FR2547404A1 - ELECTROMAGNETIC CANON - Google Patents

Abstract

CANNON FOR ELECTRIC CONDUCTIVE PROJECTILES WITH ELECTROMAGNETIC ACCELERATION DRIVE WHOSE FIELD ACTS ON THE PROJECTILE AS WELL AS WITH AN EXPLOSIVE CHARGE FOR DETONATORY COMPRESSION OF THE ACCELERATION FIELD. THE ACCELERATION DRIVE IS A 2-4 COAXIAL SYSTEM OF EXTERIOR 3-4 AND INTERNAL 4-4 CONDUCTORS WHICH IS SHORT CIRCUIT BY A 28-4 BRIDGE AND WHICH THE OTHER END PRESENTS AN INTRODUCTORY ZONE FOR THE FIELD H ACCELERATION, WHILE AN EXPLOSIVE LOAD 7-4 THAT IS IGNITED AT THE POWER SUPPLY END EXTENDS ALONG THE 2-4 COAXIAL SYSTEM FOR DETONATORY APPROXIMATION OF CONDUCTORS 3, 4 UNTIL TO ELECTRIC SHORT CIRCUIT. THE INVENTION APPLIES TO SINGLE SHOT OR REUSABLE BARRELS.

Description

Electromagnetic barrel

  The present invention relates to an electromagnetic barrel for the firing of electrically conductive projectiles with an electromagnetic acceleration drive in which the (acceleration) field acts on the projectile as well as with an explosive charge for the detonation compression of the acceleration field.

  It is customary to expel shells or projectiles

  However, it is also a well-known practice for a long time to electromagnetically accelerate projectiles or shells: cf on this subject for example the German patent 376 391. A shell or projectile is then formed at least partially by an electrically conductive material and circulates in the tube of the barrel between two rails through which a high electric current is passed Connecting the two conductors of the electric current, the shell is traveled itself by said high electric current The interaction between this flow of current and the perpendicular magnetic field of the current determines the action on the projectile of an acceleration force in the longitudinal direction of the barrel tube.

  Very high electric currents and also

  relatively long tubes of guns are required to obtain high projectile velocities by means of such an electromagnetic gun.

  It is known from the German patent application DE-OS

  22 50 803 an electromagnetic gun in which the projectile is constituted by an electrically conductive material and a number of turns of induction coils are placed along the tube of the barrel The projectile serves as a short-circuit rotor to this gun acting at inside a linear accelerator.

  The starting velocity of the projectile can be increased either by the increase of the current or, at the same time, by the increase of the electromagnetic field of acceleration For the increase of the electromagnetic acceleration field, it has been proposed to compress detonatorically said electromagnetic acceleration field so as to increase the magnetic force proportionally In a device according to the above-mentioned German Patent 376,391, the magnetic field can be compressed by joint detonation of the rails.

  current drivers behind the projectile to accelerate.

  By detonation compression of the magnetic field, generated previously by current introduction, the energy content and the pressure of this acceleration field on the projectile are increased to the point that this projectile inserted in the current circuit surrounding the magnetic field is It is greatly accelerated by the pressure prevailing transversely to the magnetic field lines. With an electromagnetic gun whose acceleration field would be detonatorically compressed, it would be possible to obtain projectile departure speeds which would significantly exceed those of known guns with propellant charges. up to 2 km / s in conventional guns; with electromagnetic guns it is hoped to obtain projectile velocities of 5 to 10 km / s, the limits being determined primarily by the carrying capacity of the shell or projectile material and

  the guide inside the barrel as well as the practicable length of the acceleration course.

  The subject of the invention is an electromagnetic gun of the type disclosed, in which the electromagnetic drive,

  With the constructional elements necessary for the detonation compression of the acceleration field, a simple structure and the acceleration effect on the shell or projectile to be fired is improved over previous devices.

