JP2012071314A - Machining method of composite material, and machining device of composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machining device and a machining method of a composite material, which can form a machined wall surface perpendicular to a work and a perpendicular hole, while suppressing heat effect of the periphery of a machining portion, even in a large structure member constituted by the composite material of a thick plate.SOLUTION: The machining method of the composite material uses the machining device equipped with a light source, deflection portions 3 (3a, 3b) which deflect a laser light 2 oscillated from the light source, an fθ lens 4 which condenses the deflected laser light 2, wherein the laser light 2 is irradiated to a portion where the machined wall surface of a member 1 to be machined is formed, so that an irradiation angle (φ) composed by a center line 7 of the fθ lens and the center line 8 of the laser light condensed by the fθ lens becomes a converging angle (δ) or more of the condensed laser light 2.

Description

  The present invention relates to a composite material processing method and a composite material processing apparatus.

  For structural members such as aircraft wings, composite materials such as carbon fiber reinforced plastic (CFRP) are used. CFRP is obtained by laminating a large number of carbon fiber sheets through a matrix such as an epoxy resin. Carbon fiber is the same quality as graphite used for crucibles, has high heat resistance, and is difficult to cut. Epoxy resins are flammable and have a softening point of about 100 ° C. and low heat resistance.

  Processing such as cutting and drilling of composite materials is currently performed by machining using a drill blade. However, in the above method, tool consumption during processing is severe, and the cost of consumables such as blade re-polishing and replacement blades is high. For this reason, a machining method using a laser has been developed as a machining method in which tools and the like are not consumed during machining (see Patent Document 1).

  When drilling a hole using a laser, as shown in FIG. 12, after drilling a through hole (piercing) at the processing start point in the center of the large hole, the focal position is constant and the outline of the large hole is circled with laser light. Process by making one round in an arc.

JP 2000-334594 A

  In general, in a laser processing apparatus, a laser oscillated from a laser oscillator is condensed through a condenser lens and irradiated onto a workpiece (workpiece) surface. Therefore, the processing shape depends on the edge shape (conical shape) of the laser beam and becomes a tapered shape. In an aircraft wing, since a hole is made in a composite material for bolting and fixing, the hole wall surface is preferably a vertical wall. Therefore, when the taper angle is large, it is necessary to perform additional machining with a drill or the like to form a vertical wall.

  In Patent Document 1, after piercing at the center of the large hole, the focal position is set on the lower surface of the workpiece, the workpiece support is tilted so that the conical focused beam edge is perpendicular to the upper surface of the workpiece, and the hole wall surface is vertical. Describes the processing method. However, the method described in Patent Document 1 is complicated in control because the X and Y axes are moved while changing the height of a plurality of support points of the support base in order to tilt the work. Further, when the workpiece is a large structure such as an aircraft wing, it is difficult to move the workpiece. Moreover, when the workpiece is a thick plate, there is a problem that circumferential machining while being penetrated may not be possible.

  Further, the laser beam condensed by the condenser lens has a Gaussian distribution of energy in the cross section. FIG. 13 and FIG. 14 show an example of a processed part that is drilled using such a laser beam. When the focal position of the laser beam is set inside and irradiated, removal processing proceeds in an energy region that is equal to or higher than the processing threshold (FIG. 13).

  When the focal position is lowered while processing, the diameter of the laser beam irradiated on the upper surface of the workpiece increases (FIG. 13). As the diameter of the laser beam increases, the energy distribution in the cross section also becomes broader. For this reason, the energy density is reduced at the peripheral portion of the laser beam, and a vignetting portion that does not reach the processing threshold occurs. That is, when the focal position of the laser beam is lowered, the laser beam peripheral portion is vignetted on the workpiece upper surface, and only the central portion of the focused laser beam enters the processing portion. The upper inner wall surface of the processed portion has a small angle with the laser irradiation direction. Therefore, the laser energy density per unit area irradiated on the wall surface is small, and the hole diameter at the upper part of the processed portion is difficult to be expanded. Accordingly, the amount of light reaching the processing portion is reduced and the hole diameter at the bottom is reduced, so that the processing may not progress midway. For example, when drilling a workpiece to be processed with a thick plate, there is a problem that piercing cannot be performed, or even if piercing can be performed, circumferential processing cannot be performed while penetrating laser light.

