JPH11277264A - Laser beam welding method and equipment therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity by eliminating an additional process of spot welding, etc. before welding, and preventing generation of a blow hole by using a simple positioning device. SOLUTION: A gap between a clamp arm 2 and a receiving arm 1 is set a total plate thickness of steel plates 10, 11 plus 0.2-0.3 mm by a stopper 8, a gap, when stacking the steel plates 10, 11, is made 0.2-0.3 mm. A gap (t) of the steel plates 10, 11, when a laser beam irradiates, is acted in an widening direction due to fusing by expansion force. By regulating the widening with the clamp arm 2, the vapor generated from a zinc plating layer can be released from the gap (t) of the steel plates 10, 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a laser welding method and a laser welding apparatus.

[0002]

2. Description of the Related Art A conventional laser welding method is disclosed in
JP-A-80669 discloses a method in which when welding steel sheets which have been surface-treated by galvanization by overlapping each other, spot welding is locally performed at predetermined intervals on a center line to be irradiated with laser light. It has been disclosed. According to this method, since the steel sheets are separated from each other with a slight gap along the center line, even when laser welding is performed, steam generated from the galvanized layer is radiated from the gap and generation of blow holes can be prevented. .

[0003]

However, in the conventional laser welding method, spot welding is performed before the main welding, so that the number of welding steps increases and the work efficiency decreases.

The present invention has been made in view of the above problems, and has as its object to eliminate the need for an extra step such as spot welding before main welding, and to prevent the occurrence of blow holes and the like by using a simple positioning device. An object of the present invention is to provide a laser welding method and a laser welding apparatus that can improve productivity.

[0005]

SUMMARY OF THE INVENTION To solve the above problems,
In order to achieve the object, a laser welding method according to the present invention has the following features. That is, in the laser welding method of superposing and welding plate materials subjected to surface treatment,
Welding is performed with the interval between the plate members regulated to a predetermined interval.

Preferably, the plate is clamped at a width such that the interval between the plate is regulated to a predetermined interval.

Preferably, the interval between the plate members is 0.2 m.
It is set to 0.3 mm from m.

[0008] Preferably, the surface of the plate material is subjected to a galvanizing treatment.

The laser welding apparatus according to the present invention has the following configuration. That is, in a laser welding apparatus that overlaps and welds the surface-treated plate materials, the laser welding device includes a clamp unit that clamps the overlapped plate materials, and the clamp unit regulates an interval between the plate materials to a predetermined interval. The plate is clamped.

[0010] Preferably, the clamping means comprises:
The plate is clamped via rollers that allow the clamp means to move relative to the plate.

Preferably, the interval between the plate members is 0.2 m.
It is set to 0.3 mm from m.

Preferably, the surface of the plate is subjected to a galvanizing treatment.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. [Laser Welding Apparatus According to First Embodiment] FIG. 1 is a diagram showing a schematic configuration of a laser welding apparatus according to a first embodiment. FIG. 2 is an enlarged view showing a welded portion in the laser welding device of FIG.

As shown in FIG. 1, the laser welding apparatus according to the first embodiment includes a base 3, a receiving arm 1 branched from the base 3 in a U-shape, and a first rotating shaft provided at the tip of the base 3. And a U-shaped clamp arm 2 rotatably supported at 7.

The receiving arm 1 and the clamp arm 2 are vertically arranged in a positional relationship facing each other. The clamp arm 2 is supported on the drive shaft of the cylinder 4 by the second rotation shaft 6 of the arm portion 5 extending rearward from the first rotation shaft 7, and the operation of the cylinder 4 in the vertical direction is performed. Is rotated about the first rotation shaft 7 in accordance with the rotation of the first arm 7, thereby adjusting the gap with the tip of the receiving arm 1. By restricting the rotation position of the clamp arm 2 by the stopper 8, the distance between the clamp arm 2 and the receiving arm 1 is set to a predetermined distance. The cylinder 4 can be slightly swung by the rotation of the clamp arm 2.
It is supported by.