  This electromagnetic gun is characterized in that the acceleration drive is a coaxial system of outer conductor and inner conductor which is electrically shortcircuited by a bridge at its end facing the projectile and whose other end has a zone

3 2547404

  introduction of the acceleration field and an explosive charge that is lit at the power supply end extends along the coaxial system for the detonating connection of the outer and inner conductors to the electrical short circuit. A basic idea of the invention thus characterized is to establish the electromagnetic drive in a coaxial system formed of an external electrical conductor and an electrical conductor Also internal uncoté of the coaxial system, is introduced into it a a strong magnetic acceleration field by inserting between the outer and inner conductors a high current pulse or by inductively inducting through a coil the magnetic field in the cavity between said outer and inner conductors of the other class, the The coaxial system is electrically short-circuited and the projectile forms at least part of this short-circuit path. In the axial direction of the coaxial system there is disposed an explosive charge which, after the introduction of the accelerating magnetic field into the coaxial system. , is also lit at the end of power supply But the explosive charge is arranged so that, by the progress in the axial direction of the detonation, the outer and inner conductors of the coaxial system are brought closer to one another so that the electromagnetic acceleration field enclosed between them is strongly compressed. compression has the effect of greatly increasing the electromagnetic acceleration field; this increase in the acceleration field propagates at the speed of light, while the wave

  This is a considerably increased field, compared to the field of electromagnetic acceleration introduced, which acts on the projectile.

  In the simplest case, the projectile may be an annular projectile which itself serves as a bridge between

  the outer and inner conductors of the coaxial system.

  Depending on the length and force of the acceleration field and the explosive charge, the projectile can be

a very high initial speed.

  In order to be able to accelerate also solid cylindrical projectiles, the projectile is housed in the outer conductor and this electric conducting projectile is connected to the inner conductor by its base, no inner conductor remaining in front of the projectile. After creation of the acceleration field and ignition of the explosive charge, the magnetic field is compressed, for example by forcing the outer conductor concentrically towards the inner conductor until it abuts against the latter; by progressing the detonation, the acceleration field is finally compressed to the point of a rupture initiation zone between the projectile and the inner conductor is torn off and the projectile is then accelerated The outer conductor can continue to be compressed After the projectile, the pulsating electromagnetic field now behind said projectile continues to compress and contributes to the projectile acceleration. In the post-projectile cavity, the projectile and lead surface material vaporizes under the effect of the detonation

  reinforced field and is at least partially ionized.

  This results in spark discharges between the torn inner conductor and the projectile as well as coughing fields of acceleration.

  It is also advantageous to let the coaxial system extend only to the shell. The electrical bridging between the outer and inner conductors is then for example the fact of a conical cavity in the center of which is placed the projectile. It plunges into a flight where it is held and is guided after acceleration. The projectile is maintained in the bypass, again with a rupture initiation zone. After introduction of the acceleration field and detonation compression of the latter, the In this case, the electromagnetic acceleration field is coupled here in the space behind the projectile. conduction of

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  This particular embodiment lends itself to the establishment of the entire electromagnetic drive in the form of a cartridge which is clamped in such a way that

  that the detonating effects do not go outward.

  The entire cartridge with the projectile can then be inserted into the barrel itself. After the projectile has been accelerated, in which the cartridge is destroyed internally, it can be exchanged and replaced by

a new one.

  According to other advantageous advantageous features of the invention: a high current pulse is introduced between the inner and outer conductors by connection contacts to generate the acceleration field, one of these connection contacts is connected to a detonator for the explosive charge and is brought into contact with the corresponding conductor of the coaxial system by the detonation of the explosive charge; at the feed end of the coaxial system, there is, to introduce the acceleration field, a field excitation coil; the field excitation coil is wound around the outer conductor and the latter has, in the region of the coil, a longitudinal slot for the introduction of the acceleration field into the space between the outer and inner conductors, said longitudinal slot being formed, after inclusion of the acceleration field, upon detonation of the explosive charge; for the impedance matching, the outer conductor of the coaxial system is spirally wound around the inner conductor, at least at the supply end; the explosive surrounds the outer conductor of the coaxial system; the explosive is placed in the cylindrical inner conductor of the

coaxial system.

