JP6053598B2 - Laser cutting method, laser emitting unit and laser cutting device - Google Patents

Description

  The present invention relates to a laser cutting method, a laser emitting unit, and a laser cutting device that perform cutting by simultaneously applying a laser beam and an assist gas to a plate material.

  Today, the laser cutting method is used for cutting various plate materials regardless of metal or non-metal. In particular, in precision cutting of thin metal sheets, the laser cutting method has many advantages, such as fewer burrs, easy handling of complicated contour shapes, and high-speed cutting. doing.

  In general, the laser cutting method locally heats and melts or evaporates a plate material with a narrowed laser beam while spraying an assist gas on the plate material, and a beam spot of the laser beam on the plate material along a preset cutting path. Move relative. Here, the assist gas not only blows and removes the melted material or evaporated material generated by cutting, but also serves to cool the plate material and to protect the laser optical system (particularly the condensing lens) from the scattered material. . Further, when oxygen gas is used as the assist gas, it also has a function of promoting melting and evaporation of the plate material by oxidation reaction heat.

JP-A-7-185874

  However, for example, a thin metal tape (plate material) such as a copper foil tape or an aluminum foil tape has a pattern in which a cutting path in the tape length direction and a cutting path in the tape width direction are alternately repeated. In the cutting process that continuously divides the laser beam, the conventional laser cutting method and apparatus have reached the limit in terms of the performance and efficiency of the cutting process.

  That is, in the conventional laser cutting apparatus, a gun type nozzle having a small-diameter tip is attached to the laser emission unit in order to spray assist gas onto the plate material to be processed with a sufficiently high pressure. For this reason, the gun type nozzle or the metal tape is moved relatively in the tape length direction with respect to the cutting path extending in the tape length direction of the metal tape, and the cutting path extending in the tape width direction on the metal tape. Moves the gun type nozzle or the metal tape relatively in the tape width direction. However, when moving either the gun type nozzle or the metal tape, it is impossible to move in two orthogonal directions alternately and at high speed (for example, at a tape feed speed of several meters / second). .

  Further, in the conventional laser cutting apparatus, when performing the cutting process, the gun type nozzle is moved relative to the plate material so that the beam spot of the laser beam goes around the outline of the cut pattern on the plate material. . Again, regardless of whether the gun type nozzle or the plate material is moved, the cutting speed is limited by the moving speed, and it is difficult to increase the speed.

  The present invention has been made in view of the practical requirements for the cutting process as described above and the problems of the prior art, and has dramatically improved the performance and efficiency of the laser cutting process that divides a plate material along a predetermined pattern path. A laser cutting method, a laser emitting unit, and a laser cutting device that can be improved in an improved manner.

  In the laser cutting method of the present invention, a laser beam oscillated and output from a laser oscillator is condensed and irradiated by a condenser lens while spraying an assist gas onto a plate material to be processed, and a beam spot of the laser beam is irradiated. A laser cutting method in which the plate is melted or evaporated along a path along which the beam spot moves to divide the plate material by relative movement, and is divided in front of the condenser lens on the optical path of the laser beam. A galvano scanner is disposed, and a nozzle having an endless loop-shaped slit is disposed downstream of the condenser lens, and the assist gas is sprayed onto the plate material through the slit-shaped distal end of the nozzle. However, the laser beam from the laser oscillator is converted into the galvano scanner, the condenser lens, and the nozzle. Irradiating the plate material through the slit-shaped tip, and scanning the laser beam by the galvano scanner so that a beam spot of the laser beam traces a preset cutting path on the plate material, The laser beam is moved in the circumferential direction within the slit-shaped tip of the nozzle.

  In the laser cutting method having the above-described configuration, the laser beam is moved in the circumferential direction in the slit-shaped tip opening of the nozzle by the scanning operation of the galvano scanner, and is condensed on the plate material. By spraying the assist gas onto the plate material with a sharp discharge flow, the beam spot of the laser beam can be continuously and rapidly moved on the plate material in a two-dimensional direction. Thereby, the plate material can be laser cut (cut out) into a contour shape corresponding to the loop shape of the slit-shaped tip opening. Furthermore, simultaneous use of laser scanning that moves the laser beam in the loop direction in the endless loop of the slit-shaped front end and the minimum relative movement (typically linear movement) between the plate and nozzle Thus, the plate material can be divided at a high speed along a certain two-dimensional cutting path (particularly a cutting path that repeats a certain pattern in the direction of the linear movement).

  In a preferred embodiment of the present invention, the plate material is a metal tape, and a cutting path having a pattern in which a cutting path in the tape length direction and a cutting path in the tape width direction are alternately repeated is set on the metal tape. In this case, the loop shape of the slit-shaped tip is a triangle. Then, in order to divide the metal tape along the cutting path, the laser beam moves in the slit tip end of the nozzle while the metal tape moves at a constant speed in the tape length direction relative to the nozzle. The operation of making a round in the turning direction is repeated at a constant cycle.

  The laser emission unit of the present invention is a laser emission unit that emits a laser beam while spraying an assist gas toward a plate material to be processed for laser cutting, and the laser beam transmitted from a laser oscillator is A condensing lens for condensing the light on the plate material, and provided in the front stage of the condensing lens on the optical path of the laser beam, so that the beam spot of the laser beam traces the cutting path set on the plate material In addition, a galvano scanner for scanning the laser beam in a two-dimensional direction and the assist gas sent from an assist gas supply unit provided at the rear stage of the condenser lens on the optical path of the laser beam are introduced. And a cylindrical nozzle body for introducing the laser beam transmitted through the condenser lens, and an endless And a slit-shaped tip opening forming the-loop shape, and a nozzle for emitting the laser beam while ejecting the assist gas from said slit-shaped tip opening.

