FR2613966A1 - METHOD FOR ASSEMBLING PRESSING TUBES BY ELECTROEXPLOSION AND DEVICE FOR IMPLEMENTING THE SAME - Google Patents

Abstract

THE PRESSING ASSEMBLY PROCESS OF TUBES 6 BY ELECTROEXPLOSION ACCORDING TO WHICH THE PRESSING ASSEMBLY OF THE TUBES 6 IS CARRIED OUT BY PRIMING THE EXPLOSION OF THE ELECTROEXPLOSIVE CARTRIDGES 5 BY A PULSE OF ELECTRIC CURRENT WITH A DURATION OF THE LONGER FROM THE FOLLOWING EQUATION: THE DEVICE, PERFORMING THIS PROCESS, INCLUDES A SOURCE I OF CONTINUOUS VOLTAGE, A SENSOR II, A SWITCH 2, AN ECLATOR 3 WITH ELECTRODES 4, INTENDED TO BE CONNECTED TO ELECTROEXPLOSIVE CARTRIDGES 5, AS WELL AS A CAPACITOR BATTERY 10 AND, CONNECTED IN SERIES, A THRESHOLD ELEMENT 12, A POWER AMPLIFIER 13, AN IGNITION CONTROL CIRCUIT 14 CONNECTED BY ITS OUTPUT TO THE CONTROL INPUT OF ECLATOR 3.

Description

The present invention relates to the field or metalworking by

deformation and has especially for

  object of electroexploding tube pressing

  sion and the device embodying this method.

  The invention can find the application in the

  design of the machines used in the production of

  energy and chemical engineering, in particular for the manufacture of heat exchanger

  other products in which the assembly must be carried out

  pressing by pressing tubes with tube plates.

  We know a method of assembly by pressing

  of electroexplosion tubes ("Electrohydraulic

  impulse tubes with tubular plates

  for heat exchangers "by B. Ya.

  rovsky, Kiev, "Naukova dumka" edition, 1980, page 41).

  on the use of pulse pressure generated

  after an electrical explosion of a driver,

  arranged in an electroexplosive cartridge filled with

  quide. Electroexplosive cartridges are mounted in

  the ends of the tubes intended for assembly by pres-

  wise. The explosion occurs by an electrical current pulse sent to a conductor. Formed as a result of

  the explosion of the driver, the shock wave reaches the

  the inner kings of the tube and deforms it by performing the

  Intimate and solid appearance of a tube with a plaque

  bes. In this case, a plasma discharge channel is

  me at the place of the exploded driver. However, this procedure

  This does not ensure the high quality of tube assemblies with tube plates. In addition, this method of assembly by pressing requires a high energy consumption

  This disadvantage is due to the fact that we do not have

  in the known process, the conditions of the interrup-

  electrical current after the formation of an impulse

  pressure pressure and after assembly by pressing the

  be, which leads to an increase in consumption

  electrical energy. The long action of the plasma of the body

  the discharge formed by the explosion of the conductor

  burns the walls of a tube and therefore

  the quality of the assemblies obtained because of

  and leaks can occur at

  burns. There is known a device implementing the known method of assembly by pressing the tubes by electroexplosion (USSR N 844 103, CI, Int.B21D 26/10 published July 07, 1981) including, connected the to each other, a source of

  voltage, a capacitor bank and a cir-

  firing nozzle consisting of a spark gap, electrodes and electroexplosive cartridges, and also a mechanism for moving the electrodes, kinematically connected thereto and provided with a motor and a selector of no electrode displacement (the step of displacement is equal

  at the distance between the electroexplosive cartridges).

  The step selector comprises, connected in se-

  a rotation angle converter for the motor shaft

  of the mechanism of displacement of the electrodes in number of im-

  pulses and a set of pulse counters with cir-

  cooked which impose the counting time.

  However, this device is characterized by the instability of the conservation of the service voltage imposed at the moment of the explosion, which leads to a decrease in the quality of the assemblies by pressing when

  low voltage and the decrease in service time.

  Defect of electrical equipment during high voltage.