The steel plates 10 and 11 have their peripheral edges disposed between the receiving arm 1 and the clamp arm 2, and are overlapped with each other for the body of an automobile by laser welding. The surfaces of the steel plates 10 and 11 are galvanized for rust prevention. The laser irradiation device 20 is provided above the clamp arm 2 and at a position that does not interfere with the turning operation of the clamp arm 2.

The distance between the clamp arm 2 and the receiving arm 1 is set by the stopper 8 so that the total thickness of the steel plates 10 and 11 is plus 0.2 to 0.3 mm. Is set to 0.2 to 0.3 mm. Steel plate 1
Reference numerals 0 and 11 are clamped at predetermined positions by other members in advance, and are fixed so that the two steel plates do not shift. The interval t is set to 0.2 to 0.3 mm when the thickness is 0.8 to 1.0 mm.
mm, the interval t is set to be smaller than 0.2 to 0.3 mm when the thickness is 0.8 mm or less, and conversely, the interval t is set to 0.2 to 0.3 when the thickness is 1.0 mm or more. It is set larger than mm.

The interval t between the steel plates 10 and 11 acts in a direction in which the laser beam is applied to expand due to the expansion force at the time of melting, but the expansion is regulated by the clamp arm 2 so that the steam generated from the galvanized layer is reduced. It is possible to escape from the interval t between the steel plates 10 and 11, and it is possible to prevent defects such as blow holes.

As shown in FIG. 2, the distal end portion 2a of the clamp arm 2 is arranged offset with respect to the receiving arm 1, so that the laser irradiation device 20 can be moved by the offset amount, and a partial laser Welding becomes possible. Furthermore, the expansion force at the time of melting easily acts on the peripheral edges of the steel plates 10 and 11 by the offset amount.

When laser welding is performed by clamping the upper and lower steel plates so that the distance between the upper and lower steel plates becomes substantially zero, steam generated from plating remains as a blowhole in the welded portion or a hole penetrates the surface of the upper plate. (Pits), which cause problems such as a decrease in strength.
By limiting the thickness to mm, it is possible to maintain a desired welding strength while securing an escape path for steam generated from plating.

In addition, even when the interval between the upper and lower plates exceeds the set value (0.2 to 0.3 mm) due to the smoothness of the steel plate, the clamp arm 2 and the receiving arm 1 suppress the set value to the set value during welding. Thus, it is possible to maintain a desired welding strength while securing an escape route for steam generated from plating.

Further, even when the interval when the upper and lower plates are overlapped with each other is less than a set value (0.2 to 0.3 mm) due to the smoothness of the steel plate, the upper and lower plates are prevented from separating due to the expansion force at the time of welding. The set value can be suppressed by the clamp arm 2 and the receiving arm 1, and a desired welding strength can be maintained while securing an escape path for steam generated from plating. [Laser Welding Apparatus According to Second Embodiment] FIG. 3 is a diagram showing a schematic configuration of a laser welding apparatus according to a second embodiment.

As shown in FIG. 3, the laser welding apparatus according to the second embodiment is provided on a robot arm 30.
The robot arm 30 has a base 33, a receiving arm 31 branched in a U-shape from the base 33, and a clamp arm 32 provided at an upper end of the base 3.

A receiving roller 3 is provided at the tip of the receiving arm 31.
5 is provided rotatably, and a pressure roller 36 is attached to a distal end portion of the clamp arm 32 via a clamp roller support portion 34.
Are provided rotatably.

The receiving roller 35 and the pressure roller 36 are vertically arranged in a positional relationship facing each other. The clamp arm 32 is provided on the base 33 so as to be movable in the vertical direction, and the interval between the receiving roller 35 and the pressure roller 36 is set to a predetermined interval.

The steel plates 10 and 11 have their peripheral edges disposed between the receiving roller 31 and the pressure roller 36. The laser irradiation device 20 is provided near the clamp arm 32 and at a position where the laser irradiation device 20 does not interfere with the vertical movement of the clamp arm 32.

