JP2002144072A - Welding equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To enable vacuum sealing of a vacuum heat insulator at low cost, with high durability and high reliability against leakage, and to easily perform vacuum sealing in a vacuum atmosphere. So that the performance of the apparatus can be prevented from deteriorating. SOLUTION: A light beam 35 is transmitted through a wall portion 11 having a light transmitting property and constituting a vacuum chamber, and the transmitted light beam 35 is irradiated on a workpiece 26 in a vacuum atmosphere to perform welding. A protective body 22 having a light-transmitting property is provided on the side of the workpiece 26 with respect to the wall portion 11 to prevent the plume 36 generated from the molten substance from reaching the wall portion 11. Ray 3
Shields 27 and 28 are provided which have holes 31 and 32 for allowing the passage of the fluid 5 and prevent the plume 36 generated from the molten substance from reaching the wall 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding apparatus, and more particularly to a welding apparatus for forming a vacuum heat insulator by evacuating the inside of a double wall and sealing an exhaust port by welding.

[0002]

2. Description of the Related Art A vacuum container such as a vacuum insulation container for a sodium-sulfur battery is evacuated to the inside of the container, that is, the inside of the double wall through an exhaust port provided in a container having a double wall structure made of stainless steel or the like. After that, the exhaust port is vacuum-sealed.

[0003] As means for this vacuum sealing, for example, there is known a device in which packing is tightened between an annular blade portion at the tip of a screw body screwed into an exhaust port and an annular blade portion formed in the exhaust port. Have been.

[0004] Alternatively, there is known an exhaust port covered with a cover plate in a vacuum chamber, and the periphery of the cover plate is sealed by brazing or electron beam welding.

[0005]

However, in the case of the structure in which the packing is sandwiched between the annular blade portions by using a screw body, it is necessary to machine the screw and the blade portion. The configuration is complicated, which leads to high costs. Further, since the screw body needs to be tightened, the work for sealing off becomes complicated. In addition, if the vacuum insulator as a product is used repeatedly in a situation where the temperature rises and falls greatly, the difference in the coefficient of thermal expansion between the screw part and the metal packing due to the temperature history may cause vacuum breakage. There is.

In the case of performing brazing, electron beam welding, and the like in a vacuum chamber, it is necessary to install an apparatus for performing such brazing, electron beam welding, and the like in the vacuum chamber, which requires a large-scale facility.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to perform vacuum sealing of a vacuum heat insulator at low cost and with high durability and high reliability against leakage. It is another object of the present invention to facilitate vacuum sealing in a vacuum atmosphere and to prevent the performance of the apparatus from being deteriorated.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is to transmit a light beam to a wall having a light transmitting property and constituting a vacuum chamber, and irradiate the transmitted light beam to a workpiece in a vacuum atmosphere. A welding apparatus for performing welding by providing a light-transmitting protective body on a workpiece side of the wall to prevent a plume generated from a molten substance from reaching the wall. It is.

The present invention is also directed to a welding apparatus for performing welding by transmitting light to a wall portion constituting a vacuum chamber having a light transmitting property and irradiating the transmitted light to a workpiece in a vacuum atmosphere. A shield is provided closer to the workpiece than the portion, and has a hole through which light rays can pass, and a shield capable of preventing a plume generated from a molten substance from reaching the wall.

[0010] With such a configuration, light from a non-vacuum atmosphere is passed through a light-transmitting wall and introduced into the vacuum atmosphere, thereby welding a workpiece inside the vacuum atmosphere. Therefore, there is no need to install equipment such as a light source in a vacuum atmosphere, that is, a large-scale equipment for welding.
Therefore, welding in a vacuum atmosphere can be easily performed.

When welding is performed in this manner, a plume, which is an updraft of metal vapor or the like, is generated. However, the plume has a light transmitting property due to a light-transmitting protective body or a shield having holes. Thus, it is possible to prevent the light from reaching the wall having the light-transmitting property of the wall.

In general, when a wall constituting a vacuum wall is made to have a light-transmitting property, it is necessary to form the wall with an expensive material such as quartz glass. The protector can be made of a less expensive material, which can prevent the plume from reaching expensive walls. By providing a perforated shield instead of the light-transmitting protective body, it is possible to further reduce the cost.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 11 denotes a thin-walled metal wall constituting a vacuum heat insulator, and vacuum evacuation is performed by a double wall of the wall 11 and another wall (not shown). Is formed. A base 13 is provided on a part of the wall body 11, and the base 13
An exhaust port 14 for communicating the internal space 12 with the outside is formed in a penetrating state. A step 15 is formed on the periphery of the exhaust port 14 on the surface of the base 13.

Numeral 16 denotes a vacuum evacuation pot, which has an opening edge 17 which is opened at the bottom of the cylindrical body, and which is arranged in a portion around the exhaust port 14 so that the evacuation port 14 is formed. Is configured to be able to cover. A packing 18 is sandwiched between the opening edge 17 and the portion of the wall 11 around the base 13. The evacuation pot 16 is connected to a vacuum pump 20 via an evacuation path 19. The top plate 21 forming a part of the wall of the evacuation pot 16 is formed of a light-transmitting material such as quartz glass.

A protective glass 22 as a protective body is provided on a portion inside the top plate 21 in the vacuum evacuation pot 16 so as to overlap the top plate 21 as shown in the figure, for example. It is preferable that the protective glass 22 is made of, for example, an article having excellent permeability of a laser beam, which will be described later, such as a part number BK-7 manufactured by Schott or a white plate glass.

