JP2007069219A - Device and method for grooving double sides by laser beam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double side grooving device and a double side grooving method using a laser beam by which double-side grooves which are small in the variation of groove properties on both sides are formed without especially increasing the cost of equipment. <P>SOLUTION: This device is a double-side grooving device by which a groove on both sides of a material to be worked is formed by projecting a laser light 2 to the material to be worked which is relatively moved and which has a laser beam head 16 which is arranged so as to irradiate the surface of the material to be worked with a laser light excited with an oscillator 14, a first nozzle 1 which is arranged so as to jet a first assisting gas 3 from the side of the surface of the material to be worked to a molten part by laser beam irradiation, a second nozzle 4 which is arranged so as to jet the second assisting gas 5 from the side of the rear surface of the material to be worked to the molten part by the laser beam irradiation, a first pressure control means 18a for adjusting the pressure of the first assisting gas and a second pressure control means 18b for adjusting the pressure of the second assisting gas. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a processing apparatus and a processing method for irradiating a laser beam to form grooves on both sides.

As a method for forming a groove in a plate material, a mechanical method by cutting, pressing, etc., a method by chemical etching, a high thermal energy beam irradiation method by laser, plasma, electron beam, etc. are known, but a method using a laser is It is characterized by the fact that it can perform high-speed processing without contact and has a simple process, and has been widely used mainly for the formation of through-grooves such as cutting, but recently it can be applied to the formation of bottomed grooves. It has become. Since the bottomed groove can be formed on both surfaces of the workpiece, it is formed coaxially and used for improving the characteristics of the workpiece or for scribing. In general, to form grooves on both sides, a method of forming a bottomed groove on one side after forming a bottomed groove on one side is used, but the bottomed groove is formed on the other side. Increase in the risk of damage to the workpiece, and misalignment of the front and back grooves. On the other hand, for example, in Japanese Patent Application Laid-Open No. 2000-109961 (Patent Document 1), as a method of manufacturing a unidirectional electrical steel sheet having excellent magnetic properties, grooves are formed on both surfaces by irradiating laser light from both the front and back surfaces of the steel sheet. It is disclosed to form.
Japanese Unexamined Patent Publication No. 2000-109961 (FIG. 3)

In the double-sided groove forming technique of Patent Document 1, since laser irradiation nozzles are provided on both the front and back surfaces of a steel plate, the step of inverting the steel plate is not necessary, but the laser equipment cost naturally increases. In addition, a condensing lens is usually mounted inside the laser irradiation nozzle. If a melt such as dross adheres to the nozzle, problems such as a decrease in the amount of laser irradiation and a deviation in the irradiation optical axis occur. In particular, the back side irradiation nozzle that irradiates laser light upward is likely to cause this problem. If the laser irradiation state from the front and back irradiation nozzles is different, the size of the grooves on both sides will change or the position will be shifted. The problem arises.
Accordingly, the present invention provides a processing apparatus and processing capable of forming a double-sided groove with less fluctuation in groove properties on both sides in a double-sided groove processing apparatus and double-sided groove processing method using a laser without particularly increasing the equipment cost. It aims to provide a method.

The double-sided groove processing apparatus using a laser according to the present invention is a double-sided groove processing apparatus that irradiates a relatively moving workpiece with laser light to form grooves on both sides of the workpiece, and is excited by an oscillator. A laser head arranged to irradiate the surface of the workpiece perpendicularly to the surface of the workpiece; and a first head arranged to inject a first assist gas from the surface side of the workpiece onto the melted portion by laser irradiation. A first pressure control that adjusts the pressure of the first assist gas, one nozzle, a second nozzle arranged to inject a second assist gas from the back side of the workpiece into the melted portion by laser irradiation Means, second pressure control means for adjusting the pressure of the second assist gas, first position control means for adjusting the position of the first nozzle, and second position control means for adjusting the position of the second nozzle. It is characterized by having.
Further, the first nozzle and the second nozzle in the present invention are arranged symmetrically with the axis center in a plane parallel to the moving direction including the laser optical axis and sandwiching the front and back surfaces of the workpiece. If it is, it is preferable.
In the present invention, the first nozzle is attached to the tip of the laser head so that its axis is coaxial with the laser optical axis, and the second nozzle is coaxial with the first nozzle. It is preferable to arrange | position in.
Moreover, it is desirable that the workpiece in the present invention is a thin plate material whose thickness direction is almost instantaneously melted by laser irradiation from the surface.

