JP6343497B2 - Laser processing method and laser processing apparatus - Google Patents

Description

  The present invention relates to a laser processing method, a laser processing head, and an apparatus for drilling holes in a plate-shaped workpiece, and more specifically, a cut piece (cutout piece) generated when drilling is performed by laser machining. The present invention relates to a laser processing method, a laser processing head, and an apparatus capable of preventing a state of being caught on the surface.

  Conventionally, holes of various shapes such as a round shape with a diameter of about 30 mm or less and a square shape with a side length of about 30 mm or less are performed on a plate-like workpiece by laser processing. As described above, when drilling a workpiece by laser processing, the cut piece cut inside the hole may be caught because the kerf width is narrow. Furthermore, in laser processing using a fiber laser, the kerf width is narrower than that in the case of a CO2 laser, and the above-mentioned catching is likely to occur.

  As described above, when the cut piece is caught on the work, the cut piece may enter between the work table and the work when the work moves relative to the work table, and the work may be scratched. In view of this, it has been proposed to provide a cutting / separating device for forcibly dropping the cut piece from the hole after the workpiece has been drilled (see, for example, Patent Document 1).

JP-A-4-367391

  The configuration described in Patent Document 1 is a configuration in which a laser processing head in a laser processing machine is provided so as to be movable up and down, and a cutting and separating device is provided separately from the laser processing head. Then, after drilling the workpiece, the laser processing head is raised, the cutting / separating device is positioned below the raised laser processing head, and the cut piece is forcibly dropped. Therefore, there is a problem that the overall configuration is complicated, and, for example, when hole processing is continuously performed at a plurality of locations, it is inefficient.

The present invention has been made in view of the above-described problems, and is a laser processing method for drilling a plate-like workpiece, and after performing piercing in the hole region, the hole contour is followed. When laser cutting is performed, a side gas for dropping a cut piece after laser cutting is ejected from a plurality of side nozzles provided around the laser nozzle in the laser processing head toward the laser cutting position. The ejection pressure of the side gas ejected from the side nozzle located outside the hole to the laser cutting processing position direction is higher than the ejection pressure of the side gas ejected from the side nozzle located inside the hole to the laser cutting processing position direction. Is characterized by a large value.

  Further, in the laser processing method, when laser cutting processing is performed along the contour of the hole, when the laser cutting processing position is close to a dimension set in advance to the contour of the hole that has already been processed, The side gas jet pressure is increased.

  Also, a laser processing apparatus for drilling holes in a plate-shaped workpiece, the laser processing head provided in the laser processing apparatus is arranged in a laser cutting processing position direction at a plurality of locations around a laser nozzle that can transmit laser light. The side nozzle control device that controls the jet pressure of the side gas from each side nozzle has already been cut and processed. A computing means for computing a distance between the hole contour position and the laser cutting position; a comparing means for comparing a computed value of the computing means with a reference value stored in advance in a reference value memory; And a side gas pressure control means for controlling the jet pressure of the side gas from all the side nozzles to be larger when the value is a value.

  In the laser processing apparatus, when the side nozzle control device performs laser cutting along the contour of the hole, a side nozzle located in the hole region and a side nozzle located outside the hole region, And a nozzle region discriminating means for discriminating between and a side gas ejection pressure ejected from a side nozzle located outside the hole region are controlled to be larger than a side gas ejection pressure ejected from a side nozzle located within the region. And a side gas pressure control means.

  According to the present invention, the laser cutting is performed because the side gas for dropping the cut piece after laser cutting is directed from the plurality of side nozzles provided in the laser processing head to the laser cutting processing position. Side gas is concentrated from the surroundings to the processing position. Therefore, the cutting piece can be forcibly dropped simultaneously with the end of the hole processing, and the efficiency of the hole processing can be improved.

It is explanatory drawing which showed notionally and schematically the structure of the laser processing head which concerns on embodiment of this invention. It is explanatory drawing which shows the positional relationship of the outline at the time of performing the laser processing of a hole, and the side nozzle with which the laser processing head was equipped. It is explanatory drawing of a functional block diagram.

  Referring to FIG. 1, a laser processing apparatus according to an embodiment of the present invention includes a laser processing head 1 that is relatively movable in the X, Y, and Z axis directions orthogonal to a plate-like workpiece W. I have. The laser processing head 1 includes a laser nozzle 3 that can transmit laser light LB. Therefore, the workpiece W is laser-cut by moving the laser processing head 1 relative to the workpiece W in the X, Y and Z axis directions and irradiating the workpiece W with the laser beam LB transmitted through the laser nozzle 3. It can be processed.

