CN218157361U

CN218157361U - Strong electromagnetic force device

Info

Publication number: CN218157361U
Application number: CN202123033909.1U
Authority: CN
Inventors: 王林兵; 车芸
Original assignee: Northwestern Polytechnical University
Current assignee: Northwestern Polytechnical University
Priority date: 2021-12-03
Filing date: 2021-12-03
Publication date: 2022-12-27
Anticipated expiration: 2031-12-03

Abstract

The invention provides a strong electromagnetic device. The inductor structure is characterized in that each spiral hollow cylindrical inductor is mutually nested and positioned on the same axis, and one end of each hollow cylindrical inductor is kept level to form a series nested inductor structure; the inductors are connected in series, are connected like a bow shape when viewed from the cross section, and keep the current direction (clockwise or anticlockwise) of each inductor consistent. The initial position of the secondary coil is close to the flush end of the hollow cylindrical inductor and can move outwards along the axis of the inductor structure. And two ends of the hollow cylindrical inductor connected in series are connected with the pulse discharge circuit to form a closed loop. The control circuit and the inductor have simple structures and high space utilization rate, can provide larger and more reliable electromagnetic thrust, and meet the requirements of occasions such as spacecraft impact power tests, dynamic mechanical property tests of materials and the like on simple control systems and high thrust.

Description

Strong electromagnetic force device

Technical Field

The invention relates to the field of spacecraft impact power tests and dynamic mechanical property tests of materials, in particular to a strong electromagnetic force device.

Background

With the rapid progress of science and technology in China, the requirements of occasions such as spacecraft impact power tests, dynamic mechanical property tests of materials and the like on the experimental power loading device are greatly improved. At present widely used disconnect-type hopkinson pole technique comes simulation spacecraft transmission and material capability test to disconnect-type hopkinson pole device's power loading device is taken as an example, and traditional disconnect-type hopkinson pole device adopts gas drive usually, needs very high atmospheric pressure just can reach high strain rate, and gas drive's transmitter occupation space is big, and traditional device can't further miniaturize. In addition, the conventional device has the disadvantages of low shooting repeatability, high noise and the like.

Aiming at the defects of the traditional pneumatic loading system, a plurality of scholars at home and abroad research the electromagnetic emission technology and adopt an electromagnetic driving method to optimize the device. At present, most of electromagnetic separation type Hopkinson bar devices drive a striker by utilizing Lorentz force generated by magnetic resistance change, and in order to avoid deceleration force and increase speed, the devices can open a circuit when the striker moves forwards to the center of a coil. This conventional method has several limitations, firstly, the length of the plunger needs to be equal to the length of the coil, and when the center of the plunger passes through the center of the coil, the plunger will no longer block the photo-sensor, thereby opening the switch and interrupting the discharge circuit, which also limits the width range of the stress wave. Second, this conventional method requires determining when the circuit is on or off by detecting the position of the plunger in the solenoid at all times and controlling the switch, which adds complexity to the circuit control system. Finally, because simulation tests such as spacecraft impact power have extremely high requirements on thrust, common electromagnetic force loading devices cannot meet the experimental requirements, and hierarchical electromagnetic force loading devices proposed by some domestic and foreign scholars face the problem of complex circuit control systems.

In summary, in the aspects of spacecraft impact dynamic tests, dynamic mechanical property tests of materials and the like, the existing electromagnetic thrust device has the defects of complex device, low thrust and the like.

Disclosure of Invention

The invention mainly aims to solve the problems of complex structure and small thrust of the conventional power loading device in experiments such as spacecraft impact power tests, dynamic mechanical property tests of materials and the like.

Therefore, the invention provides a strong electromagnetic device which has the advantages of simple structure and high thrust. The electromagnetic thrust device adopts an inductor structure with a plurality of serially connected cylindrical inductors which are nested with each other, and mainly comprises a plurality of hollow cylindrical inductors and a secondary coil.