  Further, the upper part of the processing part is deteriorated by the influence of heat because the laser beam is continuously irradiated even while the focal position of the laser beam is lowered. At this time, even if the laser power is increased, the temperature around the processed part may rise without reaching the penetration.

  Since CFRP contains a resin, its thermal conductivity is lower than that of metal, and during laser processing, heat from the laser light is stored in the vicinity of the processing portion, and the temperature around the processing portion tends to increase. In CFRP thick plate processing, the heat input from the laser beam increases, so that the periphery of the processed portion melts, causing problems such as deterioration in processing accuracy, delamination, and thermal alteration of the resin. Further, in the thick plate processing of CFRP, the periphery of the processed portion becomes 400 ° C. or higher, and the melted resin may be ejected from the hole of the carbon fiber sheet and burned. On the other hand, since metal and ceramic plates are nonflammable, discharge of the melt is not often a problem. As described above, the thick plate processing of a composite material such as CFRP is more difficult than the thick plate processing of metal or ceramic.

  The present invention has been made in view of such circumstances, and even in a large structural member formed of a thick plate composite material, while suppressing the thermal influence around the processing portion, An object of the present invention is to provide a processing apparatus and a processing method for a composite material capable of forming a vertical hole.

  In order to solve the above problems, the present invention uses a processing apparatus including a light source, a deflection unit that deflects laser light oscillated from the light source, and an fθ lens that condenses the deflected laser light. The laser beam is irradiated so that the irradiation angle (φ) formed by the center line of the fθ lens and the center line of the laser beam condensed by the fθ lens is equal to or larger than the convergence angle (δ) of the condensed laser beam. Provided is a method for processing a composite material that irradiates a portion where a processing wall surface of a processing member is formed.

  According to the above invention, by using the fθ lens, the laser beam deflected by the deflecting unit can be converged on a flat image surface and can be easily scanned at a constant speed, so that laser processing can be performed at high speed. become. By irradiating the irradiation angle (φ) and the convergence angle (δ) to a portion where the processing wall surface of the workpiece is formed as φ ≧ δ, a processing wall surface parallel to a line perpendicular to the tangent at the center of the processing area Can be formed. Further, since the irradiation angle of the laser beam can be controlled by the deflecting unit, it is not necessary to incline the workpiece, and complicated stage control and substrate height control are unnecessary.

  In one aspect of the invention described above, after irradiating the member to be processed with laser light to form a groove having a predetermined shape from the upper part of the portion where the processing wall surface is formed, the irradiation position of the laser light is determined from the width of the groove. It is preferable to move a small distance to form a focal plane groove by forming a plurality of different grooves stepwise in the same focal plane.

  By moving the laser beam irradiation position by a distance smaller than the width of the groove, in other words, the spot diameter of the laser light, the grooves constituting the focal plane groove overlap each other, thereby forming a focal plane groove with less unevenness. be able to.

  In one embodiment of the present invention, the plurality of other grooves may be formed stepwise in a direction away from the processing wall surface.

  By doing so, the laser beam is not continuously irradiated in the vicinity of the processing wall surface for a long time, so that the heat storage in the vicinity of the processing wall surface of the workpiece is reduced. Therefore, the temperature rise in the vicinity of the processed wall surface of the member to be processed (composite material) can be suppressed, and thermal alteration is less likely to occur.

  In one aspect of the invention described above, the focal plane groove formed of the groove and the plurality of other grooves is formed so that the opening width is a predetermined distance, and then the focal plane is lowered by the depth of the groove, and the opening width Repeats the step of forming another focal plane groove narrower than the previous focal plane groove, and has a side surface inclined toward the lower portion of the processed wall surface on the side facing the processed wall surface, and A hole penetrating the processed member may be formed.

  According to the above-described aspect, the hole is formed such that the opening width of the focal plane groove formed in the upper part of the workpiece is wide and the opening width is narrowed toward the lower part in the plate thickness direction. Accordingly, even if processing is performed while lowering the focal position, vignetting of the laser beam does not occur at the upper part of the workpiece. Therefore, it is possible to reliably cut and open the workpiece without stopping the processing. Further, since the frontage is widened, it becomes easy for an assist gas such as air blown to the processed portion to enter deeper. As a result, the machined portion can be efficiently cooled, and thermal alteration around the machining wall surface is suppressed.

