JP2001340987A - Welding apparatus and welding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure good and stable quality of a welded portion capable of perfectly replacing circumferential air of the welded portion with gas while fully controlling a supply amount of gas forming the welding atmosphere, and also controlling invasion of external air without producing any flow of gas during welding operation. SOLUTION: When welding a butt portion 6 of cylindrical members 1 and 2 as an object to be welded by a laser spraying unit 22, the inside of a shielded case 7 is replaced with argon gas so that argon gas 23 having heavier specific gravity than that of air is supplied into the shielded case 7 surrounding the above-described butt portion 6 through a lower part of the shielded case. Then, upon switching supply of argon gas 23 to supply of argon gas 25 by means of a gas delivering feeding portion 16, argon gas 25 is horizontally injected in the upper portion of the shielded case 7. Argon gas 23 having heavier specific gravity than that of air is caused to stay inside the shielded case 7, and invasion of air into the shielded case 7 is eventually controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding device and a welding method, for example, for welding a joint portion between cylindrical members, in particular, for controlling an atmosphere.

[0002]

2. Description of the Related Art Conventionally, in a process of fitting or abutting ends of cylindrical members and joining the overlapped or abutted portions as joints by welding, welding is performed by irradiating a spot or continuous laser beam. Methods have been implemented.

[0003] In many cases, welding of a welded material made of a material that can be welded in an oxidizing atmosphere is performed by spot or continuous irradiation of a laser beam in the atmosphere.
For a material that requires welding in a specific atmosphere, for example, an oxidizing material such as pure titanium, a titanium alloy, or a magnesium alloy that requires welding in an inert atmosphere, the following techniques are available.

[0004] First, simply, there is provided a shield gas distribution means independent of a laser optical system, and a method of irradiating a laser while spraying a gas injected from the shield gas distribution means near a welded portion, or a laser optical system. A method is used in which a coaxial shield gas injection nozzle is provided at the end of the system, and a laser is irradiated while blowing a shield gas, which is similarly injected in the same direction as the laser optical axis, near the welded portion.

However, in these methods, the area of the welded material that can be covered with the injected shielding gas is insufficient, so that a stable atmosphere cannot be formed due to the entrainment of the atmosphere, and a large flow rate of the shielding gas is always supplied. Since there is a problem to be solved, a laser welding apparatus and method disclosed in Japanese Patent Application Laid-Open No. 9-314367 have been proposed.

According to this, a housing member having an inlet, an outlet, and a laser inlet for a gas forming a welding atmosphere is provided, and one end is held between the inlet and the outlet while holding one end. The workpiece is accommodated from the outlet side, and the workpiece is irradiated with laser from the laser introduction port while continuously sending the gas from the inlet to the outlet. That is, an inlet is provided at one end of the cylindrical housing member, an outlet is provided at the other end, and a laser inlet is provided on a side surface of the housing member. Then, while continuously supplying gas from the inflow port, the air inside the housing member is replaced with gas, and the gas is continuously supplied during laser irradiation and the gas is discharged from the outflow port, so that the workpiece is processed. The surroundings can be stably covered with the gas.

[0007]

However, the above prior art has the following problems. That is, during the laser irradiation, the gas is continuously pumped between the workpiece and the housing member. Therefore, first, heat exchange between the gas and the material at the laser irradiation point hinders heating and promotes cooling. This may vary due to variations in the shape and surface condition of the workpiece, gas temperature and fluctuations in flow rate control, etc., which may cause instability in welding conditions and melting at the laser irradiation point depending on the direction of gas flow. The state may be anisotropic.

In the case where both workpieces to be joined are not held or integrated beforehand, but only one is held and the other is welded in a state depending on the degree of friction of fitting, the pressure of the gas flow to be pumped is In some cases, the workpiece may fall off from a predetermined state due to wind pressure or may be displaced, thereby making positioning impossible.

