SU1683937A1 - Pulsing laser installation for material treatment - Google Patents

Abstract

The invention relates to laser processing of materials. The purpose of the invention is to improve the quality and productivity of laser processing and simplify installation. The installation consists of throttles, charge and discharge thyristors, a capacitive storage device, a pulse transformer, a pump lamp, and an optical path. The installation also contains a thyristor control circuit, a pilot arc unit and an ignition unit. Using a resistor divider, the network voltage is fed to the input of the control unit, which generates thyristor control signals. In the positive half-cycle of the mains voltage, the input thyristor opens and the capacitive drive is charged, and in the negative half-period the output thyristors, which discharge the capacitive drive to the lamp, are charged. The installation improves processing performance by introducing a frequency of 50 Hz, simplifying the circuit by eliminating a synchronizing transformer and reducing the number of communication lines, 1 Cp. 2 Il. C / i

Description

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The invention relates to mechanical engineering and is intended for laser processing of materials.

The purpose of the invention is to improve the quality and performance of laser processing, as well as simplify installation.

FIG. 1 shows a functional diagram of a technological pulsed laser installation; in fig. 2 is an electrical circuit diagram of a control unit.

The installation contains series-connected choke 1, charge thyristor 2, capacitive drive 3, diode 4, connected to two phases of the supply mains, connected in series first

discharge thyristor 5, pulsed ignition transformer 6, pumping lamp 7 installed in quantron 8, illuminating crystal 9 and second discharge thyristor 10, protective capacitor 11, ignition unit 12, thyristor control unit 13, optically coupled unit 14 the reflecting mirror 15, the lens 16 and the product 17, in series connected resistors 18 and 19 of the voltage divider.

The on-duty arc unit is connected by the input to the three phases of the mains supply, and the output to the series-connected pumping lamp 7 and a pulse transformer 6

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The first 20 and second 21 inputs of control unit 13 are connected in parallel to resistor 19, the first 22 and second 23 outputs are connected to the control input of charge thyristor 2, the third 24 and fourth 25 outputs are connected to the control input of the second discharge thyristor 10, and the fifth 26 and sixth 27 outputs - to the control input of the first discharge thyristor 5.

The control unit 13 (FIG. 2) contains the first capacitor 28 connected between the plus and minus power, an additional voltage divider including resistors 29 and 30, resistors 31-36, second 37, third 38 and fourth 39 diodes, second 40, third 41 and fourth 42 capacitors, comparator 43, first 44 and second 45 flip-flops, the first differentiating circuit 46, the first amplifier 47 and the first isolation transformer 48, and the second differentiating circuit 49, the second amplifier 50 and the second crying tran formator 51, variable resistor 52, a switch 53, consisting of the first four-off 54, second 55, third 56, fourth 57 and buttons 58 counter- decoder.

The closing contact of the first button 54 is connected to the power supply minus, the opening contact is connected to the power supply, the switching contact is connected to the input of the second capacitor 40, the output is connected to the eighth resistor 34 and the cathode of the second diode 37 connected by an anode to the R-input of the counter-decoder 58 and through the ninth resistor 35 with the C-inputs of the first 44 and second 45 flip-flops, and the combined second switching contact of the second button 55, the second switching contact of the third button 56, the first and second switching contacts of the fourth button 57, closing the contact of which is connected to the output 1 of the counter-decoder 58, the output of which is connected to the C-inputs of the flip-flops 44 and 45 through the serially connected first closing contacts of the second 55, third 56 and fourth buttons, output 2 - with the closing contact of the third 56 buttons, output 4 - with the closing contact of the second button 55.

The output of the comparator 43 is connected to the synchronizing C-input of the counter of the decoder 58. The phase-shifting chain of the first trigger 44 contains parallel-connected variable resistor 52 and the third diode 38 connected to the forward output of the first trigger 44 and its R-input, to

to which the third capacitor 41 is connected to the power supply minus, and the phase-shifting circuit of the second trigger 45 includes the tenth resistor 36 and the fourth diode 39 connected in parallel, connected to the non-inverting output and the R-loop of the second trigger 45, to which the fourth capacitor 42 is connected to the power supply minus. works as follows.

