JPS59215291A - Laser working device - Google Patents

Abstract

PURPOSE:To provide a titled device which performs always uniform laser working in laser working which guides laser light or an object to be worked with a motor by controlling the laser input energy per unit length of a working locus by the change in the guiding speed. CONSTITUTION:A laser oscillator 1 emits laser light according to the instruction of a numerical control device 2 and motors 5, 6 guides an object 12 to be worked in X-Y directions so that the work 12 is subjected to prescribed working. The working speed changes with the working locus; said speed changes largely particularly in the small radius part or angle part. A pulse width modulator 22 controls the pulse width of laser light according to the speed change signal from encoders 20, 21 to maintain the specified laser input energy per unit length of the locus. The laser working is thus accomplished always with good sectional accuracy. Laser power may be controlled in place of controlling the pulse width.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a pulse-operable or continuous-oscillation-only laser processing apparatus for processing workpieces such as cutting and welding.

[Technical background of the invention]

In general, laser processing equipment uses a numerical controller (NC) to control a radar beam moving device f driven by motors on one, two, or often three or more axes to move the workpiece.
Processing is carried out by concentrating and moving a laser beam on the top. In other words, conventional laser processing equipment is
), where (, ) is the workpiece moving type, and (
b) is a beam moving type. In the figure, 1 is a Radhe oscillator, 2 is a numerical controller, 3 is an X-axis motor driver, and 4 is a Y-axis motor driver.
axis motor driver; 5 is an X-axis drive motor; 6 is a Y-axis drive motor; 7 is an X-axis moving table; 8 is a Y-axis moving table;
9 is a beam bender (mirror), 1o is a laser beam, 1
12 is a condensing lens, 12 is a workpiece, 13 is a fixed table, 14, 15, 16 is a beam bender, 17.
18 is a feeding mechanism, and 19 is an XY scanner.

[Problems with background technology]

The above-mentioned conventional laser processing device uses motors 5 and 6, so when the laser beam laser moves onto the workpiece 12, whether it is a workpiece movement type or a beam movement type, the motor-specific The characteristics of That is, motor 5,
6 always takes a certain amount of time when it rises from zero rotation to a predetermined rotation speed, and when it falls from a predetermined rotation speed to zero rotation. So-called slewup.

There is a slew down time.

Conventionally, in both continuous wave (hereinafter abbreviated as CW) and laser beam lasers, information on the moving speed of the laser beam on the workpiece 12 is not fed back to the laser output, and ozone luzo processing is performed. Ta. As a result, the following problems occurred during processing. That is, when processing a figure made of a laser capable of pulse operation, if we consider processing a block c1 of the figure, the numerical control device 2 controls the processing table (in the case of a moving workpiece type) or the beam scanner. (for beam moving type) 1
A block movement command is given using information such as movement position, movement distance, movement speed, etc. Further, a command is given to the laser oscillator 1 from the numerical control device 2 or manually to output a laser beam with a fixed output, a constant number of pulses, and a pulse width. When processing the workpiece 12 in this way, the rising and falling slew of one block
In the portion corresponding to the up and slew down times, the moving speed of the laser beam on the workpiece 12 becomes lower than a predetermined value, and a constant amount of energy (heat) per unit time is applied thereto.
D.
The disadvantage was that R-stage processing was not possible.

[Purpose of the invention]

The object of the present invention is to supply laser energy to a workpiece per unit length of the laser beam trajectory on the workpiece.
It is an object of the present invention to provide a laser processing device that can uniformly process workpieces of various materials and shapes even if they are processed at various speeds through controlled or constant processing.

[Summary of the invention]

The present invention provides a laser beam moving device driven by a motor with one axis or two or more axes, or a laser processing device that processes a workpiece with a laser beam using a workpiece moving table. This is a laser processing device that can controllably change a laser beam in accordance with changes in relative movement speed (or beam speed instruction signal) above.