Further, by providing a laser inlet in addition to the outlet in the housing member, the inside and outside airtightness of the housing member is extremely low. Therefore, particularly near the laser irradiation point, it is difficult to sufficiently suppress the introduction and entrainment of air while suppressing the gas flow rate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and it has been found that the supply of the gas constituting the welding atmosphere is sufficiently suppressed, and the laser irradiation point on the workpiece and the air around it are more complete. To gas and
Provided is a welding apparatus and a welding method for suppressing the invasion of air from the outside without generating a gas flow that hinders the welding efficiency in an atmosphere during the execution of welding by laser irradiation and stably ensuring the quality of a welded portion and a welding method. The purpose is to:

[0011]

In order to solve the above-mentioned problems, a welding apparatus according to a first aspect of the present invention provides a welding apparatus in which pieces to be welded are brought into contact with each other, and the contact portion is heated to thereby bring the pieces to be welded together. A gas supply means for supplying a gas having a higher specific gravity than air to the storage chamber in which the abutting portion of the workpiece is surrounded, and a gas having a specific gravity higher than the air is supplied to the storage chamber. Gas injection means for injecting gas in a substantially horizontal direction at a position above the contact portion of the workpiece so as to stay.

Further, the welding apparatus according to the second invention is characterized in that
The welding apparatus according to the invention is characterized in that a plurality of through holes are arranged at regular intervals, and further comprising a rectifying plate that partitions the storage chamber.

Further, a welding method according to a third aspect of the present invention is a welding method in which the objects to be welded are brought into contact with each other and the abutting portions are heated to join the objects to be welded. A step of supplying a gas having a specific gravity higher than air to the storage chamber in which the contact portion is surrounded, and a step of supplying a gas having a specific gravity higher than the air from the contact portion of the workpiece so that the gas having a higher specific gravity stays in the storage chamber. And heating the contact portion while injecting gas in a substantially horizontal direction at an upper position.

That is, in the welding apparatus according to the first aspect of the present invention, a gas having a specific gravity higher than that of air, which constitutes a welding atmosphere, is supplied into the storage chamber from the gas supply means, and the air in the storage chamber is replaced with the gas. The phenomenon is performed from below the storage room, and a welding atmosphere is obtained by the gas filled in the storage room.
Then, the gas is injected in a substantially horizontal direction from the gas injection means into the storage chamber at a position above the abutting portion (weld portion) between the objects to be welded, so that the gas remaining in the storage chamber below the gas injection means may be discharged. An atmosphere without flow is maintained, and the intrusion of air from the outside into the storage chamber is sufficiently suppressed. Therefore, it is possible to perform welding between the workpieces in a nearly complete welding atmosphere without gas flow.

In the welding apparatus according to the second aspect of the invention, when the gas supplied from the gas supply means fills the storage chamber from a lower position, the gas passes through each through hole of the current plate. The gas is rectified in a certain upward direction, and the air remaining in the storage chamber during the process of replacement with the gas can be extremely suppressed.

Further, in the welding method according to the third aspect of the present invention, a gas having a specific gravity higher than that of air, which constitutes a welding atmosphere, is supplied into the storage chamber, and the phenomenon of replacing the gas in the storage chamber with air is performed. From below, a welding atmosphere is obtained by the gas filled in the storage chamber. And, by injecting gas in a substantially horizontal direction at a position above the abutting portion between the workpieces, the gas staying in the storage chamber where the abutting portion between the workpieces is located is maintained in a flowless atmosphere. In addition, it is possible to sufficiently suppress the invasion of air from the outside into the storage room. In this state, the contact portion between the workpieces is heated, and welding can be performed in a near-perfect atmosphere without gas flow.

[0017]

(Embodiment 1) Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a schematic shape of a joint portion formed by abutting an end portion of a cylindrical member to be welded in the present embodiment. FIG. 2 is a schematic view showing a joint shape formed by fitting an end portion of the cylindrical member to be welded in the present embodiment. FIG. 3 is a sectional view showing a welding apparatus according to the present embodiment, and FIGS. 4 and 5 are plan views showing a current plate in the present embodiment.

In the present embodiment, the shape of the work to be welded will be described by taking as an example a solid cylindrical shape, a so-called cylindrical shape or a hollow cylindrical shape, that is, a shape having a cylindrical outer periphery. In this embodiment, for example, pure titanium or a titanium alloy, which is difficult to weld in the atmosphere, is used as the material of the workpiece. Hereinafter, the cylindrical member and the cylindrical member are collectively referred to as a cylindrical member.