  By the way, when a hole is formed in the workpiece W by performing laser cutting processing, a cut piece (cutout piece, punched waste) is generated in the hole. At the time of laser cutting by a fiber laser processing apparatus, the kerf width is smaller than that of a CO2 laser, so that the cut piece may be slightly inclined and caught in the hole.

  Therefore, in the present embodiment, immediately after the end of the laser cutting process for cutting the hole shape, that is, almost simultaneously with the end of the laser cutting process, the laser processing head 1 includes A plurality of side nozzles 5 are provided. The plurality of side nozzles 5 eject appropriate side gases such as air and nitrogen gas, and are provided at substantially equal intervals around the laser nozzle 3. Each of the side nozzles 5 is inclined with respect to the optical axis of the laser beam LB so that the side gas is directed obliquely downward toward the laser cutting position. That is, each of the plurality of side nozzles 5 is disposed on a tapered surface having a small diameter on the lower side.

  Therefore, the side gas ejected (injected) from each side nozzle 5 is collected from the vicinity in the vicinity of the laser cutting processing position. Therefore, in the vicinity of the laser cutting processing position, due to the collection of the flow of the side gas injected from each side nozzle 5 with a large jet pressure, there occurs an action of blowing down the cut pieces generated at the time of drilling. The piece can be surely dropped.

  By the way, as shown in FIG. 2, after performing piercing at the piercing position P, for example, when laser cutting is performed in the direction of arrow A (counterclockwise direction), the cut piece S is formed in the hole H to be laser processed. Will occur. As described above, when laser cutting is performed along the outline of the hole H, the plurality of side nozzles 5A to 5H provided in the laser processing head 1 are arranged in the laser cutting progress direction (arrow A direction) of the laser processing head 1. ), The position corresponding to the outline of the hole H, the position corresponding to the outside of the outline, and the position corresponding to the inside of the outline (in the region of the hole H).

  Then, in order to drop the cut piece S, for example, immediately before the end of the laser cutting process, it is ejected from each side nozzle (side nozzles 5B, 5C, 5D in FIG. 2) located in the region outside the contour line. The side gas ejection pressure is set to be larger than the side gas ejection pressure at each of the side nozzles (5F, 5G, 5H) located in the region inside the contour line (the region of the hole H). In addition, it is desirable that the ejection pressure of the side gas ejected from each side nozzle (5A, 5E) corresponding to the contour line is equal to the ejection pressure of the side gas of the side nozzle located in the outer region.

  As described above, when laser cutting is performed along the contour line of the hole H, when the cut piece S is dropped, the side gas is ejected from the side nozzles 5B, 5C, and 5D located outside the contour line. Since the pressure is larger than the ejection pressure of the side nozzles 5F, 5G, and 5H located on the inner side, an action of pressing the cut piece S in the hole H toward the center side of the hole H occurs. Therefore, the cut piece S can be dropped simultaneously with the end of the cutting of the outline of the hole H, and the catch of the cut piece S on the hole H can be suppressed. In addition, with the above configuration, when the side gas is an inert gas such as nitrogen gas, the outer side of the hole H can be cooled more effectively than the inner side of the hole H.

  Further, laser cutting is performed along the contour line of the hole H, and when the contour is cut immediately before the end of the contour cutting, that is, when the laser cutting processing position is close to a predetermined dimension, the all sides The pressure of the side gas ejected from the nozzle 5 is increased. That is, when the cutting piece S is cut and separated from the workpiece W when performing laser cutting of the hole H, the jet pressure of the side gas jetted from all the side nozzles 5 is controlled to be greater. Therefore, the cut piece S is cut and separated from the workpiece W and at the same time, the cut piece S is blown downward, so that the cut piece S can be dropped efficiently and reliably.

  As described above, in order to control the ejection pressure of the side gas ejected from each side nozzle 5, a pressure control valve is connected to each side nozzle 5 to individually control the ejection output of each side nozzle 5. Is possible.

  As described above, the laser processing apparatus (not shown) having the laser processing head 1 includes a side nozzle control device for controlling the jet power of the side gas ejected from each side nozzle 5. 7 (see FIG. 3). The side nozzle control device 7 is constituted by a computer, for example, and includes a CPU 9, a RAM 11, and a ROM 13. Further, the side nozzle control device 7 is provided with a hole position shape data memory 17 storing the position data of the hole H and the shape and dimension data of the hole H input from the input means 15.

