JPH01313113A - Bending method for sheet metal by laser beam - Google Patents

Abstract

PURPOSE:To increase bending angle and to reduce working cost by irradiating the laser beam from a bisector of the supplementary angle for the bend angle, in the stage of bending the work stock with irradiating the laser beam. CONSTITUTION:A fixing jig 5, rotating motor 6 for the jig, displacement sensor 9 and its driving device 10 are disposed on the work 1 side and on the laser beam irradiating side, a driving device 8 for the laser beam converging and irradiating part and the converging and irradiating part 7 are set up. The bending part of the work stock 1 is irradiated with the laser beam 2 through the laser converging and irradiating part 7, and the driving part 8 performes beam scaning along with the bending direction of the work stock 1. In this case, the working control is performed to make the optical axis of the laser to exist on the bisector of the supplementary angle of the angle theta detected by the sensor 9. By this method, the irradiating heat balance is equarized, a needless thermal deformation is prevented and the bending angle is increased 90 deg..

Description

[Detailed Description of the Invention] [Summary] Regarding a sheet metal bending method using a laser beam, the purpose of this invention is to improve bending accuracy and enable bending larger than 90°. Irradiate the parts that require bending,
In a sheet metal bending method that performs bending by scanning, the laser beam is always irradiated from the bisector of the supplementary angle of the bent corner, following the progress of the bending of the workpiece material caused by laser beam irradiation. Configure.

[Industrial application field]

The present invention relates to a sheet metal bending method using a laser beam.

As a method of sheet metal bending, it does not rely on mechanical means.
There is a bending method using a laser beam.

Since this laser beam bending method is non-contact, no external force acts on anything other than the bent portion, making it suitable for processing precision parts.

[Conventional technology]

As shown in Fig. 4, the conventional sheet metal bending method using a laser beam fixes one end of the workpiece 1 and scans the laser beam 2 along the line where the workpiece 1 is to be bent. It can be bent inward.

[Problem to be solved by the invention]

In the above-mentioned conventional sheet metal bending method using a laser beam, the direction in which the laser beam 2 is irradiated onto the workpiece 1 is always constant, so if the bending angle becomes large during the bending process, the workpiece Since the area of the laser beam corresponding to 1 is uneven on the left and right sides of the scanning line, variations in heat balance occur, resulting in poor bending accuracy. 90° again
The bending described above has the problem that the bent portion 1' of the workpiece blocks the laser beam 2, making processing difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet metal bending method using a laser beam that has good processing accuracy and is capable of bending larger than 90 degrees.

[Means to solve the problem]

FIG. 1 is a diagram for explaining the present invention in detail.

In the figure, 1 is the workpiece material to be processed, 2 is the laser beam, and 3
is the optical axis of the laser beam, 4 is a condenser lens that focuses the laser beam to an arbitrary spot diameter, and θ is the bending angle due to laser beam irradiation and scanning. In the present invention, the supplementary angle 180 of the bending angle θ changes as the processing progresses.
The optical axis 3 of the laser beam is always placed on the bisector of °-θ, and the angle [action] is on the bisector of the supplementary angle 180°-θ of the angle θ at which the workpiece 1 is bent by the laser beam 2. By irradiating the laser beam 2 from the center, the laser beam 2 becomes bilaterally symmetrical with respect to a predetermined bending line segment, and the heat balance becomes equal on the left and right sides of the line segment, thereby improving bending accuracy. 90° again
It is also possible to perform larger bending operations.

〔Example〕

FIGS. 2 and 3 are diagrams for explaining the present invention in detail, with FIG. 2 being a configuration diagram and FIG. 3 being a block diagram showing a control circuit.

The bending apparatus shown in FIG. 2 includes a workpiece fixing jig 5, a motor 6 for rotating the workpiece fixing jig, a laser condensing irradiation section 7, a laser condensing irradiation section driving section 8, a displacement sensor 9, and a displacement sensor 9. The workpiece fixing jig 5 fixes the workpiece 1 to be machined, and sets the workpiece fixing jig 5 so that the line segment generated by bending on the workpiece 1 coincides with the rotation axis of the motor 6. It is fixed to the motor shaft so that the workpiece 1 can be rotated at any angle.

The laser condensing irradiation unit 7 irradiates the workpiece 1 with a laser beam 2 from a laser oscillator, and the workpiece 1 is scanned in a direction in which bending is required by the laser condensation irradiation unit driving unit 8 . The displacement sensor 9 can detect the bending angle of the workpiece 1, and in order to correct the variation in the detected angle due to the distortion of the workpiece 1, the displacement sensor drive unit 10 detects the bending angle of the workpiece 1 perpendicular to the direction in which the workpiece 1 is to be bent. It is designed to be scanned in the direction.

