CN113664360A

CN113664360A - Magnetic pulse connecting device and method for double-layer circular tube and eddy current damper

Info

Publication number: CN113664360A
Application number: CN202111229993.6A
Authority: CN
Inventors: 蒋浩; 蔡达; 崔俊佳; 李光耀
Original assignee: Hunan University
Current assignee: Hunan University
Priority date: 2021-10-22
Filing date: 2021-10-22
Publication date: 2021-11-19
Anticipated expiration: 2041-10-22
Also published as: CN113664360B

Abstract

The invention provides a magnetic pulse connecting device for a double-layer circular tube, which comprises an inner tube support and an outer tube support which are coaxially arranged, wherein one end of the inner tube support is provided with a first through hole for penetrating through a wire of a coil inductor, the other end of the inner tube support is provided with an annular positioning groove matched with the outer tube, the outer tube support is connected with the top end of the inner tube support, a protective sleeve simultaneously provides radial constraint for the inner tube support and the outer tube support, the top end of the outer tube support is connected with an inner pressure plate for compressing the outer tube, the inner pressure plate is connected with a flange capable of sliding in the inner tube support along the axial direction, the flange is connected with the coil inductor, the coil inductor comprises a core cover, a core shaft and a turn line, an insulating bolt sequentially penetrates through the flange and the core cover to be connected with the core shaft, and the turn line is wound on the core shaft and is compressed by the core cover; the magnetic pulse connecting device for the double-layer circular tube is safe and efficient, can improve the forming limit of materials, is green, environment-friendly and low-carbon, does not generate very brittle metal compounds on a welding interface, and can ensure the connecting strength.

Description

Magnetic pulse connecting device and method for double-layer circular tube and eddy current damper

Technical Field

The invention belongs to the technical field of metal pipe connection, and particularly relates to a device and a method for connecting double-layer circular pipes in an eddy current damper by using a magnetic pulse forming technology, and the eddy current damper.

Background

A damper is a device that dissipates kinetic energy by outputting a resistance force. The method is widely applied to industries such as aviation, aerospace, military industry, automobiles, civil engineering and the like. The eddy current damper is one of the eddy current dampers, has the advantages of simple structure, convenience in maintenance, long service life and the like, and has wide application prospect. The basic principle of the eddy current damping vibration absorber is as follows: the conductor cuts magnetic lines of force, and eddy current generated in the conductor achieves the purpose of dissipating vibration energy through resistance thermal effect; meanwhile, the eddy current can also generate a new magnetic field opposite to the original magnetic field, so that a damping force for blocking the movement of the conductor is generated, and the effect of dissipating vibration energy is achieved. The current eddy current dampers used for structural vibration damping can be divided into two categories: the flat plate type damper has the advantages that the damping force in a plane is not limited by the direction, but the magnetic leakage problem exists; and secondly, the problem of magnetic leakage can be effectively solved by the axial force damper. To a double-deck pipe type axial force eddy current damper, the double-deck pipe structure is constituteed with the excircle nest of tubes that the magnetic conductive material made to the interior pipe that the electrically conductive material made by strong, arranges circular magnet in interior pipe inside, and whole magnetic lines of force all can the perpendicular cutting electrically conductive inner tube and the magnetic line of force can not appear in the excircle outside of tubes of strong magnetic conductivity, realizes the external shielding in magnetic field, effectively improves electric eddy current efficiency.

In the damping vibration attenuation process, the connection quality of the inner circular tube and the outer circular tube is an important factor for ensuring the normal work of the damper. The inner circular tube of the eddy current damper is usually made of aluminum alloy, the outer circular tube is generally made of steel, and the connection modes of the nonferrous metal, steel and the dissimilar nonferrous metal materials at home and abroad are roughly divided into mechanical connection and non-mechanical connection at present. The mechanical connection comprises clamping and pressing type connection, annular pressing type connection and the like; non-mechanical connections, represented by welds. When the internal aluminum pipe and the external steel pipe are mechanically crimped, the aluminum alloy is easy to lose effectiveness during connection due to poor aluminum alloy formability at room temperature; when non-mechanical welding is adopted, the difference of the thermal and physical properties of steel and aluminum is obvious, and the traditional welding method easily generates a very brittle intermetallic compound on a connecting interface to generate a larger stress gradient, so that the quality is influenced.

Disclosure of Invention

The invention aims to solve the technical problem of providing a magnetic pulse connecting device for double-layer circular tubes, which is safe and efficient, can improve the forming limit of materials, is environment-friendly and low-carbon, does not generate brittle metal compounds on welding interfaces and can ensure the connecting strength, for the connection of an aluminum inner tube and a steel outer tube in a double-layer circular tube axial force eddy current damper and the connection of other dissimilar metal tubes.

In order to achieve the purpose, the technical scheme of the invention is that the magnetic pulse connecting device for the double-layer circular tube comprises a charging switch, a step-up transformer, a high-voltage rectifier, a current-limiting resistor, a capacitor, a discharge switch, an inner tube support, an outer tube support, a protective sleeve, a limiting support, an inner pressure plate, an outer pressure plate, a flange and an inductor;

the inner tube support is provided with three stages of stepped holes, the first stage is a first through hole from the bottom and is used as a wire channel, the second stage is used for providing positioning and radial support for the inner tube, the third stage is an annular positioning groove and is used for providing positioning for the outer tube, and meanwhile, a bottom processing boss provides support for the whole device;

the outer pipe support is provided with two stages of stepped holes, the first stage is used for providing radial support for the outer pipe from the bottom, the second stage is used for providing positioning and radial constraint for the inner pressure disc, and meanwhile, the outer side of the upper end part is provided with external threads for being connected with the outer pressure disc;

