JP2586565Y2 - Laser welding equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser welding apparatus for performing welding by irradiating a workpiece with a laser beam.

[0002]

2. Description of the Related Art Techniques for cutting and welding by irradiating a workpiece with a laser beam have come into practical use. Laser welding is superior to resistance spot welding because a nozzle for irradiating a beam is not in contact with a workpiece and irradiation can be performed from one side. In Japanese Utility Model Laid-Open Publication No. 63-62291,
A laser beam cutting apparatus in which a rolling member is provided at the tip of a nozzle for irradiating a laser beam, and the rolling member moves the nozzle on a processing surface is described. Also,
Japanese Utility Model Application Laid-Open No. 60-71490 discloses a roller in which two panels each having a V-shaped flange are abutted to each other, a pair of supporting arms are held by a laser device, and the rollers are rotatably supported by the supporting arms. A laser welding apparatus in which the V-shaped flanges are rolled along a welding line integrally with a laser beam while being pressed against each other. Also,
Japanese Utility Model Laid-Open Publication No. 4-80682 discloses a robot arm.
On the fixed torch, under the overlapping flange of the workpiece
A member that receives the edge and a superposed member facing it
Drive the piston to pinch the upper edge of the flange
Laser welding robot with a fixed cylinder
ing.

[0003]

[Problems to be Solved by the Invention] When welding is performed by irradiating a workpiece with a laser beam, it is important to always keep the focal position of the beam at a predetermined portion of the welded portion in order to ensure the quality of the welded portion. is there. Further, when the workpieces are overlapped and welded, reducing the gap between the workpieces is also an important condition for obtaining a good weld. As shown in FIG. 4, when the flange portions of the upper and lower panels 21 and 22 are overlapped and the workpiece is irradiated with the laser beam 10 to perform welding, depending on the processing accuracy of the panel and the accuracy of the overlap, etc.
It is difficult to control the gap d of the flange portion shown in FIG. 5 to be constant. For example, in the case of a galvanized steel sheet, if the gap d exceeds 0.5 mm, the penetration of the welded portion becomes insufficient and good quality cannot be obtained.

[0004] Further, if the gap of the welded portion of the work is brought into close contact and the gap is set to zero, in the case of galvanized steel sheet, gas is generated from zinc, which causes the generation of holes or cavities, and welding without defects can be performed. Disappears. In the case of lap welding, it is usually necessary to maintain a gap of at least 0.05 to 0.08 mm or more. Therefore, in the welded part of the work,
It is necessary to form a gap in the range of d = 0.05 to 0.5 mm. Japanese Utility Model Laid-Open Publication No. 4-80682.
Laser welding robots use flanges with overlapping workpieces
Since a jig having a means for sandwiching
It is possible to control the range of the gap at the welded portion.
However, this jig not only requires a large scale
The holding position of the jig is limited to one position deviated from the laser beam irradiation position .

[0005] The present invention solves the above-mentioned problems, and in the case of lap laser welding, the gap between the welded portions is reduced by a simple structure.
To a specified range by holding it at multiple locations using
It is possible to hold, and the weld has a curvature
Even if the laser beam irradiation nozzle is
It is an object of the present invention to provide a laser welding apparatus capable of following a three-dimensional movement of a robot without hindrance .

[0006]

Means for Solving the Problems The present invention provides a laser beam
Of the workpiece at one end of the arm shaft attached to the
Forming a fixed flange that supports one side of the lap weld
The laser beam transmitting portion and the fixed flange are attached to the arm axis.
Fixed with a predetermined gap formed between the
A movable flange provided with a tool is installed, and the movable flange is
Possible in the area located around the laser beam transmission part
Multiple locations on each of the moving flange and the fixed flange
Of the irradiation nozzle is provided.
Attached to the robot arm via a spring that is movable in the axial direction
It is a laser welding processing device.