As a method of bringing the cylindrical members into contact with each other and joining the contact portions, for example, as shown in FIG.
A method in which the end surfaces 1a and 2a of the long cylindrical members 1 and 2 are brought into contact with each other and the butted portion (contact portion) 6 is welded;
As shown in FIG. 2, the end portions 1b,
There is a method of fitting the 2b with each other and welding the overlapping portion (contact portion) 26 thereof.

Next, a welding apparatus according to the present embodiment will be described with reference to FIGS. In FIG. 3, cylindrical members 1 and 2 are chucks 3 whose base ends are rotatable.
3 are held by a plurality of claws 4. The two chucks 3 are opposed to each other with their axes 5 aligned in the horizontal direction. The chucks 3 and 3 are rotatable about a shaft 5 at a predetermined angular velocity synchronously by a drive mechanism (not shown).

Therefore, the cylindrical members 1 and 2 held by the plurality of claws 4 and 4 of the chucks 3 and 3 have their rotation center axes horizontally aligned with each other.

The cylindrical members 1 and 2 are connected to each other at their tip surfaces 1a and 2 respectively.
a (see FIG. 1) butted against each other (hereinafter referred to as
A portion between a welded portion 6 and a portion held by the chuck 3 penetrates a side wall 8 of a box-shaped shield case 7 as a storage chamber (storage member) whose upper part is opened by an opening 21. are doing.

That is, the shield case 7 is disposed between the chucks 3, 3, and through holes 9, 9 are opposed to the center of both side walls 8 of the shield case 7 facing the chucks 3, 3. The cylindrical members 1 and 2 are inserted into the respective through holes 9 and 9. These through holes 9, 9
Side wall 8 of shield case 7 intersecting with axis 5 of chuck 3
Has been drilled.

With this configuration, the welded portion 6 of the cylindrical members 1 and 2 held by the chucks 3 and 3 is
Will be surrounded by.

The through-holes 9, 9 have cylindrical members 1, 2, respectively.
The seal members 11, 1 having the sliding holes 10, which have an inner diameter substantially the same as the outer diameter of the
1 is firmly fixed to the shield case 7 via the seal holding members 12 and 12. Note that the center of the sliding hole 10 of the seal member 11 and the shaft 5 of the chuck 3 coincide with each other.

The sealing members 11, 11 are cylindrical members 1, 2,
By using a material having a small sliding resistance between the cylindrical members 1 and 2, when the cylindrical members 1 and 2 rotate, it is possible to prevent gas from leaking from between the cylindrical members 1 and 2 and the seal members 11 and 11 and to prevent sliding. The airtightness inside and outside the shield case 7 near the hole 10 can be substantially maintained.

On the side wall 8 below the through hole 9 of the shield case 7, one gas inlet 14 as a lower inlet provided with a gas pipe joint 13 is provided. The pipe joint 13 is connected to a gas delivery unit 16 as a switching unit (gas delivery unit) via a pipe 41 so that the gas delivered from the gas delivery unit 16 flows into the shield case 7 without leakage. It has become. The gas inlet 14 has a shape in which gas expands and flows.

On the other hand, one gas injection port 18 provided with a gas pipe joint 17 is provided on the side wall 8 above the through hole 9 of the shield case 7. The pipe joint 17 is connected to the gas delivery unit 16 via a pipe 42 so that the gas delivered from the gas delivery unit 16 is injected into the shield case 7 without leakage. The gas injection port 18 has an inner diameter of the gas inlet 1.
4, and has a shape in which gas is injected in a substantially horizontal direction. The pipe joint 17 and the gas injection port 18 constitute a gas injection unit.

The gas delivery section 16 is connected to the gas cylinder 15 via a pump 40, and delivers the gas supplied from the gas cylinder 15 to the gas inlet 14 via a pipe 41 or the gas via a pipe 42. The delivery is switched to the injection port 18. The gas cylinder 15 and the pump 40
These constitute a gas supply means (gas pressure sending means).

In this embodiment, argon gas, which is an inert gas, is used as the gas having a specific gravity higher than that of the atmosphere contained in the gas cylinder 15.

