# US 10,118,256 B2 · Sheet metal processing method using laser beams and direct diode laser processing device for carrying it out > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,118,256 B2 - Document ID: US10118256B2 - Status: Granted - Kind: B2 - Application number: 15/514,079 - Filed: 2015-09-17 - Published: 2017-10-12 - Granted: 2018-11-06 - Earliest claimed: 2014-10-15 - Assignees: Amada Holdings Co., Ltd. - Applicants: Amada Holdings Co., Ltd. - Inventors: Hiroaki Ishiguro; Akihiko Sugiyama; Hiroshi Sako - Web page: https://patentgrep.com/patent/US10118256B2 ## CPC - B23K 26/38: by boring or cutting - B23K 26/0608: {in the same heat affected zone [HAZ] (B23K26/0613, B23K26/0619 take precedence)} - B23K 26/0648: {comprising lenses} - B23K 26/0665: {by beam condensation on the workpiece, e.g. for focusing} - B23K 26/0876: {in at least two axial directions} - B23K 26/14: using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor (B23K26/12 takes precedence) - B23K 26/142: for the removal of by-products - B23K 26/40: taking account of the properties of the material involved - B23K 37/0235: {the guide member forming part of a portal} - H01S 5/02251: using optical fibres - H01S 5/4012: {Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms} - B23K 2101/18: Sheet panels - B23K 2103/04: Steel {or steel} alloys - B23K 2103/05: {Stainless steel} - B23K 2103/10: Aluminium or alloys thereof - H01S 5/005: {Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping (H01S5/026, H01S5/18388 take precedence)} - H01S 5/4087: {emitting more than one wavelength} - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL ## Abstract Using a transmission fiber for transmitting laser beams of multiple wavelengths oscillated by a DDL module, and a laser processing machine for cutting a sheet metal with a processing head that condenses the laser beams of multiple wavelengths and irradiates them onto the sheet metal, a mild steel plate or an aluminum plate is cut, and by cutting a mild steel plate with a thickness greater than or equal to 1 mm and less than or equal to 5 mm, a surface roughness (Ra) of a cut surface of the cut mild steel plate is less than or equal to 0.4 μm, and when an aluminum plate with a thickness greater than or equal to 1 mm and less than or equal to 5 mm is cut, a surface roughness (Ra) of a cut surface of the cut aluminum plate is less than or equal to 2.5 μm. ## Claims ### Claim 1 A sheet metal processing method, comprising: oscillating laser beams of multiple wavelengths from a direct diode laser module; transmitting the oscillated laser beams of multiple wavelengths; and processing by cutting a sheet metal with a processing head that condenses the transmitted laser beams of multiple wavelengths and irradiates them onto the sheet metal that is a mild steel plate with a thickness greater than or equal to 3.2 mm and less than or equal to 5 mm, while using an assist gas that is oxygen with a pressure of 0.05 MPa to 0.2 MPa; said cutting creating a surface roughness Ra of a cut surface of the cut mild steel plate of less than or equal to 0.4 μm. ### Claim 2 (depends on 1) The sheet metal processing method of claim 1, wherein a focal length of a condensing lens mounted on said processing head is 150 mm to 250 mm. ### Claim 3 (depends on 1) The sheet metal processing method of claim 1, wherein in a case where a beam parameter product at an entrance of the processing head is 10.3 mm*mrad, a power of the laser beams from said processing head is 1600 W to 2000 W, a power density is 8.9×105 W/cm2 to 2.8×106 W/cm2, a beam waist diameter is 300 μm to 480 μm, and a Rayleigh length is 2.2 mm to 5.6 mm. ### Claim 4 (depends on 1) The sheet metal processing method of claim 1, wherein a nozzle diameter of a nozzle for ejecting an the assist gas is 0.8 mm to 4 mm, and a nozzle height is 0.5 mm to 1.5 mm. ### Claim 5 A sheet metal processing method, comprising: oscillating laser beams of multiple wavelengths within a range of 910 nm to 950 nm from a direct diode laser module; transmitting the oscillated laser beams of multiple wavelengths; and processing by cutting a sheet metal with a processing head that condenses the transmitted laser beams of multiple wavelengths and irradiates them onto the sheet metal that is an aluminum plate with a thickness greater than or equal to 1 mm and less than or equal to 5 mm, while using an assist gas that is nitrogen with a pressure of greater than or equal to 0.8 MPa; said cutting creating a surface roughness Ra of a cut surface of the cut aluminum plate is less than or equal to 2.5 μm. ### Claim 6 (depends on 5) The sheet metal processing method of claim 5, wherein a focal length of a condensing lens mounted on said processing head is 120 mm to 190 mm. ### Claim 7 (depends on 5) The sheet metal processing method claim 5, wherein in a case where a beam parameter product at an entrance of the processing head is 10.3 mm*mrad, a power of the laser beams from said processing head is 1600 W to 2000 W, a power density is 1.5×106 W/cm2 to 4.8×106 W/cm2, a beam waist diameter is 230 μm to 364 μm, and a Rayleigh length is 1.3 mm to 3.4 mm. ### Claim 8 (depends on 5) The sheet metal processing method of claim 5, wherein a nozzle diameter of a nozzle for ejecting the assist gas is 1.5 mm to 4 mm, and a nozzle height is 0.3 mm to 1.0 mm. ### Claim 9 A direct diode laser processing device, comprising: a direct diode laser module for oscillating laser beams of multiple wavelengths; a transmission fiber for transmitting the laser beams of multiple wavelengths oscillated by said direct diode laser module; and a laser processing machine for processing by cutting a sheet metal with a processing head that condenses the laser beams of multiple wavelengths transmitted by said transmission fiber and irradiates them onto the sheet metal, said laser processing machine being configured to: cut a mild steel plate with a thickness greater than or equal to 3.2 mm and less than or equal to 5 mm while using an assist gas that is oxygen with a pressure of 0.05 MPa to 0.2 MPa, a surface roughness Ra of a cut surface of the cut mild steel plate is less than or equal to 0.4 μm, and cut an aluminum plate with a thickness greater than or equal to 1 mm and less than or equal to 5 mm while using an assist gas that is nitrogen with a pressure of greater than or equal to 0.8 MPa, a surface roughness Ra of a cut surface of the cut aluminum plate is less than or equal to 2.5 μm, wherein the direct diode laser module for oscillating laser beams of multiple wavelengths is within a range of 910 nm to 950 nm.