the protective sleeve is used for providing radial restraint for the inner tube and the outer tube; the inner pressure plate and the outer pressure plate act together to press the outer pipe tightly, meanwhile, the inner pressure plate is provided with three through holes, the middle through hole is large in size, and the through holes on the two sides are small in size; the limiting support is provided with three threaded holes in the long axis direction, the middle threaded hole is larger in size, and the two sides are smaller in size; the flange is divided into two areas of a flange shaft and a flange plate, the shaft is provided with external threads, and the flange plate area starts to be provided with four through holes along the circumferential direction;

the inductor comprises two types, one is a coil inductor, and the other is a magnetic concentrator-coil composite inductor. The former winds a lead on a core rod made of an insulating material and is axially compressed to wrap the insulating material, and the latter nests a magnetic collector made of a high-strength and high-conductivity material outside a coil and wraps the insulating material on the outer side;

the inner tube is supported and placed on the working platform, the inner tube is matched with the second-stage stepped hole of the inner tube support, the outer tube is positioned in the third-stage stepped hole of the inner tube support, the outer tube support is sleeved outside the outer tube, the bottom of the outer tube is contacted with the upper end of the inner tube support, the protective sleeve is arranged outside the inner tube support and higher than the inner tube support, and provides restraint for the inner tube support and the outer tube support at the same time;

further, the charging loop comprises a transformer, a high-voltage rectifier, a current-limiting resistor and a capacitor; the discharge loop comprises a capacitor, a discharge switch and an inductor;

during discharging, in a charging loop, electric energy in a power grid is stored in a capacitor through a booster transformer, a rectifier, a current-limiting resistor and the like; after charging is finished, the charging loop is changed into an open circuit state, the discharging switch of the discharging loop is closed, and electric energy is released to the inductor instantly. When the coil inductor is subjected to transient discharge, a strong magnetic field and magnetic pressure are generated between the coil inductor and the inner pipe, and when the magnetic pressure is greater than the yield limit of the material of the inner pipe, the inner pipe moves outwards along the radial direction at a high speed to reach a certain condition, and then magnetic pulse connection is generated in the lap joint area of the inner pipe and the outer pipe.

When transient discharge is carried out on the magnetic collector-coil composite inductor, the pulse current flowing through the coil generates eddy current with the direction opposite to the current direction of the coil on the inner surface of the magnetic collector, the eddy current only flows on the inner surface of the magnetic collector due to skin effect, flows to the outer surface from the slit of the magnetic collector and is then concentrated on the surface of an effective working area of the magnetic collector, the eddy current and the current direction of the coil are the same at the moment, the eddy current magnetic field is superposed with the induced current magnetic field of the inner tube, a strong magnetic field is formed between the magnetic collector and the inner tube, magnetic pulse pressure is generated, and when the pulse pressure is greater than the yield limit of the material of the inner tube, the inner tube expands outwards and reaches a certain condition, magnetic pulse connection is generated in the lap joint area of the inner tube and the outer tube.

Both the coil inductor and the magnetic collector-coil composite inductor can generate a magnetic pulse welding double-layer connecting pipe and a magnetic pulse expanded connecting double-layer connecting pipe. When the inner wall of the outer pipe is not provided with an annular groove, the inner pipe is driven to impact the outer pipe at a high speed during magnetic pulse welding, and when the impact speed reaches a threshold value, a double-layer connecting pipe is welded by magnetic pulses in a lap joint area of two workpieces; when the inner wall of the outer pipe is provided with the annular groove, magnetic pulse expansion joint can be carried out, the speed of the inner pipe impacting the outer pipe is relatively low, the inner pipe is subjected to plastic deformation and expands outwards, and forms mechanical locking with the annular groove preset on the outer pipe to connect two workpieces together, so that a magnetic pulse expansion joint double-layer connecting pipe is formed; when the inner wall of the outer pipe is provided with the annular groove, composite connection can be carried out, the speed of the inner pipe impacting the outer pipe reaches a threshold value, and the lap joint area of the two workpieces generates a composite double-layer connecting pipe with magnetic pulse welding and mechanical locking.

The invention also provides a method for connecting the aluminum inner pipe and the steel outer pipe in the double-layer circular pipe axial force eddy current damper by using the device, which comprises the following steps:

step 1, preparing inner and outer pipe blank, and carrying out rust removal, oil removal and degreasing treatment on a connection area to ensure that a metal interface is bright and clean (when carrying out magnetic pulse expanded joint, a ring groove with certain width and depth is formed at a corresponding position of an outer pipe);

step 2, placing the inner pipe support on a working platform, and respectively placing the blanks of the inner pipe and the outer pipe prepared in the step 1 in a second-stage stepped hole and a third-stage stepped hole of the inner pipe support;

step 3, completing the matching of the outer pipe support and the outer pipe, and the outer pipe support and the inner pipe support, and sleeving the protective sleeve outside the inner pipe support and the outer pipe support;

step 4, connecting the inductor with the flange plate;

step 5, completing the matching of the central internal thread of the limiting support and the external thread of the flange shaft, wherein the flange shaft passes through the central through hole of the inner pressure plate and completes the connection of the limiting support and the inner pressure plate through a screw and a nut;

step 6, the whole body in the step 5 is placed in a double-layer connecting pipe to be processed, a conductor of the inductor penetrates through the first-stage hole supported by the inner pipe, the inner pressure plate tightly presses the outer pipe, the inductor is adjusted to a proper position through the adjusting screw rod and the nut, and the inductor is fastened through the nut;

step 7, connecting the outer pressing disc with the outer tube support in a threaded fit manner, and pressing the inner pressing disc tightly; connecting the conductor end of the inductor with a charging and discharging loop;

step 8, a charging switch is closed, alternating voltage in a power grid is boosted through a booster, current flows through a rectifier and is changed into direct current, a resistor enables the current in a charging loop to be reduced, the direct current charges a capacitor, the charging switch is disconnected, a discharging switch is closed, the capacitor acts energy on an inductor, sufficient magnetic pulse pressure is generated, and the inner pipe and the outer pipe are connected;

and 9, loosening the outer pressing disc, taking out the connecting piece to check the connection quality, repeating the steps 4-8, and performing multi-pass discharging at different positions.