  According to the laser emission unit having the above-described configuration, the laser beam is moved in the circumferential direction in the slit-like tip opening of the nozzle by the scanning operation of the galvano scanner to be condensed on the plate material, and the pressure is higher than the slit-like tip opening. By spraying the assist gas onto the plate material with a sharp discharge flow, the beam spot of the laser beam can be continuously and rapidly moved in the two-dimensional direction on the plate material.

  In a preferred embodiment of the present invention, the condenser lens is a telecentric fθ lens. The laser beam scanned by the galvano scanner always passes through the space in the nozzle body and the slit-like tip in parallel with the optical axis of the lens regardless of the incident position or angle of incidence on the condenser lens, and enters the cutting path on the plate. Condensate.

  As a preferred embodiment, a transparent plate that closes the opening at the upper end of the nozzle body and transmits the laser beam from the condenser lens is provided. In the nozzle body, there is provided a suspension member whose upper end is coupled to the transparent plate and whose lower end is surrounded by a slit-shaped tip end. The slit-shaped front end of the nozzle is formed so as to surround the periphery of the lower end of the suspension member.

  Preferably, the suspension member has a suspension rod that thickens in an inversely tapered manner from the top to the bottom, and the space between the side surface of the suspension rod and the side wall of the nozzle body is tapered from the top to the bottom. Narrow. With this configuration, the assist gas can be ejected sharply at a high pressure with less turbulent flow than the slit-shaped front end.

  The laser cutting device of the present invention includes the laser emitting unit, a laser oscillator that oscillates and outputs a laser beam, a laser transmission unit that transmits the laser beam from the laser oscillator to the laser emitting unit, and the laser emitting unit An assist gas supply unit that supplies assist gas to the nozzle.

  In the laser cutting device having the above-described configuration, the laser beam is moved in the circumferential direction in the slit-like tip opening of the nozzle by the scanning operation of the galvano scanner and condensed on the plate material, and a higher pressure than the slit-like tip opening is provided. By spraying the assist gas onto the plate material with a sharp discharge flow, the beam spot of the laser beam can be continuously and rapidly moved on the plate material in a two-dimensional direction.

  According to a preferred embodiment of the present invention, the plate material is provided with a moving mechanism that performs relative movement (typically linear movement) in a predetermined direction between the laser emitting unit and the plate material to be processed. It is possible to divide at high speed along a certain two-dimensional cutting path (particularly a cutting path that repeats a certain pattern in the direction of the linear movement).

  According to the laser cutting method, the laser emitting unit or the laser cutting apparatus of the present invention, the performance and efficiency of the laser cutting processing for dividing the plate material into a predetermined pattern can be dramatically improved by the configuration and operation as described above. it can.

It is a figure showing the whole laser cutting device composition in one embodiment of the present invention. It is a top view which shows the form of the board | plate material and cutting path | route in one Example. It is a front view which shows the structure of the process table mechanism in an Example. It is a perspective view which shows the structure around the table roller of the said process table mechanism. It is a perspective view which shows the structure of the trunk | drum of the said table roller. It is a perspective view which shows the structure of the optical system in a laser emission unit. It is a perspective view which shows the structure of the nozzle in an Example. It is a top view which shows the structure of the said nozzle. It is a longitudinal cross-sectional view which follows the ANA line of FIG. 6B. It is a figure which shows an example of the layout conditions set between a cutting | disconnection path | route and the loop shape of a slit-shaped front-end | tip opening in an Example. It is a figure which shows another example of the said layout conditions. It is a figure which shows another example of the said layout conditions. It is a figure which shows each step of the laser cutting process which cut | disconnects one unit of a cutting path in an Example. It is a figure which shows each step of the laser cutting process which cut | disconnects one unit of a cutting path in an Example. It is a figure which shows the loop shape and layout conditions of the slit-shaped front-end | tip opening in one modification. It is a longitudinal cross-sectional view which shows the structure of the nozzle in one modification. It is a longitudinal cross-sectional view which shows the structure of the nozzle in another modification.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
[Configuration of the entire device]

  FIG. 1 shows a configuration of a laser cutting device according to an embodiment of the present invention. The laser cutting apparatus includes a laser oscillator 10, a laser power source 12, a laser transmission system 14, a laser emission unit 16, a main control unit 18, a scanner control unit 20, an assist gas supply unit 22, a processing table mechanism 24, and a touch panel 26. Yes.

  The laser oscillator 10 is, for example, a single mode fiber laser oscillator, and includes an oscillation optical fiber having a core doped with, for example, rare earth element ions as a light emitting element, and pumping light for pumping on one end face of the oscillation optical fiber. And a pair of optical resonator mirrors that resonately amplify and output light of a predetermined wavelength that is emitted in the axial direction from both ends of the oscillation optical fiber, for example, a high output of 500 W or more And oscillates and outputs a continuous-wave or Q-switched pulsed laser beam LB having a high light collecting property.

  The laser power source 12 supplies an excitation current to a light source (generally a laser diode) of an electro-optical excitation unit of the laser oscillator 10 under the control of the main control unit 18. Although not shown, it is possible to provide a power feedback mechanism for controlling the excitation current by feeding back the power of the laser beam LB output from the laser oscillator 10 to the laser power source 12.

  The laser beam LB output from the laser oscillator 10 is folded back in a predetermined direction by, for example, a vent mirror 30 in the laser transmission system 14, and then condensed by the condenser lens 34 in the incident unit 32 to be transmitted by the transmission optical fiber 36. It is incident on one end face of. The transmission optical fiber 36 is made of, for example, an SI (step index) type fiber, and transmits the laser beam LB input from one end face in the incident unit 32 to the laser emitting unit 16.

  The laser emission unit 16 includes a scanner housing 38 connected to the end of the transmission optical fiber 36 and a nozzle 40 connected to the outlet of the scanner housing 38. The scanner housing 38 accommodates optical components such as a collimating lens 42, a galvano scanner 44 (FIG. 5), and a condenser lens 46. The condenser lens 46 is provided at the bottom of the scanner housing 38 or in the vicinity of the outlet, and is arranged coaxially with the nozzle 40. The specific configuration and operation of the optical system in the scanner housing 38 will be described in detail later with reference to FIG.

