JPH04284924A - Method and device for working metallic plate - Google Patents

Abstract

PURPOSE:To perform bending possible to obtain a fixed bending angle irrelevant to a bending width, high in quality and with accuracy in the working method for a metallic plate to bend the metallic plate with laser beam. CONSTITUTION:A laser beam from a laser beam source 2 is made to scan by the XZ table 6 on a metallic late 5 to bend it and the bent degree is detected by a load cell 9. According to the detected degree of bending, a controller 7 sets a waiting time for one scanning and the XZ table 6 is controlled by this waiting time to perform the next scanning.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bending a metal plate using a laser.

[0002] In recent years, laser machining has been put into practical use in processes such as cutting and drilling, and bending is expected to be an application field, and high-quality, high-precision bending is required. Therefore, it is necessary to appropriately set various conditions for the laser irradiating the workpiece.

0003

[Prior Art] Generally, laser processing uses the phenomenon that a workpiece absorbs focused laser light and is rapidly heated, transforming, melting, or evaporating to perform material removal, surface treatment, etc. It is a processing method.

[0004] When a thin metal plate is bent by this laser processing, the bending occurs due to the difference in expansion between the laser irradiation position and the opposite position due to rapid heating and cooling. This makes it possible to perform micro-bending processing, non-contact processing allows processing while measuring spring pressure during forming processing of springs, etc., and flexible processing by changing the laser scanning conditions. It has features such as being able to be bent into shapes.

Conventionally, when a thin metal plate is bent by a laser at a right angle, for example, the laser beam focused by a convex lens or the like is scanned linearly over the bending position of the thin metal plate multiple times. In this case, the scanning of the laser beam is the nth scanning and the nth scanning.
The waiting time between scanning for the +1st time is constant. Therefore, depending on the bending width (scanning distance of the laser beam) of the thin metal sheet, the cooling rate and the bending angle are different, and the wider the bending width, the faster the cooling rate and the larger the bending angle.

FIG. 5 shows a graph of the relationship between bending width and spring pressure in conventional laser processing. Now, the bending angle of the bent portion of the thin metal plate is in a proportional relationship with the spring pressure of the bent portion, and FIG. 5 shows the relationship with the bending width when the bending angle is replaced with the spring pressure. In this case, the thin metal plate was made of stainless steel (SUS304) with a thickness of 0.078 mm, and the scanning speed of the laser beam was 10 mm/s. As shown in Figure 5, bending width (mm) and spring pressure (g
) changes linearly up to a bending width of 20 mm;
The above changes in a gentle curve.

[0007]

[Problems to be Solved by the Invention] However, as shown in Fig. 5, the bending angle (spring pressure) at which the thin metal plate is bent during one scan of the laser beam changes depending on the bending width of the thin metal plate.
In particular, when the bending width is several mm or less, it takes a lot of time to obtain a predetermined bending angle, and there is also the problem that the area around the laser beam scan is deteriorated or discolored by heat.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a metal plate processing method that can always obtain a constant bending angle regardless of the bending width and that performs high-quality, high-precision bending. With the goal.

[0009]

[Means for Solving the Problems] FIG. 1 is a diagram illustrating the principle of the present invention. In FIG. 1, when the metal plate is bent by scanning the laser beam multiple times in the same straight line on the metal plate,
In the first step, the laser beam is scanned over the metal plate a predetermined number of times. In the second step, the degree of bending of the metal plate is detected. In the third step, a waiting time between one scan of the laser beam is set according to the detected degree of bending, and the next scan is performed during the waiting time.

[0010] Furthermore, a processing apparatus for performing the above-mentioned processing method includes a laser light source, a moving section that scans the laser light from the laser light source on a metal plate, and a detection section that detects the degree of bending of the metal plate. , the moving unit sets a waiting time between one scanning of the laser beam from the laser light source according to the degree of bending from the detection unit, and causes the next scanning of the laser beam to be performed during the waiting time. and a control section that controls the.

[0011]

[Operation] As shown in FIG. 1, first, a laser beam from a laser light source is scanned over a metal plate by a moving part, and the degree of bending is detected by a detecting part. Then, depending on the detected degree of bending, the control section sets a waiting time between scans, and controls the moving section to perform the next scan during the waiting time. That is, when the bending width is short, the waiting time is increased, and the next scan is performed after cooling is completed, as in the case where the bending width is long. This makes it possible to always obtain a constant bending angle regardless of the size of the bending width of the metal plate, and there is no thermal deterioration or discoloration, especially in minute bends, resulting in high-quality, high-precision bending processing. becomes possible.