The invention also provides an eddy current damper, which comprises the double-layer connecting pipe prepared by the connecting method.

The invention has the beneficial effects that:

1. the aluminum alloy inner pipe has the forming characteristic of high strain rate, can improve the forming limit of materials, and can solve the problem that the aluminum alloy inner pipe is easy to crack and lose efficacy at the slotting position of the outer pipe when the aluminum alloy inner pipe is connected by adopting a conventional mode at room temperature.

2. The method has the advantages of no emission, no heating, no radiation, no smoke, no waste gas, no spark, no condensed water, no auxiliary material consumption, environmental protection, low carbon, no need of continuous heat treatment and cleaning process and the like in the whole process, no brittle metal compound generated on a welding interface, and capability of ensuring the connection strength.

3. When the frequency of the magnetic pulse equipment is not high, a coil inductor is used for directly applying magnetic pressure to the double-layer connecting pipe fitting, and the coil inductance is adjusted by changing the section of a turn line and the number of turns of a coil, so that the optimization of magnetic pulse parameters is realized, and the magnetic pulse double-layer connecting pipe is obtained; for high-frequency magnetic pulse equipment, the service life of the inductor can be prolonged by adopting the magnetic collector-coil composite inductor, the geometric characteristics of the magnetic collector are changed for pipes with different diameters and wall thicknesses, the same coils can be matched for connection, the processing flexibility of the magnetic pulse connection of the pipes is obviously improved, the magnetic pulse composite inductor can be suitable for different connection conditions, and the popularization prospect is good.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a schematic view of the construction of the core lid shown in FIG. 1;

FIG. 3 is a schematic structural view of the mandrel shown in FIG. 2;

FIG. 4 is a schematic structural view of the inner tube support;

FIG. 5 is a sectional view taken along line A-A of FIG. 4;

FIG. 6 is a schematic view of the outer tube support;

FIG. 7 is a sectional view taken along line B-B of FIG. 6;

FIG. 8 is a schematic view of a protective sleeve;

FIG. 9 is a cross-sectional view taken along line C-C of FIG. 8;

FIG. 10 is a schematic view of the inner tube overlapping the outer appearance;

FIG. 11 is a schematic structural view of a spacing support;

FIG. 12 is a cross-sectional view taken along line D-D of FIG. 11;

FIG. 13 is a schematic structural view of an inner platen;

FIG. 14 is a cross-sectional view taken along line E-E of FIG. 13;

FIG. 15 is a schematic structural view of an outer platen;

FIG. 16 is a sectional view taken along line F-F of FIG. 15;

FIG. 17 is a schematic view of the flange configuration;

FIG. 18 is a schematic view of the flange of FIG. 17 from another perspective;

FIG. 19 is a schematic view of the construction of the cartridge cover shown in FIG. 3;

FIG. 20 is a schematic view of the core cap of FIG. 19 from another perspective;

FIG. 21 is a sectional view taken along line G-G of FIG. 20;

FIG. 22 is a schematic structural view of the mandrel shown in FIG. 3;

FIG. 23 is a schematic view of the mandrel of FIG. 22 from another perspective;

FIG. 24 is a sectional view taken along line H-H in FIG. 23;

FIG. 25 is a schematic view of the configuration of an annular groove;

FIG. 26 is a schematic structural diagram of another embodiment of the present invention;

FIG. 27 is a schematic view of the structure of the magnetic collector shown in FIG. 26;

fig. 28 is a schematic structural view of the insulating bakelite layer shown in fig. 27;

FIG. 29 is a schematic view of the construction of the cartridge cover shown in FIG. 28;

FIG. 30 is a schematic view of the core cap of FIG. 29 from another perspective;

FIG. 31 is a sectional view taken along line I-I of FIG. 30;

FIG. 32 is a schematic structural view of the mandrel shown in FIG. 28;

FIG. 33 is a schematic view of the mandrel of FIG. 32 from another perspective;

FIG. 34 is a sectional view taken along line L-L of FIG. 33;

fig. 35 is a schematic structural view of the insulating bakelite layer shown in fig. 28;

FIG. 36 is a sectional view taken along line J-J of FIG. 35;

FIG. 37 is a schematic view of the structure of the magnetic collector shown in FIG. 28;

fig. 38 is a cross-sectional view taken along line K-K in fig. 37.

In the figure: 1. a charging switch; 2. a step-up transformer; 3. a high-voltage rectifier; 4. a current limiting resistor; 5. a capacitor; 6. a discharge switch; 7. supporting the inner pipe; 71. a first through hole; 72. an annular positioning groove; 8. supporting the outer pipe; 9. protecting the sleeve; 10. an inner tube; 11. an outer tube; 111. an annular groove; 12. limiting and supporting; 13. an inner platen; 14. an outer pressing disc; 15. a screw; 16. a flange; 161. a flange shaft; 162. a limit nut; 17. a core cover; 18. winding; 19. an insulating bolt; 20. a mandrel; 21. a coil inductor; 23. an insulating bakelite layer; 25. a magnetic collector; 251. a protrusion; 27. magnetic collector-coil composite inductor.

Detailed Description

The technical scheme of the invention is further described in detail by combining the drawings and the specific embodiments:

referring to fig. 1-3 together, the magnetic pulse connecting device for a double-layer circular tube provided by the present invention includes an inner tube support 7 and an outer tube support 8, which are coaxially disposed and are used for providing positioning and radial support for an inner tube 10 and providing radial support for an outer tube 11, the inner tube support 7 is provided at one end thereof with a first through hole 71 for passing through a wire of a coil inductor 21, the other end thereof is provided with a ring-shaped positioning slot 72 adapted to the outer tube 11, the outer tube support 8 is connected to a top end of the inner tube support 7, the inner tube support 7 is sleeved with a protective sleeve 9, the protective sleeve 9 has a height along an axial direction not smaller than that of the inner tube support 7 and provides radial constraint for the inner tube support 7 and the outer tube support 8, the top end of the outer tube support 8 is connected to an inner pressing plate 13 for pressing the outer tube 11, the inner pressing plate 13 is connected to a flange 16 capable of sliding along the axial direction in the inner tube support 7, the flange 16 is connected with a coil inductor 21 through an insulating bolt 19, the coil inductor 21 comprises a core cover 17, a mandrel 20 and a coil 18, the insulating bolt 19 sequentially penetrates through the flange 16 and the core cover 17 to be connected with the mandrel 20, and the coil 18 is wound on the mandrel 20 and is compressed through the core cover 17.