  The nozzle 40 is connected to the outlet (lower end) of the scanner housing 38 in a posture (usually a vertically standing posture) with the slit-shaped tip end 40a facing the processing table mechanism 24, and passes through the condenser lens 34. The laser beam LB is passed through the lower part of the laser beam LB without reflection and emitted toward the plate material W on the processing table mechanism 24 from the slit-shaped tip opening 40a, and is sent from the assist gas supply unit 22 through the gas supply pipe 48. The resulting assist gas AG is sprayed onto the plate material W from the slit-shaped tip opening 40a. Specific configurations and operations of the nozzle 40 and the slit-shaped tip 40a will be described in detail later with reference to FIGS. 6A to 6C.

  The processing table mechanism 24 supports the plate material W to be processed facing the slit-shaped tip port 40a of the nozzle 40 and supports it horizontally at least immediately below it, and moves in the vicinity of the slit-shaped tip port 40a of the nozzle 40 in the horizontal direction. It is supposed to let you. The processing table mechanism 24 can take any configuration depending on the shape of the plate material W, the content of the cutting process, and the like.

The main control unit 18 includes a CPU (microcomputer), and controls the operation of the entire apparatus or each unit, particularly the laser emission unit 16 and the machining table mechanism 24 according to various programs (software) stored in the program memory. Then, information (set values, monitor information, etc.) is exchanged with the user (workers, maintenance personnel, etc.) via the input unit 26a and the display unit 26b of the touch panel 26.

[Example]

The laser cutting device, as an example, as shown in FIG. 2 (a), a thin metal tape W _T, such as a copper foil tape, aluminum foil tape as the plate material W to be processed, the metal tape W _T Is repeated over several meters or several tens of meters along the cutting path CK of a repetitive pattern similar to a pulse waveform (a pattern in which the cutting path in the tape length direction and the cutting path in the tape width direction are alternately repeated). It has an apparatus configuration and functions suitable for cutting processing. After the cutting process, the metal tape W _T is separated into two pieces (W _m , W _M ) with the cutting path CK as a boundary, as shown in FIG. As an example, he discarded the narrow strip W _m of edges, wider strip W _M is used in the electrode for example a lithium ion battery as a workpiece.

FIG. 3 shows the overall configuration of the machining table mechanism 24 in this embodiment. The processing table mechanism 24 includes a supply reel 50 for feeding the metal tape W _T, a take-up reel 52 for winding the metal tape W _T, of the nozzle 40 between the take-up reel 52 and supply reel 50 arranged opposite to the slit-shaped tip opening 40a, the slit-shaped tip opening of the nozzle 40 by placing only certain rotation angle on the outer circumferential surface of the rotation in the middle of a metal tape W _T fed from the supply reel 50 to the take-up reel 52 a table roller 54 which passes by the 40a in one horizontal direction (Y ₊ direction), and a pair of tension rollers 56 for applying tension to the metal tape W _T before and after the table roller 54.

Further, the processing table mechanism 24, as the metal tape W _T is moved in the tape feed direction (Y ₊ direction) immediately below the slit-shaped tip opening 40a of the nozzle 40 at a constant speed, supply reel 50, the take-up reel 52 And the motors 58, 60, 62 for rotating the table rollers 54, respectively, and the rotational operation (especially the rotational speed) of these motors 58, 60, 62 according to instructions from the main control unit 18 are individually and collectively controlled. And a feed control unit 64.

4A and 4B show the configuration of the table roller 54. FIG. The body 66 of the table roller 54 is configured as a hollow cylinder made of porous metal or ceramic. At both ends of the body portion 66, the flange portion or flange portion 68 for preventing the lateral displacement of the metal tape W _T is provided. Both end surfaces of the body 66 are closed, and a hollow rotating shaft 70 protruding from one end surface serves as a drive shaft of the motor 60 (FIG. 3) via a driven pulley 72, a timing belt 74 and a drive pulley (not shown). Are combined. Furthermore, the tip of the hollow rotating shaft 70 is connected to a vacuum tube (not shown) via a rotary joint (not shown). Vacuum from a vacuum device (not shown) is applied to the inside of the table roller 54 via a vacuum tube, a rotary joint, and a rotating shaft 70, and from the inside of the table roller 54 to a metal tape via a porous body 66. Given to W _T. Thus, the metal tape W _T while being adsorbed or held by a vacuum force over a rotation angle of a predetermined the barrel 66 of the table roller 54, so as to pass immediately below the slit-shaped tip opening 40a of the nozzle 40 Yes.

Further, in the body portion 66 of the table roller 54, an endless surface extending in the circumferential direction with the same shape and repeated pattern as the cutting path CK (FIG. 2) is provided on the outer peripheral surface passing directly under the slit-like tip opening 40a of the nozzle 40. The groove 76 is formed. Thus, the molten debris that during the laser cutting process occurs in the cutting path CK on the metal tape W _T is made to fall into the groove 76 beneath the pressure of the assist gas AG is blown from the slit-shaped tip opening 40a ing. Thus, without metal tape W _T is welded to the roller 54, it can be reliably cut.

  FIG. 5 shows the configuration of the optical system built in the scanner housing 38 (FIGS. 1 and 3) of the laser emission unit 16.

In the scanner housing 38, a collimating lens 42, a galvano scanner 44, and a condensing lens 46 are provided in an arrangement as shown in FIG. More specifically, the collimating lens 42 is arranged in a vertical posture in the horizontal optical axis in the vicinity of the side wall of the scanner housing 38, X-axis galvanometer mirror 80 _X of X-axis galvanometer scanners 44 _X in the collimating lens 42 is approximately 45 ° Faces horizontally with an oblique posture. The rotational drive unit of the X-axis galvano scanner 44 _X is housed in a cylindrical X-axis galvano casing 82 _X , and is connected to the scanner control unit 20 (FIG. 1) via an electric cable 84 _X.

