JPH0775786B2 - Welding method and apparatus for three-dimensional thin plate structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for welding thin plates of a three-dimensional thin plate structure, and more particularly to welding and joining thin plates by a welding head and a cutting head which receive laser light guided by an optical fiber. The present invention relates to a technique for cutting the end portions of both thin plates while leaving.

[0002]

2. Description of the Related Art Conventionally, spot welding has been widely used as a technique for welding and joining the ends of thin plates in a three-dimensional thin plate structure such as automobiles and home electric appliances. This spot welding technique is one of a pair of electrodes. Movably with respect to the other,
This is a technique for welding thin plates by energizing them with Joule heat as a heat source while sandwiching the thin plates between both electrodes. By the way, recently, a laser welding technique for welding using a laser beam as a heat source has been put into practical use, and for example, in actual utility model Sho 60-71490.
In the publication, a V-shaped joining flange portion is formed at an end portion of a pair of thin plates such as a fuel tank of an automobile, and a pair of rollers for sandwiching the joining flange portion is provided in a welding head. Is squeezed by a pair of rollers, a laser beam is emitted from the direction orthogonal to the thin plate to the abutting portions of the joint flange portions, and the butt welding is performed.

[0003]

In the welding technique using spot welding, since the spot welding is performed at predetermined intervals, the joint strength and rigidity are poor, and as a result, it is necessary to increase the thickness of the thin plate. Since it is large, it is necessary to increase the width of the joining flange part, which increases the weight.Because the head of the spot welder is quite large and heavy, it is difficult to approach the narrow part, and a large robot as a robot to attach the spot welder It becomes necessary and needs to be replaced when the electrodes are consumed.

Although welding by laser light has been put into practical use, a laser light output of 1 kw or more is required for efficiently welding thin plates of a three-dimensional thin plate structure. As a CO ₂ laser, Y
An AG laser, an iodine laser put into practical use by the applicant of the present application, and the like are known. However, since laser light such as CO ₂ laser cannot be guided by an optical fiber, there are various restrictions in use, and it is difficult to apply it to welding such as a thin plate of a three-dimensional thin plate structure. However, the iodine laser is suitable for welding thin plates of a three-dimensional thin plate structure because it can guide a fiber with a small-diameter optical fiber and increase the output. In the conventional laser welding technology, since the laser light by the mirror light guide was used, the mirror light guide system and the welding head became large and complicated,
It was almost difficult to mount it on a welding robot and perform automatic welding.

In order to weld and join the ends of the thin plates by the welding robot, it is often the case that the joining flanges bent at right angles to the ends of the thin plates are overlapped with each other and a laser beam is emitted in the plate thickness direction for welding and joining. In this case, it is desirable to cut an unnecessary portion of the joining flange after the welding joining because the width of the joining flange becomes large in order to perform the welding joining while sandwiching the joining flanges with a pair of rollers. Since a cutting process is required later, there is a problem that the cutting cost becomes expensive. An object of the present invention is to provide a welding method and apparatus for a three-dimensional thin plate structure capable of simultaneously performing welding and cutting with laser light.

[0006]

According to a first aspect of the present invention, there is provided a method for welding a three-dimensional thin plate structure, wherein the two thin plates of the three-dimensional thin plate structure are overlapped with each other, and the ends of the two thin plates are welded. In the joining method, a welding head that receives laser light guided by an optical fiber from a laser light generator, and a cutting head that receives laser light guided by a fiber from the laser light generator and welds near the welding head A state in which a cutting head fixedly provided with respect to the head and at least a pair of opposed rollers provided near the welding head are used, and the end portions of both thin plates are pressed by the opposed rollers. Then, while the welding head, the cutting head, and the roller are synchronously moved along the ends of both thin plates, laser light is emitted from the welding head in the thickness direction of both ends of the thin plates to continuously weld. It is characterized in cutting the ends of the two thin plates, leaving the welding simultaneously with welding joints in the cutting head.

A welding device for a three-dimensional thin plate structure according to a second aspect is a welding device for welding and joining the ends of two thin plates of a three-dimensional thin plate structure in a state where the ends of the two thin plates are overlapped with each other. A welding head that receives laser light guided by an optical fiber from a laser light generator and emits laser light in the thickness direction of the ends of both thin plates, and an optical fiber that is integrally formed with the welding head and is common to the welding head. A cutting head for receiving a laser beam emitted, and at least a pair of opposed rollers fixedly provided near the welding head for clamping the ends of both thin plates. It is a thing.