  According to its essential technique and the result obtained, the closest to the claimed invention is the known device for the realization of the known method of assembly by pressing the tubes by electroexplosion (B. Ya., Mazurovsky "Assembly by pressing tubes by electrohydraulic impulse in tubular plates for heat exchangers ", Kyiv," Naukova dumka "edition, 1980, page 121) comprising, connected in series with each other,

  a source of continuous voltage, a battery of

  and a discharge circuit consisting of a spark gap,

2613 96

  an electrode and electroexplosive cartridges, mc-tees in the tubes intended for the assembly with pressure with

tubular plate.

  To realize the assembly by pressing of the tu-

  With the tube plates, the electrode is electroexplosively connected to the end of a tube intended for assembly by pressing.

  in the tube plate. Then we put the source of

  continuous operation and the battery of

  then at the end of the battery charging

  mute, using a spark gap, the discharge circuit and connect the capacitor bank to the electroexplosive cartridge causing the driver to explode

  of the electroexplosive cartridge and the creation of a

  impulse flow inside the tube.

  The process of discharging the battery of

  denser is oscillatory in nature and the impulse of

  pressure is formed by the first half wave of the current.

  However, this device does not ensure the good quality of assembling the tubes with the plate

  because the device does not allow

  break the pulse of electric current at the end of the

  first half-wave of the electric current forming the impulse

  pressure pressure. As a result, the spread of half-on-

  subsequent current leads to an increase in the time of the action of the plasma of the discharge channel on the

  walls of the tube causing burns of the walls.

  In addition, the total discharge of the capacitor bank increases the time required for its subsequent charging and the preparation of a subsequent explosion,

  which reduces the efficiency of the device.

  It was therefore proposed to develop a

  assembly process by pressing tubes by electroexchange

  plosion and a device embodying this method in which

  the pulse duration of the electric current would be deter-

  undermined by the duration of its first half-wave by switching off the capacitor bank after

  formation of the first half-wave of the steady-state current

  simultaneously the service voltage imposed at the time

of the explosion.

  For stopping the electrical current pulse

  that the shock wave generated at the expiry

  "explosion time" and reflected by the walls of the tube after its assembly by pressing. To interrupt the electric current, the shock wave must come closer

  the limits of the discharge channel produced in the

  touch the exploded driver's place and compress the

  channel plasma by increasing its resistance and interrupting

  thus panting the electric current at the time of the passage of

  oscillation process of the electric current by the zero.

  To ensure the coincidence of the moment of the passage of the process of oscillation of the current by zero and the moment when the shock wave approaches the discharge channel when loading the diameter of the tubes, the possibility must be foreseen. to adjust the pulse duration of the electric current according to the diameter of the tubes or the time spent for the explosion of the conductor from the moment of the production of a current pulse, that is to say " explosion time "of the driver. To ensure a good quality of the assembly by pressing, it is necessary that at the moment when the electrode is getting closer

  of the electroexplosive cartridge and where the explosion occurs

  the capacitor bank is charged up to

a voltage required.

  The problem is solved by means of a

  assembly by electroexploding tubes

  by means of the initiation of the explosion of the electroexplosive cartridges housed in the tube ends by the pulsed electric current, characterized according to the invention, in that the pulse duration of the electric current is determined with the aid of the following equation: t = .0.8 to 1, D

= 0.8 to 1.2 (T + V

  or: T is the time of the explosion of the conductor of the electroexplosive cartridge, As

  D is the inside diameter of the tube, intended for

  press appearance, m V is the speed of propagation of the shock wave

in the liquid, m / ps.

  The problem posed is further solved by using

  of a device carrying out the claimed process, comprising

  connected in series, a source of DC voltage,

  a battery of capacitors, a spark gap with a

  trode and electroexplosive cartridges, characterized

  according to the invention in that it comprises a sensor of

  connected to the capacitor bank as well as a

  threshold element connected to the sensor output and,

  connected in series with this one, a power amplifier

  an ignition unit of the electroexplo

  sive, said unit being connected to the control input of the spark gap, and a switch with circuit breakers, the signaling outputs of the switch being connected to the DC voltage source and the spark gap, and in that the battery of capacitors is realized in the form of independent sections of connected capacitors in

  parallel to the switch through the disks

tors.