On the other hand, the Y-axis galvano mirror 80 _Y of the Y-axis galvano scanner 44 _Y is inclined by about 45 ° to the condenser lens 46 arranged in a horizontal posture with the optical axis perpendicular to the exit of the scanner housing 38. Facing vertically. Among the optics enclosure 38 faces obliquely at an angle X-axis galvanometer mirror 80 _X and Y-axis galvanometer mirror 80 _Y together also predetermined cross each other. The rotational drive unit of the Y-axis galvano scanner 44 _Y is housed in a Y-axis galvano casing 82 _Y and is connected to the scanner control unit 20 via an electric cable 84 _Y.

Among the scanner housing 38, the laser beam LB emitted at a predetermined angle of divergence from the end face of the transmission optical fiber 36, X-axis galvanometer mirror 80 _X and Y-axis galvanometer mirror 80 becomes parallel light by the collimator lens 42 _The light is sequentially incident on _Y and reflected, and finally passes through the condenser lens 46. Then, the laser beam LB having passed through the condensing lens 46, through the nozzle 40 passes through vertically downward, so as to condense the cutting path CK on the metal tape W _T. The condensing lens 46 is a telecentric fθ lens, and the laser beam LB incident from the Y-axis galvanomirror 80 _Y is always directed vertically downward parallel to the optical axis of the lens regardless of the incident position or incident angle. To collect light.

  6A to 6C show the configuration of the nozzle 40 of the laser emission unit 16. The nozzle 40 includes a triangular cylindrical nozzle body 86, a triangular prism-shaped suspension bar 88 that is suspended in the nozzle body 86, and a transparent plate, such as a glass plate 90, that supports the suspension bar 88. doing. The glass plate 90 closes the upper end opening of the nozzle body 86, and its lower surface is joined to the upper end surface 88 a of the suspension bar 88 and the upper end surface 86 a of the nozzle body 86. As the material of the nozzle body 86 and the suspension rod 88, a metal that repels light from the workpiece (plate material), such as copper, is preferably used.

  The nozzle body 86 and the suspension bar 88 have triangular end faces or cross sections that are substantially similar to each other in plan view (FIG. 6B). Further, while the side wall 86b of the nozzle body 86 is tapered from the top to the bottom, the hanging rod 88 is thickened in the reverse taper shape (FIG. 6C). Thereby, the space SP between the side surface 88b of the suspension bar 88 and the side wall 86b of the nozzle body 86 is tapered in a tapered shape from the top to the bottom. At the tip (lower end) of the nozzle 40, a slit-like tip port 40a that forms an endless loop shape (triangle) between the lower end 86c of the nozzle body 86 and the lower end 88c of the suspension rod 88 is formed. That is, the slit-shaped front end port 40a makes a round along the periphery of the lower end 88c of the suspension rod 88, and forms an endless triangular loop shape.

The laser beam LB transmitted through the condenser lens 46 passes through the glass plate 90 while narrowing the beam diameter, and passes through the space SP in the nozzle body 86 and the slit-shaped tip 40a vertically without reflection. ing. For example, when the beam diameter when the laser beam LB passes through the slit tip 40a is 20 μm, the slit width D _W (FIG. 6B) of the slit tip 40a is selected to be 70 to 100 μm. Moreover, the distance interval D _H (FIG. 6C) between the slit-shaped tip opening 40a and the metal tape W _T is selected, for example, as 100 to 300 μm.

  A gas inlet 92 is formed at the upper part of one side surface of the nozzle body 86. The tip of the assist gas supply pipe 48 is connected to the gas inlet 92. The assist gas AG sent from the assist gas supply unit 22 through the assist gas supply pipe 48 flows into the space SP in the nozzle body 86 from the gas introduction port 92, and is a narrow slit-shaped tip that is an opening of the space SP. It ejects from the end opening 40a. In particular, in this embodiment, since the space SP is narrowed in a tapered shape from the top to the bottom in the nozzle body 86, the assist gas AG is ejected sharply at a high pressure with less turbulent flow than the slit-shaped tip 40a. It is configured to do. As the assist gas AG, oxygen gas, nitrogen gas, air or the like is used.

  Next, with reference to FIGS. 7A to 8B, the operation of laser cutting in this embodiment will be described.

As described above, in this embodiment, the processing target of the plate member W is a metal tape W _T, cutting path CK constant repetitive pattern similar to the pulse waveform on the metal tape W _T is set (Fig. 2). In this case, the slit-shaped tip 40a of the nozzle 40 provided in the laser emission unit 16 needs to satisfy three conditions on the layout as shown in FIG. 7A with respect to such a cutting path CK.

In other words, it is assumed that the triangular loop of the slit-shaped front end port 40a includes three vertices A, B, and C and three sides (line segments) a, b, and c. The first condition is a fourth cutting section in which an arbitrary base, for example, a, extends in the direction opposite to the tape feeding direction (Y ₊ direction) (Y ₋ direction) in one unit (1 cycle) of the cutting path CK. overlap K ₄ (section corresponding to a horizontal base portion of the pulse), yet is shorter than the distance E of the fourth cutting section K ₄ of. The second condition is that the height h of the triangle orthogonal to the base a extends in the outward tape width direction (X ₊ direction) in one unit (one cycle) of the cutting path CK. (Interval corresponding to the vertical rising portion of the pulse) K ₁ and a third cutting interval (interval corresponding to the vertical falling portion of the pulse) K ₃ extending in the inward tape width direction (X _- direction) Is equal. The third condition is that the hypotenuses b and c can cross the third and first cutting sections obliquely.

In one unit (one cycle) of the cutting path CK, the direction (Y ₊ direction) opposite to the tape feeding direction (Y ₊ direction) from the end of the _first cutting section K _{1 to} the beginning of the third cutting section K _{3 -} section extending direction), the section corresponds to the horizontal peak portion of the second section (pulse) is K _2.

