JPH09300090A - Machining head for yag laser beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the machining head to be moved on weld line at fixed speed. SOLUTION: In this machining head, a running wheel 25 to freely run on the surface of a first member 17 and a drive motor 33 to drive a running wheel are arranged to a main body 3 of machining head for YAG laser beam, a weld line positioning means 45 which can freely run on the surface of a second member roughly orthogonally abutting to the first member 17 is arranged to a nozzle 15 of the machining head for YAG laser beam, further the distance between the weld line positioning means and the surface of second member is arranged adjustable, a focus position of an optical system 9 for condensing is made adjustable in the same plane as the first member 17, further, the running wheel is arranged so as to be driven at fixed speed by the drive motor 33.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a processing head for a YAG laser.

[0002]

2. Description of the Related Art A small YAG laser processing head 100 as shown in FIG. 3 is used for laser welding.
A condensing optical system (not shown) including a collimator lens and a condensing lens (not shown) is provided inside the YAG laser processing head 100. Laser light from a YAG laser oscillator (not shown) is guided to the inside of the YAG laser processing head 100 via an optical fiber cable 101, emitted from a laser light emitting end (not shown) of the optical fiber cable 101, and then collimated lens. Is incident on. The laser light corrected into parallel rays by the collimator lens is condensed by the condenser lens and emitted from the nozzle 102.

In the small YAG laser processing head 100 as described above, for example, two plate members 103 and 104 are used.
When welding the welded portion 104 formed of a straight line or a curved line at the contact portion, the laser processing head 100 is manually moved by the operator along the straight line or the curved line of the welded portion 104.

[0004]

It is very difficult for an operator to perform welding while manually moving a laser processing head on a straight line or a curved line of a welded portion at a constant speed.
If the moving speed of the laser processing head changes,
For example, if the moving speed is faster than the appropriate speed, incomplete welds occur and the welding strength becomes insufficient. Conversely, if the moving speed is slower than the appropriate speed, extra energy is input to the welded area, and the welded area becomes excessive. However, there is a problem in that it melts into a dent to form a dent, or the distortion due to the effect of heat increases.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to keep the distance between the laser processing head and the welded portion constant and to make the straight line of the welded portion or It is an object of the present invention to provide a processing head for a YAG laser that can be moved on a curve accurately and at a constant speed.

[0006]

As a means for solving the above-mentioned problems, the processing head for a YAG laser according to claim 1 has a laser beam emitting end of an optical fiber provided inside the laser processing head, and emits from the emitting end. In a YAG laser processing head provided with a condensing optical system for condensing a laser beam, the YAG laser processing head is run at a constant speed along a welding line of a workpiece that abuts substantially orthogonally. The gist is that a constant-speed feeding device is provided.

Therefore, the YAG laser processing head can be run at a constant speed on the welding line.

A machining head for a YAG laser according to a second aspect is the machining head for a YAG laser according to the first aspect, wherein the constant-speed feeding device is a traveling wheel that can travel on the surface of the first member. A drive motor for driving the traveling wheels is provided in the main body of the YAG laser processing head,
A welding line positioning means is provided in the nozzle of the YAG laser processing head so that the welding line can freely travel on the surface of the second member which is in contact with the first member at substantially right angles, and the welding line positioning means and the surface of the second member. Adjustable distance,
The gist of the present invention is that the focus position of the condensing optical system can be adjusted in the same plane as the surface of the first member and the traveling wheels can be driven at a constant speed by the drive motor. Is.

Therefore, the focal position of the converging optical system can be accurately aligned with the welding line existing in the same plane as the surface of the first member, and at the same time, along the welding line,
The YAG laser processing head can be run at a constant speed.