[0008]

In the method for welding a three-dimensional thin plate structure according to claim 1, when the ends of the two thin plates of the three-dimensional thin plate structure are overlapped with each other, the ends of the two thin plates are welded and joined together.
A welding head that receives laser light guided by an optical fiber from a laser light generator and a laser light guided by an optical fiber from the laser light generator in a state where the ends of both thin plates are pressed by rollers facing each other. The cutting head, which is fixed to the welding head near the welding head, and the roller are synchronously moved along the ends of both thin plates while receiving laser light from the welding head. The parts are emitted in the plate thickness direction and continuously welded, and at the same time as the welding, the ends of both thin plates are cut by a cutting head leaving a welded joint.

Since the welding head that receives the laser light guided by the optical fiber from the laser light generator is used, it is possible to perform welding and joining at a high speed with a small and lightweight welding head. Further, since the lap welding is one in which laser light is emitted from the plate thickness direction, the welding head positioning allowable range is widened, positioning of the welding head is facilitated, and high-speed welding is possible. Since the ends of both thin plates are welded while being pinched by at least one pair of rollers, welding quality can be secured. Moreover, a cutting head which is fixedly provided to the welding head near the welding head and receives laser light guided by an optical fiber from a laser light generator is used. Since the end portion of is cut, welding and cutting can be performed in one step, so the cutting cost can be reduced.

In the apparatus for welding a three-dimensional thin plate structure according to a second aspect of the present invention, when the ends of two thin plates of the three-dimensional thin plate structure are superposed, the ends of both thin plates are welded and joined together. Laser light is emitted from the welding head, which receives the laser light guided by the optical fiber from the laser light generator, in the plate thickness direction with the end portions of both thin plates sandwiched by at least one pair of opposing rollers. Weld with laser light.

As described above, since the welding head is configured to receive the laser light guided by the optical fiber from the laser light generator, the welding head can be reduced in size and weight, and as a result, high speed welding is possible. Become. Further, since the laser light is emitted from the plate thickness direction, the welding head positioning allowable range is widened, the positioning of the welding head is facilitated, and high-speed welding becomes possible. Moreover, since welding is performed with the end portions of both thin plates sandwiched by the pair of rollers, welding quality can be secured. Since the welding head is integrally formed with a cutting head that receives a laser beam guided by an optical fiber common to the welding head, the ends of both thin plates are left with a welding joint portion in parallel with welding. Can be cut.

[0012]

As described in the above section, the following effects can be obtained. According to the method for welding a three-dimensional thin plate structure according to claim 1, a laser beam is generated when the end portions of the two thin plates of the three-dimensional thin plate structure are overlapped and welded to each other. Since the welding head that receives the laser light guided by the optical fiber from the container is used, small and lightweight welding head can be used for high-speed welding joining, and because it is lap welding that emits laser light from the plate thickness direction, the welding head positioning allowable range is It becomes wider, positioning of the welding head becomes easier, and high-speed welding becomes possible, and since welding is performed with the end portions of both thin plates sandwiched by at least one pair of rollers, welding quality can be secured. Moreover, since a cutting head fixedly provided to the welding head near the welding head is used and the ends of both thin plates are cut by laser light while leaving the welded joint at the same time as the welding, the ends of both thin plates are cut. The unnecessary portion can be removed to reduce the weight of the three-dimensional thin plate structure, and welding and cutting can be performed in one step, so that the cutting cost can be significantly reduced.

According to the welding device for a three-dimensional thin plate structure of the second aspect, in the welding device for welding and joining the superposed ends of two thin plates of the three-dimensional thin plate structure, the welding head is
Since it is configured to receive the laser light guided by the optical fiber from the laser light generator, the welding head can be made smaller and lighter, resulting in high-speed welding. Further, since the laser light is emitted from the plate thickness direction, the welding head positioning allowable range is widened, the positioning of the welding head is facilitated, and high-speed welding becomes possible. Moreover, since welding is performed with the end portions of both thin plates sandwiched by the pair of rollers, welding quality can be secured. Moreover, the welding head is integrally formed with a cutting head for receiving laser light guided by an optical fiber common to the welding head, so that the ends of both thin plates are cut while leaving the welded joint in parallel with welding. Therefore, the cutting cost can be reduced, and the weight of the three-dimensional thin plate structure can be reduced.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment applies the invention to a welding technique for welding and joining the ends of a pair of thin steel plates constituting a part of a three-dimensional thin plate structure of a car body or a three-dimensional thin plate structure of a casing of home electric appliances by laser welding. This is an example of the case. As shown in FIGS. 1 to 4, the laser welding apparatus includes a laser light generator 1 and an arm 2 of a multi-joint robot for welding.
Welding and cutting head 4C attached to the hand 3 at the tip of the
The laser light generator 1 is provided with (hereinafter referred to as a head 4C) and a roller unit 5 integrally fixed to the head 4C. This is an iodine laser generator that generates a 1.3 μm laser beam, and the laser beam generated by the laser beam generator 1 is guided to the head 4C by the optical fiber 6A. However, the laser light generator 1
Is not limited to the above, and a laser light generator of YAG laser can be used.