The control circuit shown in FIG. 3 includes a laser oscillation control circuit 11 that controls the laser oscillation state based on processing conditions such as the output of the laser irradiated to bend the workpiece 1, and a laser condensing irradiation unit drive unit 8. A laser condensing irradiation unit drive circuit 12 that drives the laser beam 2 to scan it, a workpiece positioning circuit 13, a workpiece rotation motor drive circuit 14, a motor rotation angle detection circuit 15, and a voltage detection circuit that is sensor information. a displacement sensor voltage detection circuit 16 for detecting the laser beam, and a threshold data memory 17 for holding a voltage threshold value that is the output of the displacement sensor for determining that the surface of the workpiece receiving the laser beam substantially coincides with the laser optical axis 3. , a comparator 18 that compares the output voltage of the displacement sensor 9 with threshold data, a displacement sensor drive circuit 19 that drives the displacement sensor drive unit 10 to scan the displacement sensor 9, and a comparator 18 that compares the output voltage of the displacement sensor 9 with threshold data, a displacement sensor drive circuit 19 that drives the displacement sensor drive unit 10 to scan the displacement sensor 9, and compares the output voltage of the displacement sensor 9 with the displacement from the reference distance. The bending angle of the workpiece 1 is determined by adding a correction amount that corrects error components such as positioning error and waviness of the workpiece 1 to the displacement sensor voltage data memory 20 that holds relationship data with the motor rotation angle information. and a bending angle calculation circuit 21 that calculates the bending angle.

A method for bending a workpiece using the bending apparatus and the control circuit configured as described above is to fix the workpiece 1 to the workpiece fixing jig 5 and scan it while irradiating the laser beam 2 (
(perpendicular to the paper). The bending angle is detected by using the output voltage of the displacement sensor voltage detection circuit 16 as the threshold value data memory 17.
If the voltage is not within the voltage range, the comparator 18 issues a command to the workpiece positioning circuit 13 to rotate the motor 6. When the comparator 18 determines that the output voltage of the displacement sensor 9 is within the threshold value data, the comparator 18 issues a drive command for the displacement sensor drive unit 10 to the displacement sensor drive circuit 19, and outputs the displacement sensor at an arbitrary sampling time. The voltage and the corresponding displacement amount are read from the displacement sensor voltage data memory 20, and the position of the displacement sensor 9 and the displacement amount of the workpiece 1 are input to the bending angle calculation circuit 21.

It also issues a command to the motor rotation angle detection circuit 15 to output the value of the motor rotation angle to the bending angle calculation circuit 21.

The bending angle calculation circuit 21 calculates the bending angle θ of the workpiece from the rotation angle information of the motor 6 and the displacement amount information of the workpiece 1, and sends a laser beam 111 to the workpiece positioning circuit 13.
I3 and the supplementary angle 180° - θ of the bending angle θ of the workpiece 1
A command is issued to position the workpiece 1 so that the bisectors of the two lines coincide with each other.

After positioning the workpiece, the workpiece positioning circuit 13 prompts the laser oscillation control circuit 11 to perform the next process. The above steps are repeated to bend the workpiece l to a desired angle.

According to the above embodiment, the optical axis 3 of the laser beam 2 is always on the line segment produced by bending the workpiece 1 and on the bisector of the supplementary angle 180° - θ of the angle θ produced by the bending. Since the left and right sides of the line segment produced by the bending process are irradiated with an equal laser beam, accurate bending process is performed. Also, the supplementary angle of the angle θ caused by bending is 180° - 2 of θ
Since the laser beam 2 is irradiated from on the equal dividing line, bending of 90° or less is also possible.

〔Effect of the invention〕

As explained above, according to the present invention, in the sheet metal bending process using a laser beam, the line that bisects the complementary angle of 180°-θ of the angle generated by the bending and the line segment generated by the process is always used. By scanning the laser beam,
It not only controls the heat balance and prevents unnecessary thermal deformation, but also allows bending to less than 90@, which greatly contributes to improving yield and reducing processing costs.

[Brief explanation of the drawing]

Figure 1 is a diagram for explaining the principle of the present invention, Figures 2 and 3 are diagrams for explaining the invention in detail, Figure 2 is a diagram showing a bending device, and Figure 3 is a diagram showing a control circuit. The block diagram shown in FIG. 4 is a diagram for explaining a conventional sheet metal bending method using a laser beam. In the figure, 1 is the workpiece material, 2 is the laser beam, 3 is the optical axis of the laser beam, 4 is the condenser lens, 5 is the workpiece fixing jig, 6 is the motor, 7 is the laser condensing irradiation part, 8 is the laser -9 is a displacement sensor, and 10 is a displacement sensor drive unit.

Claims (1)

[Claims] 1. In a sheet metal bending method in which a laser beam is irradiated onto a portion of a sheet metal product that requires bending and the bending is performed by scanning, a workpiece material (1) produced by irradiation with a laser beam (2);
The laser beam (2) follows the progress of the bend and always starts from the bisector of the supplementary angle (180°-θ) of the bent angle (θ).
A sheet metal bending method using a laser beam characterized by irradiating.