WO2014129932A1

WO2014129932A1 - Device and method for electromagnetic stretching and removing dents

Info

Publication number: WO2014129932A1
Application number: PCT/RU2013/001051
Authority: WO
Inventors: Юрий Бориславович КУДАСОВ
Original assignee: Общество С Ограниченной Ответственностью "Саровские Магнитные Технологии"
Priority date: 2013-02-25
Filing date: 2013-11-22
Publication date: 2014-08-28
Also published as: RU2558700C2; RU2013108334A

Abstract

The invention relates to technology for the magnetic-pulse treatment of materials and can be used for forming thin-walled metal components and for removing dents. The device comprises an electromagnetic system for creating pulsed magnetic fields in a component being treated, a primary slow pulsed current source and a secondary rapid pulsed current source, wherein the direction of the secondary magnetic field is mainly opposed to the direction of the primary magnetic field. The characterizing feature of the device and the method is that the secondary current source generates a sequence of two or more current pulses. A working head can be produced in the form of a separate movable unit which is possibly equipped with handles or a holder for fixing the position thereof relative to the component. The proposed invention makes it possible to reduce peak-load working voltages and to produce a more reliable working head. The device and the method are mainly intended for removing dents on aircraft elements. The use thereof for treating, for example, steel sheets of car bodies is also possible.

Description

DEVICE AND METHOD FOR ELECTROMAGNETIC EXTRACTION AND

ELIMINATION OF DENTS The invention relates to techniques for magnetic-pulse processing of materials and can be used to form thin-walled metal parts and eliminate dents on metal elements.

A device is known for deformation of thin-walled metal parts by a pulsed magnetic field ([1] H.H. Kolm, patent US Mb 3703958, 1 1/1972), consisting of an electromagnetic system (in the form of two solenoids) and two pulsed current sources connected to an electromagnetic system. The first current source creates a constant or slowly changing magnetic field in the part, which penetrates the part, the second current source creates a rapidly changing magnetic field in the part, which causes intense eddy currents in the metal part and its deformation. Moreover, depending on the mutual direction of the magnetic fields created by the first and second current source (or the polarity of their current), the nature of the force acting on the part can be both repulsive from the electromagnetic system and attracting to it.

A device for straightening dents on metal sheets is known.

([2] BSChoe et al., US patent JV ° 7607332 B2, 10/2009), consisting of a high-frequency generator, an electromagnetic system connected to the generator and generating intense induction currents in the metal sheet, and a sheet cooling system by blowing it, for example, by air. Moreover, the electromagnetic system in the form of a coil is combined with a cooling system in a movable working head. Induction currents heat the metal sheet near the head evenly across the thickness of the sheet, and blowing the sheet cools it from the side of the head. In this case, a temperature gradient in thickness occurs in the sheet, which, due to the thermal expansion of the metal, uneven in thickness, straightens the dent. The disadvantages of this method include the following. The material of the straightened sheet should have a large coefficient of linear thermal expansion, the adherence to the sheet of heat-releasing elements on the back side with respect to the head prevents straightening or leads to unpredictable deformation of the sheet, the nature of the deformation changes if metal elements adjoining the sheet (possibly not even closely) distorting the high-frequency magnetic field.