0012

Embodiment FIG. 2 shows a configuration diagram of an embodiment of the present invention. FIG. 2 shows a metal plate processing apparatus 1 in which a laser beam from a laser light source 2 passes through an optical fiber 3 and a laser irradiation section 4.
The metal plate 5 of the workpiece (for example, the spring arm of a magnetic head) is irradiated with the light. The laser light emitted from the laser light source 2 is, for example, a carbon dioxide laser with a wavelength of 0.5 to 10 μm or a YAG (yttrium aluminum garnet) laser. Further, although not shown, the laser irradiation unit 4 focuses laser light using a lens and irradiates the metal plate 5 with the laser light. This laser irradiation unit 4 is moved in the X direction and Z direction as shown by the arrow by an XZ table 6, which is a moving unit, to scan the laser beam on the metal plate 5. controlled.

On the other hand, one side of the metal plate 5 is connected to the workpiece moving section 8.
, and the workpiece moving unit 8 moves in the Y direction as shown by the arrow. Further, the other end of the metal plate 5 comes into contact with a load cell 9 which is a detection section. This load cell 9 generally detects minute deformations of an elastic body using a strain gauge or a change in capacitance, and in the case of FIG. 2, the bending angle, which is the degree of bending of the metal plate 5, is detected as spring pressure. The detection results are displayed on the display section 10 and sent to the control section 7. The control unit 7 sets a waiting time between one scan of the laser beam according to the degree of the detected bending, and controls the XZ table 6 to perform the next scan of the laser beam during the waiting time.

Next, FIG. 3 shows a diagram for explaining the operation of the present invention. In FIG. 3, first, the control unit 7 initializes the waiting time for laser beam scanning (step (
ST)1). Normally it is set to zero time. Then, the XZ table 6 is driven to scan the laser beam from the laser irradiation section 4 in the same straight line several times on the metal plate 5. At this time, the irradiated position on the metal plate 5 instantly becomes a high temperature of 700 to 800°C, and then that part is rapidly cooled and bent. The load cell 9 detects the spring pressure of the bent portion of the metal plate 5, which corresponds to the degree of bending in proportion to the bending angle (ST3);
This value is displayed on the display section 10 and sent to the control section 7 as data.

[0015] The control unit 7 sets the waiting time for one scan of the laser beam to, for example, 2, 4, 6... seconds in accordance with the sent data (spring pressure of degree of bending) (ST4). . Therefore, by changing the waiting time for the next scan according to this setting,
The Z table 6 is controlled and the laser irradiation unit 4 is moved to perform the next scan of the laser beam (ST5). Then, ST2 and subsequent steps are repeated.

FIG. 4 shows a graph of the relationship between bending width and spring pressure according to the present invention. FIG. 4 shows a metal plate 5 similar to FIG.
Stainless steel (SUS304) with a plate thickness of 0.078 mm
, the scanning speed of the laser beam was set to 10 mm/s, and the waiting times were set to 2, 4, and 10 seconds. As shown in FIG. 4, the relationship between the bending width (mm) and the spring pressure (g) becomes flat when the waiting time is 10 seconds. In other words, by setting a long waiting time when the bending width is short, and setting a short waiting time when the bending width is long, the spring pressure is always constant and the bending angle is always constant regardless of the bending width. can be obtained.

[0017] This makes it possible to prevent thermal deterioration and discoloration, especially in minutely bent parts, resulting in higher quality and
High precision bending can be performed.

[0018]

As described above, according to the present invention, a laser beam from a laser light source is scanned on a metal plate by a moving part,
By detecting the degree of bending with the detection unit and setting the waiting time for the next scan by the control unit, a constant bending angle is always obtained regardless of the bending width, achieving high quality and high precision bending. This can improve yield.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is a flowchart for explaining the operation of the present invention.

FIG. 4 is a graph showing the relationship between bending width and spring pressure according to the present invention.

FIG. 5 is a graph showing the relationship between bending width and spring pressure by conventional laser processing.

[Explanation of symbols]

1 Processing equipment 2 Laser light source 5 Metal plate 6 XZ table 7 Workpiece moving part 9 Load cell

Claims (2)

[Claims] 1. A metal plate processing method in which the metal plate is bent by scanning a laser beam in the same straight line a plurality of times on the metal plate, the laser beam being scanned on the metal plate (5) a predetermined number of times. a step of scanning (first step), a step of detecting the degree of bending of the metal plate (second step), and a step of scanning the metal plate during one scan of the laser beam according to the detected degree of bending. a step of setting a waiting time and performing the next scan during the waiting time (third step);
A method for processing a metal plate, characterized by having the following. 2. A laser light source (2);
a moving unit (6) that scans the laser beam from 2) on the metal plate (5), a detection unit (9) that detects the degree of bending of the metal plate (5), and the detection unit (9). The moving unit (2) sets a waiting time between one scan of the laser beam from the laser light source (2) according to the degree of bending from the laser beam, and causes the next scan of the laser beam to be performed during the waiting time. a control unit (7) that controls the
) A metal plate processing device characterized by having the following.