  The present invention also provides an optical system including a light source, a deflecting unit that deflects laser light emitted from the light source, an fθ lens that condenses the deflected laser light, a center line of the fθ lens, The processing wall surface of the workpiece is formed so that the irradiation angle (φ) formed with the center line of the laser beam focused by the fθ lens is equal to or greater than the convergence angle (δ) of the focused laser beam. There is provided a processing apparatus for a composite material, comprising: a control unit that controls the optical system so as to irradiate a portion to be applied.

  According to the above invention, since the fθ lens is provided, the laser beam deflected by the deflecting unit can be condensed on a flat image surface and can be easily scanned at a constant speed, so that laser processing can be performed at high speed. . By providing the control unit, it is possible to irradiate the irradiation angle (φ) and the convergence angle (δ) to the portion where the processing wall surface of the workpiece is formed as φ ≧ δ, and therefore, the tangent at the center of the processing region A machining wall surface parallel to a line perpendicular to the surface can be formed. Further, since the irradiation angle of the laser beam can be controlled by the optical system, it is not necessary to incline the workpiece, and complicated stage control and substrate height control are not necessary.

  According to the present invention, by using a laser processing apparatus equipped with an fθ lens and irradiating a member to be processed with laser light so that an irradiation angle ≧ a convergence angle, the processing wall surface can be processed perpendicularly to the workpiece upper surface. . It is easy to handle drilling and cutting of large structures using composite materials such as aircraft wings and automobile bonnets.

It is a figure explaining the processing apparatus used in 1st Embodiment. It is a figure explaining the relationship between the incident angle to an f (theta) lens, and the irradiation angle of a laser beam. It is a figure explaining the process part which gave the drilling process. FIG. 4 is an enlarged view of a broken line area Z in FIG. It is a figure explaining the process part which gave the drilling process. It is a figure explaining the process part which gave the cutting process. It is a figure explaining the processing method of the N side edge part of a remaining material. It is a figure which is a perspective view of the to-be-processed member after a groove process. It is a figure explaining an example of groove processing. It is a figure explaining another example of groove processing. It is a figure explaining another example of groove processing. It is a figure explaining the conventional drilling method. It is a figure which shows an example of the process part drilled using the laser beam. It is a figure which shows an example of the process part drilled using the laser beam.

Below, one Embodiment of the processing method of the composite material which concerns on this invention is described with reference to drawings.
[First Embodiment]
The workpiece 1 processed in the present embodiment is a composite material and includes a layer in which a plurality of composite materials such as prepregs are stacked. The composite material is made of a resin reinforced with fibers. As the fibers, glass fibers, carbon fibers, resin fibers such as aramid resin (Kevlar), metal fibers such as stainless steel, ceramic fibers such as alumina, or wood chips are used. As the resin, an epoxy resin, a polyamide resin, a polyester resin, an acrylic resin, or the like is used. The composite material may be a member in which a layer made of a composite material is formed on a metal material such as titanium.

The processing apparatus used in this embodiment will be described with reference to FIG.
The laser processing apparatus used in this embodiment includes an optical system including a light source that oscillates laser light 2, a deflecting unit 3 that deflects laser light 2, and an fθ lens 4 through which the deflected laser light 2 passes. Is provided.
Although not shown, the light source is disposed on the back side of the paper surface of the deflecting unit 3a so as to oscillate the laser light 2 in a direction perpendicular to the paper surface.

  The deflecting unit 3 is either a galvanometer mirror system or a polygon mirror system. In this embodiment, a galvanometer mirror system is used. The galvanometer mirror system includes a first galvanometer mirror 3a and a second galvanometer mirror 3b. The first galvanometer mirror 3a is rotatable about the axis, and can deflect the laser beam 2 transmitted from the light source toward the second galvanometer mirror 3b. The second galvanometer mirror 3b is rotatable in the direction perpendicular to the axis of the first galvanometer mirror 3a, deflects the laser beam 2 deflected by the first galvanometer mirror 3a, and is directed to the fθ lens 4 at a desired angle. It can be made incident.