In the processing head for a YAG laser according to a third aspect, at least two traveling wheels are provided. Therefore, the frictional force between the traveling wheel and the first member increases, and slippage is less likely to occur, so that the welding line can be traveled at a more stable constant speed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial cross-sectional view of a YAG laser processing head, and FIG. 2 is a right side view of FIG. Now, referring to FIG. 1 and FIG.
Inside the main body 3 of the laser processing head 1, a focusing optical system 9 including a collimating lens 5 and a focusing lens 7 is provided. A laser beam LB from a YAG laser oscillator (not shown) provided with a protective window 10 for protecting the condenser lens 7 below the condenser lens 7 is transmitted through an optical fiber cable 11 to the main body of the laser processing head 1. 3 is guided inside and emitted radially from the laser light emitting end 13 provided inside the main body. This laser light emitting end 1
The laser light from the laser beam 3 is incident on the collimator lens 5, the laser light LB corrected into parallel rays by the collimator lens 5 is condensed by the condenser lens 7, and is processed from the nozzle 15 at the lower end of the laser processing head 1. The surface of the material W is irradiated.

On the main body 3 of the laser processing head 1, along the welding line 21 of the workpiece W where the first member 17 and the second member 19 abut substantially orthogonally, the laser processing head 1 is provided. There is provided a constant speed feeding device 23 for traveling the vehicle at a constant speed.

The constant speed feeding device 23 is provided with a traveling wheel 25 that can travel on the surface of the first member 17 and a driven toothed pulley 27 that rotates integrally with the traveling wheel 25. It is rotatably provided on a rotary shaft 29 provided below the unit 3.

Further, the main body 3 is provided with a handle 31 for holding and operating the processing head 1 when an operator operates the laser processing head 1. The internal space of the handle 31 is provided. Further, a driving motor 33 such as an air motor or an electric motor for rotating and driving the traveling wheels 25 is provided. Further, a toothed belt 37 is wound around the toothed pulley 35 for driving provided on the output shaft of the drive motor 33 and the toothed pulley 27 on the driven side. Further, the handle 31 has a push button switch 39 for turning on / off the power of the drive motor 33,
A slide switch 41 for adjusting the rotation speed of the drive motor 33 is provided.

The traveling wheel 25 is attached to the main body 3 at the position where the traveling wheel 25 comes into contact with the surface of the first member 17, and the focus of the focusing optical system 7 of the laser processing head 1 is obtained. Are provided on the surface of the first member 17. That is, when the traveling wheel 25 is brought into contact with the surface of the first member 17, the focal point of the condensing optical system 7 becomes the first member 1.
It is located on the surface of No. 7.

In the constant speed feeding device 23 having the above structure, when the power source of the drive motor 33 is turned on by the push button switch 39, the drive motor 33 rotates at a constant speed, and the traveling wheels 25 pass through the toothed belt 37. Will be rotated at a constant speed. By appropriately adjusting the position of the slide switch 41, the rotation speed of the drive motor can be adjusted by the drive motor control device (not shown).

Below the condensing optical system 7 of the laser processing head 1, a laser beam can pass therethrough, and at the same time, a nitrogen gas or an argon gas for shielding the welded portion from the atmosphere is used. The nozzle 15 made of an inert gas and capable of injecting a shield gas is provided, and the nozzle 15 extends below the focus position of the condensing optical system 7 and is provided on the surface of the second member 19. A nozzle extending portion 43 facing the above is provided. A welding line positioning means 45 is attached to the nozzle extending portion 43.

The welding line positioning means 45 includes a positioning screw 47 provided in the nozzle extension portion 43 and screwed into a screw hole.
It comprises a ball plunger 49 capable of fixing the positioning screw 47 at an appropriate position. A rotating sphere 51 made of hard plastics or steel is rotatably attached to the tip of the positioning screw 47. In addition, set screw 4
7 is provided with a plurality of axial positioning grooves 53 engageable with the balls of the ball plunger 49.

In the welding line positioning means 43 having the above structure, in order to align the focal position of the focusing optical system with the welding line on the surface of the first member, the rotary sphere 51 at the tip of the positioning screw 47 is set to By positioning the positioning screw 47 at an appropriate position while actually contacting the surface of the second member 19 and actually irradiating the laser beam, the deviation between the focal position and the welding line is confirmed and the positioning is performed. By moving the screw 47 again and again by an appropriate amount, the focus position can be accurately aligned with the welding line.

Processing head 1 for YAG laser as described above
In FIG. 1, for example, a case where the first member 17 and the second member 19 are welded at the abutting portion of the workpiece W in which the first member 17 and the second member 19 abut substantially orthogonally will be described with reference to FIG.

