JP3711632B2 - Laser welding apparatus and laser beam welding method - Google Patents

Description

【００２０】
表１から分かるように，本例の装置を用いることにより，従来よりも１／２から１／３の少ないガス流量により，良好な溶接加工を達成することが可能である。そして，本装置の場合には，ガス流量を過度に増やすと逆効果となることが分かる。
上記のように，本例によれば，被覆ガスの使用量を抑制しつつ欠陥の少ない溶接加工を行うことの出来るレーザー溶接装置を得ることができる。
【図面の簡単な説明】
【図１】実施形態例のレーザー溶接装置のシステム構成図。
【図２】図１の収容部材の溶接部周辺の拡大断面図。
【図３】図２のＸ−Ｘ矢視線断面図。
【図４】従来のサイドアシスト方式のレーザー溶接装置における溶接部周辺の正面断面図。
【図５】従来のサイドアシスト方式のレーザー溶接装置における溶接部周辺の平面図。
【符号の説明】
１．．．レーザー溶接装置，
１０．．．収容部材，
１１．．．流入口，
１２．．．流出口，
１３．．．導入口，
２０．．．ガス供給手段，
３０．．．光学手段，
４０．．．移動手段，
８０．．．被加工物，
８９．．．被覆ガス（シールドガス，アシストガス），[0001]
【Technical field】
The present invention relates to a laser welding apparatus and a laser beam welding method, and more particularly, to a laser welding apparatus and a laser beam welding method capable of appropriately supplying a gas covering a welded portion and enabling good welding.
[0002]
[Prior art]
When laser welding is performed, a laser beam is irradiated while the weld is covered with a shielding gas or an assist gas (so-called gas shield) in order to prevent oxidation and scattering of the weld and promote reaction. The coating gas supply method for covering the welded portion includes a side assist method in which gas is blown onto the welded portion from an angle different from the laser beam, and the optical axis of the laser beam and the axis of the nozzle are substantially in the same direction. A coaxial nozzle system that blows gas from the same direction as the laser beam is known.
[0003]
For example, in a side assist type laser welding apparatus, as shown in FIGS. 4 and 5, a workpiece 80 is mounted on a rotating jig 91, and a laser beam is perpendicular to the welding surface 801 of the workpiece 80. The shield gas is blown from the nozzle 92 having an angle slightly inclined with respect to the normal line of the welding surface 801. In the figure, reference numeral 93 denotes a lens that collects parallel light toward the welding surface 801.
[0004]
Japanese Patent Application Laid-Open No. 6-246470 discloses that a condensing lens is attached to the wall surface of a container that accommodates a workpiece to form a sealed structure, and after the internal air is discharged, a coating gas is filled into the container. Laser welding apparatuses that perform welding are proposed.
[0005]
[Problems to be solved]
However, in the side assist method and coaxial nozzle method, in which a coating gas is blown to a narrow area near the weld using a nozzle, the surrounding gas and air are entrained in the molten metal due to fluctuations in the gas flow rate and pressure. Sometimes. Then, the gas trapped in the molten metal remains in the solidification process, or when the trapped gas is not trapped, a recess is formed on the surface, and so-called blowhole defects are generated. As a result, there is a problem that the airtightness of the welded joint is lowered.
[0006]
In addition, ensuring a stable gas atmosphere in the weld and performing good welding is an issue to be pursued in laser welding.
The present invention has been made in view of such conventional problems, and provides a laser welding apparatus and a laser beam welding method capable of performing welding with few defects while stably ensuring an atmosphere of a coating gas. It is what.
[0007]
[Means for Solving the Problems]
The invention of claim 1 comprises a gas supply means capable of continuously pumping a coating gas of a welded part such as a shielding gas or an assist gas, an inlet and an outlet of the coating gas, and an inlet of a laser beam. , A housing member for accommodating the workpiece between the outlets, an optical means for irradiating the workpiece with the laser beam from the introduction port, and a workpiece for changing the irradiation position of the laser beam on the workpiece Moving means or laser beam moving means,
The workpiece moving means is a movable body that can be moved in the direction of the axis of the workpiece by attaching the workpiece.
The optical means is provided outside the housing member, and the inlet and the outlet are provided at opposite ends of the housing member in the axial direction.
The laser welding apparatus is configured to irradiate a workpiece with a laser beam while continuously feeding a coating gas from the inlet.
In the present invention, since the coating gas is continuously supplied to the housing member, the internal air is excluded, the periphery of the workpiece is covered with the coating gas during welding, and the coating gas is covered with the workpiece. And the accommodation member that accommodates the workpiece does not flow and stay.
[0008]
In addition, it is not necessary to concentrate the gas only in the vicinity of the welded portion as in the case of the conventional apparatus, and therefore it is not necessary to increase the flow velocity, so that the amount of gas supplied (flow rate) can be reduced. . That is, even if the coating gas is supplied at a relatively low speed, the shield of the welded portion does not decrease, and good welding can be performed.
[0009]
Further, since gas is not sprayed in a spot shape on the welded portion, gas or air is not trapped in the molten metal, and gas is not trapped in the molten metal. Therefore, there is no possibility that the gas is completely trapped in the metal and does not remain, or a defect that is continuously trapped from the inside to the surface without being trapped is caused.