The power supply is connected to a three-phase network of 380 V / 50 Hz. Throttle 1 limits current surge. In the positive half of the sinusoidal voltage half-period (between phases A and C) the control thyristor 2 is turned on by the control circuit, as a result of which the capacitive storage 3 is charged.

charge voltage on the capacitive drive 3. A diode 4 is used to decouple the charging device from the standby arc unit 14. In the negative half-period of the mains voltage, when the charge thyristor 2 is closed, discharge thyristor 5 is turned on by a control electrode, and the capacitive drive 3 through the secondary winding of the pulse transformer 6 is discharged to the pump lamp 7, which

installed in the quantum 8 and illuminates the crystal 9. At the end of the capacitive storage, the discharge thyristor 5 is closed.

For galvanic uncoupling of the capacitive drive 3 from the duty arc unit 14, a discharge thyristor 10 is included in the circuit, which is turned on simultaneously with the discharge thyristor 5. To protect the discharge thyristors from the action of a firing pulse, a protective capacitor 11 is used. pumping. During its operation in the secondary winding of a pulse transformer

6, a high voltage pulse is generated, which is applied through the protective capacitor 11 to the pump lamp 7 and punches it. To control the charge 2 and bit 5 and 10 thyristors, the unit serves

13 controls To maintain the pumping lamp 7 in working condition in the interval between the discharge pulses at the output of the quantron 8 through the optically stressed parts — the reflecting mirror 15 and the focusing lens 16 — leads to the place of processing the product 17. Through the resistor divider 18-19, the inputs 20 and 21 of the control circuit, the input mains voltage is applied, as a result of which the thyristor control signals 22 and 23 are generated and the thyristor control signals 24 and 27 5 and 10 are generated.

The control unit 13 (Fig. 2) operates as follows.

The mains voltage is fed to the inputs 20 and 21 of the control unit 13, in parallel with which a protective capacitor 28 is connected, which reduces the penetration of impulse noise to the input of the electric circuit. Resistors 29 and 30 set the midpoint relative to which the input voltage is applied to the input of the comparator 43 through resistors 31 and 32. The resistor 33 together with the resistor 32 is turned on in such a way that the comparator 43 is turned on according to the scheme of the threshold element - Schmidt trigger. By varying the values of resistors 32 and 33, the trigger threshold of the Schmidt trigger can be varied. Resistor 31 serves to eliminate bias from the comparator input currents. The resistor 31 is chosen equal to the sum of the resistances of the resistors 32 and 33 connected in parallel. From the output of the threshold element, square impulses with steep fronts arrive at the synchronous input C of the decoder counter 58. Pushbutton switch 53 can be used to set the division factor of the counter decoder 58. In this case, at the output of the chip, frequencies of 12.5 Hz (button 55), 25 Hz (button 56) and 50 Hz (button 57) can be heard.

Button switch 53 contains only 5 buttons. Buttons 55-57 are dependent fixed, and button 54 is independent non-fixable. An additional fifth reset button (not shown) is electrically not connected anywhere, but mechanically associated with buttons 55-57. If it is necessary to generate a single pulse by pressing the reset button, the buttons 55-57 are reset to the initial position indicated in FIG. The chain of a single start form the elements 24, 35, 37-54. In the initial state, the output O of the counter-decoder 58 through the closed contacts of the buttons 55-57 and the ninth resistor 35 is fed to the reset input R, resulting in a feedback circuit and the counter-decoder 58 does not change its state Independently of the signals at its input C. When you press the knuckles 54 One, through the differentiating chain 40 and 34, a short pulse arrives at the input R, which breaks the feedback circuit, as a result of which a single pulse is generated at the output of the counter-decoder 58.

After the appearance of the signal at the output O of the counter-decoder 58 reverse circuit

it closes again, and the decoder 58 enters a static state. The diode 37 serves to protect the input R of the counter-decoder 58 from overload on the side of the differentiating chain. On the positive fronts of the pulses generated by the counter-decoder 58, single-oscillators collected on EC triggers 44 and 45 are triggered. Since in the initial state level 1 triggers arrive at trigger 3, then when the positive edge arrives at input C on the direct outputs of triggers 44 and 45 stresses corresponding to logical 1 appear.