  It is advantageous that the device comprises a logic circuit, a second and a third switch, the second switch being connected by the signaling outputs to the circuit of the DC voltage source and connected by the control input to the first control output of the logic circuit, whose second control output is connected to the control input of the third

  switch, kinematically connected to the electrodes, the third

  sth control output of the logic circuit is connected to the input of the power amplifier and the output of

  the threshold element is connected to the first com entry

  the logic circuit connected kinematically to the electri-

  trodes. In the device according to the invention, the logic circuit may comprise a logic element AND of the control of the charge of the capacitor bank, a logic element AND of the control of the displacement of the capacitors.

  electrodes, a logic element AND of the control of the

  placement of the electrodes and a logic element AND of the explosion initiation control of the electroexplosive cartridge, whose direct input, acting as the second control input of the logic unit, is connected to the input of the electroexplosive cartridge. inversion of the logical element AND

  of the charge control of the battery of condensa-

  and the direct input of the logic element AND the control of the displacement of the electrodes, whose inversion input is connected to the direct input of the logic element AND the control of the load of the battery of

  capacitors, the direct input acting as the first

  the control input of the logical unit, the outputs of

  the logical element AND of the load control of the

  the logical element AND control of the displacement of

  trodes and the logical element AND the command of the

  the explosion of the electroexplosive cartridge acting as first, second and third

  control outputs respectively of the logic unit.

  The invention makes it possible to improve the quality of

  assembly by pressing tubes, that is to say, desuper-

  primer their burn and reduce the consumption of

electrical energy.

  In addition, the time required to recharge

  the capacitor bank is reduced, which means that

  raises the efficiency of the device implementing the

  assembly by electroexploding tubes

  if we. In addition, the invention makes it possible to stabilize the

  operating voltage at the time of the explosion and thus allows

  if to increase the operating reliability of the device implementing the pressing assembly method of

  electroexplosion tubes and also gives the possibility

  to obtain the coincidence of the moment of the passage of the cs-

  cillation of the current by the zero and the moment when the wave of

  shock is approaching the discharge channel.

  The invention will be better understood and other purposes, details and advantages thereof will become more apparent

  in the light of the following explanatory description

  different embodiments given only to

  non-limiting examples with reference to the accompanying drawings in which:

  - Figure 1 represents a synoptic block of the dis-

  positive implementing the assembly method by pressing tubes by electroexplosion, according to the invention;

  - Figure 2 shows an electroexplo

  of the device on a larger scale, depending on the

  vention; FIG. 3 represents a block diagram with a logic circuit, according to the invention;

  - Figure 4 represents a synoptic block of the selection

  step of the displacement of the electrodes, according to the invention.

tion;

  - Figure 5 shows oscillograms of the

  impulse and voltage during the explosion

  of the electroexplosive cartridge, according to the invention.

  The device implementing the assembly method by pressing the tubes by electroexplosion

  has a source I (Figure I) of continuous voltage

  on the AC circuit. A switch 2 is connected to said DC voltage source I by a signaling output and by another signaling output at the signaling output of a spark gap 3. The other signaling output of the spark gap 3 is connected to a electrode 4 which must be successively brought closer to the electroexplosive cartridges 5, housed in the ends of the tubes 6 intended to be mounted

  by pressing into a tube plate 7.

  The switch 2 has circuit-breakers 8 connected to independent sections 9 of the capacitor bank in order to impose the duration of pulses of electric current to be applied to the electrodes 4 as a function of the diameter of the tube 6. The voltage sensor 11, connected to a threshold element 12, connected in series with

  a power amplifier 13 and to a communication unit

  14 of the electroexplosive cartridge, of which

  the output is connected to the control input of the

  3 is connected to the outputs of the power source I. The electrodes 4 are mounted on a support 14 'made

  so that it can be moved vertically and horizontally

  zontalally in order to bring the electrode closer

4 of the end of the tube 6.

  Figure 2 shows an electroexchange cartridge

  plosive 5 having a conductor 15 immersed in a liquid

  16, for example, in the water filling the elec-

troexplosive 5.

  Figure 3 represents the alternative mode of

  the device carrying out the assembly process by

  pressing of the tubes by electroexplosion. The device

  alised according to this variant differs from that shown in

  Figure I in that it is provided with a mechanism 17 for de-

  placement with a motor (not shown in the Figure), intended to move the electrodes 4 in the horizontal and vertical to bring them successively

  electroexplosive cartridges 5, engaged in the ex-

  tube ends, intended for assembly by pressing with the tube plate 7. In this case, the tubes 6 are

  mounted in the tube plate 7 so as to form

  following the horizontal and the vertical (in Figure

  3, there are shown three rows of tubes according to the horizontal

  zontal and one row following the vertical).