On the inner side surface of the shield case 7,
A plate-like structure in which a plurality of through holes 19 are densely arranged at regular intervals at a position below the shaft 5 of the chuck 3, that is, at a position below the through hole 9 in the side wall 8 of the shield case 7 and above the gas inlet 14. Are provided horizontally.

Thus, the current plate 20 includes a lower portion (hereinafter, referred to as a chamber A) on the gas inlet 14 side in the shield case 7 and an upper portion including the gas injection port 18 and the welded portion 6 (hereinafter, referred to as a chamber A).
(Referred to as room B).

The through hole 19 of the current plate 20 may have a circular shape as shown in FIG. 4 or a rectangular shape as shown in FIG. In addition, the current plate 20 may have a mesh shape instead of a plate shape.

Above the opening 21 of the shield case 7, a laser irradiating device 22 is disposed as a laser irradiating means for condensing the light so that the welded portion 6 of the cylindrical members 1 and 2 is focused. . The laser irradiator 22 irradiates a predetermined pulse train with a neodymium YAG laser oscillator (not shown), sufficiently heats the welded portion 6, and
The two are welded together.

Next, a method for welding cylindrical members to each other using the above welding apparatus will be described. First, the base ends of the cylindrical members 1 and 2 are respectively held by the chucks 3 and 3, and the distal end surfaces 1 a and 2 a of the cylindrical members 1 and 2 abut against each other in the shield case 7. At this time, the cylindrical members 1 and 2 are inserted into the through holes 9 in the side wall 8 of the shield case 7,
Airtightness is maintained by the seal member 11.

Next, the argon gas in the gas cylinder 15 is delivered to the gas inlet 14 via the pipe 41 by the gas delivery unit 16, and the shield case 7 is supplied from the gas inlet 14.
Fill room A inside. The argon gas 23 flows so as to spread into the chamber A, forms a complicated flow state, entrains the air in the chamber A, and is in a mixed state with the air.

Thereafter, the mixed gas of the argon gas 23 and the air rises through the through hole 19 of the current plate 20 and starts flowing into the B room. The flow of the gas mixture 24 is regulated in the vertical direction by passing through the through holes 19 of the current plate 20.

Here, since the specific gravity of the argon gas 23 is larger than that of the air, the argon gas concentration in the chamber A increases in a short time. Then, as the argon gas concentration in the chamber A increases, the mixed gas 2 flowing into the chamber B 2
In No. 4, the argon gas concentration also increases.

Therefore, the argon gas 23 is supplied to the current plate 2
0 toward the opening 21 of the shield case 7 from the upper surface. Then, the argon gas 23 from the gas inlet 14 reaches the opening 21 and the shield case 7
Begin to overflow sufficiently from within. Therefore, air does not flow into the shield case 7 from the opening 21.

After that, the argon gas 23 that has been delivered to the gas inlet 14 is switched by the gas delivery unit 16 to deliver the gas to the gas injection port 18 via the pipe 42, and the argon gas 25 is transferred from the gas injection port 18 through the gas injection port 18. Shield case 7
Inject inside.

The argon gas 25 is injected in a substantially horizontal direction so as to block the opening 21 of the shield case 7. At this time, the argon gas 23 in the shield case 7 is
Is stirred under the influence of the argon gas 25 from the gas injection port 18 in the vicinity of the opening 21, but otherwise stays in a state where it hardly flows, for example, near the butted portion 6 of the cylindrical members 1 and 2. At the same time, the argon gas 25 overflows from the opening 21 of the shield case 7 to suppress the intrusion of air into the shield case 7.

In the present embodiment, the area of the opening 21 of the shield case 7 is 600 mm ^2, and the supply rate of the argon gas 25 from the gas injection port 18 is 2 liter / min.

In this stagnation state, the chucks 3, 3 holding the cylindrical members 1, 2 are synchronously rotated at a constant angular speed of 30 rpm at a constant speed, from the laser irradiation device 22 toward the welding portion 6 of the cylindrical members 1, 2. To irradiate a predetermined pulse train to weld the cylindrical members 1 and 2 together.

In this embodiment, the irradiation conditions are as follows: the pulse energy is 6.5 J, the pulse width is 0.005 sec, the repetition frequency is 10 Hz, and the number of emitted pulses is 8
0 pulse was set.

