JP2015044224A - Laser processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lengthen a focal depth by utilizing laser having a plurality of wavelength zones.SOLUTION: A laser processing device includes a parallel optical system 16B for changing laser having a plurality of wavelength zones into parallel light, and a condensation optical system 16C having condensation glass having a higher refraction index than crown glass so as to condense laser having passed through the parallel optical system 16B.

Description

  The present invention relates to a laser processing apparatus that performs processing by irradiating a member to be processed with a laser.

  For example, a laser processing device described in Patent Document 1 includes a plurality of fiber laser oscillation devices, a laser oscillation control device that controls on / off of oscillation of the fiber laser oscillation device, and a laser emitted from each fiber laser oscillation device. And a condensing optical system for condensing light on the processing section, and condensing a plurality of lasers at positions where the condensing distances in the optical axis direction from the condensing optical system to the condensing position are different from each other. That is, since the condensing position in the optical axis direction by the fiber laser is deviated, the effective depth of focus becomes long, and the processable range by the laser is increased.

  Further, for example, the laser processing apparatus described in Patent Document 2 is a condensing optical system that condenses a laser generated by a laser source at a desired focal length, and is configured to generate spherical aberration. It is shown. That is, due to spherical aberration, this affects the depth of focus, and a long depth of focus is obtained while the size of the focused spot remains small.

  The laser processing apparatus described in Patent Document 1 described above includes a plurality of fiber laser oscillation apparatuses. Further, the laser processing apparatus described in Patent Document 2 focuses a single wavelength laser at a desired focal length by spherical aberration.

JP 2003-290965 A International Publication No. 2008/069090

  By the way, when applying a laser oscillator that oscillates a laser having a plurality of wavelength bands, such as a semiconductor laser, if a plurality of lasers are condensed at positions where the condensing distances in the optical axis direction are different from each other as in Patent Document 1. It is possible to increase the depth of focus and increase the workable range by laser, for example, drilling, cutting and welding a thick member. However, in Patent Document 1, as shown in the drawing, a crown glass having a relatively low bending rate is used in the condensing optical system, so that the effect of increasing the depth of focus is small. Patent Document 2 focuses a single wavelength laser on a desired focal length by spherical aberration, and does not use a plurality of wavelength band lasers.

  The present invention solves the above-described problems, and an object of the present invention is to provide a laser processing apparatus capable of increasing the depth of focus by using a laser having a plurality of wavelength bands.

  In order to achieve the above-described object, a laser processing apparatus of the present invention includes a parallel optical system that uses a laser having a plurality of wavelength bands as parallel light, and a crown glass that condenses the laser that has passed through the parallel optical system. And a condensing optical system having a condensing glass having a high refractive index.

  According to this laser processing apparatus, it is possible to form the actual focal depth including the focal depth of the laser of each wavelength band longer in the optical axis direction than in the case of crown glass, and to improve the quality of the processed surface with respect to the workpiece. it can.

  Moreover, in the laser processing apparatus of this invention, flint glass is applied to the said condensing glass, It is characterized by the above-mentioned.

  According to this laser processing apparatus, flint glass is a condensing glass having a higher bending rate than crown glass, and as described above, the actual focal depth including the focal depth of the laser in each wavelength band is greater than that of crown glass. Can be formed long in the optical axis direction, and the effect of improving the quality of the processed surface with respect to the workpiece can be realized.

  In the laser processing apparatus of the present invention, a cooling mechanism for cooling at least the condensing optical system is provided.

  According to this laser processing apparatus, it is possible to improve the durability of the optical system against the heat generated by the laser.

  In the laser processing apparatus of the present invention, the actual focal depth is provided within the range of each outer end of the focal depth of the laser in each wavelength band.

  According to this laser processing apparatus, the focal depth of the laser of a plurality of wavelength bands can be made longer as the actual focal depth.

  In the laser processing apparatus of the present invention, the range of the beam diameter of the actual depth of focus is 2 (W × √2) or less.

  According to this laser processing apparatus, the actual depth of focus can be set within a range in which quality can be ensured by laser processing.

  Further, in the laser processing apparatus of the present invention, a laser output device that oscillates a laser having a plurality of wavelength bands, an irradiation head that has the parallel optical system and the condensing optical system, and irradiates the laser of each wavelength band; A moving mechanism that relatively moves the support base that supports the workpiece and the irradiation head, a relative movement between the support base and the irradiation head by the moving mechanism, and various conditions of the laser output from the laser output device. And a control device for adjustment.