The hollow cylindrical inductor is an active coil and is formed by winding a coil in a spiral manner;

the inductor structure is characterized in that all hollow cylindrical inductors are mutually nested and are positioned on the same central axis, and one end of each hollow cylindrical inductor is kept level; all the inductors are mutually connected in series, and when viewed from the cross section, the series circuit is connected like a bow, and the directions of electromagnetic force generated by all the nested inductors are kept consistent;

in the inductance structure, a certain gap is kept between every two adjacent hollow cylindrical inductors, so that the insulation and installation are facilitated.

The secondary coil can be a metal disc, and the smaller the resistivity is, the larger eddy current can be generated, and the larger electromagnetic thrust is provided; the initial position of the secondary coil is close to one end of each series cylindrical inductor which is flush with each other, and the secondary coil can move outwards along the axis of the series cylindrical inductor structure; the shape of the secondary coil can be adjusted according to the requirement, and can be a disc, a ring or a cylinder, and the like, or a combination of the disc, the ring and the cylinder.

Two ends of the inductance structure are connected with a pulse discharge circuit and are connected in series to form a closed loop; the pulse discharge circuit is the main circuit of the invention and consists of a charging circuit and a discharging circuit.

The strong electromagnetic force device provided by the invention has the following characteristics that:

1. the electromagnetic thrust device has the characteristics of simple structure, convenience in operation and the like. The inductors are connected in series, the system is provided with a pulse discharge circuit and a discharge switch thereof, and the electromagnetic thrust can be greatly improved without a complex circuit control system. Meanwhile, the initial position of the secondary coil is positioned at one end of the inductance structure and moves outwards along with the electromagnetic thrust, so that the electromagnetic deceleration force is not required to be eliminated, and the position of the plunger in the electromagnetic coil is detected at any time to judge when the circuit is switched on or switched off.

2. The electromagnetic thrust device can provide high-strength electromagnetic thrust. The invention can be regarded as that a plurality of independent single-winding coils are connected in series and used for a circuit, when a system discharges, each series coil synchronously discharges, a plurality of driving coils simultaneously act on the secondary coil to generate a superposed magnetic field and superposed thrust, and the secondary coil and a load are accelerated. Simulation proves that under the condition that the peripheral radii of the device are the same, the thrust generated by the electromagnetic thrust device is far larger than that generated by a single-coil electromagnetic thrust device.

3. The series inductor is connected in a bow shape, so that the power loading device has simplified circuit and higher space utilization rate. In a structure with a plurality of inductors nested, a control circuit of the electromagnetic thrust device is simpler, and the provided electromagnetic thrust is more reliable.

4. The number of series inductors and the number of turns of the inductance coil can be adjusted according to the thrust requirement, and the shape of the secondary coil can be adjusted according to the requirement. The active coil may also be a conical inductor, or other irregular cylindrical or conical inductor. The secondary coil may be designed in a disc shape; a groove can be designed on one side of the secondary coil to realize the fixation of the load position; it is also possible to sandwich a portion of the secondary coil within the inductive structure.

The electromagnetic thrust device has the advantages of simple structure, simplicity and convenience in operation, can obtain larger and more reliable electromagnetic force, and can be used in the occasions of spacecraft impact power tests, dynamic mechanical property tests of materials, shipboard aircraft ejection experiments, electromagnetic forming, electromagnetic cannons and the like.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention and do not limit the invention. In the drawings:

FIG. 1 is a schematic view of an electromagnetic force device of the present invention;

FIG. 2 is a schematic view of an apparatus according to example 1 of the present invention;

FIG. 3 is a schematic diagram of an electromagnetic force device including an inductor structure according to embodiment 1 of the present invention;

