JPS6224886A - Laser beam machine - Google Patents

Abstract

PURPOSE:To execute processing with high accuracy and high quality with less erosion arising from heat stan. by inputting the signals for the material quality and sheet thickness of a work to an optimum value calculating circuit and automatically controlling output, output mode and duty factor according to the relative speed of laser light. CONSTITUTION:The boundary speed to execute the selection of the output mode such as, for example, continuous output in a high-speed region and pulse output in a low-speed region is automatically set according to the relative moving speed of the work 6 when the material quality and sheet thickness of the work 6 are inputted to the optimum value calculating circuit 13. The optimum laser output and duty factor, etc. meeting the relative moving speed with respect to the material quality and sheet thickness of the work 6 are automatically controlled. As a result, the stable laser beam processing is automatically excuted with the high accuracy and high quality.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides high quality laser processing equipment, especially for cutting sheet metal parts with complex shapes at acute angles.

This invention relates to a device that can perform high-precision laser processing.

[Conventional technology]

FIG. 1 is a configuration diagram showing a conventional laser processing apparatus. In the figure, (1) is a laser oscillator, (2) is a laser beam,
(3) is a total reflection mirror that changes the direction of the laser beam (3).

(4) is a condensing lens that focuses the laser beam (3); (5)
(7) is the processing table (51?: drive motor 181i processing table (5) placed on the processing table (5) 61U),
1'! ' Drive motor that moves the Y-axis force direction Vc8, (9)
is the No. device that controls the laser oscillator (1) and the processing table (5).

Explain the action to the arrow. The laser beam (2) emitted from the laser oscillator (1) is bent and spread by a total reflection mirror (3) so that it is irradiated perpendicularly to the workpiece (6).
Ru. After that, the laser beam (2) is focused to a spot diameter smaller than the condenser lens (41Vc) and irradiated onto the workpiece (6).Here, the workpiece (6) is supported on the processing table (5). The processing table (5) is moved by the X-axis drive motor (7) and the Y-axis drive motor (8), making it possible to cut complex shapes.
) controls the operation of the laser oscillator (11, X-axis drive motor (7) and Y-axis' drive motor (8)).

[Problem that the invention seeks to solve]

Conventional laser processing equipment is constructed as described above.
Since the laser output and output form are fixed, the fine cutting area is easily affected by heat, resulting in unstable cutting quality and reduced precision. For example, FIG. 8 is a plan view showing an example of shape cutting using a conventional laser processing device. sαD is shown. Cutting start point (a).

At the corners (1) and (c) where the cutting direction changes and at the cutting stop point (d), the time on the horizontal axis (S→
The actual speed on the vertical axis, that is, the relative movement speed (erosion) of the laser beam (2) irradiated with the workpiece (61Vc) with respect to the workpiece (6) becomes slower, so the laser output remains constant. As the cutting progresses, excessive heat input may occur, especially at the acute angle cut point (C), and a melted area αS may occur due to thermal saturation, and the distance between each cutting groove may become partially widened at each point, resulting in poor cutting quality. Stable and less accurate.

In addition, given the material, plate thickness, and cutting shape of the workpiece (6), it is necessary to find the optimal cutting conditions through trial and error each time, which increases the burden on manpower and may cause problems. There was a problem in that it took a long time to process.

This invention was made to solve the above-mentioned problems. 1. For example, even when cutting a sheet metal part with a complex shape at an acute angle, the width of the cutting groove is constant and the cutting groove width is constant and there is less erosion due to saturation, resulting in high quality. It is an object of the present invention to provide a laser processing device that can perform highly accurate laser processing, shorten the processing time, and automatically perform stable processing.

[Means for solving problems]

The laser processing apparatus according to the present invention includes a relative movement speed detection device for detecting a relative movement speed of a laser beam irradiated onto a workpiece with respect to the workpiece, and a detection signal from the relative movement speed detection device. A speed vector calculation circuit that calculates a speed vector, and an output of the speed vector calculation circuit during processing based on data of the optimum laser output and optimum duty factor for the relative movement speed according to the material and plate thickness of the workpiece. An optimum value calculation circuit that calculates an optimum laser output and an optimum duty factor from a signal, a laser output control circuit that controls the output of a laser oscillator based on the output signal of this optimum value calculation circuit, and a duty factor of the laser oscillator. and a duty factor control circuit.

[Effect]

The optimum value calculation circuit in this invention can automatically set the optimum laser output condition and the optimum duty factor condition for the relative movement speed by simply inputting the signals of the material and plate thickness of the workpiece. The optimum laser output value and the optimum duty factor are calculated and determined according to the relative moving speed of the laser beam. Also, the laser output control circuit and duty factor control circuit.