  Each corner of the cutting path CK shown in FIG. 7A is substantially strictly perpendicular. However, as shown in FIG. 7B, each corner of the cutting path CK may be appropriately rounded. Further, the triangular loop of the slit-shaped tip 40a is not necessarily an isosceles triangle (b = c), and may be, for example, an unequal triangle (b ≠ c) as shown in FIG. 7C.

  The main control unit 18 inputs the above processing conditions and various set values through the operation panel 26, and stores various parameter values used for the scanning operation of the galvano scanner 44 and the tape feeding operation of the processing table mechanism 24 in a table on the memory. Store it. When an activation signal is input in a state where the metal tape WT is loaded in the processing table mechanism 24, the main control unit 18 sets the device according to a predetermined program (software) stored in the memory and the parameter value. Each part is controlled to perform laser cutting.

In this laser cutting processing, the laser power source 12 causes the laser oscillator 10 to oscillate and output a continuous wave or Q switch pulse laser beam LB with a predetermined power. The scanner control unit 20, by scanning the laser beam LB through the galvano scanner 44 of the laser emitting unit 16, the two-dimensional direction, that is X direction in the horizontal plane of the beam spot BS of the laser beam LB on the metal tape W _T (tape width direction) And in the Y direction (tape length direction). Assist gas supply unit 22 blows the assist gas AG to the metal tape W _T through the nozzle 40 of the laser emitting unit 16. Feed control unit 64 of the processing table mechanism 24, such that the metal tape W _T passes at a constant speed V _T directly under the slit-shaped tip opening 40a of the nozzle 40 in the tape feed direction (Y ₊ direction), the motor 58, 60 , 62 and the rotation speed of the supply reel 50, take-up reel 52 and table roller 54 are controlled.

In the metal tape W _T , the base material on the cutting path CK facing the slit-shaped tip opening 40a of the nozzle 40 is heated by the energy of the laser beam LB to melt or evaporate, and the melted scattered matter passes through the slit-shaped tip opening 40a. The gas is separated from the cut portion by the pressure of the assist gas AG and falls into the groove 76 of the table roller 54. As described later laps, while the metal tape W _T is moved at a constant speed V _T in the tape feed direction (Y ₊ direction), the scanning galvanometer scanner 44 through the slit-shaped tip opening 40a of the laser beam LB nozzle 40 by repeatedly moving at a variable moving direction and speed in a direction, the beam spot BS of the laser beam LB follows the cutting path CK on the metal tape W _T (trace). Thus, so that the metal tape W _T is divided along the cutting path CK.

Figure 8A and 8B, the laser cutting process of this embodiment, showing the different stages of the beam spot BS of the laser beam LB to trace one unit (one cycle) of the cutting path CK on metal tape W _T. In the drawing, a dotted cutting path <CK> is an uncut part, and a solid cutting path [CK] is a cut part.

First, as shown in FIG. 8A (a), at a certain time point t ₁ , the laser beam LB is positioned at the apex A in the slit-shaped tip opening 40a, and the first in one unit of the cutting path CK. and it is located at the starting end of the cutting interval K ₁ of. At this time, the metal tape W _T is moving at a constant speed V _T in the tape feeding direction (Y ₊ direction), and the laser beam LB is also moving in the slit-shaped tip opening 40a in a rotating direction. And moving in speed. Here, the apex A is located at the most upstream position in the slit-shaped tip opening 40a in the tape feeding direction (Y ₊ direction).

When the first cutting section K ₁ moves downstream of the apex A in the tape feeding direction (Y ₊ direction) immediately after the time t ₁ , as shown in FIG. 8A (b), the laser beam LB Moves from the apex A toward the apex B in the hypotenuse b of the slit-shaped tip 40a. Moving speed V _b of the laser beam LB at this time, the beam moving velocity component V _{Y +} in the tape feed direction (Y ₊ direction), an outward the tape width direction (X ₊ direction) of the beam moving velocity component V _{X +} a Given as a vector composition, V _b = √ (V _{X +} ² + V _{Y +} ² ). Here, the beam movement speed component V _{Y +} in the tape feed direction (Y ₊ direction) is defined by the scanning operation of the Y-axis galvano scanner 44 _Y , and is equal to the tape movement speed V _T (ie, V _{Y +} = V _T ). Be controlled.

Also, cutting path CK is not angular perpendicular (in the case of FIG. 7A) when the slit-shaped tip opening 40a is an isosceles triangle, when the length of the base a and L _a, as shown in (c) of FIG. 8A At the time point t ₂ (t ₂ = t ₁ + L _a / 2V _T ) when the starting end of the first cutting section K ₁ passes through the middle of the base a, the laser beam LB reaches the end of the first cutting section K ₁ , that is, The beam moving speed component V _X in the outward tape width direction (X ₊ direction) is controlled so as to reach the apex B. That is defined by the beam moving velocity component V _{X +} is a scanning operation of the X-axis galvanometer scanners 44 _X in the tape width direction outward (X ₊ direction) when the laser beam LB moves hypotenuse b, L _a / 2V _The speed is controlled to satisfy the condition of _T = h / V _{X +} (that is, V _{X +} = 2V _T * h / L _a ).

As described above, the metal tape W _T continues to move at a constant speed V _T in the tape feeding direction (Y ₊ direction), while the laser beam LB moves from the vertex A to the vertex B in the hypotenuse b of the slit-shaped tip 40a. by moving at a predetermined velocity V _b towards extends in the tape width direction of the outward (X ₊ direction) from the starting point the beam spot BS of the laser beam LB is in a unit cutting path CK (1 cycle) It traces the first cutting section K _1.