The inner pipe support 7 is placed on a working platform, the inner pipe 10 is placed in the inner pipe support 7, the outer pipe 11 is positioned in an annular positioning groove 72 of the inner pipe support 7, the outer pipe support 8 is sleeved outside the outer pipe 11, the bottom of the outer pipe support is contacted with the upper end of the inner pipe support 7, the protective sleeve 9 is placed outside the inner pipe support 7, meanwhile, the inner pipe support 7 and the outer pipe support 8 are restrained, the lower end of a flange 16 is connected with a coil inductor 21 through an insulating bolt 19, external threads at the upper end of the flange 16 are matched with a central internal thread hole of a limiting support 12 and then inserted into a central through hole of an inner pressure disc 13 and fastened through a nut, the inner pressure disc 13 is connected with the inner side wall of the outer pipe support 8 through threads and tightly presses the outer pipe 11, and a lead of the coil inductor 21 penetrates through a first through hole 71 on the bottom surface of the inner pipe support 7 and is connected with a charging and discharging loop; the charging loop comprises a charging switch 1, a transformer 2, a high-voltage rectifier 3, a current-limiting resistor 4 and a capacitor 5; the discharge loop comprises a capacitor 5, a discharge switch 6 and an inductor; during discharging, in a charging loop, electric energy in a power grid is stored in a capacitor 5 through a booster transformer 2, a high-voltage rectifier 3, a current-limiting resistor 4 and the like; after charging is finished, the charging loop is changed into an open-circuit state, the discharging switch 6 of the discharging loop is closed, electric energy is released instantly, when the coil inductor 21 is subjected to transient discharging, a strong magnetic field and magnetic pressure are generated between the coil inductor 21 and the inner tube 10, when the magnetic pressure is larger than the yield limit of the material of the inner tube 10, the inner tube 10 moves outwards along the radial direction at a high speed to reach a certain condition, and magnetic pulse connection is generated in the lapping area of the inner tube and the outer tube; the forming limit of the material can be improved through high strain rate forming, the problem that the aluminum alloy inner pipe is easy to crack and lose efficacy at the slotting part of the outer pipe when the aluminum alloy inner pipe is connected in a conventional mode at room temperature can be solved, no emission is generated, the whole process is free of heating, radiation, smoke, waste gas, sparks, condensed water and auxiliary material consumption, the aluminum alloy inner pipe is green, environment-friendly and low-carbon, continuous heat treatment and cleaning processes are not needed, and a very brittle metal compound is not generated on a welding interface, so that the connection strength can be ensured.

More specifically, referring to fig. 25, an annular groove 111 is formed in the inner wall of the outer tube 11, and the annular groove 111 is formed in a lap joint area between the outer tube 11 and the inner tube 10; at least one annular groove 111 is arranged, and when the inner pipe 10 is connected, the inner pipe impacts into the annular groove 111 to form a mechanical locking structure, so that the connection strength of an overlapping area can be improved.

More specifically, referring to fig. 26-28, an insulating bakelite layer 23 and a magnetic collector 25 are sleeved on the turn line 18, and the insulating bolt 19 sequentially penetrates through the flange 16, the core cover 17, the insulating bakelite layer 23 and the magnetic collector 25 to be connected with the core shaft 20; the pulse current flowing through the coil of the coil 18 generates eddy current with the direction opposite to that of the coil 18 on the inner surface of the magnetic collector 25, the eddy current only flows on the inner surface of the magnetic collector 25 due to skin effect, flows to the outer surface from a slit of the magnetic collector 25 and is then concentrated on the surface of an effective working area of the magnetic collector 25, at the moment, the eddy current has the same direction as the current of the coil, the magnetic field of the eddy current is superposed with the magnetic field induced by the inner tube, and a strong magnetic field is formed between the magnetic collector and the inner tube and magnetic pulse pressure is generated.

More specifically, the surface of the active working area of the magnetic collector 25 is a protrusion 251 extending toward the inner tube 10, and the protrusion 251 can precisely control the range of the connection area, such as aligning with the annular groove 111 on the outer tube 11, so that the inner tube 10 and the outer tube 11 form a mechanical locking structure when connected in the area of the annular groove 111, and the connection strength of the overlapping area can be improved.

More specifically, referring to fig. 2, an outer pressing plate 14 is connected to the outer tube support 8, and the outer pressing plate 14 presses the outer tube 11 through an inner pressing plate 13; when the structure is adopted, the inner pressing disc 13 is connected with the inner side wall of the appearance support 8 in a sliding mode and pressed at the top end of the outer tube 11, the outer pressing disc 14 is connected with the outer side wall of the appearance support 8 through threads, and the inner pressing disc 13 is enabled to press the outer tube 11 tightly.

More specifically, a flange shaft 161 is arranged on the flange 16, the flange shaft 161 is connected with the inner pressure plate 13 in a sliding manner, and a limit nut 162 is arranged at one end of the flange shaft 161, which extends out of the inner pressure plate 13; the limit nut 162 can limit the stroke of the coil inductor 21, so that the coil inductor 21 is prevented from excessively moving downwards to exceed the lap joint area, and normal production is guaranteed.