The head 4C includes a first lens 7 and a first lens 7.
A concave mirror 60 that converts the parallel laser light emitted from the upper half of the lens 7 by about 90 degrees and converts it into convergent light for cutting.
The parallel laser light emitted from the lower half of the first lens 7 is about 90
Concave mirror 61 for converting the direction and the convergent light for welding
And a ring-shaped gas introduction chamber 62 for introducing pressurized argon gas for gas shielding around the emitted welding laser beam 14A at the lower end of the head 4C, and the center of the emitted cutting laser beam 14B. An annular gas introduction chamber 63 for introducing a pressurized oxygen gas for injecting toward the chamber is formed, and an annular gas ejection hole 64 is formed at the lower end of the gas introduction chamber 62.
Is formed, and a plurality of injection small holes 65 for ejecting the pressurized oxygen gas toward the central portion of the molten metal melted by the cutting laser beam 14B emitted are provided at the lower end of the gas introduction chamber 63.

The cutting laser beam 14B is configured to be emitted to a position closer to the tip (free end) of the joining flange 13 than the welding laser beam 14A, and argon is introduced into the gas introducing chamber 62. Hose 66 from gas supply
The pressurized argon gas is supplied through the hose 67, and the pressurized oxygen gas is supplied to the gas introduction chamber 63 from the oxygen gas supply source through the hose 67. Since the welding laser light 14A and the cutting laser light 14B are guided to the optical fiber 6A by fiber, the optical fiber 6A has a larger diameter.

A joint flange 13 bent at a right angle with respect to the thin plate body 12 is formed at an end of the pair of thin plates 11 of the three-dimensional thin plate structure. The laser light 14A emitted from the head 4C is emitted from above the joining flanges 13 in the plate thickness direction, and the joining flanges 13 are welded to each other. To be done.

Explaining the roller unit 5, an annular portion 16 is formed at an upper end portion of the frame 15, and a head 4C is fitted in the annular portion 16 to integrally fix the frame 15 and the head 4C. In 15,
Below the head 4C, plate-shaped roller support portions 17 extending to both sides of the head 4C are provided, and fixed rollers 18 are rotatably provided on upper portions of both ends of the roller support portion 17 about an axis parallel to the axis of the head 4C. The fixed roller 18 is provided at a height position where it rolls on the upper surface of the joint flange 13 when welding is performed by the head 4C. Further, since the pair of upper and lower joining flanges 13 cooperates with the fixed rollers 18 to squeeze them, they are placed at positions corresponding to the fixed rollers 18.

The roller supporting portion 17 is provided with a movable roller 19 on a shaft in the same direction as the fixed roller 18, and the bearing member 20 for supporting the shaft of each movable roller 19 is a roller supporting portion 17.
Of the air cylinder 2 which is rotatably supported through the pin 22 and is rotatably supported by the pin 22 and is attached to the roller support portion 17 at the end opposite to the roller in a vertical direction.
When the tip end of the rod 24 of No. 3 is pin-coupled and pressurized air is supplied to the head side chamber of the air cylinder 23, the movable roller 19 is urged toward the joining flange 13 and the fixed roller 1
8 and the movable roller 19 pinch both joint flanges 13,
Further, when the pressurized air is discharged, the movable roller 19 is swung downward by about 20 to 30 degrees by the elastic force of the spring of the rod side chamber of the air cylinder 23. The rollers 18 and 19 may be formed in a drum shape with a ground contact surface having a middle or high height, or may be provided with a spherical body instead of the rollers 18 and 19.

