JPH0740075A - Butt laser beam welding equipment for sheet metals - Google Patents

Abstract

PURPOSE:To prevent a dislocation of a weld zone without increasing the size of the equipment. CONSTITUTION:In the equipment in which a preceding strip 2 and succeeding strip are abutted on each other to perform welding, both strips are sandwiched and held by a clamping device, respectively and both abutted ends are sandwiched and fixed between a back bar 6 and a clamp bar 8a. The rigidity of the clamp bar 8a is made lower as compared with that of the back bar 6, or the clamp bar 8a is divided into plural pieces in the longitudinal direction. Consequently, even if the back bar 6 is deformed, since the clamp bar 8a is deformed following the deformation, the strips can be sandwiched without a gap between both and the dislocation of the abutted ends and defective welding are prevented.

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 plate materials for butt welding two plate materials.

[0002]

2. Description of the Related Art As disclosed in, for example, Japanese Patent Application Laid-Open No. 61-67588, laser welding is performed when connecting a leading plate and a trailing plate of a plate material conveyed in the longitudinal direction. There is a device. In such a laser welding device,
In order to stabilize the position of the abutting part of both plates during welding, clamp both plates with each clamp consisting of a pair of upper and lower blocks, and fix them so that they are on the same plane before welding. There is.

In the conventional welding apparatus as described above, both ends are placed on the back bar and the ends are sandwiched between the back bar and the back bar in order to butt the both ends together without any mistake. There is also an example in which each auxiliary clamping device is provided. (JP-A-60-106685)

Some of the plate materials to be welded have a wide plate width and a long welding line length. In order to cope with the welding of plate materials of various widths, the welding line of the back bar and the clamp bar is used. It is necessary to lengthen the length in the long direction to some extent.

When a thin plate is welded by a laser, a leading plate and a trailing plate can be stably and consistently abutted in the longitudinal direction of the welding line in order to prevent the occurrence of welding defects and keep the shape of the welding bead good. Is important to.

However, when a long back bar is used as described above, the back bar is easily bent due to the pressing force of the clamp bar, and a large gap is formed between the back bar and the clamp bar. There is the problem of making a difference.

In order to prevent the back bar from bending and to eliminate the difference between the plate materials sandwiched between the back bar and the clamp bar, the back bar having high rigidity is also pressed with a large force on the clamp member having high rigidity. It is necessary. However, if such a method is adopted, the back bar,
A device (for example, a hydraulic jack) having a large pressing force as the clamp member becomes large is required, which causes a problem that the device as a whole becomes large and the cost also increases.

[0008]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the main object of the present invention is to butt and weld two plates without making a mistake and to perform good welding. The object is to provide a laser welding device to be obtained.

[0009]

According to the present invention, such an object is such that, of the pair of upper and lower clamps constituting the auxiliary clamp, the upper clamp which is pressed toward the lower clamp (back bar). The rigidity of the (clamp bar) is smaller than the rigidity of the back bar, or it is pressed toward the lower sandwiching body (back bar) of the upper and lower sandwiching bodies constituting the auxiliary clamp. The upper clamp (clamp bar) is divided in the welding line length direction, or by providing a portion with extremely low rigidity, it has the same effect as the divided one and the clamp bar pressing force can be adjusted independently. This is achieved by providing a laser welding device characterized in that

[0010]

By reducing the rigidity of the clamp bar, when the plate material is clamped, even if the back bar is deformed by the pressing force of the clamp bar, the plate material is clamped while the clamp bar is deformed according to the deformation. For this reason, since the leading plate and the trailing plate follow the same back bar surface without a gap, the leading plate and the trailing plate can be abutted with each other without any difference. Alternatively, instead of reducing the rigidity of the clamp bar, the clamp bar is divided in the longitudinal direction, and the clamp bar pressure can be adjusted independently for each of the divided parts, so that when the plate material is clamped, the clamp bar pressure is reduced. Even if the back bar is deformed by the force, each divided part of the clamp bar independently clamps the plate material in accordance with the back bar deformation. For this reason, since the leading plate and the trailing plate follow the same back bar surface without a gap, the leading plate and the trailing plate can be abutted with each other without any difference.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic side view of a main part of a laser welding apparatus to which the present invention is applied for butt-welding two plates, a leading plate and a trailing plate, to join them into one. On the bed 1 of the present apparatus, which is fixedly installed on the foundation not shown in FIG.
Leading and trailing strips 2 and 3 of about 5 to 0.5 mm
Is formed from the right side to the left side of the drawing, and the output side and the input side clamping devices 4 and 5 for selectively sandwiching the strips 2 and 3 are mutually arranged in the conveying direction. It is provided separately.