[0007]

[Function] A jig is fixed to a laser beam irradiation nozzle so as to focus on a desired welding portion of the overlap welding portion,
The movable flange is adjusted and fixed so that the gap between the overlap welding portions is within a predetermined range. When the laser beam is irradiated from the laser beam irradiation nozzle, the laser beam converges to the focal position and welds that part, and when the laser beam irradiation nozzle moves along a predetermined welding line, the fixed attached to the laser beam irradiation nozzle Welding is performed while the gap between the flange and the movable flange is maintained at the set gap between the overlapped welding portions. 3D direction of robot arm
The irradiation nozzle moves the workpiece according to the movement (teaching) of the workpiece.
When welding lap welds, work overlap
The curvature in the overlapping direction of the welded joint becomes more than a certain degree
The jig can follow the movement of the robot arm in this direction.
Although it disappears, the arm axis of the jig is
The arm is mounted movably via a spring
Laser beam irradiation Nozzle with is to follow the workpiece B
Welding continues with displacement relative to the bot arm.
After the point, the spring returns to its original position by the restoring force.

[0008]

FIG. 1 shows a welding apparatus according to the present invention, in which the flanges of upper and lower panels 21 and 22 in FIG. 4 are overlapped, and a laser beam 10 is irradiated along a welding line indicated by a broken line of a work. This shows the state in which welding is performed. The laser beam irradiation nozzle 1 holds a focusing lens inside, and focuses the laser beam transmitted from the optical fiber 9 at a predetermined focal length. The laser beam irradiation nozzle 1 is mounted on a robot arm 3 of a welding device via a holder 2. On the other hand, a jig for holding the overlap welding portion of the flange portions of the upper and lower panels 21 and 22 is attached to the laser beam irradiation nozzle 1. In this jig, a fixing portion 4, an arm shaft 5, and a fixing flange 6 are formed in a U-shape, and the fixing portion 4 is attached to the laser beam irradiation nozzle 1 by adjusting a vertical position with a fixing screw 4a. The movable flange 7 is slidably fitted, the distance between the movable flange 7 and the fixed flange 6 is adjusted, and the fixing screw 8 is tightened and fixed.

FIG. 2 shows a front view and a rear view of the movable flange 7. The movable flange 7 has a fitting hole 7 a for the arm shaft 5 and a laser beam passage hole 7 b. 7c is provided. A roller is provided on the side of the fixed flange 6 that contacts the flange of the lower panel 22, similarly to the movable flange 7.

Next, the welding operation by the above welding apparatus will be described. First, the fixing portion 4 of the jig is mounted on the laser beam irradiation nozzle 1 so that a desired welding portion of the overlap welding portion of the flange portions of the upper and lower panels 21 and 22 held on the fixing flange 6 can be focused. The fixing screw 4a is tightened and fixed by adjusting the vertical position of the jig. In the state of FIG. 1, the fixing screw 8 is loosened, and the movable flange 7 is moved up and down along the arm shaft 5 so that the distance between the fixing flange 6 and the upper and lower panels 2 is adjusted.
The gap between the overlap welding portions of the flange portions 1 and 22 is 0.0
Adjust so that it is in the range of 5 to 0.5 mm,
And fix it. When the laser beam is irradiated from the laser beam irradiation nozzle 1, the laser beam converges at a predetermined focal position through the hole 7 a of the movable flange 7, and the laser beam irradiation nozzle is moved along with the movement of the robot arm 3. 1 moves along a predetermined welding line, the fixed flange 6 and the movable flange 7 of the jig attached to the laser beam irradiation nozzle 1
Welding is performed while maintaining the gap between the overlap welding portions of the flange portions 1 and 22 within a set range. In this case, since the fixed flange 6 and the movable flange 7 are provided with rollers, respectively, the jig moves smoothly.

