JPH0357580A - Laser beam welding equipment - Google Patents

Abstract

PURPOSE:To form a stable lap joint of good quality by pressing down the vicinity of a part irradiated with a laser beam from a laser beam irradiation part on materials to be welded and making the materials to be welded in a stuck state mutually. CONSTITUTION:While the superposed plural materials 16 to be welded being made stuck mutually, the vicinity of the pressed-down part is irradiated with the laser beam 22 from the laser beam irradiation part 27. A gap between the superposed materials 16 to be welded is maintained close and almost uniform by using a pressing-down device 34 in this way. Further, since the focus position which is an important factor in laser beam welding can be maintained constant at all times, welding by using the laser beam is made possible and the lap joint of good quality is formed between the materials 16 to be welded. By this method, since the laser beam welding speed is fast, the welding time for the materials 16 to be welded can be shortened. In addition, since the laser beam welding is performed from above the plural superposed materials 16 to be welded, the time to tack-weld the materials 16 to be welded can be reduced.

Description

[Detailed description of the invention] [Industrial application fields] The present invention relates to a laser welding device.

[Prior Art] As shown in FIG. 7, a beer fermentation tank 1 has a shape having an inverted conical cone portion 3 at the lower end of a cylindrical body portion 2. A plurality of water jackets 4 are attached around the water jacket 3, each extending substantially vertically.

The fermentation temperature in the fermentation tank 1 is adjusted by flowing cooling water into the water jacket 4 as appropriate.

The body 2 of such a beer fermentation tank 1 is constructed by attaching a plurality of semi-cylindrical water jackets 4 by welding to a curved plate 5 which is formed by dividing the fermentation tank 1 into several equal parts in the circumferential direction, as shown in FIG. After that, a plurality of curved plates 5 are combined into a cylindrical shape,
It is manufactured by welding the abutting portions of the curved plates 5.

Conventionally, the water jacket 4 is attached to a curved plate by arranging a plurality of semi-cylindrical water jackets 4 along the arcuate surface of the curved plate 5 on the convex surface of the curved plate 5, as shown in FIG. After partially welding and temporarily attaching the curved plate 5, an FCAV type (Flux C
Welding lines formed at the contact boundaries between the curved plate 5 and the plurality of water jackets 4 at multiple locations (6 Fillet welding was done at the same time.

6 in FIG. 9 is an electrode of a PCAW type automatic welding device.

[Problems to be Solved by the Invention] However, the conventional pcAw type automatic welding apparatus described above has the following problems.

■ PCAW type automatic welding equipment requires a lot of heat from welders, so
A large amount of heat is transmitted to the back surface (concave surface) of the curved plate 5 by welding, and as a result, the heated back surface of the curved plate 5 oxidizes and forms an oxide film 7 on the back surface (so-called back surface). (can cause burns).

If back burn occurs on the back surface of the curved board 5, the back surface will become rough and there is a risk that bacteria will adhere there and breed, so the back surface must be polished in a post-process to prevent bacteria from adhering. However, polishing requires a great deal of time and effort.

Also, as mentioned in Section 2, the heat of the welders was high, which caused thermal deformation of the curved plate 5, water jacket 3, and jacket 4 due to welding, which adversely affected the dimensional accuracy of the fermentation tank 1.

■ FCAW type automatic welding equipment has a slow welding speed (approximately 30 cm per minute), so even if multiple electrodes 6 are used to weld multiple weld lines at the same time, it will take a long time to manufacture the fermentation tank 1. It required

■ In the pcAw type automatic welding device, it is necessary to weld the weld line formed at the contact boundary between the curved plate 5 and the semi-cylindrical water jackets 1 and 4. It is necessary to partially temporarily attach each of them to the curved plate 5, and therefore, a great deal of time and effort is required for the temporary attachment.

The present invention has been made in order to solve the above-mentioned problems, and in particular, it is an object of the present invention to provide a laser welding device that can be used for manufacturing beer fermentation tanks.

[Means for solving the problem] This study consists of a laser beam irradiation section that irradiates laser beams onto multiple overlapping objects to be welded, and a laser beam irradiated from the laser beam irradiation section on the objects to be welded. The present invention relates to a laser welding apparatus characterized in that it is equipped with a holding device that presses down the vicinity of the parts being welded to bring the objects to be welded into close contact with each other, and keeps the focal position of the laser beam constant.

[Operation] A plurality of stacked objects to be welded are held down by a holding device so that the objects to be welded are in close contact with each other, and a laser beam from a laser irradiation unit is irradiated near the held portions.

By using the holding device in this way, the gap between the stacked workpieces to be welded can be kept small and approximately uniform, and the position of the focal point, which is an important factor in laser welding, can be kept constant at all times. Therefore, welding using laser light becomes possible, and a high-quality lap joint can be formed between the objects to be welded.

[Example] Hereinafter, embodiments of the present invention will be explained with reference to the drawings. I will clarify.