More specifically, the inner pressure plate 13 is connected with a limit support 12, and the limit support 12 is arranged between the inner pressure plate 13 and the flange 16; spacing 12 is connected with interior pressure dish 13 through many screw rods 15, can avoid flange 16 to rock on the one hand, for magnetic pulse connects and provides stable work regulation, and on the other hand can avoid flange 16 and direct interior pressure dish 13 collision, avoids insulating bolt 19 to damage, leads to dismantling inconveniently.

A method of making a connection using a magnetic pulse connection device, comprising the steps of:

step 1, preparing inner and outer pipe blank, carrying out rust removal, oil removal and degreasing treatment on a connection area to ensure that a metal interface is bright and clean, and forming an annular groove with a certain width and depth at a corresponding position of outer pipe lap joint according to production requirements;

step 2, placing the inner pipe support on a working platform, and respectively placing the blanks of the inner pipe and the outer pipe prepared in the step 1 in the inner pipe support and the annular positioning groove;

step 4, connecting the inductor with the flange;

step 5, completing the matching of the central internal thread of the limiting support and the external thread of the flange shaft, wherein the flange shaft passes through the central through hole of the inner pressure plate and completes the connection of the limiting support and the inner pressure plate through a screw;

step 6, the whole body in the step 5 is placed in a double-layer connecting pipe to be processed, a lead of the coil inductor penetrates through the first through hole supported by the inner pipe, the inner pressure plate compresses the outer pipe, and the coil inductor is moved to a proper position through an adjusting screw and/or a limiting nut;

step 7, connecting the outer pressing disc with the outer tube support in a threaded fit manner, and pressing the inner pressing disc tightly; connecting the lead end of the coil inductor with a charging and discharging loop;

and 8, closing a charging switch, boosting alternating voltage in a power grid through a boosting transformer, converting current flowing through a high-voltage rectifier into direct current, reducing the current in a charging loop through a current-limiting resistor, charging a capacitor through the direct current, disconnecting the charging switch, closing a discharging switch, enabling the capacitor to act energy on a coil inductor, generating enough magnetic pulse pressure, and enabling the inner pipe and the outer pipe to be connected.

The coil inductor and the magnetic collector-coil composite inductor can generate magnetic pulse welding double-layer connecting pipes and magnetic pulse expanded connecting double-layer connecting pipes. When the inner side wall of the outer pipe is not provided with an annular groove, a coil inductor is used for directly applying magnetic pressure to the double-layer connecting pipe fitting to carry out magnetic pulse welding, the coil inductance is adjusted by changing the section of a turn line and the number of turns of a coil, the magnetic pulse parameter is optimized, the inner pipe is driven to impact the outer pipe at a high speed, and when the impact speed reaches a threshold value, the lap joint area of the inner pipe and the outer pipe and the generated magnetic pulse are welded to obtain a double-layer connecting pipe; when the inner side wall of the outer pipe is provided with the annular groove, a coil inductor can be adopted to directly apply magnetic pressure to the double-layer connecting pipe fitting to carry out magnetic pulse expansion joint, the speed of the inner pipe impacting the outer pipe is relatively low, the inner pipe is subjected to plastic deformation and expands outwards, and forms mechanical locking with the annular groove preset on the outer pipe to connect two workpieces together, so that the double-layer connecting pipe obtained by magnetic pulse expansion joint is generated; the magnetic pulse expansion joint can also be carried out by adopting a magnetic collector-coil composite inductor, the magnetic collector drives an inner pipe to be punched into an annular groove, and the inner pipe and an outer pipe form a mechanical locking structure at the annular groove for connection; the magnetic collector and the coil composite inductor can be used for composite connection, the magnetic collector punches the inner pipe into the annular groove to form a mechanical locking structure, and meanwhile, under the condition that the inner pipe impacts the outer pipe at a high speed, the lap joint of the outer pipe and the inner pipe generates magnetic pulse welding to generate a composite double-layer connecting pipe, so that the connecting strength of the double-layer connecting pipe can be further increased, and the reliability of the eddy current damper is ensured.

More specifically, the connection method further includes: and 9, loosening the outer pressing disc, taking out the connecting piece to check the connection quality, repeating the steps 4 to 8, and performing multi-pass discharging at different positions of the lapping area of the inner pipe and the outer pipe to ensure the connection reliability.

The eddy current damper comprises the double-layer connecting pipe prepared by the connecting method, and the double-layer connecting pipe is connected stably, so that the working reliability of the eddy current damper can be ensured, the service life of the eddy current damper is prolonged, and the eddy current damper has a wide application prospect.

Example one

Referring to fig. 1 to 3, the magnetic pulse connecting device for a double-layer circular tube according to the present embodiment is a magnetic pulse welding device for an aluminum inner tube and a steel outer tube in a double-layer circular tube axial force eddy current damper using a coil as an inductor, and includes: the device comprises a charging switch 1, a step-up transformer 2, a high-voltage rectifier 3, a current-limiting resistor 4, a capacitor 5, a discharge switch 6, an inner tube support 7, an outer tube support 8, a protective sleeve 9, an inner tube 10, an outer tube 11, a limit support 12, an inner pressure plate 13, an outer pressure plate 14, a screw rod 15, a flange 16, a core cover 17, a turn wire 18, an insulating bolt 19, a core shaft 20 and a coil inductor 21.

Specifically, as shown in fig. 1, a charging switch 1 is closed, a transformer 2 raises alternating current voltage from a power grid to several kilovolts, a high-voltage rectifier 3 converts alternating current into direct current, a capacitor 5 is charged after loop current is reduced through a current-limiting resistor 4, when the capacitor 5 is charged to a threshold value, the charging switch 1 is opened, a discharging switch 6 is closed, strong current is instantaneously applied to a coil inductor 21, a strong magnetic field and magnetic pressure are formed between the coil inductor 21 and an inner pipe 10, when the magnetic pressure is greater than the yield limit of a material of the inner pipe 10, the inner pipe 10 moves outwards at a high speed in the radial direction and is in impact contact with an outer pipe 11, and when the impact speed exceeds the threshold value, magnetic pulse welding is generated in the lap joint area of the inner pipe and the outer pipe.