As described above, according to the laser welding apparatus of the first aspect, it is possible to perform the welding process satisfactorily while suppressing the amount of the coating gas used.
[0010]
Also, by facing the flow inlet and outlet, Ru can be smoothly and uniformly the flow of gas.
The workpiece moving means moves the workpiece in the axial direction. This By configuring as, even when fixing the position of the laser beam source Ru can be a uniform laser beam irradiated to the weld.
[0011]
Next, the invention of claim 2 is directed to the work piece while continuously flowing a coating gas for a welded portion such as a shielding gas or an assist gas between the work piece and a housing member for containing the work piece. A method of irradiating a welded part of a laser beam with a laser beam,
The optical means is provided outside the housing member, and the coating gas inlet and outlet are provided at opposite ends of the housing member in the direction of the axis of the workpiece. Flow in layers around the workpiece,
In the interior of the receiving member, the workpiece is moved in the direction of the axis, in the laser beam welding method, which comprises irradiating a laser beam.
In this case, since gas is not sprayed in the spot shape to the welded part, the gas is completely trapped and remains in the metal without causing entrainment of gas or air in the molten metal. There is no occurrence of defects that are continuously trapped from the inside to the surface without being trapped and become perforated.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
In this example, as shown in FIG. 1, the gas supply means 20 for continuously pumping the shield gas 89, the inlet 11 and outlet 12 of the shield gas 89, and the inlet 13 of the laser beam 61 are provided. A housing member 10 that accommodates the workpiece 80 between the inflow and the outlets 11 and 12, an optical means 30 that irradiates the workpiece 80 with the laser beam from the introduction port 13, and the workpiece 80. And a laser welding apparatus 1 for irradiating the workpiece 80 with the laser beam while continuously feeding the coating gas 89 from the inlet 11. It is.
[0013]
Further, the workpiece 80 has a cylindrical surface welded portion, and the moving means 40 of the workpiece 80 is attached to the workpiece 80 and rotates around the cylindrical axis, It is a rotary moving body that can move in the direction.
And the inflow port 11 and the outflow port 12 of the accommodating member 10 are provided in the opposing both ends.
[0014]
The following is a supplementary explanation for each.
As shown in FIG. 1, the moving means 40 for the workpiece 80 includes a chuck 41 that holds the workpiece 80, and a drive member 42 that rotates the chuck 41 and moves it in the vertical direction. The drive member 42 rotates the shaft of the chuck 41 by a motor.
The gas supply means 20 includes a gas cylinder 21, a pump 22, and a pipe 23 connected to the inflow port 12, and can pressure-feed the shield gas 89 to the housing member 10.
[0015]
The optical means 30 includes a laser light source 31, a fiber cable 32 that transmits laser light emitted from the laser light source 31, and a lens group 33 that once diverges the light emitted from the fiber cable 32 and collects the light. The lens group 33 includes a collimating lens 331 (FIG. 1) that converts laser light into parallel light, and a condenser lens 332 (FIGS. 2 and 3) that collects the parallel light. In the figure, reference numeral 34 denotes a power supply device for exciting the laser light source 31.
[0016]
As shown in FIGS. 2 and 3, the housing member 10 is provided with an inlet 13 for the laser beam 61 on the side surface (cylindrical surface) of the cylindrical container, and the inlet 11 and the outlet of the coating gas 89 on the upper and lower end faces. 12 are provided. The coating gas 89 forms a laminar flow around the workpiece 80 as indicated by the arrows in FIG.
The arrangement of the inlet 11 and the outlet 12 can be reversed so that the coating gas 89 flows in the opposite direction.
[0017]
Next, a specific experimental example regarding the welding characteristics when this apparatus is used and when the conventional apparatus shown in FIGS. 4 and 5 is used will be described.
The workpiece 80 is a member formed by welding a cylindrical SUS-304 member to a cylindrical member of SCR-415 (chromium carbon steel) having a diameter of 8 to 9 mm. The laser light source 31 emits infrared light having a power of 700 W and a wavelength of 1.06 μm.
The shield gas 89 is nitrogen gas, and the diameter of the inlet 11 of the housing member 10 is 16 mm.
[0018]
And the flow rate of the gas 89 was changed as shown in the left column of Table 1, and the quality of welding was measured. The middle column in Table 1 shows the results of the welding apparatus 1 of this example, the right column shows the results when the conventional apparatus (FIGS. 4 and 5) is used, and the circles indicate good welding processing. X indicates that welding defects such as oxidation or blowholes occurred in the weld.
[0019]
[Table 1]