The closest device and method for the electromagnetic drawing of metal parts and removing dents on them (prototype) is the device and method proposed in the work ([3] KAHansen, IGHendrickson, US patent 3998081, 12/1976). The device comprises an electromagnetic system, a primary current source connected to the electromagnetic system, a secondary current source also connected to the electromagnetic system. The electromagnetic system of the prototype is made in the form of a coil wound by an electric current conductor, and its coils are isolated from each other and from the workpiece. Coil winding can be performed in various ways: a flat spiral, a multilayer flat spiral, spirals (including multilayer ones) lying in several planes at an angle to each other, etc. The primary current source connected to the electromagnetic system creates a slowly changing current pulse and, accordingly, the primary magnetic field in the area of the part. The pulse duration was chosen so that the magnetic field could penetrate through the conductive part without the appearance of noticeable ponderomotive forces in the part. Then a short secondary current pulse and, accordingly, a secondary magnetic field were generated by the secondary current source. In this case, the polarity of the secondary current pulse was opposite to the primary one; therefore, the generated secondary magnetic field was mainly opposite in direction to the primary one. The duration of the secondary pulse was chosen so that the secondary pulse did not penetrate the metal part (due to the skin effect). In this case, the magnetic field between the electromagnetic system and the part decreased due to partial compensation of the primary and secondary magnetic fields, and after the part it remained the same. It created ponderomotive force of a pulsed magnetic field, attracting a part to an electromagnetic system. Such a method and a device based on it can effectively work for relatively thin-walled parts (the thickness is much less than the characteristic dimensions along the surface) with good electrical conductivity when using strong magnetic fields (of the order of 10 T).

The method proposed in the prototype [3], contains the following sequence of actions: (1) positioning the working surface of the working head of the device containing the electromagnetic system in the form of a coil relative to the part, (2) passing a slow primary current pulse through the coil with such a duration that ponderomotive primary magnetic field forces did not deform the part, (3) passing through the coil a secondary rapidly changing current pulse with an amplitude of 50% to 80% of the primary current amplitude, and e of the secondary current must be opposite to the primary, therefore the primary and secondary magnetic fields are predominantly in the opposite direction. The duration of the secondary current pulse must be short enough to create strong deformations in the part.

The prototype suggested the use of several possible options. Between the electromagnetic system and the workpiece, an arrangement of a dielectric template was additionally allowed, the surface shape of which on the part side approximately corresponds to the desired final shape of the workpiece. An electromagnetic system can be integrated into the dielectric base, and the shape of the working surface of the dielectric base adjacent to the workpiece should approximately correspond to the desired final shape of the workpiece. To increase the efficiency of the electromagnetic system, it was proposed to use a pulsed magnetic field concentrator. The electromagnetic system was also proposed to be implemented as a separate movable unit (working head) for the convenience of working with the device. Subsequently, individual elements of the prototype were developed and refined in a series of patents. In ([4] KAHansen, IGHendrickson, US patent JY ° 4061007, 12/1977), ([5] KAHansen, IGHendrickson, US patent JV ° 4127933, 12/1978), ([6] RFOlsen, US patent 7068134 B2 , 06/2006) and ([7] FPBerg, DBSmith, US patent j \ ° 71 14242 B2, 10/2006) electromagnetic systems are presented in the form of a coil made of a rolled flat conductive sheet with an insulating gasket, and these rolls are additionally equipped with cutouts for the concentration of magnetic flux in the dent area on the workpiece. KAHansen, IGHendrickson, US patent N ° 4986102, 01/1991) used an electromagnetic system consisting of two coils connected in series. In this case, one common conclusion of both coils and two external ones is formed. Moreover, the common and one of the external terminals are connected to the secondary current source, and both external terminals are connected to the primary current source.

The works ([9] PBZieve, US patent Jfe5046345, 09/1991) and ([10] DBSmith et al., US patent N ° 6639781, 10/2003) described in detail the design of current sources based on capacitive energy storage devices in an electrical circuit additional blocking inductances are used, connected in series with the primary current source for electrical isolation of two current sources. Crowbar diode and thyristor circuits were also used in these works to prevent the oscillatory process of discharging capacitors to inductive load and recharging capacitors included in the sources of primary and secondary currents. In ([1 1] KAHansen, IGHendrickson, US patent Xs4148091, 04/1979) and ([12] KAHansen, IGHendrickson, US patent 3424116031, 09/1978) the electromagnetic system was made in the form of two separate coils with a single-turn magnetic flux concentrator magnetically coupled to both coils. In the work ([13] KAHansen, IGHendrickson, US patent jV_4135379, 01/1979), the electromagnetic system was placed in the working head of the device, made in the form of a separate movable assembly, equipped with handles for fixing the position of the head relative to the part. The prototype is intended, first of all, to eliminate dents on the elements of aircraft (wings, fuselage, air intakes). The technology proposed in the prototype with the improvements described above has been brought to commercial use by Boeing, Electroimpack (http://www.electroimpact.com) and Fluxtronic

(http://www.fluxtronic.com).