A method of cutting the unnecessary portion while welding both joining flanges 13 by the operation of the laser welding apparatus described above will be described. With both thin plates 11 positioned on an assembling jig (not shown) and set as shown, the welding / cutting head 4C is moved to one end of the joining flange 13 to release the air from the air cylinder 23. The movable roller 19 is kept separated from each pair of the fixed rollers 18, and the robot hand 3 is moved from the horizontal direction toward the joining flange 13 so that the joining flanges are formed between the fixed roller 18 and the movable roller 19. 13 is inserted relatively,
Next, air is supplied to the air cylinder 23 to clamp both joint flanges 13 by a pair of fixed roller 18 and movable roller 19, and laser light is generated in this state.

A laser beam is supplied from the device 1 to the head 4C, and also argon gas and oxygen gas are supplied, and the head 4C and the roller unit 5 integrally fixed thereto are supplied along a joint flange 13 by a robot. Both joint flanges 1 by laser light while moving at speed
3 are continuously welded and the welded portion 25 is left in parallel with the welding to remove the unnecessary portion of the joint flange 13 along the cutting line 2
Cut along 6 and remove. After welding and cutting the entire length of the joining flange 13, the supply of laser light, argon gas and oxygen gas is stopped, the air supply of the air cylinder 23 is released, and the movable roller 19 is opened downward. The head 4C and the roller unit 5 are to be removed from the joint flange 13.

As described above, while welding the pair of overlapping joint flanges 13 with the welding laser light 14A, the portion of the both joint flanges 13 separated from the welded joint 25 by a predetermined distance is cut with the laser light 14B. Can be cut with. Since the thin plate 11 is a thin plate having a thickness of about 0.8 to 1.2 mm, it can be continuously welded at high speed by laser light. In particular, since the head 4C is small and lightweight, which receives laser light not by the mirror light guide but by the fiber light guide, the load on the robot is light, a relatively small robot can be applied, and welding can be performed at high speed. .

Since the welding is not spot-like welding but continuous welding is performed over the entire length of the welding line, the welding strength is excellent, and since the laser light is concentrated locally, it can be welded with minimum welding. Small residual strain due to welding.
Moreover, since the pair of fixed rollers 18 and movable rollers 19 clamp the pressure at two locations on the upstream side and the downstream side in the welding progress direction, both flanges 13 do not move relative to each other before the weld metal solidifies, and welding quality improves. . Moreover, since welding and cutting can be performed in parallel in one step, the cutting cost can be reduced, and unnecessary portions of the joining flange 13 are removed, so that the weight of the three-dimensional thin plate structure can be reduced.

Another Embodiment 1-Refer to FIG. 5 This embodiment is an example in which a roller unit 5A is provided in place of the roller unit 5, and the construction of the welding / cutting head 4C itself is the same as that described above. The same parts as those in the above-mentioned embodiment are designated by the same reference numerals and the description thereof will be omitted. The roller unit 5A is a remarkably downsized roller unit, and includes a pair of fixed roller 30 and movable roller 31. Similarly to the above, the head 4C is loosely fitted into the annular portion 33 of the frame 32, the head 4C is fixed to the annular portion 33 by a pair of angle adjusting and fixing bolts 34, and the head 4C is attached to the frame 32 below the head 4C. Is a fixed roller holder 35 and a movable roller holder.

The fixed roller holder 35 is provided with a rudder 36, and a fixed roller 30 having a small diameter that partially projects outside the lower surface of the fixed roller holder 35 is rotatably provided. A small-diameter movable roller 31 that partially projects outside the upper surface is rotatably provided.
And a double-acting air cylinder 39 is integrally formed in an inverted shape at the base end portion of the frame 32.
When the rod 39a is pin-coupled to the base end of the movable roller holder 36 and pressurized air is supplied to the rod side chamber of the air cylinder 39, the movable roller holder 36 opens downward and pressurizes the head side chamber of the air cylinder 39. When air is supplied, the movable roller holder 36 is urged upward, and the fixed roller 30 and the movable roller 31 press the both joint flanges 13.

The welding / cutting head 4 is similar to the above in the case of welding and cutting. Therefore, the description of the welding and cutting method will be omitted. In the case of this head 4C, the head 4C with respect to the frame 32 will be described. When adjusting the tilt of the frame, loosen the pair of bolts 34 and
The inclination of the welding head 4 with respect to can be adjusted, and the pair of bolts 34 can be tightened and fixed again. Further, since only one pair of the fixed roller holder 35 and the movable roller holder 36 are provided, and they are made as small and light as possible, it is possible to perform welding even in a narrow welding place, and the roller unit 5A interferes. And the load on the robot is reduced.