In this embodiment, the gas inlet 14
And one gas injection port 18, but it goes without saying that two or more gas injection ports 18 may be provided.

In this embodiment, argon gas, which is an inert gas, is used as the gas having a specific gravity higher than that of the atmosphere. However, the gas can be appropriately selected depending on the material of the cylindrical member to be bonded. May be used.

According to the present embodiment, since the gas stays in the shield case 7 and does not flow, good quality welding is performed in an atmosphere under stable conditions, and oxidation is sufficiently suppressed by the shielding effect of argon gas. Is done. Gas injection port 18
In the case where the flow rate of argon gas from is 2 liter / min or more in the case where the area of the opening 21 of the shield case 7 is 600 mm ² , the shielding property is considered to be effective, and the gas supply amount is sufficiently suppressed.

In the shield case 7, the greater the distance between the weld 6 and the gas inlet 14 or the greater the distance between the weld 6 and the gas injection port 18, the more stable the atmospheric conditions and the better the shielding performance. Depending on the laser irradiation conditions, the gas injection port 18
Good welding may be possible even if the delivery of argon gas to the furnace is stopped or unnecessary.

(Embodiment 2) Embodiment 2 of the present invention will be described with reference to FIGS. FIG. 6 is a cross-sectional view showing a schematic shape of a joint portion formed by fitting an end of a cylindrical member to be welded in the present embodiment, and FIG. 7 is a cross-sectional view showing a welding device of the present embodiment.

The configuration of the present embodiment is the same as that of the first embodiment except for the following. The same components are denoted by the same reference numerals, and only different portions will be described.

In the present embodiment, a long cylindrical member and a short cylindrical member can be welded. As shown in FIG. 6, an end 3 of a long cylindrical member 31 serving as an object to be welded is used.
1a is fitted to the end 32a of the short cylindrical member 32, and the overlapping portion 33 is welded.

In the welding apparatus of this embodiment, as shown in FIG. 7, only the long cylindrical member 31 is gripped by the plurality of claws 4 of the rotatable chuck 3 at the base end thereof, and the short cylindrical member 31 is rotated. 32, the end 32a is fitted to the end 31a of the long cylindrical member 31, and the shaft 5 of the chuck 3 and the two cylindrical members 3
The rotating shafts 1 and 32 are held horizontally with their center axes of rotation aligned. The chuck 3 is driven by a driving mechanism (not shown).
It is rotatable about the shaft 5 at a predetermined angular velocity.

The long cylindrical member 31 penetrates the side wall 8 of the box-shaped shield case 34 having an open upper portion, and is an overlapping portion (hereinafter referred to as a welding portion) which is a fitting (coupling) portion with the short cylindrical member 32. A portion of the cylindrical member 33 is housed in the shield case 34, and the entirety of the short cylindrical member 32 fitted to the long cylindrical member 31 is housed in the shield case 34.

That is, the long cylindrical member 31 is firmly fixed via the seal holding member 12 attached to the through hole 9 formed in the side wall 8 of the shield case 7 intersecting with the shaft 5 of the chuck 3. 11 through the end 31a
Is introduced into the shield case 7. On the other hand, unlike the first embodiment, the side wall 8 facing the side wall 8 is different from the first embodiment.
No through holes are drilled.

The method of welding cylindrical members to each other using the above welding apparatus is performed by holding only the long cylindrical member 31 with the chuck 3 and fitting the short cylindrical member 32 to the long cylindrical member 31. Embodiment 1 Except for welding the welding portion 33
Therefore, the description is omitted.

According to the present embodiment, in addition to the same effect as in the first embodiment, only the long cylindrical member 31 is held, and the other cylindrical member 32 is welded in a state depending on the friction caused by fitting. In this case, since the gas constituting the welding atmosphere stays in the shield case 7, even a minute workpiece can fall off from a predetermined state due to the wind pressure caused by the flow of the gas, or can be misaligned. It can be prevented from becoming disabled.

In the first and second embodiments, an example has been described in which cylindrical members whose outer periphery has a cylindrical surface are welded to each other.
Even if one of the cylindrical members is a flexible linear member in which the element wire is formed in a close-coiled shape, welding can be performed while exhibiting the same operation and effect as those of the above embodiments.