The disadvantages of the prototype include the need to use powerful high-voltage pulsed sources of secondary current. High voltages are needed to quickly change the current in the inductance (electromagnetic system) in the secondary current pulse. In this case, the upper voltage values are in practice limited to values of the order of 30 kV for a compact portable head. Therefore, the device and method proposed in the prototype are not used to eliminate dents for poorly conductive and durable materials (steel), which require very short intense pulses of a secondary magnetic field and, as a result, a high voltage amplitude of the secondary source.

In this regard, the technical problem arises of reducing the amplitude of the secondary current and voltage arising during its formation.

The technical result is to reduce the amplitude of the voltage that occurs when the secondary current flows through the electromagnetic system, which allows to make the working head of the device more compact and more reliable. In addition, reducing the voltage amplitude allows you to create a device and method for drawing and removing dents of poorly conductive and durable materials such as sheet steel automobile bodies.

The technical result is achieved as follows. In the claimed device and method, the secondary current and, accordingly, the secondary magnetic field are formed in the form of a sequence of pulses, in contrast to a single pulse in the prototype.

Consider the mechanical action of a pulsed magnetic field on a conductive non-magnetic part in the form of a metal sheet. Notice, that, since the amplitude of the magnetic field is assumed to be very high (above 1 T), there is practically no difference between the behavior of non-magnetic and magnetic metals, because the magnetic metal is in a state of saturation of the magnetization. It is assumed that the electromagnetic system consists of a single coil to which primary and secondary current sources are connected. The coil is located near the surface of the metal sheet. We consider the primary current pulse to be very slow and, for simplicity, we assume that the primary magnetic field does not create induction currents.

First, we examine the secondary magnetic field in the form of a single pulse, as is the case in the prototype [3]. The volume force acting on the part in this case has the form ([14] A.S. Lagutin, V.I. Ozhogin, Strong pulsed magnetic fields in a physical experiment, M .: Energoatomizdat, 1988)

f (r, t) = f ₂₁ (r, t) + f ₂ (r, t), (1) where f ₂₁ (r, t) = - rot (B ₂ ) x B, and f ₂ (r, t) = - rot (B ₂ ) x B ₂ , Βι and Β ₂ are the induction vectors of the primary and secondary magnetic fields, μ is the magnetic permeability of the vacuum, g -. radius vector of a point, t is time. The distribution of the secondary magnetic field, taking into account the induction currents created by it in the part, is determined by the diffusion equation [14] B ₂ = - ΔΒ ₂ , (2) where σ is the specific conductivity of the material of the part.

The total force applied to the part is found by integration over the volume of the part

F (= Jfe, (r, f) + f ₂ (r, 1 * = F ₂₁ (+ F ₂ (0 · (3)) Note that in the case when the primary and secondary current pulses have opposite polarity normal to the surface of the sheet, the components of the forces F _{2 \} HF ₂ have different signs (with F _{2 \} acting in the direction of the electromagnetic system, and F ₂ in the opposite direction):

where F _N2l (t)> 0 and F _N2 (t)> 0.