  The displacement mechanism 17 of the electrodes 4 is kinematically connected to the selector 18 of the pitch of the translation of the electrodes 4, this selector being connected to the first control input of the logic unit 19, the second control input of which is connected to 'i er.t

  The first control output of the circuit lc-

  19 is connected to the control input of the switching

  20, connected to the supply circuit of the DC voltage source I, the second control output of the logic unit 19 being connected to the control input of the switch 21, the signaling inputs of which are connected to the control circuit. supplying the mechanism 17 to ensure the kinematic connection of the switch 21 with

  the electrodes 4. The third control output of the cir-

  logic circuit 19 is connected to the power amplifier 13. The logic circuit 19 comprises three logic elements AND whose logic element AND 22 is intended to produce the

  control signal of the charge of the battery 10 of

  densiters, the AND logic element 23 serves to produce the control signal of the displacement of the electrodes 4 while

  that the logical element ET 24 is intended to produce the

  control of the initiation of the explosion of the car-

  electroexplosive key 5. The direct input of the element

  AND logic 23 is connected to the inverting input of the

  logical element AND 22 and to a direct input of the element

  logic 24 serving as the first control input

  of logic circuit 19, this input being intended for

  receive the control signal from the position of the electricians

  a 4, sent from the output of the step selector

  translation 18 of the electrodes 4.

  The direct input of the AND logic element 22 is connected to the inversion input of the AND logic element 23 and to the other direct input of the AND logic element 24 and acts as a second control input of Single

  logic 19, this input being intended to receive the signal

  general control of the voltage of the battery 10 arrived from the voltage sensor 11 via the element of

threshold 12.

  The output of the logical element ET 22 is officially

  this first control output of the logic circuit 19,

  this output being intended to send the communication signals

  Means the charge of the battery 10 to the conwarnde input of the switch 20. The output of the logic element AND 23

  serves as the second control output of the logic circuit

  19, this output being intended to send the control signals of the displacement of the electrodes 4 to the input of

  control of the switch 21 while the output of the

  logic ET 24 serves as the third output of

  logic circuit 19, this output being intended for

  send the command signals of the boot of the explo-

  electroexplosive cartridge 5 at the entrance to the

  unit 14 via the amplifier 13.

  As spark gap 3, it is possible to use any controlled spark gap (for example, an ignitron, a trigatron). As the ignition control unit 14, it is possible to use a pulse transformer,

  a thyristor amplifier, that is to say, such a device

  who can, after the arrival of a signal at his entrance,

  form, at its output, an impulse whose parameters as-

  the start (ignition) of the spark gap 3 and the explosion of the electroexplosive cartridge 5. The DC voltage source I consists of a step-up transformer and a rectifier (not shown in the Figure)

coupled in series.

  The voltage sensor 11 (for example a divider

  voltage) and the threshold element 12, coupled to each other, constitute a voltage control circuit

of the capacitor bank 10.

  In the claimed device, the step selector 18 (FIG. 4) of the displacement of the electrodes 4 comprises a converter 25 of the rotation angle of the motor shaft (not shown in FIGS. 3, 4) in number of pulses. , this converter being connected to the input

  counting the pulse counter 26, the outputs of

  whose formation are connected to the inputs of the decoders 271I-27n decades is the number of decades equal to the number of decimal digits of the counter 26. One of the decoder outputs 271 to 27n can be connected to 261 3c he helps control members 28I to 28 on the inputs I n

  coincidence circuit, the output of which, connected to the

  resetting the counter 26 acts as the output of the selector 18 while the input of the converter

25 serves as the input of selector 18.

  Figure 5 gives the curves of the voltage ";" applied to the conductor 15 (FIG. 2) of the electroexplosive cartridge 5 and the current I (FIG. 5) passing through the conductor 15 (FIG. 2). The duration T (Figure 5) of

  the explosion is equal to the interval between

  goal (point "0") of the pulse of the electric current and the voltage peak designated by point "A". The second peak of tension on the section "AB" is caused by compression.

  of the discharge channel under the action of the reflected shock wave.