When the laser light is incident on the fθ lens 4 having an effective focal length f at an incident angle θ, the fθ lens 4 is X = fθ in the direction perpendicular to the center line from the focal position 6 of the center line 7 of the fθ lens system. It is a lens designed to focus on a distant position. The laser light incident on the fθ lens 4 is collected on a flat focal plane (image plane) 5. As the fθ lens 4, a lens capable of obtaining a desired focal plane 5 and a convergence angle (δ) is appropriately selected. The fθ lens 4 may be used as a combined fθ lens system.
Note that the optical system including the deflection unit and the fθ lens can move in the vertical direction.

Next, the processing method of the composite material using the said processing apparatus is demonstrated.
The processing apparatus having the above-described configuration is arranged so that the fθ lens 4 or the center line 7 of the fθ lens system is aligned with the vertical line at the center 6 of the region surface to be processed of the workpiece. Further, the optical system including the deflecting unit 3 and the fθ lens 4 is arranged at a height such that the focal plane 5 substantially coincides with the upper surface of the workpiece 2.

  In the processing apparatus, when the laser beam 2 is oscillated from the light source, the laser beam 2 is deflected by the first galvanometer mirror 3a toward the second galvanometer mirror 3b. The deflected laser beam 2 is deflected toward the fθ lens 4 by the second galvanometer mirror 3b. At this time, the optical system is controlled so that the irradiation angle (Φ) is equal to or larger than the convergence angle (δ) of the laser light 2 collected by the fθ lens 4. Specifically, the incident angle (θ) of the laser beam 2 to the fθ lens 4 is set.

  The convergence angle (δ) is an angle between the center line 8 of the laser light 2 and the outer peripheral line 9 (edge line) of the laser light 2. The irradiation angle (Φ) is an angle between the center line 7 of the fθ lens and the center line 8 of the laser beam condensed by the fθ lens 4. In FIG. 2, a line 7a obtained by translating the center line 7 is shown. Φ is also a deflection angle at the virtual center of the laser beam 2 viewed from the focal plane. The incident angle (θ) is an angle between the center line 7 of the fθ lens and the center line 8 of the laser beam.

The relationship between the incident angle of the laser beam 2 on the fθ lens 4 and the irradiation angle of the laser beam will be described with reference to FIG.
FIG. 2 (a):
When the incident angle (θ) of the laser light 2 to the fθ lens 4 is θ = 0, the irradiation angle (Φ) is Φ = 0. That is, the center line 8 of the laser beam overlaps with the perpendicular line at the center of the surface region to be processed of the workpiece 1 and is irradiated perpendicularly to the focal plane 5.

2 (b) and 2 (c):
When the incident angle (θ) of the laser beam 2 to the fθ lens 4 is θ> 0, the irradiation angle (Φ) is Φ> 0. Here, if the irradiation angle (Φ) and the convergence angle (δ) are Φ = δ, one edge line 9 of the laser beam overlaps with a line perpendicular to the focal plane 5 (FIG. 2B). . Further, if Φ> δ, the focal point can be moved in the direction X away from the center of the region surface to be processed of the workpiece 5 as shown in FIG. When the composite material is processed using the laser beam 2 having such an angle, a vertical wall can be formed in the composite material.

As described above, the processing range such as the hole radius can be controlled by changing the incident angle (θ) of the laser beam.
For example, let d be the diameter of the laser beam at a position going back from the focal point of the laser beam to the light source side by an effective focal length f. When f = 180 mm and d = 12 mm, the focal spot diameter is 30 μm. Since this value is considerably smaller than d, assuming that the convergence angle (δ) of the laser beam can be approximated by d / 2f, δ = 0.033 rad (1.9 °).

  Next, the irradiation procedure of the laser beam 2 will be described by taking a drilling process as an example. The laser light irradiation procedure of this embodiment includes a step of forming a focal plane groove and a step of forming a through hole. FIGS. 3A and 3B are diagrams for explaining a processed portion subjected to drilling, where FIG. 3A is a perspective view, FIG. 3B is a cross-sectional view taken along line XX in FIG. 3A, and FIG. FIG. 4 is an enlarged view of a broken-line area Z in FIG.