[Embodiments of the invention]

In the above conventional method, as mentioned above, even though the laser beam movement speed (travel distance per unit time) on the workpiece is not constant in some parts during processing, a constant amount of energy is transferred from the laser beam per unit time. The material is supplied to the workpiece and ends up being damaged. Therefore, in this invention, as described above, the pulse width of the laser beam is varied (or the pulse width of the laser beam is kept constant and the number of pulse repetitions is varied depending on the material, shape, and processing speed of the workpiece). The aim is to process workpieces of various materials and shapes uniformly at various speeds by performing processing such as cutting and welding (or while changing the output power of the laser beam).

First, the case of changing the 7617 width of the laser beam will be described. The radar processing apparatus of the present invention is constructed as shown in FIG. 2, and the same parts as in the conventional example (FIG. 1) are given the same reference numerals. In this figure, a workpiece table driven by numerically controlled X and Y two-axis DC servo motors is used as a laser beam moving device, and the laser beam is focused and irradiated onto the workpiece on the workpiece table. This is an example of cutting by cutting.

That is, the laser oscillator 1 is connected to a numerical control device (NC) 2, and this numerical control device 2 is connected to an X@ drive motor 5, which is a DC servo motor, via an X-axis motor driver 3, and a Y-axis motor. DC source via driver 4
It is connected to an X-axis drive motor 6 which is a motor. A Y-movement table 8 is provided which is driven by the X-axis drive motor 6 and is movable in the Y-axis direction. A moving table 7 is provided, and a workpiece 12 is placed on the X moving table 7. A condenser lens 11 is arranged above the workpiece 12 at a predetermined interval, and above the condenser lens 11,
A beam bender (mirror) 9 is provided at a position corresponding to the laser oscillator 1. Furthermore, in this invention, the above X
An X-axis encoder 20 and a Y-axis encoder 2 are attached to each axis of the axis drive motor 5 and the X-axis drive motor 6, respectively, and both encoders 20 and 21 are connected to a pulse width modulator 22. This pulse width modulator 22 is connected to the laser oscillator 1. A schematic block diagram of the functions of the pulse width modulator 22 is shown in FIG. 3, and a timing chart of the laser processing apparatus of the present invention is shown in FIG.

Now, during operation, the X-axis drive motor 5 and the X-axis drive motor 6
A laser beam moving device, that is, an X moving table 7 and a Y moving table 8 driven by
Change the angle of o by 90° with the beam bender 9 and attach it to the condenser lens 1.
The light is focused on the workpiece 12 and moved to perform processing.

At this time, in the present invention, the laser beam moving speed (or planned laser beam moving speed) on the workpiece 12 is detected, and the laser pulse width is changed in accordance with the change in the laser beam moving speed. That is, the number of repetitions of the laser pulse is kept constant, the pulse width is widened when the laser beam movement speed is fast, and the pulse width is widened when the laser beam movement speed is slow.
Narrow the loop width. As a result, the laser energy per unit length of the laser beam locus on the workpiece 12 is controlled or shifted.

To explain in detail, first, the speed signals in the X and Y axis directions are
The signals are inputted from the axis encoder 20 and the Y-axis encoder 21 to the pulse width modulator 22 as signals Vx and y. These signals are detected only during the period of the sample signal synchronized with the laser pulse in the sample signal, and are held until the next sample signal arrives. These retained signals V
x, VY are processed by "=VX2..4-V, 2-no operation, and further processed by W=, -V + 2, and output as an ie pulse width signal. In addition, K ,
, 2 is a positive constant. As described above, the laser beam moving speed (N) is converted into a pulse width signal proportional to it (+offset signal), laser pulse width modulation is performed, and the unit length of the laser beam on the workpiece 12 is changed. The laser energy can be kept constant.

Next, regarding the case where the number of pulse repetitions of the laser beam is changed, the laser beam movement speed (or the laser beam planned movement speed) on the workpiece 12 is detected, and the change in the laser beam movement speed is responded to. and laser par.
Change the number of repetitions of the loop. That is, the Rade pulse width is kept constant, and when the Rade beam movement speed is high, the number of repetitions is increased, and when the laser beam movement speed is slow, the number of repetitions is decreased. As a result, the laser energy per unit length of the laser beam trajectory on the workpiece 12 is kept constant or controlled.