Another Embodiment 2 ... See FIG. 6 This embodiment shows another embodiment of the welding and cutting head, and any one of the roller units can be adopted as the roller unit. The same parts as those shown in FIG. FIG. 6 shows a welding and cutting head 4D.
In this welding / cutting head 4D, a parallel laser beam emitted from the first lens 7 is provided in order to leave a space between the emitted welding laser beam 14A and the emitted cutting laser beam 14B. A prism 70 for branching the laser beam is provided, and the cutting laser beam 14B is redirected by about 15 degrees to the side opposite to the welding advancing direction by the prism 70 and then redirected downward by about 45 degrees by the concave mirror 71. The welding laser beam 14A is converted by the prism 70 in the welding progress direction by about 5 degrees, and then the rear concave mirror 7 is formed.
It is configured so that it is turned downward by about 45 degrees by 2.

Since the distance between the welding laser beam 14A and the cutting laser beam 14B is increased at the position projected on the joining flange 13, the gas introducing chambers 62 and 63 in the above embodiment are formed. It will be easier.
However, it is also possible to independently configure the welding head and the cutting head and integrally fix them with a predetermined positional relationship.

As the joining flange 13 of the thin plate 11, the joining flange 1 bent at a right angle from the thin plate body 12 is used.
Although the case of No. 3 has been described as an example, the present invention can be similarly applied to the case of welding joining flanges of various shapes formed at the ends of two thin plates. Further, the welding / cutting head and the roller unit are not limited to those of the embodiment, and are implemented in a form in which various modifications and auxiliary members are added within a range not departing from the technical idea disclosed in the embodiment. You can do it.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a welding device for a three-dimensional thin plate structure.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a vertical sectional view of a welding / cutting head and a thin plate of the welding apparatus.

FIG. 4 is a schematic bottom view of the welding / cutting head of FIG. 1.

FIG. 5 is a side view of a welding / cutting head and a roller unit according to another embodiment.

FIG. 6 is a cross-sectional plan view of a welding / cutting head according to another embodiment.

[Explanation of symbols]

 1 Laser Light Generator 4C, 4D Welding and Cutting Head 6A Optical Fiber 11 Thin Plate 12 Thin Plate Body 13 Joint Flange 14A Welding Laser Light 14B Cutting Laser Light 18,30 Fixed Roller 19,31 Movable Roller

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yukihiro Nomaguchi 2-4-1 Hamamatsucho, Minato-ku, Tokyo World Trade Center Building Kawasaki Heavy Industries, Ltd. Tokyo Head Office (56) Reference JP-A-58-47590 ( JP, A) JP 59-47083 (JP, A) JP 6-285660 (JP, A) Actual development 60-71490 (JP, U)

Claims (2)

[Claims] 1. A laser beam guided from an optical fiber from a laser light generator in a method of welding and joining the ends of two thin plates of a three-dimensional thin plate structure in a state where the ends of the two thin plates are overlapped. Receiving the welding head and from the laser light generator
With a cutting head that receives the laser light guided by the fiber
Fixed near the welding head
A cutting head provided, in a state in which the opposing at least one pair provided in the vicinity of the welding head with a roller, was nipped the end portions of both sheet at opposing rollers, the welding head and the cutting head with the while the roller is moved synchronously along the edge portions of both sheet, continuously welded with the laser beam from the welding head is emitted in the thickness direction of both thin end portions
Simultaneously with the welding, cut the ends of both thin plates leaving the welded joint.
A method for welding a thin plate of a three-dimensional thin plate structure, which comprises cutting with a cutting head . 2. The ends of the two thin plates of the three-dimensional thin plate structure are overlapped.
Weld and join the ends of these two thin plates together.
In welding equipment, laser guided by optical fiber from laser light generator
-Receives light and emits laser light in the thickness direction at the ends of both thin plates
Of the welding head and the optical head that is formed integrally with the welding head and is common to the welding head.
Cutting head that receives the laser light guided by the fiber
When fixedly set relative to the welding head in the vicinity of the welding head
At least one pair of phases for clamping the edges of both thin plates
A welding device for a three-dimensional thin plate structure , comprising: opposing rollers .