Then the normal component of the mechanical impulse embedded in the part by the Ampere force and directed towards the electromagnetic system can be estimated as

_P = lF _N dt = l (F _N2l - F _N2 ) dt> 0, (5)

Now, instead of a single pulse of a secondary current, we consider a sequence of pulses. Moreover, for simplicity, we will assume that N identical pulses of the secondary current (magnetic field) have the same shape as a single, considered above, but have a current amplitude N times smaller: Г ₂ - ^ ² ^ · Note that due to linearity of equation (2), the secondary magnetic field of each of the pulses in the sequence is simply N times smaller than a single pulse while maintaining the time dependence and its spatial distribution both outside and inside the part B ' ₂ (r, t) = ^ ² ^ ^{r, t /} ^ Then a sequence of N current pulses transfers the details mechanically th impulse

A comparison of expressions (5) and (6) for mechanical pulses shows that a sequence of N pulses of a secondary current allows a larger mechanical pulse and, therefore, a greater strain energy of the part to be enclosed than a single current pulse.

Further, we note that the voltage amplitude of the secondary current pulse can be estimated as U = L ₂ , where L is the inductance of the electromagnetic system. From here we see that with a decrease in the amplitude of the current N times, the voltage amplitude in each of the pulses of the sequence decreases accordingly. Then the energy invested by the secondary current source in the entire sequence of pulses turns out to be N times less than the energy for a single pulse of the secondary current. So we showed a sequence of secondary current pulses is more efficient than a single pulse.

The amplitude of a single pulse in a sequence cannot be reduced indefinitely, since a single pulse of a secondary current in a sequence must create a mechanical force leading to plastic deformation of the part. Otherwise, the pulses of the secondary current will excite transverse vibrations of the plate (part) without permanent deformation.

The electromagnetic system can be made in the form of (a) an ordinary wire coil of strong magnetic fields [14] or in the form of a roll of a metal sheet with an insulating pad, possibly with special cutouts for magnetic flux concentration [4-7]. It is also possible to use flat spiral coils, including multilayer and complex shapes, as proposed in the prototype [3].

To increase the efficiency of the electromagnetic system, it can be equipped with a single-turn magnetic flux concentrator, which is widely used in the technique of strong pulsed magnetic fields [14] and, in particular, in magnetic pulse processing of materials ([15] I.V. Bely, S.M. Fertik, L.T. Khimenko, Handbook of magnetic-pulse processing of metals, Kharkov, Vishcha School, 1977). Hubs used in patents can be used [1, 1.12].

In some cases, it is convenient to manufacture the system in the form of two coils [8.1, 1.12]. This does not fundamentally change the operation of the device, but it can increase its flexibility. For example, coils with a different number of turns can be made. A coil with a large number of turns is connected to the primary slow current source, and with a smaller number to the secondary one. Coils can be made isolated from each other or connected in series. A convenient option may be a coaxial coil arrangement [8].

To create a primary current pulse, you can use the sources proposed in the prototype [3] and subsequent works [8-10]. To create a sequence of powerful pulses of the secondary current, you can also use semiconductor elements capable of performing controlled on and off (IGBT transistors, lockable thyristors). The second option of the secondary current source is a parallel connection of single pulse generators, which are now well developed in pulse technology. Each of these generators can consist, for example, of a capacitor and a controlled closing key made on the basis of a vacuum or gas-filled (thyratron) spark gap or semiconductor device (thyristor, reversibly switched dinistor). When the generators are triggered at various times, a sequence of pulses is formed.

It should be noted that to isolate the primary and secondary power sources, you can use the blocking inductance, connected in series with the primary source [8-10]. Its value is selected in such a way as to block the flow of secondary current in the circuit of the primary source. Crowbar circuit should also be used to block the recharging of capacitors of primary and secondary current sources [8-10]. To control the entire system as a whole, you should use a controller.

To straighten dents on a metal sheet (part), it is necessary to have a surface that gives the part its final shape [3]. For this, a replaceable dielectric template is used, the surface of which on the part side has a surface close to the desired shape. It is necessary to take into account the elastic unloading of the part after the impulse, therefore the shape of this surface of the template does not have to coincide exactly with the given one. Instead of the template, it is possible to form the required shape of the working surface of the dielectric base, in which the electromagnetic system is integrated.

