RU1776521C - Device for generating laser radiation pulses - Google Patents

Abstract

The device relates to mechanical engineering, in particular to laser punching machines. The device makes it possible to obtain synchronization of the on / off times of the electromechanical shutter with the moments when the rotary slotted disk of the electromechanical modulator passes through the established reference positions, which are temporarily linked to the leading edges by a radiation pulse. This ensures that the shutter shutter moves during the overlap of the optical channel with the opaque part of the modulator disk. The device comprises a reference sensor 3, a position sensor 4, a synchronization device 5, consisting of an on-signal generating unit 6, an on-delay unit 7, a comparison unit 8, an off delay unit 9, and an output signal generating unit 10. 2 ill. L c

Description

FIG. 2

The invention relates to mechanical engineering, in particular to laser punching machines.

A laser pulse supply device is known, selected as a prototype, comprising a laser, an electromechanical modulator, an electromechanical shutter, control systems, a working head, a coordinate table (1).

The device does not provide the exact number of radiation pulses in the packet, and distortions in the duration and amplitude of the pulses are possible. This is because the shutter opens (and closes) at different angular positions of the modulator disk, and the shutter shutter movement can coincide in time with the radiation pulses and limit them in duration and amplitude.

An object of the invention is to expand technological capabilities.

Figure 1 shows graphs illustrating the operation of the device; figure 2 is a structural diagram of the device.

Continuous laser radiation is crossed by a high-speed rotating disk (cylinder) of an electromechanical modulator having openings for the passage of a beam. From the disk side facing the working head, the radiation has the form of periodically following pulses. Simultaneously with the modulator, impulses of a reference point Od.3 are issued. and the Udi position of the disk, the leading edges of which have a rigid temporal relationship to the leading edges of the radiation pulses. In the Pause mode, the optical channel is blocked by the shutter of the electromechanical shutter and radiation pulses are not supplied to the working head. By the command Filing, at the moment of the beginning of the next pulse IDZ, a pulse of turning on the shutter UBK is generated. The UBK pulse generates a shutter-start pulse 113at, which has a time delay of 1 backward VK, which enables the shutter to act so that the shutter moves in the interval between radiation pulses. This eliminates distortion in the duration and amplitude of the radiation pulses. The damper moves by a value of 5 Eat Df - the diameter of the laser beam. If the time Tset.input is shortened, then the influence of the second (from the origin of the reference) radiation pulse will be manifested, and if the t.del.input is increased, the third radiation pulse will be distorted. The time delay is set by the number of Udi pulses. After the shutter is opened, radiation pulses are supplied to the working head. Pulse UBx to close the shutter is formed by the command Pause

the pulse closest to it 1) df. Then, with a delay of 3v.output, a pulse U aan is generated, which ensures the backward movement of the shutter damper in a pause between

radiation pulses. The delay time is counted by the go pulses. The number of Go or impulses, as well as the time for giving the Pause command, are determined for each type of disk (cylinder) and their rotational speeds on the feeder and are entered in the form of codes into the control system. In this way, equality of amplitude, duration and number of pulses in packets is achieved.

5 The device comprises a laser 1, an electromechanical modulator 2, in the immediate vicinity of which a reference sensor 3 and a position sensor 4, a synchronization device 5, consisting of series-connected switching signal generating unit b, switching-on delay unit 7, and comparison unit 8 are arranged , node 9 delay off, node 10 of the formation of the output signal, the output of which

5 is connected to the electromechanical shutter 11, and the input is additionally connected to the output of the on-delay unit 7, the control system 12, the rotary mirror 13, the working head 14, the coordinate table 15 with the workpiece 16 laid on it, and the output of the control system 12 is connected the inputs of the nodes 6, 7, 8, 9 of the synchronization device 5 and the coordinate table drive 15, and the input with an electromechanical shutter 11, a sensor

5 3 is connected to nodes 6, 8, and the sensor 4 is connected to nodes 7 and 9.

The device operates as follows. Laser 1 produces continuous radiation, which, passing through

0 a constant-speed disk of an electromechanical modulator 2 is converted into a sequence of periodically following radiation pulses. From the reference sensor 3, pulses are sent to the synchronization device 5, the leading edges of which have a rigid temporal relationship to the leading edges of the radiation pulses. Pulses are received from the position sensor 4 to the synchronization device 5, the repetition period of which is several times smaller than the pulse repetition period from the reference sensor 3. In the Pause mode, the electromechanical shutter 11 is closed and the radiation of the laser 1 does not enter the working head 14. Controlled by control system 12, the coordinate table 15 with the workpiece 16 goes to the desired machining position. In the Feed mode, the control system 12 sends a command to the node 6 for generating an enable signal

opening the shutter 11. At the other input of the switching signal generating unit 6, pulses of the reference sensor 3 are received. On the leading edge of the pulse of the sensor 3, the first pulse after the command system 12 opens to open the shutter 11 is a pulse that is supplied to the on-delay unit 7. On the leading edge of this pulse, the on-delay unit 7 determines the countdown of the required number of pulses supplied to it from the position sensor 4. The required number of pulses is set by the control system 12. The number of pulses supplied from the position sensor 4 determines the required delay time of the shutter-on signal 11. The required delay value is determined experimentally for various types of disks and different speeds of their rotation. This data is entered into the control system 12. The criterion is the condition for the shutter shutter to move in a pause between radiation pulses. After counting the required number of pulses, the on-delay unit 7 provides a signal to the output signal generating unit 10 and to the comparison unit 8. The output signal generating unit 10 includes a shutter 11 and provides a signal to the control system 12 about this. The radiation of the laser 11 through the rotary mirror 13 is fed into the working head 14 and, focusing on the surface of the workpiece 16, performs processing (for example, drilling holes, etc.). The comparison unit 8, starting from the moment of arrival of the pulse from the on-delay unit 7, counts the number of radiation pulses supplied to the working head 14 from the pulses of the reference sensor 3.

Upon reaching the amount set by the system 12, control their number

N Mzad - K,

where Mzad is the number of pulses of laser radiation that must be passed through the shutter;

K is an integer depending on the type of modulator disk and its rotation speed (established experimentally)

The comparison unit 8 provides a signal to the turn-off delay unit 9, which operates similarly to the turn-on delay unit 7. After counting the required number of pulses from the position sensor 4, the off delay unit 9 provides a signal to the output signal generating unit 10, which turns off the shutter 11. The arrival of radiation pulses to the working head 14 is stopped. Next, the cycle repeats.

The use of a laser pulse supply device makes it possible to expand the technological capabilities of laser systems, since it provides the supply of radiation pulse packets containing the exact number of pulses, following with a high repetition rate and having a short duration, without distorting their duration and amplitude.

Claims (1)

The claims A laser pulse supply device comprising a laser, an electromechanical modulator, an electromechanical shutter, a working head, a control system connected to a coordinate table, characterized in that, in order to expand technological capabilities, reference sensors and position sensors are inserted into it, connected in series to the unit the formation of the enable signal, the on-delay unit, the comparison unit, the off-delay unit and the output signal generating unit connected to the electromechanical shutter the input and the control system, the outputs of which are connected to the second inputs of the nodes of the formation of the enable signal, the delay on, comparison and delay off, the second input of the node of the formation of the enable signal and the third comparison input are connected to the pin of the reference sensor, the third inputs of the delay and enable nodes are connected by a position transmitter, the output of the on-delay unit is connected to the second input of the output signal-forming unit, the reference and position sensors are connected to the electromechanical modulator. Displacement per / l # 00a Phys. 7