  Based on the claimed method of tube pressing assembly, the following equation was defined experimentally:

L = (0.8 to 1.2) (T + D), (I)

  o: test the pulse duration of the electric current, T is the duration of the explosion of the conductor 15 of the cartridge 5, ps, D is the inside diameter of the tube 6, m; V is the speed of propagation of the shock wave

* in the liquid, m / ps.

  Then, for a known value of the diameter

  D inner tube 6 is determined the required duration X of the current pulse using the equation (I) to ensure the condition of the interruption of the current after

  its first half-wave by the shock wave reflected in

  terminating the duration T of the driver's explosion 15 using the following equation:

, 2

T = kS, (2)

26 13966

o

  k is the constant coefficient which depends on the

  properties of the determined conductor material of the empirical relationship K = 0.2Y hl / 3 d4 / 3; S is the surface of the section of the conductor 15,

  uIt is the voltage of the battery 10 of condensa-

  applied to the conductor 15 and recorded by the voltage sensor 11,

  L is the inductance of the circuit comprising the bat-

  10 the switch 2, the spark gap 3, the electrode 4.

  d is the diameter of the conductor; h is the constant of the material of the driver

h +.

  o Po is the density of the material of the conductor; 6 is the specific electrical conductivity; and l are the heat of fusion and the specific heat of vaporization of the material of the conductor respectively.

  In the case where the coefficient k is not

  the duration T of the explosion must be determined by

  firing a control explosion according to the values

  set by the oscillograph (see Figure 5) o as already mentioned, the duration T of the explosion corresponds to the interval from the beginning (point "0") of the current pulse Xjusqu ' at peak voltage (point "A"). In the case where the duration of the pulse of the electric current is within the limits determined by equation (I), the shock wave reflected from the inner wall of the tube 6 (FIG. 1) is directed towards the axial line of the tube 6 where is the discharge channel at the time of the passage of the

  electric current I (Figure 5) by the zero, that is,

  at the moment when the energy introduced into the discharge channel is equal to zero (if T is precisely equal to

D / V) or is weak.

  Then, using the following known ratio: V2

C - (3)

O2 L

  the required capacity C of the battery 10 is found (FIG.

  capacitors and connect a required number of sections 9 to the signaling outputs of the switch 2

  using the circuit-breakers. 8. Then, the voltage is

  required UI activation to the threshold element 12 and connects the device to the network. From that moment,

  the capacitor bank 10 begins to charge.

  When the UI voltage has reached a given value, the

  threshold 12 is triggered and triggers, through

  power amplifier 13, the unit of

  lighting 14 which puts the spark gap 3 into action, and consequently

  this, the open circuit closes through the medium of

  electrode 4 and the explosion of the electroexplosive cartridge 5 occurs. By the direct shock wave, the tube 6 is pressed into the tube plate 7 while the shock wave

  reflected back to the walls of the discharge channel at

  where current I (Figure 5) has moved closer to zero

  and destroys the channel. Thanks to the particularity described above

  above, in the first place, the burns on the walls of the tube 6 are eliminated (FIG. 1) thus raising the quality of the assemblies by pressing and, secondly,

  Residual voltage U2 (Figure 5) remains on the battery 10.

  This voltage can be used for producing the following pulses of electric current to reduce

  charging time and raising the efficiency of the

  operative part. In order to detonate the next electroexplosive cartridge 5 (FIG. 1), it is necessary to hand-close the electrode 4 of the electroexplosive cartridge 5

next in the row.

  The claimed method of pressing assembly

  Electroexplosion of the tubes is achieved by

  of the device produced according to the mode shown in FIG.

Figure 3 as follows.

  Before switching on the device,

  It is necessary to perform the calculations using the equa-

  (I), (2), (3), and to impose the required operating voltage U and to connect a required number of sections 9 of the capacitor bank 10 (FIG. 3)

at switch 2.

  The operator adjusts the threshold element 12 for the required operating voltage U1 and is connected by means of the control elements 281 to 28n (FIG.

  from the co-incidence circuit 29 to the outputs of

  decoders 271 to 27n decades so that the number chosen is equal to the number of pulses generated

  by the converter 25 of the angle of rotation, of the

  motor of the mechanism 17 during the displacement of the electrodes 4 (FIG. 3) at the distance equal to the pitch of the tube plate 7. For example, if the electrodes 4 are displaced by one step, the converter 25 (FIG. 4) generates one hundred twenty seven pulses, the first, second and third inputs of the coincidence circuit 29 are connected to the output of the code "seven" of the decoder 271, at the output of the code "two" of the decoder 272 at the output of the

  code "one" of the decoder 273 respectively and the others

  of the coincidence circuit 29 are connected

at the outputs of the code "zero".