  The double-sided groove processing method using a laser according to the present invention is a double-sided groove processing method in which a relatively moving workpiece is irradiated with laser light to form grooves on both surfaces of the workpiece. In this case, a melted portion reaching the back surface is formed by vertically irradiating the gas and an assist gas is blown from both sides of the melted portion in a direction parallel to the moving direction and symmetrical. That is, a melted portion exposed on both surfaces of the workpiece is formed by laser irradiation from the surface side of the workpiece, and the melted portion is blown off from the front surface side and the back surface side to simultaneously form a recess from both surfaces. By moving the work piece so that the melted part escapes from the laser beam before being connected, the remaining melted part is solidified to form grooves on both sides.

  According to the present invention, since only one laser irradiation unit is required as a laser processing apparatus, an increase in equipment cost can be suppressed. Further, since the groove properties on both sides are almost restricted by the injection state of the assist gas, it is difficult to be affected by dross, and it is possible to form a stable continuous groove with almost no property fluctuation between the grooves.

(Embodiment 1)
Based on FIGS. 1-3, the schematic structure of the laser processing apparatus 100 in Embodiment 1 and the groove processing method are demonstrated.
The laser processing apparatus 100 is fixedly installed, and a long thin plate material 10 as a workpiece is continuously fed (X direction). A laser head 16 for irradiating the laser beam 2 is disposed above the surface side of the thin plate material 10, and is connected to the laser oscillator 14 via the fiber cable 15. The laser beam 2 can be a continuous wave or a pulse wave. The laser head 16 is in such a posture that the laser beam 2 is irradiated perpendicularly (Z direction) to the surface of the thin plate material 10 and is screw-feeded in the XYZ triaxial directions for adjusting the focal position and groove forming position of the laser. It is attached to the first position control means (not shown) that can be moved by The first nozzle 1 for injecting the first assist gas 3 onto the surface of the thin plate material 10 is attached to the tip of the laser head 16 so that its axis 31 coincides with the laser optical axis 21. Yes. An assist gas pipe 17a is connected to the side surface of the first nozzle 1, and the first assist gas 3 supplied from the first assist gas source 19a is ejected from the tip opening. A pressure adjusting valve 18a and an electromagnetic opening / closing valve 22a are provided in the middle of the assist gas pipe 17a, and the pressure and injection timing of the first assist gas 3 can be controlled.

  A second nozzle 4 for injecting the second assist gas 5 to the back surface of the thin plate material 10 is provided below the thin plate material 10 so as to face the first nozzle 1 coaxially. . The second nozzle 4 is attached to a second position control means (not shown) that can be moved by screw feed or the like in the XYZ triaxial directions for adjusting the ejection position of the second assist gas. An assist gas pipe 17b is connected to the side surface of the second nozzle 4, and the second assist gas 5 supplied from the second assist gas source 19b is ejected from the tip opening. A pressure regulating valve 18b and an electromagnetic on-off valve 22b are provided in the middle of the second assist gas pipe 17b, and the pressure and injection timing of the second assist gas 5 can be controlled. Nitrogen, oxygen, compressed air, etc. can be used for the first assist gas 3 and the second assist gas 5, and the same or different types of gases may be selected and used as appropriate.

Next, a double-sided groove processing method using the laser processing apparatus 100 will be described with reference to FIGS. FIG. 2 is a vertical cross-sectional view of the first nozzle 1 and the second nozzle 4 facing each other with the thin plate 10 interposed therebetween, and FIG. 3 is a vertical cross-sectional view of the Y direction.
First, the positions of the laser head 16 and the second nozzle 4 are adjusted by the first position control means and the second position control means. The laser beam 2 is irradiated perpendicularly to the surface of the thin plate material 10 and focused near the center in the thickness direction. At this time, the axis 31 of the first nozzle is substantially perpendicular to the surface of the thin plate material 10, but the axis 41 of the second nozzle 4 is adjusted to be concentric with the axis 31 of the first nozzle 1. This is very important. The distance from the tip of each nozzle to the surface of the thin plate 10 is also important, and is adjusted so that a predetermined gap is obtained. When the laser beam 2 is focused on the central portion of the thin plate 10 in the thickness direction, the tip of the first nozzle may not be in a predetermined position depending on the thickness. Therefore, the first nozzle 1 is independent of the laser head 16. Then, it is desirable that the position is adjustable in the Z direction.