FIGS. 1 to 5 show one embodiment of the present invention, and in the figures, parts given the same reference numerals as in FIGS. 7 to 9 represent the same parts.

A workbench 8 is installed on the foundation, and vertical brackets 9 are attached to the front and rear ends of the workbench 8.

Each vertical bracket 9 has a semi-shaft 11 extending in the front-rear direction at the apex of the fan-shaped support plate LO. The motor 2 is connected to the half shaft 11 so that the support plate 10 can be rotationally displaced via the half shaft H.

The ends of the curved plate 5 are fixed to the arcuate portions of the front and rear support plates 10, respectively. A corrugated plate 15 having the same curvature as the curved plate 5 as a whole is formed by connecting the plurality of semi-cylindrical parts t3 with an arcuate part 14, and the corrugated plate 15 is placed on the convex surface of the curved plate 5.

The curved plate 5 and the corrugated plate 15 constitute a welded object I6.

Rails 17 extending in the front-rear direction are provided on both sides of the workbench 8 on the foundation, and between the rails 17, a gate-shaped traveling cart 18 that straddles the curved 6 face plate 5 and the corrugated plate 15 is movable along the rails 17. Deploy.

A vertical main pipe 20 is supported at the center of the upper side of the gate-shaped traveling trolley l8 via a ball screw mechanism l9 so as to be freely raised and lowered, and a laser beam 22 from a laser oscillator 21 installed on the foundation is transmitted using a mirror 23. so that it can enter the upper end of the main pipe 20.

As shown in FIG. 2, the nozzle pipe 24 is slidably fitted into the lower end of the main vibrator 20 as shown in FIG. 26, and the nozzle pipe 24, condensing lens 25, and nozzle 26 constitute a laser beam irradiation section 27.

A flange 28 is attached to the outer periphery of the nozzle vipe 24, an arm 29 is attached to the lower surface of the flange 28 at a position forward and backward in the moving direction of the concave traveling trolley l8, and a presser roller 30 is attached to the lower end of the arm 29 so as to be freely movable.

At this time, the length of the arm 29 is adjusted in advance so that the distance between the condensing lens 25 and the object to be welded I6 is a gap 1 that allows the best weld 7 to be obtained through a preliminary test.

A flange 31 is attached to the outer periphery of the lower end of the main pipe 20, and the flange 31 is attached to the main pipe 20 and the nozzle vipe 24. , 28 is interposed with a spring 32 that urges the nozzle pipe 24 downward.

Furthermore, a cylindrical cover 33 is attached to one flange 3I.

flanges 28, 31, spring 32, arm 29,
The presser device 34 is horizontally moved by the presser roller 30 or the like.

Note that 35 is a lap joint formed between the objects 16 to be welded.

Next, the operation will be explained.

The workpiece 16 supported on the workbench 8 via the vertical bracket 9 and the support plate 10 is rotationally displaced via the motor 2, the half shaft 11, and the support plate lO, and one side a of the workpiece 16 is It should be located at the center of the width of the arcuate portion i4 of the corrugated board 1 and plate 15 located on the side, or directly below the laser beam irradiation section 27.

8 Next, move the gate-shaped traveling trolley 18 along the rail 17 to the welding point L.
6 to the rear end C side, actuating the ball screw mechanism 19,
The presser roller 30 presses the welded object I6 with a predetermined pressing force via the flange 31, spring 32, flange 28, and arm 29, and the main pipe 20 is lowered so that the welded objects I6 come into close contact with each other.

In this state, the laser beam 22 is oscillated from the laser oscillator 21, and the oscillated laser beam 22 is guided to the upper end of the main pipe 20 via the mirror 23. At the same time, the gate-shaped traveling cart 18 is moved at a speed of about 2 m/min The object to be welded 16 moves from the rear end C side to the front end d side.

Then, the laser light 22 guided to the upper end of the main pipe 20
The light passes inside the main pipe 20, is focused by the condensing lens 25 of the nozzle pipe 24 fitted into the lower end of the main pipe 20, and is irradiated from the nozzle 26 to the workpiece IB, and the circle of the corrugated plate 15 on the workpiece I6 is A lap joint 35 extending along the arcuate portion 14 is formed at the width center position of the arcuate portion l4, and the corrugated plate 15 and the curved plate 5 are welded together.

At this time, since a corrugated plate 15 having a shape in which a plurality of semi-cylindrical portions 13 are connected by a circular arc portion l4 is used, a lap joint 35 is formed between the circular arc portion 14 of the corrugated plate 15 and the curved surface plate 5. Therefore, it becomes possible to perform welding using the laser beam 22.

Furthermore, when welding the objects 16 to be welded using the laser beam 22, the penetration shape of the lap joint 35 changes depending on the gap S between the objects 16 to be welded. FIG. 5 is a photograph showing the relationship between the gap S and the penetration shape. According to FIG. A part of the penetration that should have become 35 accumulates in the gap S and forms a bulge, causing the lap joint to become 35.
It can be seen that the strength of is significantly reduced. In the present invention, by providing a presser roller 30 and welding from the presser so that the objects 16 to be welded are brought into close contact with each other, the gap S
Since it is possible to eliminate or make it small and uniform, it is possible to form a high-quality lap joint 35 even in a large product such as a beer fermentation tank where manufacturing errors are unavoidable. I can do it.