Through the resistor 52, the charge of the capacitor 41 begins. When the voltage across it reaches the actuation level of the reset input R, the level O is established at the forward output of the trigger and the capacitor 41 begins to discharge. A diode 38 is used to speed up the process. The pulse duration depends on the nominal value of parts 41 and 52 and it determines the delay time. At the same time, the trigger 45 works in a similar way. Through the inverse outputs of the triggers 44 and 45, the pulses pass through the differentiating chains 46 and 49, respectively, which produce short pulses. Their duration is chosen sufficient to include thyristors 2,5,10. These pulses are amplified in amplifiers 47 and 50 and transmitted through transducer transformers 48 and 51 to control electrodes of the thyristors 2,5,10. On outputs 22 and 23, charge thyristor 2 is controlled and the selection of the capacitor 41, the resistor 52 selects the delay time, such that the output pulse is generated in the second half of the non-positive half-cycle of the mains voltage.

Resistor 52 can change the time of generation of control pulses, and hence the charge voltage of capacitive storage 3. From the outputs 24 and 25, 26 and 27, the pulses go to the control electrodes of the discharge thyristors 5 and 10. The nominal parts 42 and 36 are selected Thus, the discharge control pulses fall on the negative half-period of the mains voltage.

The invention allows to improve the quality, productivity of laser processing, to simplify the method of setting up a laser installation.

Claims (2)

1. An impulse laser machine for processing materials containing a choke, a charge thyristor, a first discharge thyristor, an ignition transformer, a pumping lamp, a second discharge thyristor and a capacitive drive connected to the cathode of the charge thyristor in series with one phase of the mains supply. , parallel to the ignition transformer and the pump lamp are included a protective capacitor and a pilot arc unit, the inputs of which are connected to the phases of the supply network, as well as the thyristor control unit, six outputs They are connected to control inputs and cathodes, respectively, of charge and discharge thyristors, characterized in that, in order to improve the quality of laser processing performance, as well as to simplify the installation, it is equipped with a diode and voltage divider connected by a single output to the charging anode The other is connected to the second phase of the mains supply, the cathode of the diode and the first input of the thyristor control unit vn, the second input of which is connected to the middle output of the voltage divider, the diode anode is connected to the cathode of the second discharge thyristor. 2. Installation according to claim 1; I differ from the fact that the thyristor control unit contains parallel to its inputs a first capacitor, an additional voltage divider connected between the plus and minus power, six resistors, the second, third and fourth diodes, the third and fourth capacitors, comparator, the first and second triggers, the first differentiating circuit connected in series, the first amplifier and the first isolating transformer, as well as the second differentiating circuit connected in series, the second amplifier of the second discharge A transformer, a variable resistor, a switch consisting of four two-position first, second, third, fourth buttons, as well as a decoder counter, the closing contact of the first button connected to the power supply minus, the breaking contact with power plus, the switching contact with one the output of the second capacitor, the second output connected through the first resistor with the power plus and the cathode of the second diode connected by the anode to the input of the counter-decoder and through the second resistor to the C inputs of the first and second trigger Ers and the combined second switching contact of the second button, the second switching contact of the third button, the first and second switching contacts of the fourth button, the closing contact of which is connected to output 1 counter-decoder, the output of which is connected to the C-inputs of flip-flops via serially connected first closing contacts of the second, third and fourth buttons, output 2 - with the closing contact of the third button, output 4 - with the closing contact of the second button, the output of the comparator is connected to the synchronizing C - input of the counter-decoder, phase-shifting chain of the first trigger, the parallel connected variable resistor and the third diode are connected to the forward output of the first trigger and its R input, which is connected through the capacitor to the power supply minus, and the phase shifting chain of the second trigger connected in parallel to the third resistor and the fourth diode is connected to the noninverting output and The R input of the second trigger, which is the fourth capacitor, is connected to the power supply minus, the comparator’s output through the fourth resistor is connected to the fifth resistor and the comparator's forward input, reverse to od which is connected through a sixth resistor to The first input of the block, the secondary output of the additional voltage divider, is connected to the fifth resistor and the second input of the block; the outputs of isolating transformers are connected to the outputs of the block. go Cvj OO -e1ge