The technical idea having the following configuration is derived from the specific embodiment described above. (Additional remarks) (1) In a welding apparatus in which ends of cylindrical members are fitted or abutted to each other and the overlapped portion or the abutted portion is heated from the outer periphery and the two are joined by welding, specific gravity is higher than air constituting a welding atmosphere. A gas pumping means for supplying a gas having a large size, and a welded portion of the cylindrical member rotatably held and a portion surrounding the welded portion are formed by a side wall opened only upward, and the side wall is formed by at least one of both cylindrical members. A shield case, which is rotatably penetrated and has an inflow port through which gas is introduced into the interior below the welded portion of the cylindrical member and an injection port for horizontally injecting gas into the interior above the welded portion, Laser irradiation means for condensing and irradiating a laser to the welded portion of the cylindrical member through the shield case opening, and supplied by the gas pressure means Gas delivery means for switching and delivering gas to the inflow port and the injection port, and having a gas delivery means, and irradiating a laser to a welded portion of the cylindrical member while switching and delivering the gas. Welding equipment.

(2) The inside of the shield case is divided into two chambers between the welded portion and the gas inlet by a rectifying plate in which a plurality of through holes are densely arranged at regular intervals. The welding device for a cylindrical member according to supplementary note (1), characterized in that:

(3) In a welding method in which the ends of the cylindrical member are fitted or abutted to each other, the overlapped portion or the abutted portion is heated from the outer periphery, and the two are joined by welding, the heating point of the cylindrical member and its After the gas having a higher specific gravity than the atmosphere constituting the welding atmosphere is delivered to the inlet and filled in the shield case containing the periphery, the delivery is switched to the injection port and the gas is horizontally injected. And irradiating a laser to the welded portion of the cylindrical member by the laser irradiating means.

(4) In a welding apparatus in which the objects to be welded are brought into contact with each other and the abutting portions are heated to join the objects to be welded together, the housing in which the abutting portions of the objects to be welded are surrounded. A welding apparatus comprising: gas supply means for supplying a gas having a specific gravity higher than that of air in a room so as to stay therein.

(5) In a welding apparatus in which the objects to be welded are brought into contact with each other and the abutting portions are heated to join the objects to be welded, the housing in which the abutting portions of the objects to be welded are enclosed. Gas supply means for supplying an inert gas to the chamber, and gas injection for injecting the gas in a substantially horizontal direction at a position above the contact portion of the workpiece so that the inert gas stays in the storage chamber. Means.

(6) In a laser welding apparatus in which the objects to be welded are brought into contact with each other and the abutting portion is irradiated with a laser beam to join the objects to be welded, the upper portion is opened, and A box-shaped storage member surrounding the contact portion, gas supply means for supplying a gas having a specific gravity higher than air from a lower inlet provided at a lower portion of the storage member, and a gas having a specific gravity higher than the air Gas injection means for injecting a gas similar to the gas in a substantially horizontal direction from an upper injection port provided at a position above the contact portion of the workpiece, so that the gas stays inside the storage member, A laser welding apparatus comprising:

(7) The laser welding apparatus according to appendix (6), wherein the object to be welded has a cylindrical outer periphery.

(8) One of the workpieces is a flexible linear member in which a wire is formed in a tight coil shape, and the other is a cylindrical member into which the linear member can be fitted. The laser welding apparatus according to supplementary note (6), wherein:

(9) The apparatus further comprises switching means for switching a gas having a specific gravity larger than that of the air so as to be supplied from one of the upper injection port and the lower inlet. The laser welding apparatus according to any one of (8).

(10) A plate-shaped rectifying plate having a plurality of through-holes arranged at regular intervals is provided between the workpiece and the lower inlet. The laser welding apparatus according to any one of (9).

(11) The object to be welded is characterized in that the workpiece is rotatably supported by the housing member.
The laser welding apparatus according to any one of (1) to (10).