The distance between the receiving roller 35 and the pressure roller 36 is set so as to be 0.2 to 0.3 mm plus the total thickness of the steel plates 10 and 11, and the distance t when the steel plates 10 and 11 are superposed is 0.2. From 0.3mm.

In the second embodiment, in addition to the effects of the first embodiment, the steel plates 10, 11 are clamped in the vertical direction by the receiving roller 35 and the pressing roller 36, so that each of the rollers 35, 36 The movement of the robot arm 30 with respect to the steel plates 10 and 11 is allowed, and the steel plates 10 and 11 are fixed and the robot arm can be relatively moved along the periphery of the steel plate to perform welding.

It should be noted that the present invention can be applied to modifications or changes of the above embodiment without departing from the spirit thereof.

[0030]

As described above, according to the first aspect of the present invention, the steam generated from the surface treatment layer is released from the predetermined interval by welding while regulating the interval between the plate members to the predetermined interval, and the blow hole is formed. And the like can be prevented from occurring, and the productivity can be improved.

According to the second aspect of the present invention, the gap between the plate members can be easily set by clamping the plate material with a width that is regulated to a predetermined interval.

According to the third aspect of the present invention, the interval between the plate members is set to 0.2 mm to 0.3 mm, so that a desired escape strength of the steam generated from the surface treatment layer is secured while maintaining a desired welding strength. it can.

According to the fourth aspect of the present invention, since the surface of the plate is galvanized, blow holes and the like due to steam generated from the galvanized layer can be prevented.

According to a fifth aspect of the present invention, there is provided a clamp means for clamping the superposed plate materials, and the clamp means clamps the plate materials so as to regulate the interval between the plate materials to a predetermined interval. The vapor generated from the surface treatment layer is released at predetermined intervals, and the desired welding strength can be maintained while preventing the occurrence of blow holes and the like.

According to the sixth aspect of the present invention, the clamping means clamps the plate through a roller which allows the clamp to move relative to the plate, thereby fixing the plate and clamping the plate. Can be relatively moved along the plate material for welding.

According to the seventh aspect of the present invention, by setting the interval between the plate members to be 0.2 mm to 0.3 mm, it is possible to maintain a desired welding strength while securing an escape path for steam generated from the surface treatment layer. it can.

According to the eighth aspect of the present invention, since the surface of the plate is galvanized, blowholes and the like due to steam generated from the galvanized layer can be prevented.

[0038]

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a schematic configuration of a laser welding apparatus according to a first embodiment.

FIG. 2 is an enlarged view showing a welded portion in the laser welding device of FIG.

FIG. 3 is a diagram illustrating a schematic configuration of a laser welding apparatus according to a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 31 ... Receiving arm 2, 32 ... Clamp arm 3, 33 ... Base part 4 ... Cylinder 8 ... Stopper 10, 11 ... Steel plate 20 ... Laser irradiation device 30 ... Robot arm

Claims (8)

[Claims] 1. A laser welding method for superposing and welding plate materials having been subjected to surface treatment, wherein the welding is performed while regulating the interval between the plate materials to a predetermined interval. 2. The laser welding method according to claim 1, wherein the plate is clamped at a width such that the interval between the plate is regulated to a predetermined interval. 3. The laser welding method according to claim 1, wherein an interval between the plate members is set to 0.2 mm to 0.3 mm. 4. The laser welding method according to claim 1, wherein a galvanizing process is performed on a surface of the plate material. 5. A laser welding apparatus for superposing and welding plate materials subjected to surface treatment, comprising a clamp means for clamping the superposed plate materials, wherein the clamp means regulates an interval between the plate materials to a predetermined interval. A laser welding apparatus characterized in that the plate material is clamped so as to perform the operation. 6. The laser welding apparatus according to claim 5, wherein the clamping unit clamps the plate via a roller that allows the clamp to move relative to the plate. 7. The laser welding apparatus according to claim 5, wherein an interval between the plate members is set to 0.2 mm to 0.3 mm. 8. The laser welding apparatus according to claim 5, wherein a galvanizing process is performed on a surface of the plate material.