Apparatus and method for laser welding

Abstract

A laser welding apparatus and method reduce the effect of the fume resulting from a weld. An air injecting nozzle is installed at a laser processing head. The injecting direction of air from the air injecting nozzle is set such that the air flows across a laser beam irradiated from the laser processing head while the air flow avoids direct contact with the laser irradiating point on the work piece.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:

FIG. 1 is a schematic diagram illustrating a remote welding system constructed in accordance with an embodiment of the invention;

FIG. 2 is a block diagram illustrating a control system of the remote welding system constructed in accordance with an embodiment of the invention;

FIGS. 3 a and 3b are side views illustrating the operations of a fume and air injection according to an embodiment of the invention;

FIG. 4 is a diagram illustrating an air injecting nozzle (injecting port) and an injection range of an air injected from the nozzle;

FIG. 5 is a schematic diagram illustrating a remote welding system constructed in accordance with a second embodiment of the invention;

FIG. 6 is a block diagram showing a control system of the remote welding system constructed in accordance with the second embodiment;

FIG. 7 is a diagram illustrating the operation of an air injection according to the second embodiment;

FIGS. 8 a and 8b are diagrams illustrating the operation of a remote welding system constructed in accordance with a third embodiment of the invention;

FIG. 9 is a schematic diagram illustrating a remote welding system constructed in accordance with a fourth embodiment of the invention;

FIG. 10 is a schematic diagram illustrating a laser processing head when viewed from a laser outlet side;

FIG. 11 is a block diagram illustrating a control system of the remote welding system constructed in accordance with the fourth embodiment;

FIGS. 12 a to 12c are diagrams illustrating the first operation of an air injection according to the fourth embodiment;

FIGS. 13 a and 13b are diagrams illustrating the second operation of an air injection according to the fourth embodiment;

FIG. 14 is a schematic diagram illustrating a system constructed in accordance with a fifth embodiment of the invention;

FIG. 15 is a side view illustrating an operation according to the fifth embodiment;

FIG. 16 is a schematic diagram illustrating a system constructed in accordance with a sixth embodiment of the invention;

FIGS. 17 a and 17b are schematic diagrams illustrating an experimental device; and

FIG. 18 is a graph illustrating the result from an experiment wherein a laser welding is performed.

Claims

1. An apparatus for conducting laser welding, comprising: a laser irradiating unit for irradiating a laser beam; anda first fluid injecting unit for injecting a fluid in a first fluid injecting direction to remove a fume produced by the laser beam on a work piece from a path of the laser beam to the work piece, wherein the first fluid injecting unit is positioned proximal to the laser irradiating unit.

2. The apparatus according to claim 1 wherein the first fluid injecting unit is positioned such that the first fluid injecting direction is generally toward the work piece.

3. The apparatus according to claim 1 wherein the first fluid injecting unit is positioned such that a laser irradiating point on the work piece is not included within an injection range of the fluid.

4. The apparatus according to claim 1, further comprising: an irradiating direction changing unit operable to change an irradiating direction of the laser beam using a reflecting mirror.

5. The apparatus according to claim 1 wherein the laser irradiating unit is positioned at an end of a robotic arm.

6. The apparatus according to claim 5, further comprising: a fluid injecting position moving unit operable to move the first fluid injecting unit.

7. The apparatus according to claim 6 wherein the fluid injecting position moving unit is operable to move the first fluid injecting unit from a first position to a second position.

8. The apparatus according to claim 5, further comprising: a second fluid injecting unit for injecting the fluid in a respective fluid injecting direction to remove the fume from the path, the second fluid injecting unit positioned proximal to the laser irradiating unit and having a fluid injecting direction different from the first fluid injection direction; anda switching unit operable to control the fluid to be injected from any of the fluid injecting units.

9. The apparatus according to claim 1 wherein the first fluid injecting unit is positioned generally opposite to a moving direction of the laser irradiating point and transverse to the laser beam.

10. The apparatus according to claim 1, further comprising: at least a second fluid injecting unit for injecting the fluid in a respective fluid injecting direction to remove the fume from the path, and wherein the fluid injecting units are positioned produce a vortex when fluid is simultaneously injected from the fluid injecting units.

11. The apparatus according to claim 1, further comprising: a fluid flow path around the laser irradiating unit, wherein the first fluid injecting unit is installed within the fluid flow path.

12. The apparatus according to claim 1, further comprising: a lens protecting element positioned proximal to a laser emitting port of the laser irradiating unit, wherein the first fluid injecting unit has a first fluid injecting nozzle positioned to inject the fluid along the lens protecting element; anda deflecting plate positioned to deflect the fluid in the first fluid injecting direction, the first fluid injecting direction transverse to the laser beam.

13. The apparatus according to claim 12, further comprising: a plurality of fluid injecting nozzles including the first fluid injecting nozzle installed in two positions, a first position closer to the lens protecting element and a second position away from the lens protecting element; and whereinthe first fluid injecting nozzle is installed in the first position at a first pressure;a second of the plurality of fluid injecting nozzles is installed in the second position at a second pressure; andthe first pressure to higher than the second pressure.

14. An apparatus for conducting laser welding, comprising: means for irradiating a laser beam; andmeans for injecting a fluid in a first fluid injecting direction to remove a fume produced by the laser beam on a work piece from a path of the laser beam to the work piece; and wherein the injecting means is positioned proximal to the irradiating means.

15. A method of conducting laser welding incorporating a laser irradiating unit and at least one fluid injecting unit, the method comprising: irradiating a laser beam on a work piece; andinjecting a fluid from the at least one fluid injecting unit in a direction to remove a fume produced by the laser beam on a work piece from a path of the laser beam to the workpiece; and wherein the at least one fluid injecting unit is positioned proximal to the laser irradiating unit.

16. The method according to claim 15, further comprising: establishing a laser irradiating point on the work piece outside an injection range of the fluid.

17. The method according to claim 15, further comprising: changing an irradiating direction of the laser beam using a reflecting mirror.

18. The method according to claim 15, further comprising: installing the laser irradiating unit at an end of a robotic arm.

19. The method according to claim 15, further comprising: moving the at least one fluid injecting unit to inject the fluid opposite to a moving direction of a laser irradiating point on the work piece.

20. The method according to claim 15, further comprising: moving the at least one fluid injecting unit to a position wherein the at least one fluid injecting unit does not interfere with the work piece and a peripheral structure of the work piece.

21. The method according to claim 15 wherein the at least one fluid injecting unit includes a first fluid injecting unit and a second fluid injecting unit, each having a different fluid injecting direction, the method further comprising: controlling the fluid to be injected from either the first or the second injecting unit so that the fluid path is opposite to a moving direction of a laser irradiating point on the work piece.

22. The method according to claim 15 wherein the at least one fluid injecting unit includes a first fluid injecting unit and a second fluid injecting unit, each having a different fluid injecting direction, the method further comprising: producing a vortex by extracting the fluid from the first and second fluid injecting units.

23. The method according to claim 15 wherein the laser irradiating unit includes a laser emitting port and a lens protecting element installed at the laser emitting port, the method further comprising: injecting the fluid along the lens protecting element; anddeflecting the fluid in the direction wherein the direction is transverse to the laser beam.

24. The method according to claim 23, further comprising: setting a first pressure of a first fluid injecting nozzle, wherein the first fluid injecting nozzle is a first distance from the lens protecting element; andsetting a second pressure of a second fluid injecting nozzle, wherein the second fluid injecting nozzle is a second distance from the lens protecting element; andwherein the first pressure is higher than the second pressure and the first distance is less than the second distance.