The output and duty factor of the laser oscillator are automatically controlled based on the output signal from the optimum value calculation circuit. It is possible to perform high-precision laser processing with one corner being constant and the part quality 6, and moreover, it is possible to shorten the processing time and to achieve stable cutting.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. Note that the same reference numerals are given to the parts corresponding to those of the conventional embodiment described above, and the explanation thereof will be omitted.

FIG. 1 is a block diagram showing a laser processing apparatus according to an embodiment of the present invention, and FIG.

tll is attached to the X @ drive motor (7), and the workpiece +61KjK-IM f'L L/-f light (2)
(lυ is Y′MB
It is attached to the drive motor (8), and the laser beam (2)
A Y-axis pair movement speed detection device detects the relative movement speed in the Y-axis direction with respect to the workpiece (6). A speed vector calculation circuit for calculating (13 corresponds to the material and thickness of the workpiece (62). It stores the optimum laser output and breakthrough duty factor for the above relative movement speed, and calculates the optimum laser output and the optimum duty factor. Based on the data of the factor, the steepest laser output value and the optimum duty factor value are calculated and determined from the output signal of the speed vector calculation circuit αa. 1!9 controls the duty factor of the laser oscillator (1) based on the output signal from the optimum value calculation circuit 3. Figure 2 shows the duty factor control circuit for relative movement speed (m7fnm).
This is an example of a characteristic diagram showing the optimum laser output (W) αQ for a given period of time, and the vertical axis is the average laser output. This fL is extracted from a fine cut area determined in advance. In the figure, area (A) if laser output is pulse output, area (B)
) Output in continuous output format.

FIG. 3 is an explanatory diagram illustrating switching the output form of the laser beam (2) according to the relative movement speed.

FIG. 4 is an example of a custom-made diagram showing the peak value of the optimum laser output (hereinafter referred to as the optimum peak value) for the relative movement speed stored in the optimum value calculation circuit Q:lK.

FIG. 5 is also an example of a percentage chart showing the optimum duty factor for the relative movement speed, which is also stored in the optimum value calculation circuit (13).

Next, the operation will be explained with reference to FIGS. 1 to 5. The optimum value yL calculation circuit α3 calculates the speed V at the output mode switching point, which is determined from the characteristic diagram in Fig. 2 according to each material and board thickness.
C, as well as the optimum peak output and optimum duty factor (Figs. 4 and 5) for the relative movement speed corresponding to each material and each plate thickness are stored. When the material and plate thickness of the workpiece (61) are input to the optimum value calculation circuit W&(131), continuous output is generated in the high speed region according to the relative movement speed of the workpiece (6).

In the ejection speed region, a speed VC for switching the output form, such as pulse output, is automatically set.

Furthermore, as the optimum peak output for the relative movement speed ■ according to the material and plate thickness of the workpiece (6), the optimum peak output P+=a+ is selected when the output form is continuous output.
V+b+ (duty is 10G), and optimum peak output P2=a2V+t selected in the case of pulse output
)2 and the relative movement speed ■optimal duty factor D=CV +d (however, al.

bl, a2. b2. C and d are constants determined by the quality and plate thickness, etc. are automatically set. Next, from the rotational speed of the X-axis drive motor (7) and the X-axis drive motor (8) that move the processing table (5) that supports the workpiece (6), the X-axis and Y-axis pair movement speed detection device aQ is determined. .

The relative moving speeds VX and Vy in the axial direction of the cylinder are detected by the υ, and the velocity vector calculation circuit α2 [Ji]
The signal of the actual speed, that is, the relative moving speed of the laser beam (2) irradiated on the workpiece (6) with respect to the workpiece (6) when the knife is drawn, is sent to the optimum value calculation circuit α3. Output. In the optimum value calculation circuit a3, the speed VC of the output mode switching point set as described above is compared with the relative movement speed v1. the result.

If the relative movement speed v1 is larger, the output form is continuous. Output P+i is P11=a1Vi+J
Determined from the formula. On the other hand, if the relative movement speed ■1 is smaller, the output form becomes a pulse, and the overgrain peak output condition P2=a2V+b selected as described above is
2, and the duty factor condition D=Cv+
Based on the above relative movement speed v1, the optimum peak output P21tri P2i=a2V1+t)2 is further calculated based on the optimum duty factor DiFIDi=cV.
Determined from the formula 1+d. Figure 2.

As mentioned above, the straight line representing the optimum laser output condition shown in the %note figure is extracted from the fine cut region where no burrs occur on the lower side of the laser cut surface.
The custom-made diagram shown in the figure and the custom-made diagram shown in FIG. 5 are extracted from a predetermined area based on the characteristic diagram shown in FIG. 2 so that the width of the cutting groove is constant even when cutting at an acute angle. That is, when the output form is a pulse, the cutting groove width is stabilized by decreasing the duty factor and increasing the peak output as the relative movement speed decreases. Note that switching the output format according to the relative movement speed means that the roughness of the cut surface, which affects cutting quality, is rough in the low speed region in the case of continuous output.