  The invention will be better understood from the description

  DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS TAKEN AS NON-LIMITING EXAMPLES AND SHOWN SCHEMATICALLY BY THE DETAILED DRAWING, IN WHICH: FIG. 1 is a partial axial cross-sectional view of a one-shot gun provided with an acceleration drive; electromagnetic projectile comprising a coaxial system; FIG. 2 similarly represents a part of another one-shot gun: FIG. 3 is a partial representation of the single-shot gun according to FIG. 2, after acceleration of the projectile; FIG. 4 is a view in partial axial section of a reusable barrel comprising an electromagnetic drive for a projectile to shoot; FIG. 5 represents in axial longitudinal section a cartridge accommodating the electromagnetic acceleration drive of the reusable barrel according to FIG. 4; Figure 6 is an axial longitudinal sectional view of an electromagnetic acceleration drive according to the invention; FIG. 7 schematizes' 1 detonation flare of the

  internal conductor of the coaxial system for an electromagnetic acceleration drive according to the invention.

  From one figure to another, the identical elements or identical action are provided with the same reference signs,

  however with the addition of the number of each embodiment beyond a dash.

  FIG. 1 shows a single-shot gun 1-1 comprising an electromagnetic acceleration drive, a coaxial system 2-1 of an outer conductor 2-1 and a cylindrical inner conductor 4-1. The cylindrical inner conductor has, for reasons of stability, a steel core 51 30 The outer conductor 3-1 is likewise surrounded by a layer of steel 6-1 This steel casing 6 1 is surrounded, over the entire length of the barrel to a 1-1, of a layer of explosive 7-1 which is itself surrounded by

  outside by a steel tube 8-1.

  This single-shot gun fires an annular projectile 9-1 which circulates in the gap between the outer and inner conductors. The projectile itself is made of electrically conductive material, so that the outer and inner conductors are short-circuited. the interior and at least the rear part of the projectile are of good electrical conductor material, for example copper; the head of the projectile may comprise, to increase the force of perforation, a hard metal core. To accelerate the projectile, there is introduced between the outer and inner conductors, at the feed end, not shown here, a high current pulse by which an annular magnetic field H is generated in the space between said conductors. after the introduction of the high current pulse between the outer and inner conductors, the explosive envelope 7-1 is annularly lit, so that a concentric detonation wave 15 flows in the longitudinal direction of the gun at a single stroke. 1-1 and press the steel casing 6-1, with the outer conductor 3-1, against the inner conductor 4-1 until there is a short circuit between the outer and inner conductors The core of steel 5-1 stacks another deformation Figure 1 corresponds to a state in which the explosive of the casing 7-1 is already lit and the outer and inner conductors of the coaxial system already short The magnetic field is included in the cavity 10-1 between the bottom of the projectile 25 and the narrowing zone of the outer and inner conductors and is further compressed by the detonation continuing its progression. The current is directed from the outer conductor to through the projectile, towards the inner driver and returns to the narrowing zone between

  external and internal conductors The compression of the magnetic field is added to the effect of the current to exert on the projectile 9-1 a strong pressure, so that said projectile is accelerated and expelled from the barrel The steel tube 8 1 of The outer grip is centered inward, and destroyed by detonation of the explosive.

  FIG. 2 shows a 1-2 shotgun for cylindrical projectile 9-2 which includes a coaxial 2-2 electromagnetic acceleration system of the projectile with a

  outer conductor 3-2 and inner conductor 4-2.

  The inner conductor 4-2 goes from the feed end not shown to the bottom of the projectile, to which it is connected by a rupture initiation zone 11-2 The projectile itself bears against the cylindrical outer conductor 3-2 and is guided by it during acceleration The outer conductor is surrounded by a steel shell 6-2, itself surrounded by an explosive charge 7-2 The entire device is clamped to the outside by a steel tube 8-2 The outer conductor 3-2 is still pulled in the direction of acceleration of the projectile beyond the latter and serves there

  barrel for said projectile gas.

  This one-shot gun 1-2 is also shown in FIG. 3 after the introduction of a high current pulse between the outer and inner conductors and after the ignition of the explosive charge around the outer conductor. The magnetic field H is compressed into the cavity -2 between the projectile 9-2 and the zone of narrowing 20 between the outer and inner conductors and bears against the field of the projectile A pressure on the bottom of the projectile value given by the location of 11-2, the projectile 9-2 exits the inner conductor 4-2 and is expelled from the barrel completing the end of its course while being guided by the outer conductor 3-2 Once the projectile is torn off the internal conductor, the compression of the acceleration field continues Under the effect of the detonation, the surface material vaporizes the inner and outer conductors and the projectile towards the cav This material is at least partially ionized. These spark discharges and current paths within the ionized plasma ensure the return of current between the outer conductor and the inner conductor so that the compression of the acceleration 35 as well as the pressure increase related thereto on the projectile and continue after the rupture of the inner conductor It is formed at the same time in the cavity 10-2, after a transition phase, a complicated electromagnetic field

  with variable oscillation modes over time.