  In grooving, first, the electromagnetic valves 22a and 22b are opened, and the pressure-adjusted first assist gas 3 and second assist gas 5 are injected onto both surfaces of the traveling thin plate material 10. In this state, a processing start signal is input to the laser oscillator 14 from the outside, and the surface of the traveling thin plate 10 is irradiated with the laser light 2 from the laser head 16 through the first nozzle 1. Since the laser beam 2 is irradiated so as to be focused near the center of the thin plate material 10, the laser irradiation portion is melted almost instantaneously from the front surface to the back surface. At this time, since the first assist gas 3 is injected toward the front surface and the second assist gas is injected toward the rear surface, the surface side of the melting portion 11 is sputtered 20 on the surface side with the first assist gas 3. Then, the back surface side of the melting part 11 is blown off by the second assist gas 5 as spatter 20 on the back surface side. That is, as schematically shown in FIGS. 2 and 3, in the laser irradiation portion, the molten metal is removed from both the front surface side and the back surface side, and concave portions 12 and 13 are formed on both surfaces. If the central part of the melted part 11 is left without being blown, the recesses 12 and 13 are not connected, and bottomed grooves are formed on the front and back surfaces.

  In order to leave the central portion, the thin plate material 10 is traveling, and the melted portion 11 is cooled and solidified away from the laser irradiation range. Therefore, according to the thickness of the thin plate material 10 and the traveling speed v, This can be achieved by appropriately adjusting the pressure and flow rate of the one assist gas 3 and the second assist gas, particularly the pressure. Specific conditions should be set through trial machining. In the present invention, the shape and position of the groove are substantially determined by the travel speed of the thin plate material and the pressure and flow rate of the first assist gas 3 and the second assist gas. By providing 18a, 18b and a flow rate adjusting valve (not shown), it can be precisely controlled. Further, devices (not shown) such as a condenser lens inside the laser head 16 are protected from scattered matter such as sputtering by the first assist gas 3, and the irradiation state of the laser light 2 hardly changes. Furthermore, since the second nozzle 4 may have a hollow penetrating structure, even if the scattered object enters, it falls down and there is almost no fluctuation in the pressure and flow rate of the second assist gas 5 due to the scattered object entering. In this way, the melted portion 11 is formed by the laser beam 2 from one surface of the thin plate material 10 moving at a constant traveling speed v, and the first assist gas 3 and the second precisely controlled from both surfaces are formed. Since the assist gas 5 is injected and a predetermined amount of the melt is blown off, the bottomed grooves 12 and 13 with little property variation can be formed continuously.

(Embodiment 2)
In the first embodiment, the configuration in which the first nozzle 1 is attached to the tip of the laser head 16 has been described. However, the laser head 16 and the first nozzle 1 may be separated as shown in FIG. . Also in this case, the laser head 16 is arranged so that the laser beam 2 is irradiated perpendicularly to the surface of the thin plate material 10. In the laser head 16, as in the first embodiment, it is desirable that the internal device is protected from scattered matter and the like, and a protective nozzle 1a similar to the first nozzle 1 is attached to the tip portion to assist the internal device protection. It is desirable to eject gas. The first nozzle 1 has an axis 31 in a plane (XZ) parallel to the traveling direction (X direction) of the thin plate member 10 including the laser optical axis, and is inclined with respect to the traveling direction. Are arranged so as to be sprayed obliquely onto the surface of the melting part 11. The second nozzle is disposed so as to be symmetrical with the first nozzle 1 on the back surface side with the thin plate member 10 interposed therebetween. Thereby, the front surface side and the back surface side of the melted part 11 by the laser light are sputtered and blown off in the same direction along the advancing direction, so that equivalent grooves are formed on both surfaces. Since not only the first assist gas 3 but also the protective assist gas acts on the surface side of the melted portion, it is desirable to provide the pressure adjusting valve 18c and the electromagnetic opening / closing valve 22c also on the protective assist gas pipe 17c.