In the step of forming the focal plane groove, first, a laser beam 2 whose irradiation position is aligned with the processing start point (C) above the portion where the processing wall surface is formed is irradiated along a predetermined shape (contour). 3 to form the grooves _{C 1,} as shown in (c). The predetermined shape in the present embodiment is a circle (radius fθ) assuming a bolt hole for bolting.
The laser light irradiation conditions (pulse frequency, power, etc.) are appropriately set depending on the processing apparatus used, the material of the workpiece, and the like. The laser beam oscillation method may be either pulse oscillation or continuous oscillation.

When a composite material made of an epoxy resin reinforced with carbon fiber is used as a workpiece, for example, a laser processing apparatus having a pulse width of 300 f (femto) seconds, a wavelength of 532 nm, a pulse frequency of 20 kHz and a power of 1.2 w is used. When a laser beam is irradiated at, a groove having a processing depth (Δt) of 0.06 mm can be formed.
For example, when a laser having a pulse width of 1 n (nanosecond) and a wavelength of 532 nm is used and laser light is irradiated under the conditions of a pulse frequency of 50 kHz and a power of 8 w, a groove having a processing depth (Δt) of 0.4 mm may be formed. it can.
For example, when a laser having a pulse width of 400 nsec and a wavelength of 1065 nm is used and laser light is irradiated under the conditions of a pulse frequency of 50 kHz and a power of 35 w, a groove having a processing depth (Δt) of 1.5 mm can be formed.

After forming the grooves C _1, it moves radially inward the irradiation position of the laser beam 2 in the same focal plane. At this time, the movement width of the irradiation position of the laser light 2 is the same as or smaller than the spot diameter of the laser light. Then, along the circumference of the C ₁ groove while irradiating a laser beam 2 is turning once, to form the grooves C ₁ and the groove C ₂ concentric. Then, by moving the irradiation position of the laser beam 2 in the same manner as the grooves C _2, while successively reducing the radius, stepwise grooves C ₁ and the groove concentric to form to the groove C _n, a first focal plane groove Is processed. The opening width of the focal plane groove is a predetermined distance L, and n is an integer at which the opening width (distance from point C to point D) reaches the predetermined distance L.
The predetermined distance L is calculated from the equation (1).
L = t · tan (φ + δ) (1)
t is the thickness of the workpiece.

  Note that the “irradiation position” is preferably the focal position of the laser beam 2, but also includes irradiation with a small defocus and a larger spot diameter at the processing point.

  In the step of forming a through hole, the focal plane is lowered by the depth of the groove, and the step of forming another focal plane groove whose opening width is narrower than the previous focal plane groove is repeated to form a hole that penetrates the workpiece. To do. The through hole has a side surface inclined so as to approach the lower portion of the processing wall surface on the side facing the processing wall surface.

After forming the focal plane groove from the point C to the point D, the irradiation position is moved from the point D outward in the radial direction by ΔL. Further, the focal plane 5 is moved downward by Δt in the thickness direction of the workpiece 1, and the irradiation position is adjusted to the point E. The focal plane 5 may be moved by moving the optical system with respect to the workpiece. ΔL is calculated from Equation (2).
ΔL = Δt · tan (φ + δ) (2)

While irradiating the laser beam 2 to the point E, it is rotated once to form a groove E ₁ concentric with the groove C ₁ . The laser irradiation conditions are the same as the formation of grooves C _1. Subsequently, the irradiation position of the laser beam 2 is moved outward in the radial direction by a width equal to or smaller than the spot diameter. Next, while irradiating with a laser, it is rotated once to form a groove E ₂ concentric with the groove C ₁ . Then, by moving the irradiation position of the laser beam 2 in the same manner as the grooves E _2, while sequentially increasing the radius, stepwise forming the grooves C ₁ and the groove concentric to the groove E _m, the second focal plane groove Is processed. m is an integer necessary for the groove width of the second focal plane groove to reach the distance L-ΔL (point F).

Next, the focal plane 5 is translated downward by Δt, and the irradiation position is adjusted to the point G. While irradiating a laser beam 2, to turn once, thereby forming a groove C ₁ and the groove G ₁ concentric. Subsequently, as with the grooves C ₂ to C _n , the grooves G ₂ to _Go are formed up to the point H while decreasing the radius in order, and the third focal plane groove is processed. o is an integer necessary for the groove width (from point G to point H) of the third focal plane groove to reach the distance L−2ΔL.