  The swirling current is however distributed over the walls of the cavity so that the projectile is the seat of a pressure increase during the compression of the field. Said projectile can thus be further guided as a

  conventional projectile in the outer conductor and at the same time be further accelerated by the compression of the latter.

  FIGS. 4 and 5 show a reusable barrel 1-4 with electromagnetic acceleration drive for a 9-4 projectile. The acceleration drive assembly is housed with the coaxial system 2-4 in a cartridge. is introduced into a barrel 21-4; it consists of a steel bushing 22-4 into which the acceleration system 2-4 is inserted. This acceleration system itself consists of an outer conductor 3-4 and a conductor The inner conductor 4-4 is a copper tube or, as in the previous figures, a cylindrical copper tube with a steel core. The outer conductor 3-4 is surrounded by an explosive envelope. 4; between the explosive casing and the cartridge socket is placed a shock-proof layer 23-4 The cartridge is closed rearward by an insulating cover 24-4 & This cover is traversed by the connection con25 tact 25-4 of the inner conductor as well as pi a cylindrical connection contact 26-4 for the outer conductor The cylindrical connection contact 36-4 of the outer conductor 3-4 is placed inside the outer conductor and does not first touch this latest. An annular wire detonator 27-4 for the explosive envelope 7-4 is connected to the connecting contact 26-4 of the outer conductor. At the front end of the cartridge, the inner conductor 4-4 and the outer conductor 3-4 are short circuited by a conically shaped bridge 28-4.

  from this conical bridge, the point of which is directed towards the inner conductor, a rupture zone 29-4 results.

  At the anterior end of the funnel the hollow conductor system is closed by a brass plate 30-4 in the center of which is held a projectile 9-4 The projectile 9-4 comprises, on its bottom penetrating into the cavity li5 mitée by the bridging 28-4 and the copper plate 30 4, a

  shear edge 31-4 against copper plate 30-4.

  Cylindrical projectile Outputs a 32-4 bore internally coated with copper which passes through the front face of the cartridge, so that it projects slightly beyond this bore. The cartridge 20-4 is inserted without play into the barrel 21-4. The projectile 9-4 tip then enters a barrel 33-4 lined internally with a good electrically conductive material, for example copper at its end. rear, the barrel 21 4 is closed by a cover not shown in which are attached parts to the connecting contacts 25-4 and 26-4 due to the large diameter of the outer conductor relative to the caliber of the projectile, achieve, in this embodiment of the acceleration system 2-4, the compression of the field over a shorter length of the hollow conductor of the coaxial system. A high current pulse is introduced between the connection contacts 25-4 and 26-4. part of the energy of this high current pulse is fed to the ring-shaped detonator 27-4, so that the explosive envelope starts in annular form; the outer conductor 3-4 of the coaxial system is forced inwards by this priming and finally comes into contact with the cylindrical connection contact 26-4 The high current pulse is now introduced between the internal current and the external conductor 30 of the system coaxial The detonation of the explosive envelope

  7 4 pushes the outer conductor 3-4 towards the inner conductor until the short circuit occurs.

  The time flowing to the annular short-circuit on this end of the coaxial system is determined by the choice of the distance between the outer conductor and the inner conductor and chosen so that a field of maximum intensity is included in the resulting cavity between the driver

  outside, the inner conductor and the 28-4 conical bridge.