When the laser beam LB reaches the end of the first cutting section K ₁ , that is, the vertex B, the galvano scanner 44 temporarily stops the movement of the laser beam LB at the position of the vertex B. On the other hand, the metal since the tape W _T is moved at a constant speed V _T to without interruption tape feeding direction (Y ₊ direction), the laser beam LB is slit-shaped tip opening 40a on a metal tape W _T while located at the apex B of The second cutting path K ₂ is relatively moved at the speed V _T in the direction (Y ₋ direction) opposite to the tape feeding direction (Y ₊ direction). Thus, as shown in (d) of FIG. 8A, with L _a / 2V _T or L _K2 / V _T elapsed time t ₃ from the time point t _2, the laser beam LB and the second end of the cutting interval K ₂ To reach. Here, L _K2 is the distance of the _second cutting section K ₂ , and L _K2 = L _a / 2 in the example of FIG. 7A.

Thus, while the metal tape W _T continues to move in the tape feeding direction (Y ₊ direction) at a constant speed V _T , the laser beam LB stops at the apex B of the slit-shaped tip 40a for a certain period of time, so that the laser beam The beam spot BS of LB extends in the direction (Y ₋ direction) opposite to the tape feeding direction (Y ₊ direction) from the end of the first cutting section K ₁ in one unit (1 cycle) of the cutting path CK. Two cutting sections K ₂ will be traced.

When the laser beam LB reaches the end of the second cutting section K ₂ , the galvano scanner 44 resumes the scanning operation, and the laser beam LB moves from the vertex B toward the vertex C as shown in FIG. 8B (e). It moves in the hypotenuse c of the slit-shaped tip 40a. Here, the vertex C is located on the most downstream side in the slit-shaped tip opening 40a in the tape feeding direction (Y ₊ direction).

The speed V _c when the laser beam LB moves in the hypotenuse c is the beam movement speed component V _{Y + in} the tape feed direction (Y ₊ direction) and the beam movement speed in the inward tape width direction (X ₋ direction). Given as a vector composition with the component V _X− , V _c = √ (V _X− ² + V _{Y +} ² ). Also in this case, the beam moving speed component V _{Y +} in the tape feeding direction (Y ₊ direction) is defined by the scanning operation of the Y-axis galvano scanner 44 _Y and is equal to the tape moving speed V _T (ie, V _{Y +} = V _T ). Controlled. Also, the tape width direction of the inward _- beam movement velocity component V _X- is in the (X-direction) is defined by the scanning operation of the X-axis galvanometer scanners 44 _X, the _{L a / 2V T = h /} V X- conditions The filling speed (V _X− = 2V _T * h / L _a ) is controlled.

Thus, while the metal tape W _T continues to move in the tape feeding direction (Y ₊ direction) at a constant speed V _T , the laser beam LB moves from the vertex B to the vertex C in the hypotenuse c of the slit tip 40a. By moving at a predetermined speed V _c , the beam spot BS of the laser beam LB moves inward in the tape width direction (X) from the end of the second cutting section K ₂ within one unit (one cycle) of the cutting path CK. The third cutting section K ₃ extending in the ₋ direction) is traced. Then, as shown in (f) in FIG. 8B, when t ₄ when from the time point t ₃ has elapsed L _c / V _c, the laser beam LB reaches the apex C.

When the laser beam LB reaches the end of the third cutting section K ₃ , that is, the vertex C, the galvano scanner 44 switches the moving direction of the laser beam LB to a direction (Y ₋ direction) opposite to the tape feeding direction (Y ₊ direction). . Thus, as shown in (g) in FIG. 8B, the laser beam LB towards the vertex C to vertex A moves through the bottom a slit-shaped tip opening 40a at a predetermined speed V _a. In this case, the next one unit starting point of the cutting path CK moving in the tape feeding direction (Y ₊ direction) arrives just below the vertex A of the slit-shaped tip 40a, and at the same time, the opposite direction (Y ₋ as well laser beam LB moves in direction) arrive at the same vertex a, the beam moving velocity V _a is controlled. That is, the condition of (E−L _a ) / V _T = L _a / V _a may be satisfied, and V _a = L _a * V _T / (E−L _a ) by the scanning operation of the Y-axis galvano scanner 44 _Y. Controlled.

Thus, while the metal tape W _T continues to move at a constant speed V _T in the tape feed direction (Y ₊ direction), the laser beam LB moves from the vertex C to the vertex A in the bottom side a of the slit-shaped tip 40a. By moving at _a predetermined speed Va, the beam spot BS of the laser beam LB moves in the tape feed direction (Y ₊ direction) from the end of the third cutting section K ₃ within one unit (one cycle) of the cutting path CK. and opposite direction _- traces the cutting section K ₄ of the fourth extending direction (Y direction) (last). Then, as shown at (h) in FIG. 8B, when t ₅ has elapsed L _a / V _a from the time t _4, the laser beam LB reaches the vertex A. From this time t ₅ , the laser cutting process for the next unit (one cycle) of the cutting path CK is repeated in exactly the same operation as described above.

As described above, in this embodiment, while moving at a constant speed V _T to the metal tape W _T is the tape length direction parallel to the tape feeding direction (Y ₊ direction), and the nozzle 40 is physically stationary while blowing the assist gas AG in metal tape W _T in a sharp plume of small high pressure turbulent than the slit-shaped tip opening 40a state, the slit-shaped tip port of the laser beam LB nozzle 40 by scanning galvanometer scanner 44 by repeatedly moving at a variable moving direction and moving speed in the circumferential direction through the 40a, continuously and fast without interruption cutting path CK of the repeating pattern similar to the pulse waveform on the metal tape W _T (e.g. 5 m (With a tape feed speed of at least / sec). That is, the metal tape W _T can dramatically improve the performance and efficiency of the laser cutting for cutting along the cutting path CK.