To the focal wall reaches the bottom (point B) of the workpiece, the groove E ₁ to E _m, repeats the processing steps of the groove G _{1 ~} groove G _o, to form a plurality of focal plane groove. At this time, each focal plane groove is formed such that one side surface coincides with the processing wall surface and the opening width is narrower than the previous focal plane groove. Specifically, the end surface on the side away from the processing wall surface of the focal plane groove is processed so as to move to the processing wall side by ΔL each time the focal plane is lowered by one. By doing so, it is possible to machine a hole hollowed in a wedge shape having a side surface inclined at an angle (φ + δ) so as to approach the lower part of the workpiece 1. When the focal plane reaches point B, the hole is penetrated in the plate thickness direction of the workpiece 5. When the remaining material whose side surface is tapered is removed, a hole having a vertical wall surface is formed. Note that the processing start point may be set so that the radius of the concentric circle increases from the point D to the point C instead of the point C.

  The hole having the vertical wall surface can be formed with a radius greater than or equal to φ ≧ δ. When φ = δ, the processing removal amount is the smallest. Usually, the fθ lens sgalvano mirror scanning optical system is used for trimming (removing a film of a minute portion such as wiring) or marking (engraving), and the focal spot diameter is about 12 to 50 μm. In order to reduce the spot diameter, the laser beam diameter d is as large as 8 to 30 mm. However, it is not necessary to reduce the spot diameter in the drilling process of the composite material. Rather, in order to increase the processing speed, the spot diameter should be large, and 50 to 300 μm is preferable. Therefore, d may be about 1 to 7 mm. When d is small, the beam convergence angle δ is small. For example, vertical drilling with a radius of 3 mm or more when d = 4 mm and a radius of 1.5 mm or more (φ / θ = 0.65) when d = 2 mm is possible. Even in the case of machining a large hole with a radius of 50 mm, the smaller d is, the smaller δ is, and the smaller the machining removal amount is.

[Second Embodiment]
With reference to FIG. 5, another example of drilling will be described. In the present embodiment, the workpiece and the processing device to be used are the same as those in the first embodiment. 5A and 5B are diagrams for explaining a machined portion subjected to drilling, where FIG. 5A is a top view, FIG. 5B is a cross-sectional view taken along line KL in FIG. 5A, and FIG. Sectional drawing in the -J line is shown. In the present embodiment, similarly to the first embodiment, first, the laser beam 2 is irradiated onto the processing start point above the processing surface 20, and the laser beam 2 is irradiated as it is along a predetermined shape (contour) to form the groove C. ₁ is formed. The predetermined shape in the present embodiment is a square.

The irradiation procedure of the laser beam 2 is the same as that of the first embodiment except that the calculation method of the predetermined distance L is different.
The predetermined distance L differs between the KL cross section in FIG. 5B and the IJ cross section in FIG. K-L cross-section, a predetermined distance _{L 1} and the predetermined distance _{L 2} in I-J cross-section (diagonal) is calculated from each of formulas (3) and (4).
L ₁ = t · tan (φ ₁ + δ) (3)
L ₂ = t · tan (φ ₂ + δ) (4)
L ₂ = √2L ₁
φ ₂ > φ ₁
φ ₁ : Maximum required angle of irradiation angle (Φ) in KL section φ ₂ : Maximum required angle of irradiation angle (Φ) in IJ section (diagonal)

Further, in order to form a hole having a vertical wall, it is necessary that φ ₁ ≧ δ in the KL cross section.

[Third Embodiment]
An example of the cutting process will be described with reference to FIG. FIGS. 6A and 6B are diagrams for explaining a processed part subjected to cutting, where FIG. 6A is a top view and FIG. 6B is a cross-sectional view taken along line AA in FIG. In FIG. 6A, a circular broken line indicates a laser irradiable range. In the present embodiment, the workpiece and the processing device to be used are the same as those in the first embodiment.

In the present embodiment, as in the first embodiment, first, the laser beam 2 is irradiated to the machining start point C above the machining wall surface 30, and the laser beam 2 is irradiated as it is along a predetermined shape (contour) to form a groove. to form a C _1. The predetermined shape in the present embodiment is a straight line.
In this embodiment, the processed like region for wider than the irradiation range of the laser beam, by moving the workpiece 21 to form a groove C ₁ having a predetermined shape. For example, the workpiece 21 is held on a holding table that can move back and forth and right and left. The irradiation position of the laser beam 2 is aligned and fixed at the processing start point C of the workpiece 21 and irradiation is started. By moving the holding table in the cutting direction S (one direction), a groove C ₁ having a predetermined shape is formed in the workpiece 21.