It is fine in the high-speed range, whereas in the case of pulse output, it becomes coarse in the low-speed range and rough in the high-speed range, so this is an important factor to enable higher quality laser cutting. Next, the laser output and duty factor are controlled by controlling the laser oscillator (11 ms) based on the output signal of the laser output control circuit I and the duty factor control circuit (+1, the optimum value calculation circuit 0).

After that, as in the case of the conventional technology, the laser beam (2) is irradiated onto the workpiece (6), and the laser beam (2) is controlled to the appropriate laser output, output form, and duty factor. As shown in Figure 6, stable, high-quality, high-precision acute-angle cutting can be performed automatically. FIG. 6 is a plan view showing a workpiece processed by a laser processing apparatus according to an embodiment of the present invention.

In addition, although the case where the processing table (51?) was moved was explained in the above embodiment, the laser beam (2) may be moved.

Further, in the above embodiment, the optimum peak output and the optimum duty factor are expressed in straight lines, but they may be expressed in concave lines.

That is, it may be a green curve representing the optimum laser output condition expressed in terms of average output.

Furthermore, in the above embodiment, a case was explained in which the output form of the laser oscillator [11] was switched between continuous output and pulse output, but depending on conditions such as material, plate thickness, relative movement speed, etc. Effect similar to fj! : To wither.

Furthermore, in the above embodiment, the workpiece (6) was moved two-dimensionally, but the workpiece (6) was moved three-dimensionally,
Alternatively, even in the case of movement with more incident light than that, the same effect as in the above embodiment can be obtained by controlling the output, output form, and duty factor of the laser beam (2) according to the amount of zero-synthesized velocity vectors. can be obtained.

〔Effect of the invention〕

As described above, the present invention provides a relative movement speed detection device for detecting the relative movement speed of a laser beam irradiated onto a workpiece with respect to the workpiece, and a detection device from the relative movement speed detection device. A speed vector calculation circuit that calculates a speed vector from a signal, and a speed vector calculation circuit that calculates a speed vector according to the size and thickness of the workpiece. An optimum value calculation circuit that calculates the optimum laser output and optimum duty factor from the output signal of the speed vector calculation circuit during processing based on the data of the optimum laser output and the optimum duty factor for the relative movement speed, and the optimum value. It is equipped with a laser output control circuit that controls the output of the laser oscillator based on the output signal of the arithmetic circuit and a duty factor control circuit that controls the duty factor of the laser oscillator. It enables high-quality, high-precision laser machining with a constant cutting groove width that minimizes erosion due to thermal saturation even when cutting at acute angles, etc. Moreover, it reduces the machining time and automatically performs stable machining. be.

[Brief Description of the Drawings] Fig. 1 shows a laser processing device jI according to an embodiment of the present invention.
FIG. 2 is a custom-made diagram showing the optimum laser output for the relative movement speed according to an embodiment of the present invention, and FIG. 3 is a block diagram showing the optimum laser output according to the relative movement speed. ), FIG. 4 is a custom-made diagram showing the optimum peak output for relative movement speed according to an embodiment of the present invention, and FIG. 5 is a diagram showing the optimum peak output for relative movement speed according to an embodiment of this invention. 6 is a plan view showing an example of cutting processing by a laser processing device according to an embodiment of the present invention, and FIG. 7 is a 14IN diagram showing a conventional laser processing device. Is Figure 8 an example of cutting using a conventional laser processing device? The plan view shown in FIG. 8 is a characteristic diagram showing the relationship of relative movement speed with respect to time in the processing example of FIG. 8. In the figure, (1) is a laser oscillator, and (2) is a laser beam. (6) is the workpiece, (II is the X-axis relative movement speed detection device. 9 is a duty factor control circuit. In each figure, the same or equivalent parts are indicated by the same reference numerals.

Claims (2)

[Claims] (1) A relative movement speed detection device that detects the relative movement speed of the laser beam with respect to the workpiece in a device that processes a workpiece by irradiating the workpiece with a laser beam generated from a laser oscillator; A speed vector calculation circuit calculates a speed vector from the detection signal of the device, and calculates the speed at the time of processing based on the data of the optimum laser output and optimum duty factor for the relative movement speed according to the material and thickness of the workpiece. an optimum value calculation circuit that calculates an optimum laser output and an optimum duty factor from an output signal of the vector calculation circuit; a laser output control circuit that controls the output of the laser oscillator based on the output signal of the optimum value calculation circuit; and the laser A laser processing device characterized by being equipped with a duty factor control circuit that controls the duty factor of an oscillator. (2) The laser processing apparatus according to claim 1, wherein the optimum value calculation circuit switches the output form of the laser beam to a continuous output form when the relative movement speed is greater than a predetermined value, and to a pulse output form when the relative movement speed is smaller than a predetermined value.