Further, a back bar 6 is provided between the clamp devices 4 and 5 so as to be vertically movable by a driving device (not shown) so as to selectively support the lower surfaces of the strips 2 and 3 to be conveyed. A laser emitting portion 7 of a YAG laser for laser welding the strips 2 and 3 to each other is installed above it so as to be selectively movable up and down by a driving device (not shown). Further, clamp bar devices 8 and 9 for sandwiching and positioning the abutting ends of the strips 2 and 3 with the back bar 6 at the time of welding are provided.

It should be noted that, in this apparatus, before the strips 2 and 3 are butt-welded to each other, the respective butt end surfaces 2a and 3a thereof are joined.
A shearing device (not shown) for cutting a is provided. Therefore, when cutting the abutting end faces 2a, 3a, the back bar 6, the laser emitting portion 7, and the clamp bar 8 are separated from the strips 2, 3 to some extent.

In this embodiment, both clamp devices 4, 5 are used.
Are configured identically to each other, and the output clamp device 4 on the right side of the drawing will be described below. The output side clamp device 4 includes upper and lower clamp blocks 4a and 4b for supporting the front and back surfaces of the strip 2 from above and below, and an upper side clamp block 4.
The air cylinder 11 is capable of pressing a toward the lower side. An air supply device 12 capable of controlling pressure is connected to the cylinder 11.

Further, both clamp bar devices 8 and 9 are also constructed symmetrically with each other, and the following will show the output side auxiliary clamp device on the right side of the drawing. The delivery side auxiliary clamp device 8 is composed of a clamp bar 8a and an air cylinder 13 for pressing the clamp bar 8a downward.
Then, the air supplied from the air supply device 14 is supplied to the air cylinder 13 via the pressure adjuster 18.

In the welding apparatus thus constructed, for example, a state in which the leading side plate 2 is clamped by the delivery side auxiliary clamp device 8 will be described below with reference to FIG. In FIG. 2, the back bar 6 is bent so that its central portion is dented, for example, by supporting both end portions in the longitudinal direction, and the upper surface of the back bar 6 is abutted with the preceding strip 2 to be welded. The end is placed.

Then, each air cylinder is driven to press down the clamp bar of the delivery side auxiliary clamp device, and the preceding strip is sandwiched and fixed between the back bar and the clamp bar. At this time, by making the clamp bar 8a less rigid than the back bar 6, the clamp bar can follow the deformation of the back bar.

By doing so, the back bar 6
The leading plate 2 can be clamped without a gap between the clamp bar 8a and the clamp bar 8a, and similarly, the trailing plate 2 is also trailed without a gap between the back bar and the clamp bar 9a of the output side clamp bar device 9. The strip 3 can be clamped. Therefore, the abutting ends of the strips 2 and 3 can be abutted with each other without causing a misalignment, and a good butt welding can be obtained. In order to make the clamp bar better follow the deformation of the back bar, it is preferable to use a plurality of air cylinders and to arrange a plurality of rolling points of the clamp bar in the longitudinal direction.

Further, of a pair of upper and lower clamps forming the auxiliary clamp, the upper clamp (clamp bar) which is pressed down toward the lower clamp (back bar) is divided in the lengthwise direction of the welding line, and each clamp is independent. An embodiment of the present invention in which the clamp bar pressing force can be adjusted will be described below.

