Laser beam machining head and laser beam machining apparatus having same

• US 20020017509A1
• Filed: 08/10/2001
• Published: 02/14/2002
• Est. Priority Date: 08/10/2000
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries Machine Tool Co., Ltd. (Nidec Corporation)
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Hashimoto, Yoshio, Watanabe, Masao, Ishide, Takashi, Akaba, Takashi, Fujie, Daijiro
• Granted Patent: US 6,608,281 B2
• Time in Patent Office: Days
• US Class Current: 219/121.63
• CPC Class Codes: B23K 26/0604 by a combination of beams
• CPC Class Codes: B23K 26/0608 in the same heat affected zone [HAZ] B23K26/0613, B23K26/0619 take precedence
• CPC Class Codes: B23K 26/067 Dividing the beam into multiple beams, e.g. multifocusing
• CPC Class Codes: B23K 26/082 Scanning systems, i.e. devices involving movement of the laser beam relative to the laser head
• CPC Class Codes: B23K 26/0884 in at least in three axial directions, e.g. manipulators, robots
• CPC Class Codes: B23K 26/144 the fluid stream containing particles, e.g. powder
• CPC Class Codes: B23K 26/1476 Features inside the nozzle for feeding the fluid stream through the nozzle
• CPC Class Codes: B23K 26/348 in combination with arc heating, e.g. TIG [tungsten inert gas], MIG [metal inert gas] or plasma welding laser beam for starting a welding or cutting arc B23K9/067

Abstract

A coaxial laser beam machining head, and a laser beam machining apparatus having it are provided. The head is small in size, free from the risk of damaging optical instruments, and inexpensive. The head comprises a collimating lens array, a first reflecting mirror for dividing laser light into a first divisional laser beam and a second divisional laser beam, a second reflecting mirror for further reflecting the first divisional laser beam to form a space portion between both divisional laser beams, a focusing lens array for focusing both divisional laser beams onto a portion to be welded, and a GMA electrode disposed in the space portion coaxially with the laser beams; or comprises a collimating lens array, a first reflecting mirror for reflecting part of laser light to form a space portion in a body of the laser light, a second reflecting mirror for further reflecting the part of the laser light, a focusing lens array for focusing the body of the laser light and the part of the laser light onto a portion to be welded, and a GMA electrode disposed in the space portion coaxially with the body of the laser light.

Claims

1. A laser beam machining head comprising:

one collimating optical system for making laser light into a parallel beam;

a first reflecting mirror for reflecting part of the laser light made into the parallel beam by the collimating optical system to divide the laser light into two beams, a first divisional laser beam and a second divisional laser beam;

a second reflecting mirror for further reflecting the first divisional laser beam reflected by the first reflecting mirror to form a space portion between the first divisional laser beam and the second divisional laser beam;

one focusing optical system for focusing the first divisional laser beam and the second divisional laser beam onto a portion to be machined; and

a tip machining portion of machining means disposed in the space portion between the first divisional laser beam and the second divisional laser beam coaxially with the laser beams.

2. The laser beam machining head of claim 1, wherein

the second reflecting mirror is rendered normally and reversely rotatable, whereby spacing between a focused tip of the first divisional laser beam and a focused tip of the second divisional laser beam is adjustable.

3. The laser beam machining head of claim 1, wherein

the first reflecting mirror is rendered movable, whereby a division ratio for the first divisional laser beam and the second divisional laser beam can be adjusted, and the second reflecting mirror is rendered normally and reversely rotatable, whereby spacing between a focused tip of the first divisional laser beam and a focused tip of the second divisional laser beam can be adjusted.

4. The laser beam machining head of claim 1, wherein

an optical axis of the collimating optical system and an optical axis of the focusing optical system are displaced in a direction perpendicular to the optical axes, whereby the collimating optical system is moved over toward one side relative to the focusing optical system so that the first divisional laser beam reflected by the first and second reflecting mirrors is entered into other side of the focusing optical system.