  Further, the side nozzle control device 7 includes a hole machining program memory 19 that stores a hole machining program for performing laser cutting of the hole H. Further, the side nozzle control device 7 is provided with program analysis means 21 for analyzing a program stored in the hole machining program memory 19. Further, the side nozzle control device 7 is provided with a nozzle region discriminating means 23. This nozzle area discriminating means 23 is composed of a side nozzle 5 located within the hole H area and a side nozzle located outside the hole H area based on the laser cutting direction of the hole H analyzed by the program analyzing means 21. 5 is discriminated.

  That is, when the laser cutting direction of the hole H is clockwise, it is determined that the side nozzle 5 located on the right side of the moving direction in which the center of the laser processing head 1 moves is located in the region of the hole H. . Then, the side nozzle 5 located on the moving line on which the center moves and on the left side in the moving direction is determined to be located outside the hole H region. In the case where the laser cutting direction is the counterclockwise direction, the determination is made contrary to the above.

  Further, the side nozzle control means 7 is provided with a calculation means 25 for performing various calculations, and calculates a calculation value as a calculation result of the calculation means 25 and a reference value stored in the reference value memory 27 in advance. Comparison means 29 for comparison is provided. The calculation means 25 has a function of calculating the distance between the laser cutting position of the hole H and the contour line already laser cut. That is, the calculation means 25 calculates a dimension L (see FIG. 2) in which the laser cutting position LP approaches the contour line that has already been laser cut immediately before the end of the laser cutting of the hole H.

  The calculated value L by the calculating means 25 is compared with a reference value stored in advance in the reference value memory 27 by the comparing means 29. The reference value memory 27 stores a reference value of the dimension L as a parameter corresponding to the material and thickness of the workpiece W. As a result of comparison by the comparison means 29, a side gas pressure control means 31 is provided for controlling the ejection pressure of the side gas ejected from each of the side nozzles 5 when the calculated value ≦ the reference value. The side gas pressure control means 31 controls the pressure of the side gas ejected from each side gas nozzle 5 by controlling each pressure control valve connected to each side gas nozzle 5.

  In the configuration as described above, when laser processing of the hole H is performed, the hole processing program stored in the hole processing program memory 19 is analyzed by the program analysis means 21, and the laser processing direction of the hole H is analyzed. As described above, when the laser processing direction of the hole H is known, the nozzle region discriminating unit 23 discriminates the side nozzle 5 located in the hole H region and the side nozzle 5 located outside the hole H region. . That is, when the laser processing direction of the hole H is clockwise, it is determined that the side nozzle 5 located on the right side of the traveling direction of the laser processing head 1 is located in the region of the hole H. In the case of counterclockwise rotation, it is determined that the left side is in the hole H.

  As described above, when the laser processing direction of the hole H is known, the side nozzle 5 located inside the hole H and the side nozzle 5 located outside the hole H are discriminated by the nozzle region discriminating means 23. The side nozzle 5 on the contour line of the hole H is determined to belong to the outside as described above. As described above, when the side nozzles 5 located inside and outside the hole H are determined, when the cut piece S falls into the hole H, the side gas pressure control means 31 causes the inside (inside) of the hole H to fall. Control is performed so that the ejection pressure of the side gas ejected from the side gas located outside the hole H is larger than the ejection pressure of the side gas from the side nozzle 5 located at the same position. Therefore, when the cut piece S falls into the hole H, the cut piece S tends to be urged toward the center of the hole H.

  And just before the end of the cutting of the hole H, as described above, the jet pressure of the side gas from the side nozzle 5 located outside the hole H is kept larger than the jet pressure of the side gas of the side nozzle 5 inside. Thus, the distance L between the laser processing position LP and the contour line of the hole H is calculated by the calculation means 25. The calculated value L of the calculating means 25 and the reference value stored in the reference value memory 27 are compared by the comparing means 29. When the reference value ≧ the calculated value L, the control is performed under the control of the side gas pressure control means 21. The ejection pressure of the side gas from all the side nozzles 5 is controlled to be larger.