Next, a case will be described in which the output power of the laser beam is changed. The configuration of the laser processing apparatus in this case is as shown in FIG. 5, and a laser power setting device 23 is used instead of the pulse width modulator 22 in the above embodiment (see FIG. 2). The schematic functions of the device 23 are shown in a block diagram as shown in FIG. 6, and the timing chart of this modification is shown in FIG. The speed (or t, which is the expected laser beam movement speed) is detected, and a feed pack is applied to the laser power setting device 23.

In this way, when the laser beam movement speed is fast, the laser output/F power is increased, and when the laser beam movement speed is slow, the laser output power is decreased. As a result, the laser energy per unit length of the laser beam locus above the workpiece 12 is controlled or controlled.

To explain in detail, first, the velocity in the X and Y axis directions (i - Q
Input the signals Vx, My, etc. from the X-axis encoder 20% to the laser power setting device 23 from the Y-axis encoder 2). These signals are detected by the Zannnordert for the duration of the sample signal and are held until the next sample signal arrives. These retained No. 48 V x , V y
Fi, V: VX2 + V,! (D is subjected to arithmetic processing, and further arithmetic processing is performed on W = By converting the moving speed signal into a voltage signal proportional to it (ten offset signal) and using it as a laser output power setting signal, the laser output power is modulated. For example, in a CW carbon dioxide laser, the discharge current value is modulated, ) The laser energy per unit length of the Radhe beam on the workpiece 12 can be made constant.

〔Effect of the invention〕

According to the present invention, while changing the pulse width of the laser beam according to the material, shape, and processing speed of the workpiece 12 (or by keeping the pulse width of the Rede beam constant1 and not changing the number of pulse repetitions), (or while changing the output power of the laser beam), the energy is supplied to the workpiece 12, and the energy is controlled or stopped per unit length of the laser beam trajectory on the workpiece 12. Even if workpieces 12 made of various materials and shapes are machined at various speeds, the workpieces 12 can be uniformly machined.

[Brief explanation of drawings]

1(a) and 1(b) are block diagrams showing a conventional laser processing device, FIG. 2 is a block diagram showing a laser processing device W according to an embodiment of the present invention, and FIG. 3 is a block diagram showing a conventional laser processing device W. A block diagram showing an e-hat changer used in the device, FIG. 4 is a signal waveform diagram showing the evening chart of the second device, and FIG. 5 is a laser processing device according to a modification of the present invention. A configuration diagram showing
FIG. 6 is a block diagram showing a laser power setting device used in the device shown in FIG. 15, and FIG. 7 is a signal waveform diagram showing a timing chart of the device shown in FIG. 1 ~ Laser oscillator, 2... Numerical Fii device F4, 3
...X-axis motor driver, 4...Y-axis motor driver, 5...X-axis drive motor, 6...Y-axis drive motor, 7...X movement table, 8...X movement table ,
9... Beam bender, 1θ... Laser beam, 11
...Condensing lens, I2...Workpiece, 20...X
Axis encoder, 21-...Y-axis encoder, 22...°
Pulse width modulator, 23...laser power setting device. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 (b) 9 Figure 2 Figure 3 Figure 4 (Sea 1-'s Halus T%) Figure 5 Figure 6

Claims (4)

[Claims] (1) In a laser processing device that processes a workpiece with a laser beam using a laser beam moving device driven by a motor with one or more axes or a workpiece moving table, The laser energy per unit length of the laser beam trajectory on the workpiece is controlled ( (or - change), and is capable of uniformly processing workpieces made of various materials and shapes at various speeds. (2) The radar processing apparatus according to claim 1, wherein controlling and changing the laser beam means changing the pulse width of the laser beam. (3) The laser processing apparatus according to claim 11, wherein controlling and changing the laser beam means changing the number of pulse repetitions of the laser beam. (4) The laser processing apparatus according to claim 1, wherein controlling and changing the laser beam means changing the output/power of the laser beam.