JPH0216199B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a laser perforation device for continuously creating perforations at predetermined intervals in a long strip-shaped workpiece (hereinafter referred to as a raw material), such as cigarette filter wrapping paper, using a pulsed laser beam. It is related to. A conventional device of this type is shown in FIG. In the figure, 1 is the original fabric, 2 is a drive device operated by a feeding device (not shown) that continuously sends the original fabric 1 in the direction of arrow A, 3 is a smoke exhaust box for exhaust smoke generated during laser processing, and 4 is a smoke exhaust box. An exhaust port from the smoke exhaust box 3, 5 a surface plate, 6 a slit provided on the surface plate 5, and 7 a laser head located opposite the slit 6, which focuses and outputs a pulsed laser beam. be. In such a laser aperture device, a highly efficient CO ₂ pulse laser is usually used as the laser, and this is focused by a lens in the laser head 7 to perform an aperture operation on the original fabric 1 near the focal position. Note that since the web 1 is long and has poor rigidity, in order to keep the relative positional relationship of the web 1 constant with the laser head 7 while it is running, a constant tension is always applied by the drive device 2, and a flat It can be run on a well-finished surface plate 5. Also,
A slit 6 is provided on the surface plate 5 at a position opposite to the laser head 7, and by operating the exhaust port 4 communicating with the smoke exhaust box 3 at the bottom of the surface plate 5, the slit 6 side is made negative pressure and the original fabric is removed. 1 to surface plate 5
This ensures stable running of the raw material 1.
Furthermore, it is effective to form the slit 6 into a long groove in the direction perpendicular to the running state of the web 1, especially for thin web materials or materials that tend to shrink in the direction perpendicular to the running direction. It is known. Furthermore, the slits 6 provided in the surface plate 5 are configured so that the laser beam that did not contribute to the opening and the debris (burnt residue) caused by thermal decomposition of the original fabric 1 can easily pass through. In the conventional apparatus configured as described above, while the original fabric 1 is moved in the direction of the arrow by the drive device 2, a pulsed laser is irradiated from the laser head 7 to form continuous apertures at predetermined intervals. Further, during this hole-opening work, exhaust is performed through the exhaust port 4. Since the conventional laser hole-opening device is configured as described above, the burnt residue generated during hole-opening of the web 1 adheres to both sides of the slit 6 (especially on the downstream side) and grows. There was a problem in that the laser beam would hit the cinders that blocked the slit 6, creating a risk of fire.
In addition, the burnt residue also grows in the upper part of the slit 6 and enters between the surface plate 5 and the web 1, contaminating the product, lifting the web 1, and changing the laser focal position, which reduces the quality of the holes in the web 1. The disadvantage was that it affected the In order to prevent these problems, it is necessary to frequently clean the vicinity of the slit 6, which has the drawback of poor workability. This invention has been made in order to eliminate the drawbacks of the above-mentioned conventional methods, and uses an air blow nozzle that blows compressed air in the opposite direction to the running direction of the workpiece through a slit near the opening position of the original fabric 1. It is an object of the present invention to provide a laser drilling device that is safe, efficient, and capable of stabilizing the quality of drilling by making it difficult for burnt debris to adhere to the slit. An embodiment of the present invention will be described below with reference to FIG. In the figure, 8 is a compressed air introduction pipe, and 9 is an air blow nozzle provided near the opening position of the slit 6 portion of the surface plate 5. The nozzle 9 injects the laser toward the laser aperture position in a direction opposite to the running direction A of the web 1. Therefore, the structure is such that the burnt debris that falls through the opening and tries to adhere to the wall surface of the slit 6 is blown away by the compressed air from the air blow nozzle 9 and is discharged from the smoke exhaust box 3 via the exhaust port 4. Operate. In FIG. 2, parts that are the same as or corresponding to those of the conventional device shown in FIG. 1 are given the same reference numerals. In the laser aperture device configured in this way, cigarette filter wrapping paper (chip paper)
As a result of using air blow as the original fabric 1, if there was no air blow, it would have been necessary to clean the burnt residue every 15 minutes, but with air blow, there is almost no need for cleaning. Ta. The condition table of this experimental result is
Shown in the table.

[Table] Even if compressed air is blown from the air blow nozzle 9, burnt residue will gradually accumulate in the slit 6, so it is necessary to periodically clean it, but when not in operation ( When the pressure of compressed air is increased several times and is injected from the nozzle 9 during non-opening operation), the accumulated combustion residue is instantly blown away and the slit 6 can be easily cleaned. Furthermore, during hole-opening operation, it is necessary to always send air at an appropriate pressure so that the original fabric 1 is not lifted up by the pressure of the compressed air from the nozzle 9. In the above example, chip paper was used as the perforation material, but even if it is thermally decomposed, there will be no residue (burnt residue).
It is also possible to target workpieces that leave residue, such as cloth, composite materials, etc. Furthermore, the same effect can be achieved even when using a laser other than a CO ₂ laser, such as another gas laser or a YAG laser. As described above, according to the present invention, an air blow nozzle that blows compressed air in the opposite direction to the traveling direction of the workpiece through the slit near the opening position of the workpiece is provided, so that the combustion This has the effect of making it difficult for laser apertures to adhere, making it possible to perform laser apertures safely, efficiently, and with stable aperture quality.

[Brief explanation of drawings]

Figure 1 is a cross-sectional side view of a conventional laser hole drilling device.
FIG. 2 is a cross-sectional side view of a laser according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Workpiece, 2... Drive device, 3... Smoke exhaust box, 4... Exhaust port, 5... Surface plate, 6... Slit, 7... Laser head, 8... Compressed air introduction pipe, 9...Air blow nozzle. In addition, in the figure,
The same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A laser head that focuses and outputs a pulsed laser beam, a feeding device that continuously drives a long strip-shaped workpiece in which an opening is formed by the laser beam from this laser head, and a position facing the laser head. A surface plate is provided with a slit, and a surface plate that sucks and holds the workpiece through the slit, and a surface plate that sucks and holds the workpiece through the slit, and passes through the slit to the vicinity of the opening position of the workpiece in a direction opposite to the running direction of the workpiece. An air blow nozzle blows compressed air, and an exhaust port is provided at the bottom of the surface plate and exhausts the compressed air blown from the air blow nozzle to the outside of the surface plate while sucking the workpiece. A laser hole drilling device characterized by comprising a smoke exhaust box.