Specifically, referring to fig. 4 and 5, the inner tube support 7 is provided with three stages of stepped holes, the first stage from the bottom is a first through hole 71, which is used as a wire passage passing through the coil inductor 21; the second stage provides positioning and radial support for the inner tube 10, the third stage provides a circular positioning groove 72 for positioning the outer tube 11, and the bottom is provided with a boss extending radially outward to provide support for the whole device.

Specifically, referring to fig. 6 and 7, the outer tube support 8 is provided with two stages of stepped holes, the first stage is used for providing radial support for the outer tube 11 from the bottom, the inner diameter of the stepped holes is 128mm, the second stage is used for providing positioning and radial constraint for the inner pressure disc 13, and meanwhile, the outer side of the upper end part is provided with external threads for being connected with the outer pressure disc 14.

In particular, referring to fig. 8 and 9, the protective sleeve 9 is a thick-walled circular tube for providing radial restraint for the inner tube support 7 and the outer tube support 8.

Specifically, as shown in fig. 10, the inner tube 10 is made of 6063 aluminum alloy, and has an outer diameter of 116mm, a wall thickness of 1mm and a height of 150mm, the outer tube 11 is made of Q235 steel, and has an outer diameter of 128mm, a wall thickness of 5mm and a height of 150mm, a length of a lap joint area between the inner tube and the outer tube is 100mm, and a gap between the inner tube and the outer tube is 1 mm.

Specifically, referring to fig. 11 and 12, the limiting support 12 is provided with three threaded holes in the long axis direction, the middle threaded hole has a larger size, and the two sides have smaller sizes; the middle threaded hole is matched with the flange shaft 161, and the two threaded holes are matched with the screw rods 15.

Specifically, referring to fig. 13 and 14, the middle of the inner pressure plate 13 is provided with three through holes, the middle through hole has a larger size, and the through holes on the two sides have a smaller size; the middle threaded hole is matched with the flange shaft 161, and the two threaded holes are matched with the screw rods 15.

Referring to fig. 15 and 16, an inner thread adapted to the outer tube support 8 is formed on the inner side wall of the outer platen 14, a through hole is formed in the middle of the outer platen, and the inner diameter of the through hole is larger than the maximum distance between the screws 15, so that the screws 15 can be adjusted to lift the coil inductor 21, and the outer diameter of the coil inductor is smaller than the outer diameter of the inner platen 13, so that the inner platen 13 presses the outer tube 11.

Specifically, referring to fig. 3 to 24, a coil inductor 21 winds a coil 18 on a mandrel 20 made of an insulating material, wraps the insulating material and is pressed by a core cover 17, the outer side of the coil 18 wraps the insulating material, a red copper coil with a cross section of 5 × 7mm is selected, the number of turns is 3, the outer diameter of the coil is 110mm, the axial length of an effective working area is 15mm, and the discharge energy is 45 kJ.

Specifically, the inner tube support 7 is placed on a working platform, the inner tube 10 is placed in a second-stage stepped hole of the inner tube support 7, the height of the inner tube 10 along the axial direction is not less than the height of the inner tube support 7, the outer tube 11 is positioned in an annular positioning groove 72 of the inner tube support 7, the outer tube support 8 is sleeved outside the outer tube 11, the bottom of the outer tube is contacted with the upper end of the inner tube support 7, the protective sleeve 9 is placed outside the inner tube support 7, the height of the protective sleeve 9 along the axial direction is not less than the height of the inner tube 10, meanwhile, the inner tube support 7 and the outer tube support 8 are restrained, the lower end of the flange 16 is connected with the coil inductor 21 through an insulating bolt 19, an external thread on a flange shaft 162 is matched with a central internal threaded hole of the limit support 12 and then inserted into a central through hole of the inner pressure plate 13 and is fastened through a limit nut 162, the limit support 12 and the inner pressure plate 13 are positioned and fastened through a screw rod 15, the nut is fastened, the inner pressure plate 13 compresses the outer tube 11 tightly, the inner pressure disc 13 is pressed tightly through the threaded connection of the outer pressure disc 14 and the outer tube support 8, the lead of the coil inductor 21 penetrates through the first through hole 71 of the inner tube support 7 to be connected with the charge and discharge loop, and the whole tool is assembled.

When the device is used for carrying out magnetic pulse welding on the aluminum inner tube and the steel outer tube in the double-layer circular tube axial force eddy current damper, the device comprises the following steps:

step 1, preparing inner and outer pipe blanks of a certain size to be connected, and carrying out rust removal, oil removal and degreasing treatment on a connection area to ensure that a metal interface is bright and tidy;

step 2, placing the inner pipe support 7 on a working platform, and respectively placing the blanks of the inner pipe and the outer pipe prepared in the step 1 in the second-stage stepped hole and the annular positioning groove 72 of the inner pipe support 8;

step 3, sleeving the outer tube support 8 outside the outer tube 11 to enable the inner wall of the outer tube to be in contact with the outer wall of the outer tube 11, meanwhile, contacting the bottom of the outer tube support 8 with the top of the inner tube support 7, and sleeving the protective sleeve 9 outside the inner and outer support tubes;

step 4, connecting the coil inductor 21 with a flange plate at the lower end of the flange 16 by using an insulating bolt 19, ensuring that the inductor 21 and the flange 16 are coaxial, and simultaneously ensuring that the inductor 21 and the flange 16 are sufficiently insulated;

step 5, matching the central internal thread of the limiting support 12 with the external thread on the flange shaft 162 to integrally penetrate through the central through hole of the inner pressure plate 13, completing the connection of the limiting support 12 and the inner pressure plate 13 through the screw rod 15 and the nut, ensuring that the flange 16 is coaxial with the inner pressure plate 13 and realizing the axial positioning of the flange 16;