  With the progression of the detonation angle, the acceleration field is enclosed in the cavity 10-4 between the outer and inner and compressed conductors, as has been explained with reference to FIG. By bridging 28-4, the outer conductor is abruptly shrunk concentrically towards the end of the compression phase. Under the correspondingly large increase in the induced current, the bridging 28-4 vaporizes from the breaking initiation zone 29-4, although that the strong field of acceleration now enters the cavity of the conical bridge and that the bottom of the projectile now becomes a wall portion of the cavity in which the field is compressed. The prevailing field pressure shears the edge 31-4 from the bottom of the projectile, so that the projectile is now expelled from the gun 3-4 with maximum acceleration values As well on the projectile as on the barrel exerts very high pressures which reach ju up to the mega-G zone (G: gravitational acceleration), but which only act for short moments, so that these pressures can be absorbed by appropriate sizing of the cartridge, the projectile and the barrel During the complete detonation of the explosive envelope 7-1, the anti-shock layer 23-4 vaporizes but the envelope of the cartridge sleeve 22-4 is not damaged. canon, we exchange the cartridge for a new one. The conical embodiment of the 28-4 bridge with

  the breaking initiation zone 29-4 is given by way of example.

  Thus, the fracture initiation zone can also be transferred into a cylindrical tube surrounding the inner conductor and connected conically to the outer conductor in conical form. the compression of the acceleration field in the final phase, as this avoids the formation of separate cavities in which the energy of the field is unnecessarily converted into heat. For the impedance matching, it is also possible to realize the external conductor partially , preferably close to the area

  feeding, spiraling or winding around the inner conductor, which complicates exclusively the original magnetic field without exerting any influence on the function de nement principle.

  FIG. 6 shows an acceleration system 2-6 belonging to a single-shot gun or a reusable barrel. The coaxial system 2-6 has an outer conductor 3-6 and an inner conductor 4-6 which, at inner end, turned towards the projectile, here not shown, are again short-circuited by a conical-shaped bridge 28-6 At the opposite end of the coaxial system, the outer and inner conductors are also connected together in conical form and open into a conical portion 34-6 covering a large portion of the section of the acceleration system 2-6 and embedded in the explosive envelope 7-6 This conical portion 34-6 serves to guide the detonation waves and to distribute them over the entire section of the explosive envelope At this end of the coaxial system, a field excitation coil 35-6, whose field is introduced into the cavity between the outer and inner conductors through a narrow longitudinal slot 36-6 of the outer conductor is wound on the circumferential cylindrical portion of the outer conductor 3-6. The acceleration system described above is closed outwardly by a steel tube 8-6; the back end and

  the front end are closed to them respectively by an end piece 37-6 and a holding piece 38-6.

  The end piece 37-6 is traversed by the allusion cables 39-6 for a detonator 40-6 which in turn initiates an amplifying charge 41-6. This amplifying charge then also starts the explosive of the envelope 7. The connection contacts 42-6 required for the field excitation coil 35-6 pass under insulation through the steel tube 86 and are connected by a switch 43-6 to a capacitor bank 44-6. capacitor 44-6, with appropriate connection, is connected to a battery-45-6 battery through another switch 46-6 The

  The operation of the acceleration drive is dependent on a start command 47-6 connected to the ignition wires 39-6, the switch 43-6 and the switch 46-6.

  The start command further receives, via a line 48-6, a capacitor bank 44-6, a signal on the voltage thereof, and a line 49-6 a trigger signal.

shooting.

  If a projectile is to be fired, the firing signal at the start command 47-6 is taken via line 49-6 Switch 46-6 closes, so that the accumulator battery 45-6 6 Charges the capacitor bank 44-6 As soon as the start command 47-6 receives on line 48-6 the indication that the capacitors have the voltage required for the high current pulse for the excitation coil field 35-6, on the one hand the switch 43-6 closes and, on the other hand, the ignition pulse is fed to the detonator 40-6 by the ignition cables 39-6 The pulse high current in the field excitation coil 7-6 has the effect of producing, through

  the longitudinal slot 36-6 of the outer conductor 3-6, a magnetic field HO direction first axial in the cavity between the outer and inner conductors.

  By triggering the detonation in the envelope 7-6, the outer conductor 3-6 is immediately compressed, so that the longitudinal slot 36-6 closes and the magnetic field is enclosed in the cavity between the outer and inner conductors As already explained for the embodiment according to FIGS. 4 and 5, the outer conductor and, consequently, also the magnetic field, which is furthermore compressed As a result of the geometrical data of both the In the cavity between these outer and inner conductors and the bridging 28-6, the initially axial magnetic field is transformed into an annular magnetic field H and further compresses by sudden collapse of the conical bridge 28-6 in the manner of that of the cladding. a hollow charge the magnetic field, more compressed, as described above, in the funnel-shaped portion of the bridge, acts directly on the bottom of the electrical conductor, here not shown, of the next projectile and

the latter is accelerated.