  Therefore, the cut piece S in the hole H is cut and separated from the workpiece W in a state where it is biased toward the center of the hole. At this time, since the ejection pressure of the side gas ejected from each side nozzle 5 is controlled to be larger, the cut piece S that has been cut and separated can be reliably dropped into the hole H simultaneously with the end of the laser cutting process. Is. After cutting and separating the cut piece S from the work W, the laser nozzle 3 is relatively moved in the direction of the center of the hole H while holding the pressure of the side gas ejected from each side nozzle 5 at a higher level. It is desirable to do. In this way, the cut piece S can be reliably dropped into the hole H by moving the laser nozzle 3.

  As understood from the above description, according to the present embodiment, before the end of laser cutting of the hole H, side gas is ejected from each side nozzle 5, and the cut piece S in the hole H is cut and separated from the workpiece W. In doing so, since the ejection pressure of the side gas ejected from each side nozzle 5 is controlled to be larger, the cut piece S is effectively separated into the hole H at the same time as the cut piece S is cut and separated from the workpiece W. Can fall. At this time, the pressure of the side gas ejected from the side nozzle 5 located outside the hole H is controlled more greatly than the pressure of the side gas ejected from the side nozzle 5 located inside the hole H. It is. Therefore, when the cut piece S is separated from the workpiece W, the cut piece S tends to be pressed and urged toward the center of the hole H, and is prevented from being caught in the hole H. Therefore, the cutting piece S can be more reliably dropped from the hole H.

  The present invention is not limited to the embodiment described above, and can be implemented in other forms by making appropriate changes. That is, the timing for ejecting the side gas from each side nozzle 5 may be performed simultaneously with the start of laser cutting. At this time, dross or the like generated during the laser cutting process can be effectively blown down the cutting groove.

  The side gas is ejected from the side nozzle 5 when the laser cutting position LP reaches the position of the interval dimension L or when it reaches a position larger than the interval dimension L by a preset dimension. It is good also as a structure which ejects side gas. In this case, the consumption of side gas can be suppressed.

  Further, as described above, the side gas ejected from each side nozzle 5 in order to drop the cut piece S into the hole H is ejected in a pulsating manner, even if intermittently ejected, and the ejection pressure is repeatedly increased and decreased. You may do it. In this case, a vibration is applied to the cut piece S, and the cut piece S can be more reliably dropped.

DESCRIPTION OF SYMBOLS 1 Laser processing head 3 Laser nozzle 5 Side nozzle 7 Side nozzle control device 17 Hole position shape data memory 23 Nozzle area discrimination means 25 Calculation means 27 Reference value memory 29 Comparison means 31 Side gas pressure control means

Claims (4)

A laser processing method for drilling holes in a plate-shaped workpiece, and after performing piercing in the hole region, laser cutting is performed along the hole contour, and the laser processing head is surrounded by a laser nozzle. When a side gas for dropping a cut piece after laser cutting is directed from a plurality of side nozzles provided to the laser cutting processing position, the laser nozzle is positioned from the side nozzle located inside the hole. A laser processing method characterized in that a jet pressure of a side gas ejected from a side nozzle located outside the hole toward a laser cutting machining position is larger than a jet pressure of a side gas jetted to the side. The laser processing method according to claim 1, wherein when laser cutting processing is performed along the hole contour, the laser cutting processing position is close to a dimension set in advance to the already cut hole contour. A laser processing method characterized by further increasing a jet pressure of a side gas from a side nozzle. A laser processing apparatus for drilling holes in a plate-shaped workpiece, and a laser processing head provided in the laser processing apparatus is directed to a laser cutting processing position direction at a plurality of locations around a laser nozzle that can transmit laser light. The side nozzle control device for controlling the jet pressure of the side gas from each of the side nozzles is a configuration of a hole that has already been cut and processed. A computing means for computing a distance dimension between the contour position and the laser cutting processing position; a comparing means for comparing a computed value of the computing means with a reference value stored in advance in a reference value memory; And a side gas pressure control means for controlling the jet pressure of the side gas from all the side nozzles to be larger. 4. The laser processing apparatus according to claim 3, wherein the side nozzle control device is positioned outside the hole region and the side nozzle positioned in the hole region when performing laser cutting along the contour of the hole. Nozzle area discriminating means for discriminating between side nozzles, and the ejection pressure of the side gas ejected from the side nozzle located outside the hole area is larger than the ejection pressure of the side gas ejected from the side nozzle located in the area. And a side gas pressure control means for largely controlling the laser processing apparatus.

Images