JPS63207485A - Method for controlling pulse laser suitable for dull roll working by plural q switching lasers - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for the pulse waveform of a Q-switched laser used for dulling a roll using laser light.

[Conventional technology]

Roll dulling methods include shot blasting, electrical discharge machining, and a method of processing the roll surface using a laser. Japanese Patent Publication No. 58-25557 describes a device for dulling the surface of a roll using a laser.

It was announced by Special Publication No. 60-2156. Tokuko Showa 6
The device No. 0-2156 is a device that uses a light source such as a YAG laser or a ruby laser to generate a pulsed laser using a Q switch to dull the roll surface.

In the dull processing of rolls, the predetermined frequency, pulse width,
It is necessary to perform periodic processing on the roll surface using a pulsed laser with a peak value or the like. There are two ways to obtain such pulsed laser output: one is to pulse continuous wave (CW) laser output using a mechanical optical device (chopper, shutter, etc.), and the other is to use a pulsed laser such as pulse excitation or Q-switch pulse. be.

Since the Q-switch pulse does not require mechanical equipment, it has the characteristics that the equipment can be made smaller and simpler than the former, and at the same time, frequency control is easy and the control range is wide.

However, when the Q switch changes the frequency, the oscillation excitation conditions change, so the pulse waveform, peak output, etc. change simultaneously, making stable dull processing impossible. Furthermore, as shown in FIG. 2, the peak value (Pl) of the leading pulse becomes extremely larger than the subsequent pulses (P21Par P4...).

Also, Japanese Patent Publication No. 60-2156 does not disclose any solutions to the above-mentioned disadvantages.

[Problem that the invention seeks to solve]

If the peak values of the pulse train differ greatly, the first pulse P1
Since the depth of the protrusion is determined by , the effect of P2 to P4 becomes small, and the controllability as a comprehensive pulse group is not good, so this problem needs to be solved.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention combines a laser beam group using a plurality of Q-switched lasers and a Q-switched control system, and controls the Q-switching time and the pulse peak value of each laser. The present invention provides a pulsed laser control method suitable for dull roll processing, which is characterized by configuring a pulse group suitable for surface dull processing. 4 Below, the method related to the present invention will be explained using the drawings.

FIG. 1 shows the basic configuration of the pulsed laser control device of the present invention when the number of pulses is four. 08C1 to 03C4 are laser oscillators. QSI to QS4 are Q switches and 03
It is set to C1-08C4. 10 is a Q switch control system, from which Q switch signals Q1 to Q4 are sent out, and from 08C1 to 08C4, the laser beam LBI is
~LB4 occurs. Laser beams LBI to LB4 are combined into a parallel laser beam group LBP by bending mirrors M1 to M7 and combining mirrors TMI to TM3. The laser beam group LBP is condensed by the condensing lens FL, and becomes a condensed laser beam group LFP at the condensing point FP as if one laser beam were condensed. 20
is the surface of the roll to be processed. Figure 1 shows an example of four laser beams, but the number can be any number.As the number increases, the depth of the hole increases almost linearly, meeting the required quality of the roll surface roughness for dull processing. You will also need to select the number.

Figure 3 shows the ideal pulse waveform when performing rolled dull processing, where τ0 is each pulse width, and τ1 is the leading pulse PLI.
and the second pulse PL2, τ2 is the same at this PL
2 and PL3. As shown in Figure 3, the ideal pulse waveform suitable for rolled dull processing is PL1=PL2
=-=PLn and τ1=τ2=...=τn-1.

A specific control circuit of the Q-switch control system 10 is shown in FIG. 4, and the time relationship of control signals is shown in FIG.

Fig. 4 is composed of a pulse generator PG that determines the frequency fO of the pulse group, and one-shot multivibrators OMI to OM4 that determine the pulse intervals 1 to τ3 within the pulse group. ○M1 to OM4 are synchronized at the rising edge of each input signal.

That is, the output signal fO from the pulse generator PG is
Input to MI clock CK1. As a result, the pulse width τ1 set by OMI is synchronized with the rising signal of fo.
The pulse Q1 of Q1 is generated, and at the same time, a signal signal with the opposite polarity to Ql is outputted and inputted to the clock CK2 of 0M2, and by the same action, Q2. Qz occurs. 0M3,0M4
The same applies to

As mentioned above, the frequency fO of the pulse group for dull processing is P
G is set, a pulse group is generated with a certain time delay in synchronization with the leading signal, and it becomes possible to implement Q switch control of LBI to LB4.

〔Example〕

Using the method according to the present invention, pulse waveform control of four Q-switched lasers was performed to perform rolled dull processing.

The pulse waveform control conditions of the Q-switched laser are as follows.

τINτ4: 5μ5 LBI-LB4: 2kw f (1: 20kHz FL: 25nn As a result, the hole shape has an inner diameter of 100μm and a roughness value of 2.2μ
m dull processing, and the transfer rate to the steel plate is as high as 80%.
Wear resistance has also been improved 6 [Effect of the invention] Since the peak value can be set for each pulse in the pulse group, it is possible to control the melting and evaporation phenomena of the irradiated object during the drilling process for surface roughening, and to obtain the appropriate hardness. A hole can be formed. Also, since the pulse interval of the pulse group can be controlled,
Furthermore, it is possible to perform hole machining suitable for dull machining, which is highly effective.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a pulsed laser output device according to the present invention, and FIG. 2 is a waveform diagram showing the state of laser output of a pulse group using a Q switch. FIG. 3 is a waveform diagram showing the output state of the pulse group according to the present invention, FIG. 4 is a block diagram showing a specific control circuit of the Q-switch control system, and FIG. 5 is a timing chart showing the time relationship of control signals. . 10: Q switch control system 20: Surface of processed roll osct~05C4: Laser oscillator 05I~QS4: Q switch old~M7: Bending mirror TM
I~TM3: Synthetic mirror FL: Condensing lens LBI~
LB4: Laser beam LBP: Laser beam group FP: Focusing point LFP: Laser focusing beam group PG: Pulse generator OM1 to OM4: One-shot multivibrator 2
■Taku 3 times

Claims (1)

[Claims] In a device that dulls the surface of a roll using a Q-switched laser, multiple Q-switched lasers and laser beams oscillated by a Q-switch control system are combined into a laser beam group, and the Q-switch time of the laser beam group is sequentially controlled. A plurality of Q switches characterized in that the pulses of each laser are delayed to form a pulse group with intervals, and the pulse peak value of each laser is controlled to a predetermined value to form a pulse group suitable for dulling a roll surface. A pulsed laser control method suitable for laser dull roll processing.