  According to this laser processing apparatus, by adjusting the relative movement between the support base and the irradiation head by the moving mechanism and various conditions of the laser output from the laser output apparatus, the actual focus including the focal depth of the laser in each wavelength band is added. By forming the depth longer in the optical axis direction and improving the quality of the processed surface with respect to the processed member, the processed member can be processed with a laser.

  According to the present invention, the depth of focus can be increased by using a laser having a plurality of wavelength bands.

FIG. 1 is a schematic configuration diagram schematically showing a laser processing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram schematically showing an irradiation head of the laser processing apparatus according to the embodiment of the present invention. FIG. 3 is an explanatory diagram schematically showing the depth of focus.

  Hereinafter, an embodiment of a laser processing apparatus according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. For example, although this embodiment demonstrates as a case where a plate-shaped workpiece is processed, the shape of a workpiece is not specifically limited. The shape of the workpiece can be various shapes. Further, in the present embodiment, a case where a hole is formed in a workpiece, a case where the workpiece is cut on a straight line, or a case where the workpiece is welded will be described, but the machining position on the workpiece, that is, By adjusting the laser irradiation position, a shape other than a hole or a straight line, for example, a shape having a bending point or a curved shape can be obtained. In this embodiment, the laser beam and the workpiece are moved relatively by moving the workpiece. However, the laser may be moved, and both the laser and the workpiece are moved. You may let them.

  FIG. 1 is a schematic configuration diagram schematically illustrating a laser processing apparatus according to the present embodiment, and FIG. 2 is a schematic configuration diagram schematically illustrating an irradiation head of the laser processing apparatus according to the present embodiment. FIG. 3 is an explanatory diagram schematically showing the depth of focus.

  As shown in FIG. 1, the laser processing apparatus 10 includes a laser output device 12, a guide optical system 14, an irradiation head 16, a moving mechanism 18, a support base 20, and a control device 22. The laser processing apparatus 10 processes the workpiece 8 by irradiating the workpiece L installed on the support base 20 with the laser L. Here, in this embodiment, the laser processing apparatus 10 sets the surface of the member 8 to be processed as an XY plane and the direction orthogonal to the surface of the member 8 as a Z direction.

  Here, the workpiece 8 of this embodiment is a plate-shaped member. As the workpiece 8, a member made of various materials, for example, Inconel, Hastelloy, stainless steel, ceramic, steel, carbon steel, ceramics, silicon, titanium, tungsten, resin, plastics, glass or the like is used. it can. The workpiece 8 includes fiber reinforced plastics such as CFRP (Carbon Fiber Reinforced Plastics), GFRP (Glass Fiber Reinforced Plastic), GMT (Glass Long Fiber Reinforced Plastic), iron alloys other than steel plates, Members made of various metals such as aluminum alloys and other composite materials can also be used. Moreover, when welding, you may have a mechanism which supplies a filler material, powder, etc.

  The laser output device 12 is a device that outputs a laser. The laser output device 12 oscillates a laser having a plurality of (two in this embodiment) wavelength bands. An example of the laser output device 12 is a semiconductor laser oscillator.

  The guide optical system 14 is an optical system that guides the laser output from the laser output device 12 to the irradiation head 16. The guide optical system 14 of this embodiment is an optical fiber. The guide optical system 14 has one end connected to the laser emission port of the laser output device 12 and the other end connected to the irradiation head 16. The guide optical system 14 outputs the laser output from the laser output device 12 toward the incident end of the irradiation head 16. The configuration of the guide optical system 14 is not limited to this. The laser processing apparatus 10 may guide the irradiation head 16 by using a combination of a mirror and a lens as the guide optical system 14 and reflecting or condensing the laser. Or you may guide directly to the irradiation head 16 from the laser output apparatus 12. FIG.

  The irradiation head 16 irradiates the workpiece 8 with the laser L output from the guide optical system 14. Details of the irradiation head 16 will be described later.