After forming the grooves C _1, moves the irradiation position of the laser beam 2 in the same focal plane in the direction away from the processing wall 30 (the direction from the point M to point N). At this time, the movement width of the irradiation position of the laser light 2 is the same as or smaller than the spot diameter of the laser light. The laser beam 2 is fixed, to form parallel grooves C ₂ on the groove C ₁ by moving the workpiece 21 in a direction opposite to the S. Then moved into the groove C ₂ cutting direction the irradiation position of the laser beam 2 in the same manner as S (previously the opposite direction), stepwise form parallel grooves in a groove C ₁ to the groove C _p, first The focal plane groove is processed. p is an integer at which the groove width (from point M to point N) of the first focal plane groove reaches a predetermined distance L. The predetermined distance L is calculated as in the first embodiment.

  In the step of forming the through hole, similar to the first embodiment, the focal plane is lowered by the depth of the groove, and the step of forming another focal plane groove whose opening width is narrower than the previous focal plane groove is repeated. A hole penetrating the processed member is formed.

  In the present embodiment, since the predetermined shape is a straight line, the movement of the irradiation position for narrowing the opening width of the focal plane groove is performed in the direction from the point M to the point N or in the opposite direction. Further, the formation of the plurality of focal plane grooves after the second focal plane groove is performed by fixing the laser beam 2 and moving the workpiece 21 as in the formation of the first focal plane groove.

  Until the focal plane reaches the lower part (point O) of the workpiece 21, the focal plane groove is repeatedly formed to form a through hole. At this time, each focal plane groove is formed so that one side surface coincides with the processed wall surface 30 and the groove width is narrower than the previous focal plane groove. Specifically, the end surface of the focal plane groove on the side away from the processing wall surface 30 is processed so as to move to the processing wall surface side by ΔL each time the focal plane is lowered by one. By doing so, a hole hollowed in a wedge shape having a side surface 32 inclined at an angle (φ + δ) so as to approach the lower portion of the workpiece 21 can be processed.

  By moving the irradiation position of the laser light 2 to the opposite side in the diameter direction from the point M, it is possible to perform the same processing as described above on the target position across the center line 7 of the fθ lens.

As a modification of the present embodiment, a remaining material processing method will be described. FIG. 7 shows the N-side end of the remaining material 33.
First, the N-side end of the remaining material 33 is moved on the opposite side across the center line 7 of the fθ lens. It is preferable to arrange the point N at a target position with respect to the point M across the center line 7 of the fθ lens. The predetermined distance L is a width of the tapered portion 34 included in each focal plane (a distance from the processing wall surface 35 to the other end portion). In this modification, the end portion of the remaining material 33 is made a vertical wall surface by cutting away the tapered portion 34 at the end portion of the remaining material 33. Vignetting can be avoided in the processing of the ends. Therefore, the laser beam 2 may be irradiated to the point N at an angle such that Φ ≧ δ, and the irradiation position may be moved vertically downward to the point P for processing. By doing so, the cutting amount can be minimized.

[Fourth Embodiment]
An example of grooving will be described with reference to FIGS. FIG. 8 is a perspective view of the workpiece after groove processing. 9A and 9B are diagrams for explaining an example of the groove processing. FIG. 9A is a cross-sectional view, and FIG. 9B is a top view of FIG. 10A and 10B are views for explaining another example of the groove processing. FIG. 10A is a cross-sectional view, and FIG. 10B is a top view of FIG. FIGS. 11A and 11B are diagrams for explaining another example of the groove processing, in which FIG. 11A is a cross-sectional view, and FIG. 11B is a top view of FIG. In FIG. 9B, FIG. 10B, and FIG. 11B, a circular broken line indicates a laser irradiable range. In the present embodiment, the workpiece and the processing device to be used are the same as those in the first embodiment.