The workpiece W consisting of the first member 17 and the second member 19 is placed and fixed on the work table or the jig 55. A welding line 21 exists at a portion where the first member 17 and the second member 19 contact each other, and the welding line 21 is a straight line or a curved line depending on the planar shapes of the first member 17 and the second member 19.

First, the traveling wheels 25 of the laser processing head 1 are set on the first member 17 at the corners of the first member 17 and the second member 19. If the traveling wheel 25 of the laser processing head 1 is set on the first member 17, the focus of the condensing optical system is automatically set on the first member 17, so next, this focus is set on the welding line 21. Will be adjusted to

In order to focus on the welding line 21, the rotary sphere 51 at the tip of the positioning screw 47 is brought into contact with the surface of the second member 19 as described above, and the positioning screw 47 is appropriately adjusted. Fix the position and check the deviation between the focus position and the welding line by actually irradiating the laser beam, and move the positioning screw 47 again and again by an appropriate amount to accurately set the focus position on the welding line 21. Can be adjusted to

Next, when the push button switch 39 is pressed to drive the drive motor 33, the traveling wheels 25 rotate and the laser processing head 1 moves along the welding line 21 to the first position.
It moves on the member 17 at a constant speed (in the direction on the back side of the paper surface in FIG. 1, and in the right direction in FIG. 2). At the same time that the laser processing head 1 moves, YAG laser light is emitted from a laser oscillator (not shown), and the welding line portion is continuously welded.

In order to prevent the focal point from deviating from the welding line during traveling, the direction of the traveling wheels of the laser processing head 1 should be set slightly inward of the direction of the welding line (toward the inside of the material). A component force such that the rotating sphere 51 of the positioning screw 47 of the welding line positioning means 43 is pressed against the second member 19 does not cause the focal point to separate from the welding line during traveling, and the worker can also use the laser. The processing head 1 can be easily moved along the welding line.

[0026]

According to the inventions of claims 1 to 3, the laser processing head can be moved at a constant speed along a straight line or a curved line of a welded portion.
The welding strength of the welded portion becomes uniform, and high quality welding can be performed. Further, since excess energy is applied to the welded portion, the welded portion is excessively melted to form a dent, and welding defects such as distortion due to thermal influence are eliminated, so that the production efficiency is improved.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a YAG laser processing head according to the present invention.

FIG. 2 is a right side view of FIG.

FIG. 3 is a diagram showing a conventional processing head for a YAG laser.

[Explanation of symbols]

 1 Processing Head for YAG Laser 3 Main Body 5 Collimating Lens 7 Condensing Lens 9 Condensing Optical System 10 Protection Window 11 Optical Fiber Cable 13 Laser Light Emitting End 15 Nozzle 17 First Member 19 Second Member 21 Welding Line 23 Constant Speed Feeding Device 25 Traveling Wheel 27 Toothed Pulley 29 Rotating Shaft 31 Handle 33 Drive Motor 35 Toothed Pulley 37 Toothed Belt 39 Push Button Switch 41 Slide Switch 43 Nozzle Extension 45 Welding Line Positioning Means 47 Positioning Screw 49 Ball Plunger 51 Rotating Sphere 53 Positioning groove 55 Jig W Work material

Claims (3)

[Claims] 1. A YAG laser processing head in which a laser light emitting end of an optical fiber is provided in a laser processing head and a converging optical system for condensing laser light emitted from the emitting end is provided. The YAG laser processing head is characterized in that a constant speed feeding device is provided for causing the YAG laser processing head to travel at a constant speed along the welding line of the workpiece to be abutted. 2. The constant speed feeding device is provided with a traveling wheel that is capable of traveling on the surface of a first member and a drive motor that drives the traveling wheel in a main body of the YAG laser processing head, The nozzle of the processing head for the YAG laser is provided with a welding line positioning means that can freely travel on the surface of the second member that abuts the member substantially orthogonally, and the distance between the welding line positioning means and the surface of the second member is set. The focus position of the condensing optical system is adjustable on the same plane as the surface of the first member, and the traveling wheels are driven by the drive motor at a constant speed. The processing head for a YAG laser according to claim 1. 3. The YAG laser processing head according to claim 2, wherein at least two traveling wheels are provided.