(12) In the welding method in which the objects to be welded are brought into contact with each other and the abutting portions are heated to join the objects to be welded together, the housing in which the abutting portions of the objects to be welded are surrounded is described. A step of supplying the gas so that a gas having a higher specific gravity than air stays in the chamber, and a step of heating the contact portion of the workpiece while the gas stays in the storage chamber, A welding method comprising:

(13) In the laser welding method in which the objects to be welded are brought into contact with each other and the abutting portion is irradiated with a laser to join the objects to be welded, the abutting portion of the object to be welded is surrounded. Supplying a gas having a specific gravity higher than that of air to the storage chamber, and substantially horizontally at a position above the contact portion of the workpiece so that the gas having a specific gravity higher than that of air stays in the storage chamber. Irradiating the contact portion with a laser while injecting gas in the direction.

(14) In a laser welding method in which the objects to be welded are brought into contact with each other and the abutting portion is irradiated with a laser beam to join the objects to be welded, the upper portion is open, and A step of supplying a gas having a specific gravity higher than air from a lower inlet provided at a lower portion of the box-shaped storage member surrounding the contact portion; and a gas having a specific gravity higher than the air stays inside the storage member. A step of injecting a gas similar to the gas in a substantially horizontal direction from an upper injection port provided above a contact portion of the object to be welded. Method.

According to the welding apparatus described in the appendix (1), while the supply of the gas constituting the welding atmosphere is sufficiently suppressed, a high-purity atmosphere with stable conditions is formed, so that good welding quality can be maintained. Can be obtained.

According to the welding device of the supplementary note (2), the gas constituting the welding atmosphere is more completely and smoothly replaced with air, so that a highly pure atmosphere with stable conditions can be obtained. As a result, good welding quality can be stably obtained.

According to the welding method described in the appendix (3), while the supply of the gas constituting the welding atmosphere is sufficiently suppressed, a high-purity atmosphere with stable conditions is formed, whereby good welding quality can be stably maintained. Can be obtained.

According to the welding device described in Appendix (4), a gas having a specific gravity higher than that of air is supplied into the storage chamber, and the inside of the storage chamber is replaced with the supply gas from air to retain the gas, thereby reducing the atmosphere of welding. By forming a high-purity atmosphere with stable conditions while sufficiently suppressing the supply of constituent gas, good welding quality can be stably obtained.

According to the welding device described in the appendix (5), the air in the storage chamber is replaced with the supplied inert gas and is retained to prevent the flow of the inert gas, and is stored with the inert gas injected substantially in the horizontal direction. By suppressing the intrusion of air into the room, while suppressing the supply of gas that constitutes the welding atmosphere,
By constructing a highly pure atmosphere with stable conditions,
Good welding quality can be stably obtained.

According to the welding device described in the appendix (6), a gas having a specific gravity higher than that of air is supplied into the storage member from the lower part of the storage chamber, and the internal air is removed from the opening in the upper part of the storage member to remove the gas from the storage member. After the replacement, the supply of the gas is stopped after the inside of the storage member is filled with the gas, and then the same gas as the gas is injected in a substantially horizontal direction by gas injection means located above the contact portion between the workpieces. In addition to suppressing the intrusion of air into the storage member, and retaining gas in the storage member,
Good welding is achieved by forming a high-purity atmosphere with stable conditions by at least preventing the flow of gas around the abutting part between the workpieces, while sufficiently suppressing the supply of the gas that constitutes the welding atmosphere. Quality can be obtained stably.

According to the welding device described in the appendix (7), the workpieces can be joined with good welding quality to the workpieces having a cylindrical outer periphery.

According to the welding device described in the appendix (8), the close-coiled linear member and the cylindrical tubular member can be joined with good welding quality.

According to the welding device of the appendix (9), the filled gas is retained in the storage member, and the supply of the gas constituting the welding atmosphere is sufficiently suppressed, and the high-purity atmosphere with stable conditions is obtained. With this configuration, good welding quality can be stably obtained.

According to the welding device described in the appendix (10), the gas constituting the welding atmosphere in the housing member is more completely and smoothly replaced with air, so that a highly pure atmosphere with stable conditions can be obtained. , Whereby good welding quality can be stably obtained.

According to the welding device of the appendix (11), the storage member can be fixed, the workpiece can be rotated, and the workpieces can be joined with good welding quality from the outer periphery of the workpiece.

According to the welding method described in the appendix (12), a gas having a specific gravity higher than that of air is supplied into the storage chamber, the gas is retained in the storage chamber, and the supply amount of the gas constituting the welding atmosphere is sufficiently suppressed. However, by forming a high-purity atmosphere with stable conditions, good welding quality can be stably obtained.