FIG. 3 shows an embodiment of the present invention.
The parts denoted by the same reference numerals indicate similar parts. Figure 1,
The welding device shown in FIG.
Is sequentially performed along the three-dimensional movement of the robot arm 3 along the scan path of the robot arm 3. However, when the welding portion is flat because the jig holding the weld portion is fixed to the laser beam irradiation nozzle 1. Can be applied, but when the curvature of the welded portion exceeds a certain level, the jig becomes difficult to move and it becomes difficult to follow the laser beam irradiation nozzle 1. In this embodiment, the scanning path of the laser beam irradiation nozzle 1 is rotatably moved in a three-dimensional direction by holding the jig holding the welded portion movably in the vertical direction (Z direction) with respect to the laser beam irradiation nozzle 1. Even when it is set, the laser beam irradiation nozzle 1 can follow. The jig attached to the laser beam irradiation nozzle 1 has a fixed portion 12, an arm shaft 15, and a fixed flange 16 formed in a U-shape, and the movable flange 7 similar to that shown in FIG. The fixing screw 8 is tightened and fixed by adjusting the distance from the fixing flange 6. The shaft 11 is inserted through this jig, the coil spring 13 is interposed, and the shaft 11 is fixed to the robot arm 3. Other points are the same as described for FIGS.

In the above embodiment, the laser beam irradiation nozzle 1 is held movably in the vertical direction (Z direction) with respect to the robot arm 3 and is restrained in the remaining two directions (X and Y directions). Even when the portion has a curvature (vertical direction in the figure), the laser beam irradiation nozzle 1 can follow the three-dimensional movement of the robot arm 3 by the expansion and contraction of the coil spring 13. That is, robot
According to a predetermined movement (teaching) in the three-dimensional direction of the program 3
The irradiation nozzle 1 welds the overlap welding part of the work
When going, the vertical curvature of the welded part of the work
Degrees, the movement of the robot arm 3 in this direction
A jig with multiple holding points around the laser beam
This jig cannot be used to follow the robot arm 3
Movably mounted in the direction of via a coil spring 13
Therefore, the laser beam irradiation nozzle 1 works with the jig
Is displaced relative to the robot arm 3 following the
Continuing, after passing through this welding point, the coil spring 13 is restored.
Return to original position with force.

FIG . 2 shows an arrangement in which a roller is disposed on the contact surface between the fixed flange and the movable flange that sandwich the welded portion, but it is of course possible to use a rolling member such as a hard ball. Instead of providing a laser beam passage hole in the movable flange, a notch may be formed from the side surface to allow the laser beam to pass.

[0014]

[Effects of the Invention] In the present invention, a simple jig to be attached to a laser beam irradiation nozzle is attached to a robot arm via a spring.
By attaching Te, positive clearance of welds in a predetermined range
It can be adjusted precisely and the weld has a curvature.
The laser beam irradiation nozzle is the tertiary robot arm
It is possible to perform the welding to follow without any trouble to the original direction of movement
Becomes

[Brief description of the drawings]

FIG. 1 is a front view of a welding device according to the present invention .

FIG. 2 is a front view and a back view of a movable flange.

FIG. 3 is a front view of the embodiment of the present invention.

FIG. 4 is a perspective view of a welded product.

FIG. 5 is a sectional view of a welded portion.

[Explanation of symbols]

1 laser beam irradiation nozzle 2 holder
3 Robot arm 4 Fixed part 5 Arm axis
6 Fixed flange 7 Movable flange 8 Fixing screw

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-135494 (JP, A) JP-A-60-210386 (JP, A) Fully open 63-62291 (JP, U) Really open Showa 60- 71490 (JP, U) Practical application Microfilm (JP, U) (58) Photographs of the contents of the specification and drawings attached to the application of Japanese Patent Application No. 2-124448 (Japanese Utility Model Application No. 4-80682) Int.Cl. ⁶ , DB name) B23K 26/00-26/18

Claims (1)

(57) [Scope of request for utility model registration] 1. A laser beam irradiation nozzle attached to a
To one end of the overlapped welded part of the work
Form a fixed flange to hold the
Form a predetermined gap between the beam transmission part and the fixed flange.
The movable flange provided with a fixture for fixing the
Installed around the laser beam transmission part of the movable flange
The movable flange and the fixed flange
Provide a plurality of opposing holding parts on each of the
A spring that makes the arm axis movable in the axial direction of the irradiation nozzle
A laser welding apparatus characterized by being mounted on a robot arm via a robot .