[0020]
As can be seen from Table 1, by using the apparatus of this example, it is possible to achieve a good welding process with a gas flow rate that is 1/2 to 1/3 smaller than the conventional one. And in the case of this apparatus, it turns out that it will become an adverse effect if the gas flow rate is increased too much.
As described above, according to this example, it is possible to obtain a laser welding apparatus that can perform welding with few defects while suppressing the amount of coating gas used.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a laser welding apparatus according to an embodiment.
FIG. 2 is an enlarged cross-sectional view around a welded portion of the housing member of FIG.
3 is a cross-sectional view taken along line XX in FIG.
FIG. 4 is a front sectional view of the vicinity of a welded portion in a conventional side-assist type laser welding apparatus.
FIG. 5 is a plan view of the periphery of a welded portion in a conventional side-assist type laser welding apparatus.
[Explanation of symbols]
1. . . Laser welding equipment,
10. . . Receiving member,
11. . . Inflow,
12 . . Outlet,
13. . . Introduction,
20. . . Gas supply means,
30. . . Optical means,
40. . . transportation,
80. . . Work piece,
89. . . Coating gas (shield gas, assist gas),

Claims (2)

A gas supply means capable of continuously pumping a coating gas of a welded portion such as a shield gas or an assist gas; an inlet and an outlet of the coating gas; and an inlet of a laser beam. An accommodating member for accommodating a workpiece; optical means for irradiating a laser beam from the introduction port toward the workpiece; and a workpiece moving means for changing a laser beam irradiation position on the workpiece or a laser beam Transportation means,
The workpiece moving means is a movable body that can be moved in the direction of the axis of the workpiece by attaching the workpiece.
The optical means is provided outside the housing member, and the inlet and the outlet are provided at opposite ends of the housing member in the axial direction.
A laser welding apparatus configured to irradiate a workpiece with a laser beam while continuously feeding a coating gas from the inlet. A method of irradiating a welded portion of a workpiece with a laser beam while continuously flowing a coating gas of a welded portion such as a shielding gas or an assist gas between the workpiece and a housing member that accommodates the workpiece. Because
The optical means is provided outside the housing member, and the coating gas inlet and outlet are provided at opposite ends of the housing member in the direction of the axis of the workpiece. Flow in layers around the workpiece,
In the interior of the receiving member, the workpiece is moved in the direction of the axis, the laser beam welding method, which comprises irradiating a laser beam.

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