In the case where each corner cutting path CK on metal tape W _T is rounded as shown in FIG. 7B, each vertex A of the slit-shaped tip opening 40a, B, the moving speed of the laser beam LB near the C Appropriate changes (deceleration or acceleration) may be applied. That is, the corner of the cutting path CK becomes larger as the deceleration period or acceleration period of the laser beam LB is longer, and the curve becomes smaller as the deceleration period or acceleration period is shorter. When the deceleration period or the acceleration period is extremely short, it is angular as shown in FIG. 7A.

Further, as shown in FIG. 7C, even when the slit-like tip opening 40a of the nozzle 40 has a loop shape of an unequal triangle (b ≠ c), the beam when the laser beam LB moves on the hypotenuses b and c. The overall operation of laser cutting is almost the same as in the case of an isosceles triangle, except that the moving speeds V _b and V _c (particularly the speed component V _{X in the} tape width direction) are different.

[Other Embodiments or Modifications]

The laser cutting device of the above embodiment, it is possible to slit-shaped tip opening 40a of the nozzle 40 may have a trapezoidal loop shape, subjected to a similar laser cutting and the examples on a metal tape W _T. In this case, the trapezoidal loop of the slit-shaped tip 40a only needs to satisfy the layout conditions as shown in FIG. 9, and in addition to the above three conditions in the case of the triangular loop, the length f of the upper side d is the cutting path. it is added as a fourth condition shorter than the second distance F of the cutting section K ₂ of CK. Then, in the upper side d, while the metal tape W _T is moved by a distance F in the tape feed direction (Y ₊ direction), the tape feeding through the upper side d the laser beam LB towards the vertex B "from the vertex B ' Laser scanning is performed so as to move in the direction (Y ₊ direction) by a distance f, and a trapezoidal lower end surface corresponding to the loop shape of the slit-shaped front end 40a is formed in the nozzle body 86 of the nozzle 40. A square pole suspension rod (not shown) is provided suspended in the air.

Thus, slit-shaped tip opening 40a of the nozzle 40 may have a loop shape of a square, the loop shape of any polygon in accordance with the pattern of the cutting path further is set on a metal tape W _T Can have.

Further, the above embodiment, the metal tape W _T and the plate material W to be processed, interrupted in the same direction while securing the laser emission unit 16 (particularly the nozzle 40) moves the metal tape W _T tape in the longitudinal direction thereof It was related to the laser cutting process that divides continuously. However, in the laser cutting apparatus of the above-described embodiment, laser cutting processing is performed in which a plate material W of an arbitrary material having an arbitrary shape is moved in an arbitrary direction (particularly, an arbitrary two-dimensional direction) on the processing table mechanism 24. Can do.

  Alternatively, as another embodiment, a laser in which both the nozzle 40 and the plate material W are preferably fixed, and the laser beam LB is moved in the circumferential direction in the slit tip 40a by the galvano scanner 44 in the laser emission unit 16. By performing scanning, it is also possible to perform laser cutting processing (laser cutting processing) for cutting out an arbitrary pattern on an arbitrary plate material W. In this case, the slit tip 40a is not limited to a standard figure such as a polygon, a circle, or an ellipse, and may have an arbitrary loop shape that directly defines a desired contour of a pattern to be cut out.

  In this embodiment, while the nozzle 40 and the plate material W are both stationary, the laser beam LB is made to circulate in the slit-shaped tip port 40a only by scanning the galvano scanner 44, so that the slit-shaped tip port is formed on the plate material W. A pattern having a contour corresponding to the loop shape of 40a can be cut out. According to this method, the cutting speed is controlled by the laser scanning operation speed of the galvano scanner 44. Therefore, when the nozzle 40 or the plate material W is moved in a two-dimensional direction according to the contour of the pattern to be cut (conventional method). Compared with this, laser cutting can be realized at an extremely high speed and in a short time.

  The structure and material of each part of the nozzle 40 can be variously modified. For example, as shown in FIG. 10A, the nozzle body 86 can be configured as a rectangular cylinder or a cylindrical body having a uniform thickness (or diameter) from the upper end to the lower end. The suspension bar 88 provided suspended in the nozzle body 86 is not necessarily solid, and may be a hollow body. Moreover, the lower end surface of the suspension bar 88 can have an arbitrary contour shape. Therefore, in the hanging rod 88, the shape of the lower end surface and the shape of the upper end surface or the cross-sectional shape of the intermediate portion may be dissimilar.

  Furthermore, it is possible to replace the single member suspension bar 88 with a composite member. For example, as shown in FIG. 10B, an upper plate member 92 joined to the glass plate 90, a lower plate member 94 defining a loop shape of the slit-shaped tip 40a, an upper plate member 92, and a lower plate member 94. It is also possible to provide a composite suspension member 98 integrally connected to the connecting rod member 96 in the nozzle body 86. In such a composite suspension member 98, only the lower plate member 94 at the tip of the nozzle is made of a highly reflective metal (for example, copper), and the other members 94 and 96 provided in the nozzle 40 are separate members. For example, you may comprise with resin etc.

  In the above embodiment, the laser oscillator 10 is not limited to a single mode fiber laser oscillator, but may be another type of fiber laser oscillator, YAG laser oscillator, or the like. The laser transmission system 14 may be configured such that the transmission optical fiber 36 is omitted. Of course, the nozzle 40 of the laser emitting unit 16 can be configured to be movable.