FIG. 4 is a schematic diagram showing the directions of inductor currents in embodiment 1 of the present invention;

description of reference numerals: 1-a base; 2. 3, 4-active coil; 5-a transmitting tube; 6-a secondary coil; 7-an incident rod; 8-strain gauge; 9-sample; 10-a transmission rod; 11-a buffer; 12. 13-a scaffold; 14-the ground; 15-strain gauge; 16-a power supply; 17-a charge switch; 18-a step-up transformer; 19-a rectifier; 20-a capacitor bank; 21-discharge switch.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. The described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1

The present embodiment provides an electromagnetic separation type hopkinson pressure lever (SHPB) experimental apparatus, and the following describes in detail the technical solutions provided by the embodiments of the present invention with reference to fig. 2, fig. 3, and fig. 4.

The structural characteristics of the embodiment are as follows: three coaxial hollow cylindrical coils with the same length are mutually nested in series, and a disc-shaped secondary coil is arranged on the right side of the hollow cylindrical driving coil.

The concrete structure is as follows:

fig. 2 is a schematic view of the apparatus of embodiment 1, and referring to fig. 2, the system includes: the device comprises a base 1, an active coil 2, an active coil 3, an active coil 4, a transmitting tube 5, a secondary coil 6, an incident rod 7, a strain gauge 8, a sample 9, a transmission rod 10, a buffer 11, supports 12 and 13, a strain gauge 15 and a main circuit;

the base 1, the active coil 2, the active coil 3, the active coil 4, the emitter tube 5, the secondary coil 6, the incident rod 7, the sample 9, the transmission rod 10, the buffer 11, and the like are held on the same central axis;

the base 1 is a cylindrical structure with a groove, and two sides of the base are perpendicular to the rail and used for placing an active coil; the transmitting tube 5 is covered on the base 1, the inner wall of the transmitting tube is horizontal and smooth, and the transmitting tube is used for placing the secondary coil 6 and guiding the secondary coil to move in the horizontal direction; the base 1 and the transmitting tube 5 are made of metal materials and have the functions of fixing the position of an inductor and preventing a magnetic field from leaking.

As shown in fig. 3, in this embodiment, the inductor structure in which the series cylindrical inductors are nested with each other is composed of an active coil 2, an active coil 3, and an active coil 4; the driving coil is a hollow cylindrical inductor and is formed by spirally winding a copper wire; the periphery of the inductor is sleeved with an insulating shell which plays an insulating role; the axial side surfaces of the driving coils are parallel, and the radial side surfaces of the driving coils are flush.

A gap is reserved between the insulating shell on the periphery of the driving coil 2 and the inner wall surface of the base and keeps parallel, and the gap can be used for magnetic flux to pass through;

as shown in fig. 4, when viewed from the cross section of the inductor, the inductors nested in series are connected in a bow shape, and the current directions (clockwise or counterclockwise) of the inductors are consistent;

the secondary coil 6 is a metal disc and is also a transmitting coil in an experiment, the secondary coil 6 can move rightwards along a central axis in the transmitting tube to impact the incident rod 7, and instant thrust is provided for the incident rod 7.

The damper 11 is a damping device, and plays roles of damping thrust, fixing position, and the like for the transmission rod 10.

The strain gauge 15 can collect stress waves of the incident rod 7 and the transmission rod 10; other testing equipment can be further installed in the experiment, such as a camera is installed near the sample to detect the deformation information of the sample 9.

The main circuit of the embodiment is composed of a charging circuit and a discharging circuit. In the pulse discharge circuit connected in series at two ends of the inductance structure, the charging circuit consists of a power supply 16, a charging switch 17, a step-up transformer 18, a rectifier bridge 19 and a capacitor bank 20, and the discharge circuit consists of a discharge switch 21, the capacitor bank 20 and

active coils

2, 3 and 4;

the specific implementation steps are as follows:

when the electromagnetic thrust system works, the circuit is electrified, the charging switch 17 is closed, the discharging switch 21 is opened, the alternating current power supply 16 is transformed by the step-up transformer 18 and rectified by the diode rectifying circuit 19, then the capacitor bank 20 is charged, and the capacitor bank 20 stores energy. When the charging voltage reaches the set voltage, the discharging may be started.