step 6, the whole body in the step 5 is placed in a double-layer connecting pipe to be connected, a lead of a coil inductor 21 penetrates through a first through hole 71 of an inner pipe support 7, an inner pressure plate 13 compresses an outer pipe 11, the position of the inductor 21 is adjusted through an adjusting screw 15 and a nut, the working area of the coil inductor 21 is ensured to be opposite to the overlapping area of the inner pipe and the outer pipe, and the coil inductor is fastened on a flange shaft 161 through a limiting nut 162;

step 7, connecting the outer pressing disc 14 with the outer tube support 8 in a threaded fit manner, and pressing the inner pressing disc 13 tightly; connecting the lead inlet and outlet ends of the coil inductor 21 with a charging and discharging loop;

step 8, closing a charging switch 1, boosting alternating voltage in a power grid through a boosting transformer 2, converting current into direct current after flowing through a high-voltage rectifier 3, reducing the current in a charging loop through a current-limiting resistor 4, charging a capacitor 5 through the direct current, disconnecting the charging switch 1 when the energy reaches 45kJ, closing a discharging switch 6, enabling the capacitor 5 to act on the coil inductor 21 with the energy, generating enough magnetic pulse pressure, and enabling inner and outer pipes to be connected to form a double-layer connecting pipe;

and 9, loosening the outer pressing disc 14, taking out the connecting piece to check the connection quality, repeating the steps 4 to 8, and performing multi-pass discharging at different positions of the lap joint area of the inner pipe and the outer pipe.

Example two

Referring to fig. 25, the technical solution provided in this embodiment is substantially the same as that of the first embodiment, except that: the diameter of the outer tube 11 is changed, an annular groove 111 is formed in the inner wall of the lap joint position of the outer tube 11, the inner diameter of the first-stage stepped hole of the outer tube support 8 is changed, and the discharge energy is changed.

Specifically, the inner tube 10 material is 6063 aluminum alloy, its external diameter 116mm, wall thickness 1mm, height 150mm, outer tube 11 material is Q235 steel, its external diameter 126mm, wall thickness 5mm, height 150mm, the outer tube is in 48mm departments away from the upper end and is offered width 4mm, the annular of degree of depth 1mm, inside and outside pipe overlap joint regional length 100mm, contact between inside and outside pipe, the outer tube supports first order shoulder hole internal diameter 126mm, select the red copper circle line of 5 x 7mm in cross-section, the number of turns 3, coil external diameter 110mm, effective work area axial length 15mm, discharge energy 30 kJ.

Specifically, the charging switch 1 is closed, the transformer 2 raises alternating current voltage from a power grid to thousands of volts, the high-voltage rectifier 3 converts alternating current into direct current, the capacitor 5 is charged after loop current is reduced through the current-limiting resistor 4, when the capacitor 5 is charged to 30kJ, the charging switch 1 is opened, the discharge switch 6 is closed, strong current instantly acts on the coil inductor 21, a strong magnetic field and magnetic pressure are formed between the coil inductor 21 and the inner pipe 10, when the electromagnetic pressure is greater than the yield limit of a material of the inner pipe 10, the inner pipe 10 is subjected to plastic deformation and expands outwards along the radial direction, mechanical locking is carried out on a preset groove of the outer pipe 11 to connect two workpieces together, and magnetic pulse expansion connection double-layer connecting pipes are generated.

EXAMPLE III

Referring to fig. 26 to 28, the technical solution provided in this embodiment is substantially the same as that of the first embodiment, except that: an insulating bakelite layer 23 and a magnetic collector 25 are sleeved on the ring wire 18, and the insulating bolt 19 sequentially penetrates through the flange 16, the core cover 17, the insulating bakelite layer 23 and the magnetic collector 25 to be connected with the core shaft 20; the core cover 17, the turns 18, the insulating bakelite layer 23, the magnetic collector 25 and the mandrel 20 constitute a magnetic collector-coil composite inductor 27.

Specifically, the inner tube 10 material is 6063 aluminum alloy, its external diameter 116mm, wall thickness 1mm, height 150mm, and outer tube 11 material is Q235 steel, its external diameter 128mm, wall thickness 5mm, height 150mm, inside and outside pipe overlap joint region length 100mm, clearance 1mm between inside and outside pipe, the outer tube supports first order shoulder hole internal diameter 128 mm.

Specifically, referring to fig. 28 to 38, the magnetic concentrator-coil composite inductor 27 winds the turns 18 on the core shaft 20 made of an insulating material, and is compressed by the core cover 17, the turns 18 wrap the insulating material, the red copper turns with the cross section of 5 × 7mm are selected, the number of turns is 9, the outer diameter of the coil is 59mm, the axial length of the effective working area is 45mm, the maximum diameter of the magnetic concentrator 25 is 113mm, the effective working area is the projection 251, the length of the projection 251 in the axial direction is 8mm, and the discharge energy is 30 kJ.

Specifically, as shown in fig. 26, the charging switch 1 is closed, the transformer 2 increases the ac voltage from the power grid to several kilovolts, the high-voltage rectifier 3 converts the ac power to dc power, the current limiting resistor 4 reduces the loop current, the capacitor 5 is charged, when the capacitor 5 is charged to 30kJ, the charging switch 1 is opened, the discharging switch 6 is closed, a strong current is instantaneously applied to the magnetic collector-coil composite inductor 27, the pulse current flowing through the turn line 18 generates an eddy current with an opposite current direction on the inner surface of the magnetic collector 25, according to the skin effect, the eddy current flows on the inner surface of the magnetic collector 25, turns to the outer surface at the slit of the magnetic collector 25, and then is concentrated on the surface of the effective working area of the magnetic collector 25 to flow, at this time, the direction of the eddy current is the same as the coil current, the eddy current magnetic field is superposed with the magnetic field of the inner tube 10, a strong magnetic field is formed between the effective working area of the outer wall of the magnetic collector 25 and the inner tube 10, and a pulse magnetic pressure is generated, when the magnetic pressure is larger than the yield limit of the material of the inner pipe 10, the inner pipe 10 moves outwards in the radial direction at a high speed and is in impact contact with the outer pipe 11, and when the impact speed exceeds a threshold value, magnetic pulse welding is generated in the lap joint area of the inner pipe and the outer pipe, so that the magnetic pulse welding double-layer connecting pipe is formed.