9. The laser beam machining head of claim 1, wherein

the tip machining portion of the machining means is a GMA electrode, a TIG electrode, a filler wire, an assist gas nozzle, or a powder nozzle.

12. The laser beam machining head of claim 1, wherein

the tip machining portion of the machining means is the assist gas nozzle, and the assist gas nozzle is a divergent nozzle.

15. A laser beam machining apparatus comprising:

the laser beam machining head of claim 1;

a laser oscillator for oscillating laser light;

laser light transmission means for transmitting the laser light oscillated by the laser oscillator to the laser beam machining head; and

laser beam machining head moving means for positioning and moving the laser beam machining head to an arbitrary position.

5. A laser beam machining head comprising:

one collimating optical system for making laser light into a parallel beam;

a reflecting mirror for reflecting part of the laser light made into the parallel beam by the collimating optical system to withdraw the part of the laser light out of a body of the laser light, thereby forming a space portion in the body of the laser light;

one focusing optical system for focusing the body of the laser light, where the space portion has been formed, onto a portion to be machined; and

a tip machining portion of machining means disposed in the space portion of the body of the laser light coaxially with the body of the laser light.

10. The laser beam machining head of claim 5, wherein

the tip machining portion of the machining means is a GMA electrode, a TIG electrode, a filler wire, an assist gas nozzle, or a powder nozzle.

13. The laser beam machining head of claim 5, wherein

the tip machining portion of the machining means is the assist gas nozzle, and the assist gas nozzle is a divergent nozzle.

16. A laser beam machining apparatus comprising:

the laser beam machining head of claim 5;

a laser oscillator for oscillating laser light;

laser light transmission means for transmitting the laser light oscillated by the laser oscillator to the laser beam machining head; and

laser beam machining head moving means for positioning and moving the laser beam machining head to an arbitrary position.

6. A laser beam machining head comprising:

one collimating optical system for making laser light into a parallel beam;

a first reflecting mirror for reflecting part of the laser light made into the parallel beam by the collimating optical system to withdraw the part of the laser light out of a body of the laser light, thereby forming a space portion in the body of the laser light;

a second reflecting mirror located outside the body of the laser light and adapted to reflect the part of the laser light reflected by the first reflecting mirror so as to be parallel to the body of the laser light and be in contact with or in proximity to an outer peripheral surface of the body of the laser light;

one focusing optical system for focusing the body of the laser light, where the space portion has been formed by the first reflecting mirror, and the part of the laser light reflected by the first and second reflecting mirrors, onto a portion to be machined; and

a tip machining portion of machining means disposed in the space portion of the body of the laser light coaxially with the body of the laser light.

7. The laser beam machining head of claim 6, wherein

the first reflecting mirror is inserted into the laser light, which has been made into the parallel beam by the collimating optical system, along a diametrical direction of a cross sectional plane of the laser light and obliquely relative to an optical axis of the laser light, and is also inclined in a direction perpendicular to a direction of insertion of the first reflecting mirror, whereby the part of the laser light is reflected obliquely to an outside of the body of the laser light.

8. The laser beam machining head of claim 6, wherein

an optical axis of the collimating optical system and an optical axis of the focusing optical system are displaced in a direction perpendicular to the optical axes, whereby the collimating optical system is moved over toward one side relative to the focusing optical system so that the part of the laser light reflected by the first and second reflecting mirrors is entered into other side of the focusing optical system.

11. The laser beam machining head of claim 6, wherein

the tip machining portion of the machining means is a GMA electrode, a TIG electrode, a filler wire, an assist gas nozzle, or a powder nozzle.

14. The laser beam machining head of claim 6, wherein

the tip machining portion of the machining means is the assist gas nozzle, and the assist gas nozzle is a divergent nozzle.

17. A laser beam machining apparatus comprising:

the laser beam machining head of claim 6;

a laser oscillator for oscillating laser light;

laser light transmission means for transmitting the laser light oscillated by the laser oscillator to the laser beam machining head; and

laser beam machining head moving means for positioning and moving the laser beam machining head to an arbitrary position.