According to the welding method described in the appendix (13), a gas having a specific gravity higher than that of air is supplied and filled into the storage chamber, and then the gas is ejected in a substantially horizontal direction to retain the gas in the storage chamber. In the state, by irradiating the laser to the abutting portion of the welded articles with each other, the supply amount of the gas constituting the atmosphere is sufficiently suppressed, but by forming a high-purity atmosphere with stable conditions, a good Welding quality can be obtained stably.

According to the welding method of Appendix (14), a gas having a specific gravity higher than that of air is supplied into the storage member, the gas is supplied from the lower part of the storage chamber, and the internal air is supplied from the opening at the upper part of the storage member. Excluded and replaced with the gas, supply of the gas is stopped after the inside of the storage member is filled with the gas, and then the same gas as the gas is discharged by the gas injection means located above the contact portion between the workpieces. Injection is performed in a substantially horizontal direction to prevent outside air from entering the storage member, and the gas is retained in the storage member. By forming a stable and high-purity atmosphere under conditions that prevent the flow of gas around the contact portion, good welding quality can be stably obtained.

[0086]

As described above, according to the first aspect of the present invention,
According to the welding apparatus described above, a stable and high-purity atmosphere is formed under conditions that prevent the flow of gas at least around the abutting portion between the workpieces while sufficiently suppressing the supply amount of the gas constituting the welding atmosphere. Thereby, good welding quality can be stably obtained.

According to the welding apparatus of the second aspect of the present invention, the gas constituting the welding atmosphere in the storage chamber is more completely and smoothly replaced with air, so that the condition can be stably increased. A pure atmosphere can be obtained, and thereby good welding quality can be stably obtained.

Further, according to the welding method of the third aspect of the present invention, while the supply amount of the gas constituting the atmosphere is sufficiently suppressed, a high-purity atmosphere with stable conditions is formed, whereby good welding quality is obtained. Can be obtained stably.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a schematic shape of a joint portion formed by abutting an end of a cylindrical member to be welded in Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view showing a schematic shape of a joint portion formed by fitting an end portion of a cylindrical member to be welded in the first embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating the welding device according to the first embodiment of the present invention.

FIG. 4 is a plan view showing a current plate according to Embodiment 1 of the present invention.

FIG. 5 is a plan view showing a current plate according to Embodiment 1 of the present invention.

FIG. 6 is a cross-sectional view showing a schematic shape of a joint portion formed by fitting an end portion of a cylindrical member to be welded in Embodiment 2 of the present invention.

FIG. 7 is a sectional view showing a welding device according to a second embodiment of the present invention.

[Description of Signs] 1, 2, 31, 32 Cylindrical member 1a, 2a End face 1b, 2b End 6 Butt 7, 34 Shield case 13, 17 Pipe joint 14 Gas inlet 15 Gas cylinder 16 Gas delivery part 18 Gas injection port DESCRIPTION OF SYMBOLS 20 Rectifier plate 21 Opening 22 Laser irradiation device 23, 25 Argon gas flow 26, 33 Overlapping part 40 Pump 41, 42 Pipe

Claims (3)

[Claims] 1. A welding apparatus for joining objects to be welded by bringing the objects to be joined into contact with each other and heating the contact portion, wherein the contact portion of the object to be welded is enclosed. A gas supply means for supplying a gas having a specific gravity greater than air to the workpiece; and a gas supply means for supplying a gas having a specific gravity greater than the air to a substantially horizontal direction at a position above the contact portion of the workpiece so that the gas remains in the storage chamber. And a gas injection means for injecting gas into the welding device. 2. A plurality of through holes are arranged at regular intervals,
The welding apparatus according to claim 1, further comprising a rectifying plate that partitions the storage chamber. 3. A welding method for joining objects to be welded by bringing the objects to be welded into contact with each other and heating the abutting portion, wherein the contact chamber of the object to be welded is surrounded. Supplying a gas having a specific gravity higher than that of air into the storage chamber so that the gas having a higher specific gravity than the air stays in the storage chamber. And heating the contact portion while spraying water.