JP2002192379A - Laser welding method and apparatus - Google Patents

Abstract

(57) Abstract: A gap is formed between superimposed works without using an insert material or the like, and the works are welded. A positioning mechanism (16) includes a plate-shaped tool (56) attached to a substrate (54) and a tool (60) attached to a side surface of the tool (56) through a shim member (58) in a substantially parallel manner with a predetermined space therebetween. Be composed. The triangular tool 56 has a point 62 formed at a junction between an inclined surface 56b and an inclined surface 56c adjacent both ends of an upper surface 56a attached to the lower surface of the substrate 54. A tool 60 whose shape is substantially similar to the tool 56
Is provided between the lower surface of the substrate 54 and the upper surface 60a.
And inclined surfaces 60b adjacent both ends of the upper surface 60a
A sharp point 66 is formed at the junction between the tool and the inclined surface 60c, and is attached to the tool 56 together with the shim member 58. The difference l3 between the length l1 of the point 62 and the length l2 of the point 66 is obtained by adding the plate thickness T2 of the upper work W2 and the gap H through which zinc gas escapes from between the lower work W1 and the upper work W2. Set to length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art For example, a method disclosed in Japanese Patent No. 2743708 is known as a laser welding method for performing welding by irradiating a laser beam while superimposing works.

[0003] In this laser welding method, welding is performed with a thin insert material interposed between galvanized works. In this case, the melting point and the boiling point of the organic material constituting the insert material are selected to be lower than the melting point and the boiling point of zinc. Therefore, by irradiating a laser beam with the insert material interposed between the works, the insert material is first vaporized, and then the galvanized material is vaporized.
At that time, a gap is formed between the works by first vaporizing the insert material, and the works are welded to each other while the vaporized zinc component of the galvanized material is led out from the gap.

[0004]

However, in the laser welding method according to the prior art, an operation of interposing an insert material between galvanized workpieces is required. Requires the intervention of technical engineers. As a result, a problem has been pointed out that the production cost rises. Further, for example,
There is a disadvantage that the work of inserting the insert material into a large-sized member such as an automobile body is very complicated.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned drawbacks. For example, it is an object of the present invention to easily form a gap between overlapped works without interposing an insert material or the like and weld the works. As a result, the production process can be simplified and the production cost can be reduced.
Even if the workpiece is a large member such as a car body,
It is an object of the present invention to provide a laser welding method and a laser welding method capable of performing welding without performing a complicated operation.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a laser welding method for welding workpieces by superimposing the workpieces and irradiating a laser beam to the superimposed portion. The tool presses the lower work, and the other tool welds the works by irradiating a laser beam with the upper work pressed against the lower work so as to have a gap.

The present invention also relates to a laser welding apparatus for superimposing works, and irradiating a laser beam to the superposed portion to weld the works,
A positioning mechanism for positioning a welding portion of the workpiece, wherein the positioning mechanism is provided on at least one set of tools arranged substantially parallel to each other at a predetermined interval and on the one set of tools; Holding tip having different lengths, the length of at least one holding tip is set longer than the length of the other holding tip, and the length of the other holding tip is determined by the one holding tip. The upper work is set to have a gap with respect to the lower work in a state where the lower work is pressed.

According to the present invention, the lower work overlapped is held down by the long holding tip of the tool, and the upper work is held down by the short holding tip of the tool. It becomes possible to.

Further, according to the present invention, the amount of deformation of the upper work due to welding heat can be controlled based on the overlapped lower work, so that a gap between the upper and lower works can be secured stably. .

In this case, since the set of tools has a holding tip portion which is formed in a substantially triangular shape and presses the work, the upper and lower works are pressed linearly by the holding tip portion in line contact. Therefore, the plastic deformation of the work can be suppressed small, and the positional accuracy of the work can be improved, which is preferable.

Further, in this case, if the length of the other tool is adjusted by the thickness of the shim member engaged with the tool, the difference from the length of one tool is optimally maintained. It is.

Therefore, according to the laser welding method and the apparatus according to the present invention, when, for example, galvanized workpieces are overlapped and welded, the lower workpiece is pressed by the long holding tip and the short holding tip is used by the short holding tip. By irradiating the laser beam while pressing the upper work, the galvanized material applied to the work is vaporized, and a gap can be stably secured between the upper work and the lower work. The zinc component flows out, and the workpieces can be reliably welded to each other, so that superposition welding of good quality without spatter or blow holes can be performed.

Further, since it is not necessary to press the work with a large force as in a conventional welding apparatus of the type pressing with a roller, there is an advantage that the accuracy of the work is not adversely affected.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a laser welding method according to the present invention in relation to a welding apparatus for carrying out the method will be described below in detail with reference to FIGS. I do. In addition, this laser welding device,
Its use is not limited, and is preferably used, for example, in a case where a galvanized steel plate such as a roof portion of an automobile is overlapped and welded.