Example four

Referring to fig. 25, the technical solution provided in this embodiment is basically the same as that of the third embodiment, except that: referring to the device of example 3, the diameter of the outer tube 11 was changed, and the inner wall of the overlapping portion of the outer tube 11 was formed with the annular groove 111, and the inner diameter of the first-stage stepped hole of the outer tube support 8 was changed to change the discharge energy.

Specifically, the inner tube 10 material is 6063 aluminum alloy, its external diameter 116mm, wall thickness 1mm, height 150mm, outer tube 11 material is Q235 steel, its external diameter 126mm, wall thickness 5mm, height 150mm, the outer tube is in keeping away from upper end 48mm department and offers width 4mm degree of depth 1mm annular, inside and outside pipe overlap joint regional length 100mm, contact between inside and outside pipe, the outer tube supports first order shoulder hole internal diameter 126mm, select 5 x 7 mm's red copper circle line in cross-section, the number of turns is 9, coil external diameter 59mm, effective working area axial length 45mm, magnetic concentrator maximum diameter 113mm, effective working area is arch 251, arch 251's height 8mm along vertical direction, discharge energy 25 kJ.

Specifically, the charging switch 1 is closed, the transformer 2 raises alternating current voltage from a power grid to thousands of volts, the high-voltage rectifier 3 converts alternating current into direct current, the capacitor 5 is charged after loop current is reduced through the current-limiting resistor 4, when the capacitor 5 is charged to 25kJ, the charging switch 1 is opened, the discharge switch 6 is closed, strong current is instantaneously acted on the magnetic collector-coil composite inductor 27, a strong magnetic field and magnetic pressure are formed between the magnetic collector-coil composite inductor 27 and the inner pipe 10, and when the magnetic pressure is greater than the yield limit of a material of the inner pipe 10, the inner pipe 10 is subjected to plastic deformation and expands outwards along the radial direction, and the inner pipe 11 is mechanically locked with a preset groove to connect two workpieces together to form the magnetic pulse expansion double-layer connecting pipe.

The above examples are only for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides a magnetic pulse connecting device for double-deck pipe which characterized in that: the inner tube support (7) and the outer tube support (8) are coaxially arranged and used for providing positioning and radial support for an inner tube (10) and providing radial support for an outer tube (11), one end of the inner tube support (7) is provided with a first through hole (71) used for penetrating a lead of a coil inductor (21), the other end of the inner tube support is provided with an annular positioning groove (72) matched with the outer tube (11), the outer tube support (8) is connected with the top end of the inner tube support (7), a protective sleeve (9) is sleeved on the inner tube support (7), the height of the protective sleeve (9) along the axial direction is not smaller than that of the inner tube support (7) and provides radial constraint for the inner tube support (7) and the outer tube support (8), the top end of the outer tube support (8) is connected with an inner pressure plate (13) used for compressing the outer tube (11), the inner pressure plate (13) is connected with a flange (16) capable of sliding along the axial direction in the inner tube support (7), the flange (16) is connected with a coil inductor (21) through an insulating bolt (19), the coil inductor (21) comprises a core cover (17), a mandrel (20) and a turn line (18), the insulating bolt (19) sequentially penetrates through the flange (16) and the core cover (17) to be connected with the mandrel (20), and the turn line (18) is wound on the mandrel (20) and is compressed through the core cover (17).

2. The magnetic pulse connecting device for the double-layer circular tube as claimed in claim 1, wherein: an annular groove (111) is formed in the inner wall of the outer pipe (11), and the annular groove (111) is formed in the lap joint area of the outer pipe (11) and the inner pipe (10).

3. A magnetic pulse connecting device for a double-layer round pipe as defined in claim 1 or 2, wherein: the coil (18) is sleeved with an insulating bakelite layer (23) and a magnetic collector (25), and the insulating bolt (19) sequentially penetrates through the flange (16), the core cover (17), the insulating bakelite layer (23) and the magnetic collector (25) to be connected with the core shaft (20).

4. A magnetic pulse connecting device for a double-layer round pipe as defined in claim 3, wherein: the magnetic collector (25) is provided with a protrusion (251) extending towards the inner pipe (10).

5. A magnetic pulse connecting device for double-layer round tubes as claimed in claim 1, 2 or 4, wherein: an outer pressing disc (14) is connected to the outer tube support (8), and the outer pressing disc (14) presses the outer tube (11) through the inner pressing disc (13).

6. The magnetic pulse connecting device for the double-layer circular tube as claimed in claim 5, wherein: be equipped with flange axle (161) on flange (16), flange axle (161) and interior pressure dish (13) sliding connection, the one end that interior pressure disk (13) were stretched out in flange axle (161) is equipped with stop nut (162).

7. The magnetic pulse connecting device for the double-layer circular tube as claimed in claim 6, wherein: be connected with spacing support (12) on interior pressure disk (13), spacing support (12) are located between interior pressure disk (13) and flange (16).

8. A joining method using the magnetic pulse joining apparatus for double-layer round pipes according to claim 7, characterized by comprising the steps of:

step 1, preparing inner and outer pipe blank, and carrying out rust removal, oil removal and degreasing treatment on a connection area to ensure that a metal interface is bright and tidy;

step 4, connecting the inductor with the flange;

9. The connecting method according to claim 8, further comprising: and 9, loosening the outer pressing disc, taking out the connecting piece to check the connection quality, repeating the steps 4 to 8, and performing multi-pass discharging at different positions of the lapping area of the inner pipe and the outer pipe.

10. An eddy current damper, characterized in that: comprising a double-layer connecting tube prepared by the connecting method according to claim 8 or 9.