JPH0585274B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a laser processing apparatus, and particularly to a structure for obtaining pulsed laser light optimal for laser processing.

[Conventional technology]

To operate this type of conventional apparatus, an operator sets a laser output value to a predetermined value depending on the object to be processed.

In order to set this output value, various factors such as the average output value of the laser beam, pulse frequency, pulse width, and machining speed must be set each time depending on the workpiece.

[Problem that the invention seeks to solve]

With conventional equipment, operators set the various factors of the laser processing device to predetermined values for each workpiece based on their experience and intuition, so once the various factors are set, the predetermined energy value is maintained during processing. Processing had to be done with a sluggish pulsed laser beam from start to finish, making it impossible to deal with changes in the machined area or the effects of external disturbances, making it difficult to obtain good finishing accuracy. .

The present invention has been made to solve the above-mentioned problems, and it is possible to set the laser output according to the workpiece and to emit laser light with an optimal energy value without being affected by disturbances during processing. The objective is to obtain a laser processing device that can process by irradiating.

[Means for solving problems]

The present invention provides means for determining the pulse frequency of the pulsed laser beam according to the processing speed of the workpiece, and also optimizes the energy value of the pulsed laser light based on data values such as the material and plate thickness of the workpiece. A laser processing apparatus is constructed by providing a control means.

[Effect]

According to the present invention, an operator can determine the material of the workpiece,
By setting data values such as plate thickness and machining speed, it irradiates pulsed laser light with the optimal energy value for machining, and also automatically corrects and controls the energy value in response to the effects of external disturbances. This enables superior machining in terms of energy savings.

〔Example〕

The present invention will be explained below based on the embodiment shown in FIGS. 1 and 2. The figure is a configuration diagram showing the main parts of the laser processing apparatus according to the present invention.
is the machining speed command signal V _f of the workpiece (Fig. 2 a)
is input, the machining speed command signal V _f is integrated by an integrating circuit using the operational amplifier circuit IC ₁ , and when this integrated voltage reaches a certain voltage, the N-gate thyristor conducts and generates a pulse to control the machining speed. Convert it to a pulse frequency and convert it into a pulse frequency command signal V ₂
(Figure 2 c) V/F conversion circuit outputs as 2
is input as the output setting command signal V _P that commands the setting of the output value of the pulsed laser light according to data values such as the material and plate thickness of the workpiece, and this input signal and the output feedback amount signal V _PF of the output laser light are input. When _the output feedback amount _is larger compared to
constant output arithmetic circuit equipped with a comparator that increases and outputs a constant output value signal |V ₃ | when |V 3 |
4 is a pulse generation circuit which outputs a pulse output signal by inputting the frequency command signal V ₂ of the V/F conversion circuit 1 as a set signal of the flip-flop and resetting the flip-flop with the output voltage V ₆ of the pulse width control circuit 4; receives the pulse output signal V ₄ (Fig. 2 e) from the pulse generation circuit 3 and receives the triangular wave signal V ₅ (second wave signal) having a constant rising time constant.
This is a pulse width control circuit which generates the signal _shown in FIG. In this way, the pulse generated in the pulse generation circuit 3 by inputting the reset signal from the pulse width control circuit 4 is controlled to have a predetermined pulse width, and is outputted from the pulse generation circuit 3 as a pulsed laser beam having a predetermined energy value. It is configured to

To explain the case of cutting a steel plate using the laser processing device having the above configuration, the cutting speed of the steel plate is input to the V/F conversion circuit 1 as a cutting speed command signal V _f , and the material, thickness, etc. The data value is input to the constant output calculation circuit 2 as the output setting command signal V _P. Then, V/F conversion circuit 1
is output to the pulse generation circuit 3 as a pulse frequency command signal V ₂ corresponding to the cutting speed. This signal V ₂ is inputted as a flip-flop set signal, generates a pulse in the pulse generation circuit 3, and controls the pulse width. A pulse output signal V ₄ is output to the circuit 4. This output signal V ₄ becomes a triangular wave signal V ₅ in the pulse width control circuit 4, and is sent to the flip-flop of the pulse generation circuit 3 as a reset signal in response to the constant output value signal V ₃ inputted from the constant output calculation circuit 2. The pulses generated by the pulse generation circuit 3 are irradiated onto the steel plate as a rectangular pulsed laser beam whose energy is controlled to a predetermined energy value, thereby cutting the steel plate. Also, at this time, the pulsed laser beam sends an output feedback amount signal to the constant output calculation circuit 2.
It is fed back as V _PF , compared with the output setting command signal V _P by the constant output calculation circuit 2, corrected to the optimal energy value for cutting the steel plate, and sent as a constant output value signal |V ₃ | to the pulse width control circuit 4. It will be sent to

Furthermore, it is clear that the machining speed command signal V _f may be a machining speed setting signal from a variable resistor or the like, or a machining speed feedback signal from a tachogenerator or the like.

Further, the configuration of each circuit is not necessarily limited to the above embodiment, and it goes without saying that the same effect can be achieved as long as the circuit has the same function.

In the above embodiment, the laser output is fed back, but the discharge current may also be controlled.

〔Effect of the invention〕

As described above, according to the laser processing apparatus according to the present invention, the operator inputs data values such as the material and plate thickness of the workpiece,
If you set the machining speed, the workpiece will always be irradiated with a pulsed laser beam that is set to the optimal energy value and a constant pulse frequency that corresponds to the machining speed without being affected by disturbances, regardless of the machining speed. It is possible to maintain a constant machining accuracy at all times, and to achieve excellent energy saving effects.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a main part of a laser processing apparatus according to the present invention, and FIG. 2 is a diagram showing output voltage waveforms from each element. In the figure, 1 is a V/F conversion circuit, 2 is a constant output calculation circuit, 3 is a pulse generation circuit, and 4 is a pulse width control circuit.

Claims (1)

[Scope of Claims] 1. A laser processing device that processes a workpiece by irradiating laser light as a pulse wave, comprising: a frequency command means for determining and commanding a pulse frequency based on a processing speed of the workpiece; a material of the workpiece; A constant output setting means for calculating and setting the output value of the laser beam based on data values such as plate thickness, and a command from the frequency command means and a command from the constant output setting means to keep the laser output per pulse constant. 1. A laser processing device comprising: pulse control means for controlling a pulse frequency and an output value (average value) of a laser beam in response to changes in processing speed. 2. The laser processing apparatus according to claim 1, wherein the frequency command means is configured as a V/F conversion circuit. 3. Claim 1, characterized in that the constant output setting means includes a comparator that compares a feedback signal of the laser output value with a calculation output according to the workpiece to correct and control the laser output value. The laser processing device according to item 1 or 2.