FIG. 3 shows a state where the leading plate 2 is clamped by the exit side auxiliary clamp device 8. In FIG. 3, the back bar 6
However, for example, by supporting both end portions in the longitudinal direction, it is bent so as to indent the center portion thereof, and the abutting end portion of the preceding strip 2 to be welded is placed on the upper surface of the back bar 6. There is.

Then, each air cylinder is driven to press down the clamp bar of the output side auxiliary clamp device, and the preceding strip is sandwiched and fixed between the back bar and the clamp bar. At this time, by dividing the clamp bar 8a into a plurality of pieces in the longitudinal direction, the clamp bar can follow the deformation of the back bar.

By doing so, the back bar 6
The leading plate 2 can be sandwiched between the back bar and the clamp bar 9a of the delivery side auxiliary clamp device 9 without any space between the back bar and the clamp bar 9a. The strip 3 can be clamped. Therefore, the abutting ends of the strips 2 and 3 can be abutted with each other without causing a misalignment, and a good butt welding can be obtained.

Also, the same effect as dividing the clamp bar 8a can be obtained, and an example of the clamp bar 8a formed by providing a portion having extremely small rigidity at an appropriate position in the welding line length direction is shown in FIG. Show.

In FIG. 4, the clamp bar 8a is provided with notches 20a to 20c at several positions along the length of the welding line, and the rigidity of the notches 20a to 20c is the rigidity of the other parts of the clamp bar 8a. It is much smaller than. Therefore, the deformation of the cutouts 20a to 20c makes it easier for the clamp bar 8a to follow the deformation of the back bar, and the same effect as when the clamp bar 8a is divided can be obtained.

In a facility where it is necessary to appropriately weld several kinds of strips having widely different plate widths, the number of divisions of the clamp bar or the number of parts having low rigidity is relatively large so as to correspond to each plate width. It is good to have many.

[0026]

As described above, according to the present invention, the back bar, the clamp, the clamp bar, and the clamp bar pressing device can be downsized, and the device can be made compact and inexpensive. Stable welding is possible over the entire length of the welding line without any misalignment.

[Brief description of drawings]

FIG. 1 is a schematic side view of a main part of a laser welding apparatus to which the present invention is applied.

FIG. 2 is a view taken along line II-II in FIG.

FIG. 3 is a view taken along line II-II of FIG. 1 according to another embodiment of the present invention.

FIG. 4 is a schematic view of a clamp bar according to another embodiment of the present invention.

[Description of Reference Signs] 1 bed 2, 3 strip 2a, 3a butt end surface of strip 4, 5 clamp device 4a, 4b clamp block 6 back bar 7 laser head 8, 9 auxiliary clamp device 8a-c, 9a clamp bar 11 cylinder 12 Pressure source supply device 13 Air cylinder 14 Air pressure supply device 15 Cylinder 16 Pressure source supply device 17 Air cylinders 18 and 19 Air pressure adjusting device 20a-c Notches

Claims (3)

[Claims] 1. A laser having a main clamp for fixing the movement of the whole plate material and an auxiliary clamp for fixing only the vicinity of the abutting portion of the plate material. A welding device,
Laser welding, characterized in that, of the pair of upper and lower clamps forming the auxiliary clamp, the rigidity of the upper clamp (clamp bar) that is pressed toward the lower clamp (back bar) is smaller than the rigidity of the back bar. apparatus. 2. An upper clamp (clamp bar) that is pressed down toward a lower clamp (back bar) among a pair of upper and lower clamps that constitute an auxiliary clamp is divided in the welding line length direction, and each clamp is independent. The butt laser welding apparatus for thin plates according to claim 1, wherein the clamp bar pressing force can be adjusted. 3. An upper clamp body (clamp bar) that is pressed down toward a lower clamp body (back bar) of a pair of upper and lower clamp bodies that form an auxiliary clamp is rigid at an appropriate position in the welding line length direction. 2. The butt laser welding apparatus for thin plates according to claim 1, wherein a very small portion of is formed.