  As shown in FIG. 1, the moving mechanism 18 includes an arm 30 and a drive source 32 that moves the arm 30. The arm 30 supports the irradiation head 16 at the tip. The drive source 32 can move the arm 30 in the three-axis directions of XYZ. The moving mechanism 18 can irradiate the laser L from the irradiation head 16 to various positions of the workpiece 8 by moving the arm 30 in the XYZ directions by the drive source 32. The moving mechanism 18 has a position detector 34 that detects the position of the irradiation head 16 in the XYZ directions. In the present embodiment, the moving mechanism 18 is a mechanism that moves the irradiation head 16 using the arm 30 and the drive source 32. However, a mechanism that moves the irradiation head 16 using an XY stage, an XYZ stage, or the like can also be used.

  The support table 20 supports the workpiece 8 at a predetermined position. In the laser processing apparatus 10, the support base 20 may be configured as an XY stage that moves the workpiece 8 in the XY direction.

  The control device 22 controls the operation of each unit. The control device 22 adjusts various conditions of the laser output from the laser output device 12 or moves the irradiation head 16 by the moving mechanism 18 to adjust the position of the irradiation head 16 with respect to the workpiece 8.

  The laser processing apparatus 10 outputs a laser from a laser output apparatus 12. The laser processing apparatus 10 guides the output laser L to the irradiation head 16 by the guide optical system 14. The laser processing apparatus 10 moves the irradiation head 16 by the moving mechanism 18 while detecting the position of the irradiation head 16 in the XYZ directions by the position detector 34. Thereby, the laser processing apparatus 10 can process the workpiece 8.

  Hereinafter, the irradiation head 16 will be described with reference to FIG. As shown in FIG. 2, the irradiation head 16 includes a parallel optical system 16B that converts the laser incident from the guide optical system 14 into parallel light inside the casing 16A supported by the moving mechanism 18, and a parallel optical system. A condensing optical system 16C that condenses the laser beam that has been made parallel light by 16B on the optical axis S is provided. Note that the parallel optical system 16B shown in FIG. 2 is a schematic one, and the lens configuration is not limited.

  The condensing optical system 16C has a condensing glass having a refractive index higher than that of the crown glass so as to condense the laser that has passed through the parallel optical system 16B. That is, the condensing optical system 16C condenses on the optical axis S by refracting the laser of each wavelength band made parallel light by the parallel optical system 16B with a refractive index higher than that of the crown glass. The difference in focal length between the lasers L1 and L2 in the wavelength band is larger than that in the case of crown glass, and the focal positions F1 and F2 are greatly separated in the optical axis direction (the direction along the extending direction of the optical axis S). For this reason, the positions of the focal depths B1 and B2 of the lasers L1 and L2 are far apart in the optical axis direction as compared with the case of the crown glass, and the actual focal depths including the focal depths B1 and B2 of the lasers L1 and L2 are added. BP is formed longer in the optical axis direction than in the case of crown glass.

  Here, the depth of focus B will be described with reference to FIG. As shown in FIG. 3, the laser beam L having the incident beam diameter D is condensed by the condensing optical system 16C, and the focal position F has the smallest beam diameter. The distance in the optical axis direction from the condensing optical system 16C to the focal position F is referred to as a focal distance f. A half of the beam diameter at the focal position F is defined as a beam radius W. In the range in the optical axis direction with respect to the focal position F, the range where the beam diameter is 2 (W × √2) or less is the focal depth B. The range of the focal depth B is a range in which the quality can be ensured by laser processing. The larger the focal depth B with respect to the thickness of the workpiece 8, the better the quality of the processed surface. Note that the angle θ with respect to the optical axis S of the laser L in FIG. 3 is half of the beam divergence angle, and is represented by λ / πW. λ is the wavelength of the laser.

  That is, as shown in FIG. 2, if the actual focal depth BP including the focal depths B1 and B2 of the lasers L1 and L2 in the respective wavelength bands is formed longer in the optical axis direction than in the case of crown glass, the workpiece The quality of the processed surface with respect to 8 can be improved. As shown in FIG. 2, the actual focal depth BP is such that the inner ends of the focal depths B1 and B2 of the lasers L1 and L2 in each wavelength band overlap each other, and the range of the outer ends of the focal depths B1 and B2. In FIG. 2, the beam diameter is 2 (W × √2) or less due to the influence of the beam diameters of the lasers L1 and L2, and is smaller than the outer edge range of each of the focal depths B1 and B2. .