[0015] Laser welding apparatus 10 according to the present embodiment.
Has an original position return mechanism 12, a laser beam head 14, and a positioning mechanism 16, as shown in FIG.
It is attached to the tip of the robot arm 18.

The home position return mechanism 12 includes a robot arm 18
The support bracket 20 includes an upper surface plate 22 and a side plate 24 extending in a longitudinal direction substantially orthogonal to the upper surface plate 22. An actuator 2 such as an air cylinder is provided on the upper surface plate 22.
A guide member 2 slidably supports a moving member 30 described later on an inner side surface 24a of the side plate 24.
8 is attached. One side of the moving member 30 slidably supported by the guide member 28 is screwed on one side to a rod 32 of the actuator 26 via a nut 34, and is directed to the robot arm 18 side on the other side. An integrally formed bent portion 36 is provided. Therefore, the moving member 3
0 is guided by the guide member 28 and the actuator 2
6 are provided so as to be able to reciprocate along the longitudinal direction (vertical direction in FIG. 1) under the driving action of No. 6. A screw member 40 screwed onto the upper surface of the bent portion 36 via a nut 38 has a function of adjusting the stroke amount of the laser beam head 14, and the laser beam is increased or decreased by increasing or decreasing the screw amount of the screw member 40. The displacement stroke of the head 14 is adjusted. The elastic member 42 attached to the lower surface of the side plate 24 has a stopper and a shock absorbing function when the screw member 40 abuts.

A base plate 44 is fixed to the other side of the moving member 30. The laser beam head 14 for irradiating the laser beam L is attached to the base plate 44. This laser beam head 14
Holds a condensing lens (not shown) inside, and converges a laser beam L sent through an optical fiber 46 at a predetermined focal length to irradiate the work W.

The bottom surface 48 of the bent portion 36 of the moving member 30
Is provided with a guide member 52. The guide member 5
2 has a plate-like holding portion 50 that extends downward at a predetermined angle in FIG. 1, for example, according to the converging angle of the laser beam L. On the other side of the guide member 52, a positioning mechanism 16 for positioning the work W is supported.

As shown in FIGS. 2 and 3, the positioning mechanism 16 includes a plate-like tool 56 mounted on a substrate 54 attached to the other side of the guide member 52, and the tool 5
And a tool 60 attached to the side surface of the tool 56 via a shim member 58 disposed substantially parallel to and separated by a predetermined distance along the side surface of the tool 6. In this case, the tools 56 and 60 form a set.

The tool 56 has a triangular shape. In this case, the tool 56 has an upper surface 56a attached to the lower surface of the substrate 54, and inclined surfaces 56b, 56c adjacent both ends of the upper surface 56a, and the inclined surfaces 56b, 56c extend downward. A point 62 is formed at the junction of these inclined surfaces 56b and 56c. The point 62 is provided with a length 11 along the vertical direction downward from the upper surface 56a,
When irradiating the laser beam L to the work W composed of the superposed lower work W1 and upper work W2, the upper work of the lower work W1 is pressed to press the lower work W1. In this case, the inclined surface 56b is provided so as to be inclined downward at a predetermined angle, for example, along the converging angle of the laser beam L.

On the other hand, the tool 60 whose shape is substantially similar to the tool 56 is composed of a lower surface of the substrate 54 and an upper surface 60a of the tool 60.
A shim member 64 is interposed between the upper surface 60a and the joint between the inclined surface 60b and the inclined surface 60c adjacent to both ends of the upper surface 60a. Attached to the tool 56 together with 58. The point 66 is provided with a length 12 along the vertical direction below the upper surface 60a, and functions so as to press the upper surface of the upper work W2 and press the upper work W2. The shim member 58 has a function of adjusting the interval between the tools 56 and 60, that is, the interval between the sharp ends 62 and 66 (holding tip).

As described above, the tips 62 and 66 formed on the tools 56 and 60 have the lengths l1 and l2 from the lower surface of the substrate 54, respectively, so that the lower workpiece W1 and the upper workpiece W2 overlap. Hold down the top of each.
Therefore, the lengths l1 and l2 are set in a relation of l1> l2.

The shim member 64 is provided at the point 6 of the tool 60.
6 has a function of adjusting the length l2. The length l2 of the point 66 is such that a gas such as a galvanized material is formed between the plate thickness T2 of the upper work W2 and the overlapped lower work W1 and upper work W2 in a state where the lower work W1 is pressed by the point 62. The gap H (see FIG. 3) through which the gas escapes is set to be maintained.

In other words, the length 11 of the point 62 and the point 6
The difference l3 from the length l2 is the thickness of the upper workpiece W2,
The length is set to the sum of the gap H for allowing the zinc gas to escape from between the overlapped lower work W1 and upper work W2.

Laser welding apparatus 10 according to the present embodiment
Is basically configured as described above, and its operation and effect will be described next.