  After putting the installation into operation, the

  the electrodes 4 (Figures 3)

  15 (Figure 2) of the first electroexplo

  5 (Figure 3) in the row and position the

  26 (Figure 4) to "0". At this time, if the voltage of the battery 10 (FIG. 3) has reached the required value U1 and the threshold element 12 has come into action, the logic element ET 24 also comes into action and the signal is

  sent through amplifier 13 and the uni-

  ignition tee 14 for the actuation of the spark gap 3 causing the explosion of the electroexplosive cartridges 5 2s 1 3 6 while the electrodes 4 continue to delaze to the next electroexplosive cartridge 5 in a corresponding row If at this time , the voltage of the battery 10 is less than the required value and the threshold element

  12 is not actuated, the logical element ET 23 is action-

  born and the switch 21 operates by disconnecting the

  the displacement mechanism 17 and the electrodes 4 stop. After the voltage U1 has reached the required value, the threshold element 12 is actuated. At this moment, in the first place, the logic element ET 24 is actuated and

  engages the spark gap 3 via the amplification

  13 and the unit 14 which causes the explosion of the cartridge 5, in the second place, the signal on the output of the AND logic element 23 disappears and, consequently, the second switch 21 is disconnected. At this time, the motor of the moving mechanism 17 starts and the electrodes 4 continue to move to the next electroexplosive cartridge 5 in the row. In the diagram, the two variants of

following operation.

  1. The charging time of the battery 10 is less than

  the time required for the movement of electro-

  4 from an electroexplosive cartridge 5 to the other cartridge 5 in the row. In this case, at the moment when the voltage U1 has reached the imposed value, the element of

  Threshold 12 (Figure 3) comes into action and the element is replaced.

  This element disconnects the charging circuit by means of

  second switch 20. At the moment when the

  electrodes 4 have moved closer to the cartridges 5, the

  step reader 18 sends the control signal of the

  at the first control input of the logic circuit 19. In this case, the logic element ET 24 operates in a similar manner to the case described above by causing

  the explosion of the electroexplosive cartridge 5, the bat-

  10 discharges, the signal of the threshold element 12 disappears on the second control input of the circuit

26 1366

  logic 19 and on the output of the logic element AND 22,

  the second switch 20 connects the power supply circuit

  Source 1 and the cycle starts again.

  2. The charging time of the battery 10 is greater than the travel time of the electrodes 4 from an electroexplosive cartridge 5 to the other. In this case, when the electrode 4 has approached the next cartridge 5, the signal is sent from the output of the step selector 18 while the threshold element 12 produces no signal at its output. In this case, the logical element ET 23

  is activated and the signal appears at its output, which

  snaps through the switch 21 the motor

  of the moving mechanism 17. The electrodes 4 stop

  and the charge of the battery 10 continues. At the moment when the voltage U1 has reached the imposed value, the element of

  threshold 12 comes into action, the signal appears on the

  control output of the logic circuit 19, accordingly

  firstly, the logical element ET 24 is ac-

  The control signal appears on the third control output and the electroexplosive cartridges 5 explode. In the second place, the signal disappears on the

  second control output of the logic circuit 19

  on the switch 21, while the electrodes 4

  continue to move towards the electroexplo

  next 5 in each row.

  In the case where the charge time of the bat-

  10 is equal to the travel time of the electrodes 4, the signals appear simultaneously on the inputs of

  control of the logic circuit 19, the element ET 24 of

  the action starts, the signal appears at the entrance of

  the amplifier 13 and the spark gap 3 is actuated.

  By using a threshold element 12 in this circuit and connecting it to the output of the voltage sensor 11, it is possible to determine the instant when the

  voltage reaches the required value UI.