  As described above, the laser processing apparatus 10 of the present embodiment has a parallel optical system 16B that uses a laser having a plurality of wavelength bands as parallel light, and a crown glass that collects the laser obtained from the parallel optical system 16B. And a condensing optical system 16C having a condensing glass having a high refractive index, so that the actual focal depth BP including the focal depths B1 and B2 of the lasers L1 and L2 in each wavelength band is more light than that in the case of the crown glass. It can be formed longer in the axial direction, and the quality of the processed surface for the workpiece 8 can be improved.

  Moreover, in the laser processing apparatus 10 of this embodiment, it is preferable that flint glass is applied to the condensing optical system 16C in condensing glass. The flint glass is a condensing glass having a higher bending rate than that of the crown glass. As described above, the actual focal depth BP obtained by adding the focal depths B1 and B2 of the lasers L1 and L2 in each wavelength band is larger than that of the crown glass. It can be formed long in the optical axis direction, and the effect of improving the quality of the processed surface with respect to the workpiece 8 can be realized.

  Moreover, it is preferable that the laser processing apparatus 10 of this embodiment is provided with the cooling mechanism 24 which cools at least the condensing glass.

  The cooling mechanism 24 is an air cooling mechanism as shown in FIG. 2, for example, and an air supply pipe 24 </ b> A that communicates with the inside and outside of the casing 16 </ b> A is formed in the casing 16 </ b> A of the irradiation head 16. A tube 24B is formed. An air supply pump 24C is provided in the air supply pipe 24A. The cooling mechanism 24 supplies cooling gas (dry air or dry nitrogen) to the inside of the casing 16A via the air supply pipe 24A by the air supply pump 24C, and discharges the gas inside the casing 16A from the exhaust pipe 24B. The optical systems 16B and 16C inside the casing 16A are cooled. The air-cooled gas is supplied after fine dust (micron order) in the gas is removed by a filter used in semiconductor manufacturing, for example. This is to prevent the lens from being burned out by the laser beam due to the attachment of minute dust or the like to the lens. Although not clearly shown in FIG. 2, the optical system (in FIG. 2) parallel optical system 16B existing between the air supply pipe 24A and the exhaust pipe 24B in the casing 16A is formed by a plate-like lens support plate. The outer peripheral portion is supported with respect to the casing 16A, and air can be passed through the casing 16A between the air supply pipe 24A and the exhaust pipe 24B by forming a vent hole in the range support plate. Thereby, as shown in FIG. 2, the air-cooled gas can be flowed through a path that licks the lens surface, and the lens can be efficiently cooled. Here, although only the air cooling mechanism is described, it becomes possible to cool more efficiently by using both the water cooling mechanism and the air cooling mechanism.

  By providing such a cooling mechanism 24, it is possible to improve the durability of the optical systems 16B and 16C against the heat generated by the laser. In particular, flint glass applied to the condensing glass of the condensing optical system 16C has poor heat resistance. For this reason, by providing the cooling mechanism 24, the durability of the flint glass can be improved, the durability of the apparatus can be improved, the processing time can be extended, and the processing accuracy can be improved.

DESCRIPTION OF SYMBOLS 10 Laser processing apparatus 16 Irradiation head 16A Casing 16C Condensing optical system 16B Parallel optical system 24 Cooling mechanism

Claims (6)

A parallel optical system in which a laser having a plurality of wavelength bands is parallel light;
A condensing optical system having a condensing glass having a refractive index higher than that of the crown glass so as to condense the laser that has passed through the parallel optical system;
A laser processing apparatus comprising:   The laser processing apparatus according to claim 1, wherein flint glass is applied to the condensing glass.   The laser processing apparatus according to claim 1, further comprising a cooling mechanism that cools at least the condensing optical system.   The laser processing apparatus according to claim 1, further comprising an actual depth of focus within a range of each outer end of the depth of focus of the laser in each wavelength band.   The laser processing apparatus according to claim 4, wherein a range of a beam diameter of the actual focal depth is 2 (W × √2) or less. A laser output device for oscillating a laser having a plurality of wavelength bands;
An irradiation head that has the parallel optical system and the condensing optical system and irradiates a laser of each wavelength band;
A moving mechanism for relatively moving a support base for supporting a workpiece and the irradiation head;
A relative movement between the support base and the irradiation head by the moving mechanism, and a control device for adjusting various conditions of the laser output from the laser output device;
The laser processing apparatus according to claim 1, further comprising:

Images