The proposed device and method can be used to process parts from poorly conductive and dielectric materials. To do this, use a metal sheet superimposed on the part (satellite) [15]. As a rule, a soft sheet of copper is used as a satellite condition. The electromagnetic system acts on the satellite, which in turn carries away the workpiece. For the proposed device, a metal sheet (satellite) should be superimposed on the part from the side of the opposite electromagnetic system, i.e. The part must be between the satellite and the electromagnetic system. Then the movement of the satellite in the direction of the electromagnetic system will lead to deformation of the part.

The invention is illustrated by figures. In Fig.1 schematically shows a device for drawing metal and removing dents, in Fig.2 - pulse shapes of primary, secondary and full currents.

A device for extracting metal and removing dents (figure 1) contains:

(a) the charger of the primary current source 1,

(b) the charger of the secondary current source 2,

(c) managed keys 3, 4, 5, and 6,

(g) a primary current source 7, consisting of a capacitor bank 8, a thyristor switch 9, and a cube diode 10,

(e) a secondary current source consisting of three sources of single current pulses 1 1, 12, 13, each of which consists of a capacitor bank 14, 15, 16 and a thyristor switch 17, 18, 19,

(e) blocking inductance 20,

(g) a controlled crowbar consisting of a thyristor switch 21 and a resistor 22,

(h) an electromagnetic system in the form of a coil 23, made of a roll of copper sheet with a dielectric gasket, which has a cutout for magnetic flux concentration, and adjacent to the part 24, which is a flat metal sheet with a dent,

(i) a dielectric template 25, which is a flat thin sheet of solid dielectric located between the electromagnetic system and the part,

(k) a controller 26 that controls the operation of keys 3, 4, 5, 6 and thyristor keys 9, 17, 18, 19, 21. The electromagnetic system 23 in this example is the working head. Previously, the working head 23 should be positioned relative to the workpiece 24 so that the dent to be removed is in the region of magnetic flux concentration (magnetic field lines are schematically shown in figure 1 by dashed ovals). The working head should fit snugly on the template 25, and the template to the workpiece.

An example of the design of the device, including for implementing the method of drawing metal and removing dents, is presented in figure 1. Charger 1 has a charging voltage of 3 kV, charger 2 has a charging voltage of 15 kV, and the polarity of charger 2 is the opposite of the polarity of charger 1. The capacitors 8, 14, 15, 16 are charged before the start of the operating cycle. Since charging time is not limited, charging currents may be small (less than 1 A). Therefore, managed keys 3, 4, 5, 6 can be made on the basis of mechanical relay switches with a maximum permissible open-circuit voltage of 3 kV for a key of 3 and 15 kV for keys 4, 5, 6. The capacitor 8 has a capacity of 10 mF and the maximum allowable voltage of 3 kV, capacitors 14, 15 and 16 have capacities of 1 μF at the maximum allowable voltage of 15 kV. The controlled key 9 is made on the basis of the thyristor T453-630 (32 cells). The DI153 diode is used as a crowbar diode 10. The keys 17, 18, 19, 21 are thyristor columns of TBI371-160 thyristors (at least 10 cells), 16 pieces each. Ballast inductance 20 has a nominal inductance of 60 μH and a maximum allowable voltage of 20 kV, resistor 22 has a nominal resistance of 0.5 ohms. The coil 23 is wound with a flat copper tape 0.45 mm thick with a 50 micron thick Kapton strip gasket (Kapton, Du Pont) similar to the design of the coil in the patent [4]. The length of the coil is 100 mm, the inner diameter is 20 mm, the outer diameter is 40 mm, the cross section of the coil in the region of maximum magnetic flux concentration is 20x 10 mm ² . The effective inductance of the electromagnetic system is approximately 27 μH for the primary current pulse and 20 μH for the secondary current (at a frequency of 50 kHz). The calculation was carried out according to the methodology ([16] P.L. Kalantarov, L.A. Tsetlin, Calculation of inductances (reference book), L .: Energoatomizdat, 1986). The decrease in inductance for the secondary current pulse is due to the skin effect in the part. The inner frame of the coil is made of structural fiberglass, outside the coil is bandaged with ARMOS high-modulus high-strength para-aramid thread, the entire electromagnetic system is filled with an epoxy compound based on epoxy resin SEDM-3 with boron nitride filler. The polymerization should be carried out under vacuum with heating the resin to 80 ° C. As a template, a flat sheet of structural fiberglass 0.5 mm thick is used. The workpiece is a steel sheet (St.20) with a thickness of 0.8 mm, with a dent in the linear dimensions of not more than 20 mm and a depth of 5 mm. The controller is based on the National Instruments industrial modular control complex.