  As described above, the workpiece only needs to be of a material and thickness such that the thickness portion is instantaneously melted by laser irradiation, and not only steel materials but also glass materials can be targeted. . The applicable thickness varies depending on the thermal conductivity and the energy of the laser used, but a steel sheet having a thickness of 1 mm or less is suitable. Depending on the energy level of the laser, the size of the melted portion differs in the thickness direction, and the width and shape of the grooves formed on both surfaces may differ. For example, if the surface area of the melted part is large and the area on the back side is small, the groove on the front side may be larger in width and depth than the groove on the back side, but to separate a small plate from a large plate There is no problem as a scribing groove. In the above description, the laser beam is irradiated from above the workpiece. However, the laser beam can be irradiated from below. In this case, it is conceivable that dross adheres to the condensing lens installed in the lower laser head, thereby changing the position of the melted part and causing the groove formation position to shift somewhat overall. There is no change in the properties between the grooves formed in. Note that although the assist gas is used to blow off the melt, a liquid such as water may be used.

  Using the laser processing apparatus of the first embodiment, groove processing was performed on both surfaces by changing the pressure of the assist gas. The workpiece is made of a long stainless steel material with a thickness of 0.6 mm and is run at a speed of 6 m / min. The 1 Kw laser beam from the first nozzle side is focused at a position of 0.3 mm from the surface of the workpiece. Were irradiated with a spot diameter of 0.15 mm. The tip opening inner diameter of the first nozzle is 1.7 mm, the tip opening inner diameter of the second nozzle is 1 mm, and nitrogen gas is used for both the first assist gas (first AG) and the second assist gas (second AG). . The results are shown in Table 1.

  The grooves in Examples 1 to 3 were almost rectangular, and the positional deviation between the front and back surfaces was within 0.03 mm. In Comparative Examples 1 and 2, the front and back grooves were connected to form a through groove.

It is a schematic block diagram of the laser double-sided groove processing apparatus in Embodiment 1. 6 is a schematic diagram for explaining groove processing on both surfaces by the laser double-sided groove processing apparatus of Embodiment 1. FIG. It is a schematic diagram which shows the cross section seen from said groove | channel formation direction. It is a schematic block diagram of the laser double-sided groove processing apparatus in Embodiment 2.

Explanation of symbols

  1: 1st nozzle, 2: Laser beam, 3: 1st assist gas, 4: 2nd nozzle, 5: 2nd assist gas, 10: Thin plate material, 11: Melting part, 12: Surface side groove (concave part), 13 : Back side groove (recess), 14: Laser oscillator, 15: Fiber cable, 16: Laser head, 17: Assist gas piping, 18: Pressure adjusting valve, 19: Assist gas source, 20: Sputter, 21: Laser optical axis , 22: electromagnetic on-off valve, 31: first nozzle axis, 41: second nozzle axis

Claims (5)

A double-sided groove processing apparatus that forms a groove on both surfaces of a workpiece by irradiating a relatively moving workpiece with laser light,
A laser head arranged to irradiate the surface of the workpiece perpendicularly with the laser beam excited by the oscillator, and a first assist gas to be injected from the surface side of the workpiece onto the melted portion by laser irradiation. A first nozzle disposed in the nozzle, a second nozzle disposed to inject a second assist gas from the back side of the workpiece into the melted portion by laser irradiation, and the pressure of the first assist gas. A first pressure control means for adjusting; a second pressure control means for adjusting the pressure of the second assist gas; a first position control means for adjusting the position of the first nozzle; and a first pressure control means for adjusting the position of the second nozzle. A double-sided groove processing apparatus using a laser, comprising: a two-position control means. The first nozzle and the second nozzle are arranged in a symmetrical manner with the axis thereof in a plane parallel to the moving direction including the laser optical axis and sandwiching the front and back surfaces of the workpiece. A double-sided groove processing apparatus using a laser according to claim 1. The first nozzle is attached to the tip of the laser head so that its axis is coaxial with the laser optical axis, and the second nozzle is arranged so that its axis is coaxial with the first nozzle. The double-sided groove processing apparatus using a laser according to claim 1. The double-sided groove processing by a laser according to any one of claims 1 to 3, wherein the workpiece is a thin plate material whose thickness direction is almost instantaneously melted by laser irradiation from the surface. apparatus. In a double-sided groove processing method in which a relatively moving workpiece is irradiated with laser light to form grooves on both sides of the workpiece,
A laser is characterized in that a laser beam is irradiated perpendicularly on the surface of a workpiece to form a melted portion reaching the back surface, and an assist gas is blown from both sides of the melted portion in parallel to the moving direction and symmetrically. Double-sided groove processing method.

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