  By using the logic circuit 19 in which

  the first control output is connected to the switching

  20, the second switch 21 and trcisiMrme, through the power amplifier 13 and the ignition unit 14, the spark gap 3, was successful, in the first place, to cut the circuit charging, if the battery 10 has been charged and the electrode 4 has not yet approached the electroexplosive cartridge, and, secondly, to stop the displacement of the electrode 4, if the electrode 4 has already reached the electroexplosive cartridge 5 and the battery 10 has not yet reached

  loaded. In addition, the functioning of the

  placement 17 is performed in the device shown

  in Figure 3 automatically while the

  made according to the first mode represented on the

  gure 1 requires the participation of an operator.

  The use of the device shown on the

  Figure 3 allows the automatic assembly of

  pressing by pressing the tubes 6 in the tube plates

  7 with the different steps and to ensure, at the time of the

  plosion of the electroexplosive cartridge 5, a voltage

service required.

EXAMPLE I

  With the aid of the device, implementing the claimed method (the voltage of the battery UI is 50 kV, the capacitance C of the battery 10 is 32 YF, the inductance L is 18 μH), it has been carried out the assembly by pressing of a tube 6, whose internal diameter D

  is equal to 13 mm. The surface of the section S of the conductor

  The aluminum explosive nozzle is 1.1 mm 2. The speed

  V propagation of the shock wave in the liquid is 1430 m / s. Then, the value of the D / V ratio is determined

D / V = 9 (ps).

  The duration T (Figure 5) of the explosion was de-

  completed by means of a contraction explosion according to a

  oscillogram. T = 20 s. Pulse duration was chosen

sits within the limits: D

= 0.8 to 1.2 (T + -> 0.8 to

1,2 (20 + 9) = 23.2 to 34.8 (juice).

  The battery 10 has eight sections 9. The battery

  The capacitance of each section 9 CI is 4.0 "F, which ensures the pulse duration of the electric current

= LC1 = 26.6 is. This value

  satisfies the conditions of the suppression of burns of the walls. So, in order to remove the burn on the tube

  6, connect a single section 9. If the duration of the

  pulse F goes beyond the limits _, D = 0.8 to 1.2 (T +) the current does not stop and the discharge channel does not deteriorate

  and, therefore, equation (I) of the claimed process

  the assembly by pressing the tubes by electroexchange

plosion is not fulfilled.

  For the control, the oscillogram was

process.

  The curves U, I on the oscillogram (FIG. 5) denote the voltage and the intensity of the electric current respectively. The section "CA" corresponds to the moment of the explosion of the conductor 15. The section "AB" corresponds to the moment when the shock wave approaches the limits of the discharge channel (we see the peak of tension resulting from

  increasing the resistance of the channel).

  U2 is the residual voltage of the battery 10

  after the interruption of the electric current.

  Using, in the process claimed for assembly by pressing tubes by electroexplosion,

  the electric power pulse, the duration of which is

  sine of the sum of the duration of the driver explosion

  and the quotient of the division of the diameter D of the tube,

  pressed assembly, by the speed V of the propaga-

  of the shockwave in the liquid, we succeeded in

  to satisfy the conditions under which the shock wave refi

  reaches the limits of the discharge channel at the moment when the electric current is close to zero and thus create the conditions necessary for closing the discharge channel

  and breaking the electric current in the circuit. This-

  This allows to separate the capacitor bank 10 after

  the formation of the first half-wave of the electric current

  by reducing the duration of the action of the plasma of the channel on the walls of the tube, thereby reducing the degradations, by raising the quality of the assemblies made. By adjusting the duration Z of the current pulse by means of the choice of the capacitance according to the ratio t2 rL, it is possible to vary, in wide ranges, the pulse duration L of the electric current without reconstructing the discharge circuit of the current. 'installation. Using,

  in the operative part implementing the procedure, the

  mutator 2 coupled between the source 1 and the spark gap 3 having

  circuit-breakers 8 connected to sections 9 of the bat-

  ter 10, we give the possibility to choose a capacity

  required battery 10 without changing the charging circuit.

  ment. The additional advantage of the process lies in that, approaching the charge channel, the shock wave compresses it while increasing its resistance (cf.

  section AB in Figure 2) and ensuring the slowdown

  the discharge of the battery 10 and the reduction of

the consumption of energy.

EXAMPLE 2

  The assembly is carried out by pressing a tu-

  be 6, whose inner diameter D is 13 mm.