In the present embodiment, the member to be processed is held by a holding base that is movable in the in-plane direction, and the center line 7 of the fθ lens is aligned with the center of the width of the groove planned for the member to be processed. The predetermined shape is a straight line.
In FIG. 9, similarly to the first focal plane groove of the third embodiment, the irradiation position of the laser beam 2 is fixed at a predetermined position, and the workpiece 41 is moved to move the grooves C ₁ to C _q (first). 1 focal plane groove). At this time, the predetermined distance L is the opening width L _3. The opening width L ₃ refers to the point Q, to R point situated diametrically opposite. q is an opening width of the first focal plane grooves are an integer required to reach the predetermined distance L _3.
In the present embodiment, the all L ₃ the opening width of the focal plane groove after, to form a plurality of focal plane groove to reach a predetermined depth.

In Figure 10, while fixing the workpiece 41, by scanning the laser beam 2 from the point Q to the point R, to form a groove C ₁ in the opening width direction (the direction from the point Q to the point R). Thereafter, the workpiece 41 is moved in a direction U parallel to the machining wall surface 40. At this time, the movement width of the workpiece 41 (that is, the movement width of the irradiation position of the laser light 2) is the same as or smaller than the spot diameter of the laser light. The first focal plane groove (groove C ₁ to groove C _r ) is formed by repeating the operation of forming the groove and moving the workpiece. r, the length of the first focal plane the groove (the length of the processing wall 40 parallel to direction) is an integer required to reach a predetermined distance L _4.

In FIG. 11, the laser beam 2 is scanned from the point Q to the point R while the workpiece 41 is fixed, and the groove C ₁ is formed in the direction from the point Q to the point R. In FIG. 10, the line connecting the point Q and the point R is perpendicular to the machining wall surface 40, but in FIG. 11, the line connecting the point Q and the point R is oblique to the machining wall surface 40. I made it. Otherwise, the first focal plane groove is formed as in FIG. In the groove processing, when the convergence angle (δ) of the laser beam 2 is large, the aperture width (distance from the point Q to the point R) increases when the laser beam 2 is moved in the direction perpendicular to the processing surface 40. Therefore, the opening width (width in the direction perpendicular to the processing wall surface) can be reduced by moving the laser beam 2 in an oblique direction with respect to the processing surface 40.

1, 11, 21, 41 Workpiece member 2 Laser beam 3 Deflection section 4 fθ lens 5 Focal plane 6 Center of the region surface to be machined of the workpiece 7 Centerline of fθ lens 8 Centerline of laser beam 9 Outer circumference of laser beam Line 10, 20, 30, 35, 40 Processed wall surface 32 Inclined side surface 33 Remaining material 34 Tapered portion

Claims (5)

Using a processing apparatus comprising a light source, a deflection unit that deflects the laser light oscillated from the light source, and an fθ lens that condenses the deflected laser light,
The laser beam is irradiated so that the irradiation angle (φ) formed by the center line of the fθ lens and the center line of the laser beam condensed by the fθ lens is equal to or larger than the convergence angle (δ) of the condensed laser beam. A method of processing a composite material that irradiates a portion where a processing wall surface of a processing member is formed.   After irradiating the workpiece with laser light and forming a groove having a predetermined shape from the upper part of the place where the processing wall surface is formed, the irradiation position of the laser light is moved by a distance smaller than the width of the groove. The composite material processing method according to claim 1, wherein a plurality of different grooves are formed stepwise in the same focal plane to form a focal plane groove.   The method of processing a composite material according to claim 2, wherein the plurality of different grooves are formed stepwise in a direction away from the processing wall surface. After forming the focal plane groove composed of the groove and the plurality of other grooves so that the opening width is a predetermined distance,
Decreasing the focal plane by the depth of the groove, repeating the process of forming another focal plane groove whose opening width is narrower than the previous focal plane groove,
4. The composite material according to claim 2, wherein the composite material has a side surface inclined so as to approach the lower portion of the processed wall surface on a side facing the processed wall surface, and forms a hole penetrating the workpiece. Processing method. A light source;
An optical system composed of a deflection unit that deflects laser light emitted from a light source, and an fθ lens that condenses the deflected laser light;
The laser beam is irradiated so that the irradiation angle (φ) formed by the center line of the fθ lens and the center line of the laser beam condensed by the fθ lens is equal to or larger than the convergence angle (δ) of the condensed laser beam. A control unit for controlling the optical system so as to irradiate a portion where a processing wall surface of the processing member is formed;
A composite material processing apparatus comprising:

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