Note that the rear end C side of the workpiece 1B is fixed as the lap joint 35 is shaped, so the presser roller 30 on the rear end C side is not necessarily required, and the presser roller 30 at least If it is provided only on the tip d side of the object 16, the object to be welded 16
It can play the role of a presser.

However, when the presser roller 30 is provided on the rear end C side, the main pipe 20 can be reliably supported so that the axes of the main pipe 20 and the nozzle pipe 24 are always aligned, and the condensing lens 25 and the The gap l between the workpiece 16 and the workpiece 16 can be reliably kept constant.

Incidentally, if the width of the arcuate portion {4 of the corrugated plate l5 is wide, pressing rollers 30 may be provided on the left and right sides to guide the laser beam irradiation section 27.

In this way, when laser welding is completed for one circular arc portion 14, the workpiece 16 is rotationally displaced by the motor l2, and the circular arc portion 14 adjacent to the circular arc portion 14 for which welding has been completed is moved directly below the nozzle 26. After placing the weld in position 11, all the arcuate portions l4 are welded by repeating the above steps. By doing this, the semi-cylindrical part 13 of the corrugated board 15 and the curved board 5
A water jacket 4 is formed in the space between.

Since laser welding requires low heat from the welder, there is no fear that the back side of the curved plate 5 will be backburned by the heat of welding, and therefore the effort of polishing the back side of the curved plate 5 after welding can be eliminated.

Furthermore, since laser welding requires less heat from the welder, there is little thermal deformation of the welded object 16 due to welding, and it is therefore possible to manufacture beer fermentation tanks with high dimensional accuracy.

In addition, laser welding has a fast welding speed of about 2 m/min, so
Beer fermentation tanks can be manufactured in a short time.

Furthermore, since a single piece of corrugated board 15 is used,
It takes almost no effort to temporarily attach the corrugated board 15 to the curved board 5 (only partial clamping is enough), and therefore the temporary attachment process can be omitted, reducing the effort and time required for the work. .

FIG. 6 shows a state in which both ends of the width of the circular arc portion l4 of the corrugated plate l5 are welded by the laser welding apparatus of the present invention, and even in this manner, the water jacket 4 can be formed on the curved plate 5. In addition, the strength of the water jacket 4 can be increased compared to that shown in FIG.

It should be noted that the laser welding apparatus of the present invention is not limited to the above-described embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

[Effects of the Invention] As explained above, the laser welding apparatus of the present invention can provide various excellent effects as described below.

■ Since the laser beam is irradiated from the laser beam irradiation part to multiple overlapping objects to be welded, welding using laser beam 13 is also possible when attaching a water jacket to a beer fermentation tank. It becomes possible to do this.

■ Laser light generates less heat from the welder, so backburning on the workpiece can be prevented.

■ Laser light generates less heat for the welder, so it can prevent thermal deformation of the welded object.

■ Laser light has a fast welding speed, so it is possible to shorten the welding time for the object to be welded.

■ Since the laser beam welds multiple objects to be welded one on top of the other, it is possible to reduce the effort required to temporarily attach the objects to be welded.

■ Since the holding device presses the vicinity of the parts of the plurality of objects to be welded that are irradiated with the laser beam and brings them into close contact with each other, the gaps between the objects to be welded can be eliminated or made small and uniform. At the same time, since the positional relationship between the focal point of the laser beam and the object to be welded can be kept constant, a stable lap joint of good quality can be obtained.

[Brief explanation of drawings]

FIG. 1 is an overall perspective view of an embodiment of the present invention, FIG. 142 is a cross-sectional view of the laser beam irradiation part of FIG. 1 viewed from the side,
Figure 3 is a front view of the workpiece to be welded by the apparatus of the present invention, Figure 4 is a perspective view of the workpiece after welding, and Figure 5 is the penetration shape of the lap joint into the gap between the workpieces. Figure 6 is a front view of the workpiece being welded at a different welding position, Figure 7 is a side view of the beer fermentation tank, and Figure 8 is the workpiece welded using conventional welding equipment. FIG. 9 is a front view of the object to be welded, showing the welding method of FIG. 8. In the figure, 16 indicates an object to be welded, 22 indicates a laser beam, 27 indicates a laser beam irradiation section, and 34 indicates a holding device.

Claims (1)

[Claims] 1) A laser beam irradiation section that irradiates laser light onto multiple overlapping objects to be welded, and a laser beam irradiation section that irradiates the objects to be welded together by pressing the vicinity of the part of the objects to be welded that is irradiated with laser light from the laser beam irradiation section. 1. A laser welding device characterized by comprising: a presser device for keeping the parts in close contact with each other.