During discharging, the discharge switch 21 is closed, the capacitor bank 20 instantaneously discharges to the active coil bank, and the current generates a magnetic field around the active coil; as shown in fig. 4, the directions of the currents of the inductors (clockwise or counterclockwise at the same time) are the same, so that the directions of the magnetic fields generated by the inductors are the same;

the magnetic field will generate induced eddy currents in the secondary coil 6, and the induced eddy currents will induce a magnetic field around the secondary coil 6 in a direction opposite to that of the magnetic field of the active coil, and the opposite magnetic field will generate a strong electromagnetic thrust F between the active coil and the secondary coil 6, the magnitude of which can be controlled; the electromagnetic thrust F acts on the load and is represented by a compression stress wave.

The strong thrust pushes the secondary coil 6 to move rightwards quickly in the transmitting tube 5 along the central axis to impact the incident rod 7, so that instant thrust is provided for the incident rod 7, and the thrust is transmitted into the incident rod 7 of the Hopkinson bar through the secondary coil 6, so that thrust loading of the Hopkinson bar is realized; the instantaneous thrust of the incident rod 7 collides with the buffer damping transmitted by the transmission rod 10 to extrude the sample 9;

stress pieces attached to the incident rod 7 and the transmission rod 10 transmit information such as stress waves to the measuring instrument to provide data for experiments, and measures such as installing a camera near the sample 9 to detect sample deformation information and installing temperature measuring equipment to measure sample temperature information can be adopted to detect various data such as dynamic mechanical properties of materials.

In this embodiment, 3 driving coils are synchronously energized, that is, the driving coils 2, 3, and 4 provide a magnetic field for the secondary coil 6 together, so that the secondary coil 6 and the hopkinson bar obtain a larger thrust and acceleration.

It should be noted that the shape of the secondary coil of the present invention can be adjusted as required. The secondary coil can be in the shape of a metal disc, a circular ring or a cylinder, and the like, and can also be a combination of a disc, a circular ring and a cylinder.

It should be noted that the number and the number of turns of the series inductors in the present invention are not limited by the embodiments, and more inductors can be nested under the permission of practical situations.

The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A strong electromagnetic force device is characterized by comprising a plurality of hollow cylindrical inductors and a secondary coil;

the inductor is an active coil and is a hollow cylindrical inductor formed by winding coils in a spiral manner, and a plurality of inductors are connected in series to generate a superposed magnetic field;

and the secondary coil moves under the action of the superposed magnetic field of the driving coil and the action of pulse electromagnetic force.

2. A strong electromagnetic force device as claimed in claim 1, wherein each of said hollow cylindrical inductors is nested within each other on a same central axis, and one end of each of said hollow cylindrical inductors is flush with each other; the inductors are connected in series, are similar to a bow-shaped connection when viewed from the cross section, and enable the current directions of the inductors to be consistent and uniformly flow along the clockwise or counterclockwise direction.

3. A strong electromagnetic force device as claimed in claim 1 wherein said secondary coil is initially positioned adjacent a flush end of said hollow cylindrical inductor and is movable outwardly along the axis of said hollow cylindrical inductor.

4. A strong electromagnetic force device as claimed in claim 1, wherein said secondary coil is adjustable in shape as desired, and may be a disk, a ring, a cone, or a cylinder, or a combination of a disk, a ring, a cone, and a cylinder.

5. A strong electromagnetic force device as claimed in claim 1, wherein said plurality of hollow cylindrical inductors connected in series are connected at both ends to a pulse discharge circuit to form a single closed loop connected in series; the pulse discharge circuit is a main circuit and consists of a charging circuit and a discharge circuit; the system controls the pulse discharge circuit and the discharge switch thereof to realize the control of the electromagnetic thrust.