drive coil in a transmitter, as simulated by a finite element method. After the armature is accelerated by the five-stage drive coil, the axial motion speed can reach 60.68 m / s.

[0043] like Figure 4 The figure shows the rotation speed curve of the armature rotating around the axial direction in the finite element simulation under the action of the five-stage drive coil in the transmitter provided by a specific embodiment of the present invention. After the armature is accelerated by the five-stage drive coil, the rotation speed can reach .

[0044] In summary, the armature and electromagnetic coil launcher provided by the present invention comprise a head, middle, and tail sections connected in sequence. The middle section includes a spiral structure for generating a circumferential rotational force, and the spiral structure is composed of at least one helical wire. The structural design of the electromagnetic coil launcher's armature combines the advantages of both induction and magnetoresistive coil launchers. The cylindrical tail section achieves axial acceleration based on the principles of the magnetoresistive coil launcher, while the spiral structure in the middle section primarily rotates the projectile in the circumferential direction, based on the principles of the induction coil launcher. The same drive coil can both accelerate the tail section and rotate the spiral structure. Therefore, as the number of drive coils increases, both the launch speed and the rotation speed gradually increase. This allows the armature to simultaneously accelerate axially within the launcher while generating a torque around the armature axis to cause the armature to rotate. This reduces potential instabilities such as roll and yaw during flight, thereby improving flight accuracy and stability.

[0045] The present invention improves the armature of the electromagnetic coil transmitter by adding a spiral structure in the armature. By changing the mechanical structure, the armature is spontaneously rotated. While the armature is axially accelerated in the transmitter, a torque is applied around the armature axis to cause the armature to rotate, thus avoiding a complex electromagnetic control system.

[0046] After the armature of the present invention is accelerated by the multi-stage drive coil of the transmitter, the armature can achieve a stable rotation speed, effectively improving the aerodynamic stability of the armature, reducing disturbances during flight, and thus improving the stability of the armature flight.

[0047] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the embodiments disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and variations can be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. An armature, characterized in that: It includes a head, a middle part and a tail part connected in sequence; the middle part includes a spiral structure for forming a circumferential rotation force, and the spiral structure is composed of one or more spiral lines.

2. The armature according to claim 1, characterized in that The head is a cone or a hemisphere, the tail is a cylinder, and the middle part also includes a connecting rod and an insulating tube. The connecting rod is arranged in the insulating tube. The two ends of the insulating tube are fixedly connected to the head and the tail respectively. A spiral groove is provided on the outer surface of the insulating tube. The spiral wire is wound in the spiral groove and is encapsulated and reinforced to fix the spiral wire.

3. The armature according to claim 2, characterized in that One end of the connecting rod is fixedly connected to the bottom surface of the head, and the other end is fixedly connected to the bottom surface of the tail; one end of the spiral line is fixedly connected to one end of the connecting rod, and the other end of the spiral line is fixedly connected to the other end of the connecting rod; the spiral line extends from the side surface of one end of the connecting rod through the outer surface of the insulating tube to the side surface of the other end of the connecting rod.

4. The armature according to claim 2, wherein: The insulating cylinder is made of insulating material.

5. The armature according to claim 2, wherein: The connecting rod is a cylinder, the insulating cylinder is a hollow cylinder, and the insulating cylinder surrounds the connecting rod.

6. The armature according to claim 5, characterized in that The inner diameter of the insulating tube is greater than or equal to the outer diameter of the connecting rod, the outer diameter of the insulating tube is less than or equal to the bottom diameter of the head and the diameter of the tail, and the outer diameter of the spiral structure is less than or equal to the bottom diameter of the head and the diameter of the tail.

7. The armature according to claim 2, characterized in that The connecting rod and the spiral structure are both made of conductive materials.

8. The armature according to claim 1, wherein: The pitch of the helical structure is greater than or equal to the diameter of the helical line.

9. The armature according to claim 1, wherein: In the spiral structure, the direction of the spiral line is left-handed or right-handed, and the number of spiral turns of the spiral line is greater than or equal to 0.

5.

10. An electromagnetic coil transmitter, characterized in that: The invention comprises a drive coil and the armature according to any one of claims 1 to 9.

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