In preparation for operation, the keys 3, 4, 5, 6 are closed, so the capacitors 8, 14, 15, 16 are charged to the rated voltage of the chargers. Directly before the operating cycle, the controller opens the keys 3, 4, 5, 6.

The duty cycle begins by turning on the thyristor switch 9.

The capacitor 8 through the inductance 20 is discharged to the coil of the electromagnetic system 23 and creates a primary current in it. Upon reaching the maximum of the primary current, the Crowbar diode 10 is turned on, which prevents the polarity reversal of the voltage across the capacitor 8. The duration of the primary current pulse is about

ms (see figure 2). The maximum primary magnetic field in the area of the part is about 8 T, with a primary current of 20 kA. The depth of the skin layer of steel St.20 at a frequency of 100 Hz is more than 20 mm [15], therefore, the primary magnetic field almost completely penetrates the part without noticeable weakening and without deforming the part. Near the maximum of the primary magnetic field, the controller turns on thyristor switches 17, 18, and 19 sequentially at intervals of 150 μs. At This generates a sequence of pulses of a secondary current, which in the coil of the electromagnetic system has a direction opposite to the primary one. Near the maximum current of each of the pulses, the controller includes a controlled crowbar 21 and puts the discharge into aperiodic mode. The resistor 22 serves to reduce the duration of the trailing edge of the pulse. The duration of each pulse is about ί ₂ = 12 μs (see figure 2). Since the inductance of the coil 23 is much smaller than the inductance of the blocking inductance 20, the current flows almost completely through the coil 23. The amplitude of the secondary current in it is at least 3 kA, and the amplitude of the secondary magnetic field is not less than 1.3 T. In pauses of current between pulses, the Crowbar key is turned off. Figure 2 shows schematically the primary current pulse 1 _\ , the pulses of the single pulse generators / ₂₁ , 1c, 1g ^{and the} total current pulse in the coil of the electromagnetic system /.

The depth of the skin layer of steel St.20 at a frequency of 50 kHz is 0.85 mm, so the secondary magnetic field effectively creates induction currents and deforms the part. Assuming that the secondary field is completely shielded by the part, and the primary field penetrates completely through the part and that the lines of magnetic field induction are parallel to the surface pressure on the surface of the part, we can evaluate as =

our case is 7 MPa. The internal stress at the edge of the deformable region in the part can be calculated using standard expressions: for a round plate of radius a and thickness h, it is hinged but supported along the edge a _r

p ([17] I.A. Birger, R.R. Mavlyutov, Resistance of materials, Moscow: Nauka, 1986). With dimensions a = 10 mm, / = 0.8 mm, the maximum radial stress is more than 1000 MPa, which significantly exceeds the yield strength of steel St.20. Therefore, at each pulse from the sequence of secondary pulses, plastic deformation of the part will occur. Note that the mass of the electromagnetic system is about 1 kg, which allows the working head to be made in the form of a separately movable and even portable unit similarly [13].

Instead of using a secondary current source consisting of several parallel-connected single current pulse generators, as shown above, a source of current pulse sequences based on IGBT transistors can be used. So, for the example discussed above, it is possible to use an assembly of 7 sequentially connected MTKI-1000-25 modules manufactured by OAO Elektrovypryamitel. Note that, unlike thyristors, these IGBT modules have very short turn-on and turn-off times (less than 3 μs), which allows the formation of sequences of secondary current pulses that are diverse in number and duration using a single key.