  FIG. 7 represents a part of a coaxial system 2-7 comprising an outer conductor 3-7 and an inner conductor 4-7. The acceleration field is introduced into the cavity between the inner and outer conductors by a coil of field excitation 35-6 isolated The compression of the acceleration field is obtained here by a detonatory flare of the inner conductor, which can be established for this purpose in cylindrical form with insertion of explosive 50-7 in the cylindrical part. the detonation of this explosive, the cylindrical inner conductor 4-7 flares up and is pushed back against the outer conductor 3-7, so that there occurs a short circuit and the field

  acceleration H is enclosed.

Claims (2)

  1.An electromagnetic card for firing electrically conductive projectiles with an electromagnetic acceleration drive whose (acceleration) field acts on the projectile as well as with an explosive charge for the detonatory compression of the accelerating field, said barrel characterized in that the acceleration drive is a coaxial system of outer conductor (3) and inner conductor (4) which is electrically bypassed by a bridge (28) at its projectile-facing end (9). and whose other end has an area of introduction <25, 26, 35) for the field   acceleration (H) and that an explosive charge (7, 50) that is ignited at the power supply end extends along the coaxial system (2) for the detonating approach of the outer and inner conductors (3, 4) to the electrical short circuit.   2, Canon according to claim 1, characterized in that the projectile (9-1) is an annular projectile which itself serves as a bridging between the outer (3 1) and inner (4-1) conductors of the coaxial system (2). -1) o 3 Canon according to claim 1 characterized in that the projectile (9-2) is held in the outer conductor (3-2), established in a barrel, the coaxial system (2-2) 25 and the bottom electrical conductor of the projectile (9-2) is connected to the inner conductor (4-2) by a primer area rupture (11-2).   4. The barrel as claimed in claim 1, wherein the coaxial system (2-4, 2-6) is short-circuited electrically on the front end facing the projectile (9-4) by a conical bridge (284). 28-6), the tip of which is connected to the inner conductor (4-4, 4-6) and which has a rupture initiation zone (29) which is tear-off during the compression of the acceleration field (H) by the high field intensity in the final phase, the electrical conducting projectile being held in a tube (32, 33) of the barrel (1) on the bottom of the funnel-shaped cavity delimited by the bypass.   Cannon according to any one of the claims   1 to 4 characterized in that the acceleration drive (2-4, 26) is established in a cartridge (20) provided with an outer grip (8), which is insertable into a barrel body (21). ) and replaceable by a new cartridge after firing the projectile (9).   6 Canon according to any one of the claims   1 to 5, characterized in that, in order to generate the acceleration field (H), a high current pulse is intro ductable between the inner and outer conductors (4-4, 3-4) by connection contacts (25- 4, 26-4), one of these connection contacts (26-4) being connected to a detonator (27-4) for the explosive charge (7-4) and being   contact with the corresponding conductor (3-4) of the coaxial system (24) by detonation of the explosive charge.   Barrel according to one of the claims   1 to 5 characterized in that it comprises, at the supply end of the coaxial system (2-6), a field excitation coil (35-6, 35-7) for introducing the field of The barrel according to claim 7, characterized in that the field excitation coil (35-6) is wound around the outer conductor (36) and that it is present in the region of said coil. a longitudinal slot (366) for introducing the acceleration field into the space between the outer and inner conductors (3-6,4-6), said longitudinal slot (36) being formed after inclusion of the acceleration field during the pursuit of   detonation of the explosive charge (7-6).   9 Canon according to any one of the claims   Characterized in that, for the impedance matching, the outer conductor (3) of the coaxial system (2) is spirally wound around the inner conductor, this   at least at the feeding end.   The barrel according to any of the claims   1 to 9 characterized in that the explosive (7-1, 7-6) surrounds the outer conductor (3) of the coaxial system.   11 Canon according to any one of the claims   1 to 10 characterized in that the explosive (7-7) is placed in the cylindrical inner conductor (4-7) of the coaxial system (2-7).