  Capacitor battery capacitance C 10

  is equal to 32 yF (the capacity is not adjustable).

The inductance L is 18 pH.

  The area of the section S of the aluminum conductor 15 is 1.1 mm 2. The velocity V of propagation of the shock wave

in the liquid is 1430 m / s.

  I. We determine the value of the ratio V = 9 (ps) v 2. Using equations (2) and (3), we transform equation (I) by reducing it to:

S [U, -2/3 D

= () + -, and

L V

  it is solved with respect to the voltage U k3 / 2 L (Ur F = - D / V) 3/2 U1 is the required voltage applied to the battery 10

  which ensures the realization of equation (I) for a

  imposed on them the capacity C of the battery 10 equal to

32 PF.

  3. We find the value of the coefficient k for the aluminum conductor: k = 0.2thl / 3 d 4/3 for h = 0.92.1018 s. m d = 1.2 mm; k = 76.6 (J) 1/3 4. We find the UI value

3/2 3/2

U k L = (76.61 / 3) I8 = 22.3 (kV)

3 'L-D / V (3, I4 18.32 - 9) 3/2

  This value makes it possible to satisfy the equation

  (I) according to the claimed method, that is, the

  The moment T of the pulse of the current claimed will be such that, after the passage of the first half-wave of the electric current, the latter will be interrupted and, consequently, the burns on the walls of the tubes 6 will be eliminated.

  which ensures the improvement of the quality of the assemblies

  by pressing the tubes with a tube plate.

2613 6

Claims (4)

  1. Assembly method by pressing tubes by electroexplosion made by initiation of an explosion   of electroexplosive cartridges by a pulse of   electricity, the cartridges being housed in the ex-   tubes, characterized in that the initiation of the explosion of the electroexplosive cartridges (5) takes place   by a current pulse whose duration (t) is de-   completed using the following equation: D = 0.8 to 1.2 (T + V),   o T is the time of the explosion of the conductor (15) of the electroexplosive cartridge (5), ps, D is the inside diameter of the tube intended for assembly by pressing, m V is the speed of propagation of the wave of choc in the liquid, m / ps.   2. Device implementing the method con-   form according to claim 1, comprising, interconnected,   a source (I) of DC voltage, a battery of   densifiers (10) a spark gap (3) with an electrode (4) and electroexplosive cartridges (5), characterized in that it comprises a voltage sensor (II) connected to the battery (10), a threshold element (12). ) connected to the   sensor output (11) and connected in series with an ampli-   power supply (13) and an ignition control circuit (14) of the electro-explosive circuit, said circuit being connected to the control input of the spark gap   (3), a switch (2) and circuit breakers (8), the outputs   signaling elements of the switch being connected to the source (I) of DC voltage and the spark gap (3),   and in that the capacitor bank (10) is   independent sections (9) of the condensa-   connected in parallel with the switch (2) by the intermediate circuit breakers (8). 3z f z X6   3. Device according to claim 2, zarac-   characterized in that it comprises a logic circuit (19), --switches (20, 21), one (20) of the switches being connected via the signaling outputs to the source power supply; (I) DC voltage and through the control input to the first   control output of the logic circuit (19), the second of which   the control output is connected to the control input of the switch (22) kinematically connected to the electrodes (4), the third control output of the logic circuit   (19) being connected to the input of the power amplifier   (13), while the exit of the threshold element   (12) is connected to the first control input of the circuit cooked logic (19).   4. Device according to claim 3, characterized   characterized in that the logic circuit (19) comprises an element   AND (22) of the control of the battery charge.   capacitor field (10), an AND element (23) of the electrode displacement control (4) and an AND logic element (24) of the electroexplosive cartridge explosion initiation control (5) , whose direct input acting as the second control input of the logic circuit (19) is connected to the inverting input of the AND logic element (22) of the capacitor bank load control and to the direct input of the AND logic element (23) of the displacement of the electrodes (4), whose inversion input is connected to   the direct input of the logical element AND (22) of the com-   charge of the capacitor bank (10)   acting as the first entry of   logic and in that the outputs of the logical element   that AND (22) of the control of the loading, of the element   ET (23) of the control of the electro-   (4) and the AND logic element (24) of the   the initiation of the explosion of the electroexplo   sive (5) act as first, second and third   control outputs of the respective logic circuit (19) is lying.