Claims

CLAIM

1. Device for electromagnetic extraction and elimination of dents, containing an electromagnetic system for creating pulsed magnetic fields in the workpiece, a primary pulse current source connected to an electromagnetic system to create a slowly varying primary magnetic field pulse, a secondary pulse current source also connected to an electromagnetic system to create a rapidly changing pulsed secondary magnetic field during the pulse of the primary magnetic field, and tion of the secondary magnetic field is preferably opposite to the direction of the primary magnetic field, characterized in that the secondary power source is a generator of a sequence of two or more current pulses.

2. The device according to claim 1, containing the above-mentioned electromagnetic system, made in the form of a coil, which is made of an electrically conductive material, the turns of which are electrically isolated from each other and from the workpiece, and the primary and secondary current sources are connected in parallel to its terminals.

3. The device according to claim 1, containing a magnetic flux concentrator in an electromagnetic system.

4. The device according to claim 1, characterized in that the electromagnetic system is made in the form of two coils made of electrically conductive material, the turns of which are electrically isolated from each other and from the workpiece, with a primary current source connected to the terminals of the first coils, and the terminals the second coil - secondary current sources.

5. The device according to claim 1, characterized in that the electromagnetic system is made in the form of two coils made of electrically conductive material, the turns of which are electrically isolated from each other and from the workpiece, while the coils are connected in series, forming one common conclusion for both coils and two external outputs, and have the same direction of winding, with the common terminal of both coils and one of the external terminals connected to the secondary current source, and both external terminals to the primary current source.

6. The device according to claim 1, characterized in that the secondary current source is made in the form of a set of parallel-connected sources of single current pulses starting at different points in time.

7. The device according to any one of claims 1 to 6, containing a dielectric pattern that is installed between the electromagnetic system and the workpiece, and the surface shape of which on the part side is approximately corresponding to the desired final shape of the workpiece.

8. The device according to any one of claims 1 to 6, containing a dielectric base, in which an electromagnetic system is integrated, the shape of the working surface of the dielectric base adjacent to the workpiece, approximately corresponds to the desired final shape of the workpiece.

9. The device according to any one of claims 1 to 6, containing a working head in which the electromagnetic system is located, and which is made in the form of a separate movable unit, equipped with handles or a holder for fixing its position relative to the part.

10. The device according to any one of claims 1 to 6, characterized in that it contains an additional inductance, which is connected in series with the primary current source for electrical isolation of the primary and secondary current sources.

1 1. The device according to any one of claims 1 to 6, containing a controller for controlling and synchronizing the operation of its nodes.

12. The method of electromagnetic extraction and elimination of dents, which consists in the fact that the working surface of the working head containing the electromagnetic system to create a pulsed magnetic field in the workpiece is positioned relative to the workpiece, and then by passing the primary current through the electromagnetic system create a pulse of slowly changing primary magnetic fields then By passing the secondary current through the electromagnetic system, a rapidly changing secondary pulsed magnetic field is generated during the primary magnetic field pulse, the direction of the secondary magnetic field being set predominantly opposite to the direction of the primary magnetic field, characterized in that the secondary pulsed magnetic field is formed as a sequence of two or more pulses.

13. The method according to p. 12, characterized in that the electromagnetic system is made in the form of two separate coils made of electrically conductive material, and the primary current is passed through one of the coils, and the secondary current is passed through the other.

14. The method of claim 12, comprising the step of manufacturing a magnetic flux concentrator in an electromagnetic system.

15. The method according to item 12, comprising the step of installing a dielectric template between the electromagnetic system and the workpiece.

16. The method according to any one of paragraphs.12-15, comprising the step of manufacturing a working head in the form of a separate movable assembly.

17. The method according to any one of paragraphs.12-15, characterized in that for processing the part with low electrical conductivity, a metal sheet is preliminarily applied to it from the side opposite to the location of the working head.