First, as shown in FIG. 1, a zinc-plated long work W includes a lower work W1 and an upper work W.
2 and are positioned by the positioning mechanism 16. Specifically, the moving member 30 is lowered under the driving action of the actuator 26, and the positioning mechanism 16
Hold down.

Here, as shown in FIG. 3, the laser welding apparatus 10 according to the present embodiment
, The positioning mechanism 16 is moved forward and the arrow A
Displace in the direction. Therefore, the upper surface of the lower work W1 and the upper surface of the upper work W2 are pressed by the point 62 of the tool 56 and the point 66 of the tool 60, respectively, and the lower work W1 and the upper work W2
Is irradiated between the tool 56 and the tool 60 (see FIG. 4).

The lower work W1 and the upper work W2 are irradiated vertically with the laser beam L, and the lower work W1 and the upper work W2 are irradiated with the laser beam L.
Irradiates the zinc plating applied to the lower work W1 and the upper work W2. However, the length l2 of the point 66 is equal to the plate thickness T2 of the upper workpiece W2.
And a gap H where the gas of the galvanized material escapes from between the lower workpiece W1 and the upper workpiece W2. The generated gap between the workpieces W1 and W2 can be optimally corrected.

Further, the gas of the galvanized material vaporized from the gap H flows out, and the lower work W1 and the upper work W2 can be reliably welded.

When welding the lower work W1 and the upper work W2, the tip 62 of the tool 56 and the tool 60 are welded.
In the case where the point 66 has welding heat, it may be cooled by a cooling mechanism (not shown).

After the welding of the lower workpiece W1 and the upper workpiece W2 is completed, the lower workpiece W1 and the upper workpiece W2 are welded.
Is conveyed to the next step and finally completed as a product.

[0032]

As described above, according to the present invention,
By holding the overlapped lower work with the long holding tip of the tool and pressing the upper work with the short holding tip of the tool, the gap between the upper work and the lower work can be set to a desired interval.

Further, according to the present invention, since the amount of deformation of the upper work caused by welding heat can be controlled based on the superposed lower work, the gap between the superposed upper work and the lower work can be stably secured. can do.

Therefore, for example, when superimposing and welding galvanized workpieces, the lower workpiece is held down by the long tip and the upper workpiece is pushed by the short tip to irradiate a laser beam to the upper workpiece and the lower workpiece. Since a gap can be stably secured between the upper work and the lower work, for example, the applied zinc plating is vaporized, the vaporized zinc component flows out from the gap to reliably weld the upper work and the lower work. Lap welding of good quality without spatters or blowholes becomes possible.

[Brief description of the drawings]

FIG. 1 is an explanatory side view showing a state in which a part of a laser welding apparatus according to the present embodiment is broken.

2 is a partially omitted enlarged side view showing the vicinity of a positioning mechanism of the laser welding apparatus in FIG.

FIG. 3 is a partially omitted enlarged explanatory view showing the vicinity of a positioning mechanism of the laser welding apparatus as viewed from the direction of arrow Z in FIG. 1;

FIG. 4 is a partially omitted enlarged perspective view showing the vicinity of a positioning mechanism of the laser welding apparatus in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Laser welding apparatus 14 ... Laser beam head 16 ... Positioning mechanism 50 ... Holding part 52 ... Guide member 54 ... Substrate 56, 60 ... Jig member 58, 64 ... Shim member 62, 66 ... Tip H ... Gap L ... Laser beam W … Work W1… Lower work W2… Upper work

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Koji Oda 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. (72) Jun Kitagawa 1-10-1 Shinzayama, Sayama City, Saitama Hondae Engineering F Co., Ltd. F-term (reference) 4E068 BF00 CA14 CB05 DA14 DB15

Claims (4)

[Claims] 1. A laser welding method for welding workpieces by superimposing workpieces and irradiating a laser beam to the superimposed portion, wherein one tool of a positioning mechanism presses a lower workpiece, A laser welding method, wherein the other tool welds the workpieces by irradiating a laser beam in a state where the upper workpiece is pressed against the lower workpiece so as to have a gap. 2. A laser welding apparatus for superimposing works and irradiating a laser beam to the superposed part to weld the work, wherein a positioning mechanism for positioning a welded part of the work is provided. The positioning mechanism comprises: at least one set of tools disposed substantially parallel to each other at a predetermined interval; and holding tip portions having different lengths provided on the one set of tools. The length of one holding tip is set longer than the length of the other holding tip, and the length of the other holding tip is lower than the length of the lower workpiece by pressing the lower workpiece by the one holding tip. A laser welding apparatus, wherein the upper workpiece is set to have a gap. 3. The laser welding apparatus according to claim 2, wherein said one set of tools has a holding tip portion formed in a substantially triangular shape and pressing said workpiece. 4. The laser welding apparatus according to claim 2, wherein a length of said another tool is adjusted by a thickness of a shim member engaged with said tool.