DESCRIPTION OF SYMBOLS 10 Laser oscillator 12 Laser power supply 16 Laser emission unit 18 Main control part 20 Scanner control part 22 Assist gas supply part 24 Processing table mechanism 40 Nozzle 40a Slit-shaped front end 44 Galvano scanner 46 Condensing lens 54 Table roller 86 Nozzle main body 88 Hanging stick 90 glass plate

Claims (21)

By irradiating the laser beam oscillated from the laser oscillator with the condenser lens while irradiating the assist gas on the plate to be processed, and moving the beam spot of the laser beam relatively A laser cutting method in which the plate material is divided by melting or evaporating along a path along which the beam spot moves,
On the optical path of the laser beam, a galvano scanner is disposed in front of the condenser lens, and a nozzle having an endless loop shape is disposed in the rear stage of the condenser lens,
While spraying the assist gas onto the plate material through the slit-like tip of the nozzle, the laser beam from the laser oscillator is passed through the slit-like tip of the galvano scanner, the condenser lens, and the nozzle. And irradiate the plate
The laser beam is scanned by the galvano scanner so that the beam spot of the laser beam traces a preset cutting path on the plate material, and the laser beam is caused to pass through the slit-shaped tip of the nozzle. Move it around,
And a laser cutting method.   The laser cutting method according to claim 1, wherein a loop shape of the slit-shaped tip opening is a polygon.   The laser cutting method according to claim 2, wherein a loop shape of the slit-shaped tip opening is a triangle. As a unit of the cutting path, the plate member has a first cutting section extending from the starting point in the first direction by an arbitrary first distance, and orthogonal to the first direction from the end of the first cutting section. A second cutting section extending an arbitrary second distance in the second direction, and a third cutting section equal to the first distance in a direction opposite to the first direction from an end point of the second cutting section. A third cutting section extending by a distance and a fourth cutting section extending from the end point of the third cutting section by an arbitrary fourth distance in the second direction are set,
The slit-shaped front end is shorter than the fourth distance and has a first side as a base that can overlap the fourth cutting section, a height equal to the first or third distance, A second side that can cross diagonally with the first cutting section, and a third side that can cross diagonally with the third cutting section in the middle of cutting,
When dividing one unit of the cutting path on the plate material, the laser beam moves in the slit shape while the plate material moves in a direction opposite to the second direction relative to the nozzle. In the front end opening, in order to cut the first cutting section, it moves in the second side toward the second vertex facing the first side, and cuts the second cutting section. Therefore, the third vertex is stopped at the second vertex, and the third vertex from the second vertex toward the third vertex where the first side and the third side intersect to cut the third cutting section. And moving in the first side from the third vertex toward the first vertex to cut the fourth cutting section,
The laser cutting method according to claim 3.   When the division of one unit of the cutting path on the plate material is continuously repeated a plurality of times or innumerable times in the second direction, while the relative movement of the plate material with respect to the nozzle is continued, the slit 5. The laser cutting method according to claim 4, wherein the circular movement of the laser beam at the tip end is continuously repeated a plurality of times or countless times at a constant period. The plate material is a metal tape,
A cutting path of a pattern that alternately repeats a cutting path in the tape length direction and a cutting path in the tape width direction is set on the metal tape,
In order to divide the metal tape along the cutting path, the laser beam moves in the slit shape of the nozzle while the metal tape moves at a constant speed in the tape length direction relative to the nozzle. The operation of making a round in the circumferential direction in the tip is repeated at a constant cycle.
The laser cutting method according to claim 3. A laser emitting unit that emits a laser beam while spraying an assist gas toward a plate to be processed for laser cutting,
A condensing lens for condensing the laser beam transmitted from the laser oscillator on the plate material;
To scan the laser beam in a two-dimensional direction so as to trace the cutting path set on the plate, the beam spot of the laser beam being provided in front of the condenser lens on the optical path of the laser beam. With the galvo scanner
A cylinder that is provided in the rear stage of the condensing lens on the optical path of the laser beam and introduces the assist gas sent from the assist gas supply unit and introduces the laser beam transmitted through the condensing lens A laser emitting unit comprising: a nozzle body having a slit-like tip opening having an endless loop shape, and a nozzle that emits the assist gas from the slit-like tip opening and emits the laser beam.   The laser emitting unit according to claim 7, wherein the condenser lens is a telecentric fθ lens.   9. The laser emission unit according to claim 7, further comprising a transparent plate that closes an opening at an upper end of the nozzle body and transmits the laser beam from the condenser lens. 10.   10. The suspension member according to claim 7, wherein an upper end is coupled to the transparent plate and a lower end is surrounded by the slit-shaped tip end in the nozzle body. Laser emission unit.   The laser emitting unit according to claim 10, wherein a lower end surface of the suspension member is polygonal.   The laser emitting unit according to claim 11, wherein a lower end surface of the suspension member is a triangle.   The laser emitting unit according to any one of claims 10 to 12, wherein the suspension member has a suspension rod that becomes thicker in an inversely tapered shape from above to below.   The laser emitting unit according to claim 13, wherein a space between a side surface of the suspension bar and a side wall of the nozzle body is tapered from the top to the bottom.   The laser emitting unit according to any one of claims 10 to 14, wherein the laser beam passes through the nozzle body and the slit-shaped tip port without reflection. The laser emission unit according to any one of claims 7 to 15,
A laser oscillator that oscillates and outputs a laser beam;
A laser transmission section for transmitting the laser beam from the laser oscillator to the laser emission unit;
An assist gas supply unit that supplies assist gas to the nozzle of the laser emitting unit.   The laser cutting device according to claim 16, further comprising a moving mechanism that performs a relative movement in a predetermined direction between the laser emitting unit and a plate to be processed.   The laser cutting device according to claim 17, wherein the moving mechanism includes a processing table mechanism that conveys the plate material so that the plate material passes in the predetermined direction in the vicinity of the slit-shaped distal end in a stationary state. The plate material is a metal tape,
The working table mechanism has a roller that puts the metal tape on the rotating outer peripheral surface at a certain rotation angle and passes the vicinity of the slit-shaped tip end,
The laser cutting device according to claim 18.   The roller has a cylindrical body portion containing a porous metal or ceramic connected to a vacuum mechanism, and is applied to an outer peripheral surface of the roller by a suction force of the vacuum applied to the inside of the body portion from the vacuum mechanism. The laser cutting device according to claim 19, which holds the metal tape that is placed thereon.   21. The laser cutting device according to claim 20, wherein a groove is formed on the outer peripheral surface of the roller at a position facing the cutting path on the metal tape.

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