An operating rod 23 and a rotating shaft 24 pass through the center of the top plate 21 and the protective glass. The working rod 23 and the rotating shaft 24 are both formed of a metal material, and are arranged in a state in which the hollow rotating shaft 24 is fitted on the concentric or solid working rod 23. The rotation shaft 24 is configured to be able to slide in a circumferential direction in an airtight state inside a seal member 25 provided over the top plate 21 and the protective glass 22. Although not shown, an airtight holding member such as an O-ring is also arranged between the inner periphery of the rotating shaft 24 and the outer periphery of the working rod 23. The action rod 23 is configured to be slidable in a gas-tight state in a direction penetrating the rotation shaft 24, and is provided in a state in which a distal end portion protrudes from the rotation shaft 24.

Inside the pot 16, a metal sealing plate 26 is attached to the tip of the action rod 23 protruding from the rotation shaft 24. As shown in the figure, the sealing plate 26 is configured such that the action rod 23 moves the inside of the rotation shaft 24 to the exhaust port 1.
4, when sliding in the direction approaching to 4, the peripheral edge portion is configured to fit into the peripheral step portion 15 of the exhaust port 14. The attachment of the sealing plate 26 to the working rod 23 can be performed by appropriate means. For example, it can be attached not only by a mechanical means such as a screw, but also by an adhesive or a simple means such as a double-sided adhesive tape.

Inside the evacuation pot 16, a pair of metal shielding disks 27 and 28 are attached to the outer periphery of the rotating shaft 24 at a predetermined distance in the longitudinal direction of the rotating shaft 24. ing. A driven gear 29 is attached to the outer periphery of the rotary shaft 24 outside the evacuation pot 16. The shielding disks 27 and 28 and the driven gear 29 can be integrally rotated via a rotating shaft 24.

As shown in FIGS. 1 to 3, through holes 30, 31, 32 are formed in the driven gear 29 and the shielding disks 27, 28 at the same positions in the circumferential direction and the radial direction, respectively. I have. That is, these through holes 30, 31, 3
2 is a sealing plate 26 fitted in the step 15 as shown.
Is formed at a position corresponding to the peripheral portion of. Driven gear 2
A drive gear 34 driven by a motor 33 is meshed with 9.

In such a configuration, when the internal space 12 is evacuated, the evacuation port 16 is covered with the pot 13 on the wall body 11 through the packing 18 so that the evacuation port 14 is formed by the pot 16. cover. At this time, the operation rod 22 is pulled up to close the sealing plate 26.
Away from the exhaust port 14.

When the vacuum pump 20 is operated in this state,
The inside of the pot 16 is evacuated, whereby the pot 16 is pressed against the base 13 on the wall 11 by the action of atmospheric pressure, and the packing 18 is compressed between the opening edge 17 and the wall 11, The required sealing condition is achieved. When the vacuum pump 20 is continuously operated, the internal space 12 is evacuated. The exhaust gas is guided to an exhaust passage 19 through a gap between the pot 16 and the shielding disk 28.

When the internal space 12 has reached the required degree of vacuum, the operating rod 23 is pushed down as shown in the figure, and the peripheral edge of the sealing plate 26 is fitted into the step portion 15. Close mouth 14. Then, in this state, the laser beam 35 is introduced into the pot 16 from outside. This laser beam 35 passes through the through hole 3 of the driven gear 29.
After passing through zero, the light passes through the top plate 21 and the protective glass 22, and then passes through the through holes of the shielding disks 27 and 28,
Irradiation is performed on the peripheral portion of the sealing plate 26 fitted in the step portion 15. Thereby, the peripheral portion of the sealing plate 26 and the step 15 of the base 13 are welded to each other.

That is, the top plate 21 and the protective glass 22 which transmit the laser beam 35 from a non-vacuum atmosphere
Then, the peripheral edge of the sealing plate 26 is welded to the base 13 by being introduced into the pot 16 in a vacuum atmosphere. For this reason, it is not necessary to install a device such as a light source, that is, a large-scale device for welding, inside the pot 16, and therefore, it is possible to easily weld the sealing plate 26 in a vacuum atmosphere inside the pot 16. Can be. In addition, because of the configuration of sealing off by welding, the vacuum sealing portion in the completed vacuum heat insulator has an advantage that durability and reliability against leakage are extremely high. In addition, the diameter of the exhaust port 14 can be made larger than that of a screw-in type or the like, so that the time for evacuation can be greatly reduced.

At this time, for example, the sealing plate 26 is pressed against the step portion 15 by the action rod 23 to prevent the floating from occurring due to the thermal strain.
Approximately 8 points of tack welding are performed. After that, welding with the laser beam 35 is performed over the entire circumference of the sealing plate 26. In this case, the laser beam 35 moves in the circumferential direction along the peripheral edge of the sealing plate 26, but the driven gear 29 and the shielding disks 27 and 28 are driven by driving the motor 33.
Are rotated together, so that the through holes 30, 31,
32 is made to follow the path of the laser beam 35.

As described above, the metal sealing plate 26 is
At this time, a plume 36, which is an updraft of metal vapor, is generated. When the plume 36 adheres to the top plate 21 made of quartz glass, the top plate 21 becomes dirty, and thereby the laser light 35
Is reduced. As a result, the heat is absorbed by the top plate 21 so that sufficient heat input cannot be introduced into the welded portion of the sealing plate 26, and the top plate 21 is melted and damaged by the absorbed heat. Therefore, if no measures are taken, the sealing plate 26
Is only welded once to three times, and the expensive top plate 21 formed of quartz glass or the like must be replaced.

However, according to the present invention, the protective glass 22
Is provided, the plume 36 generated at the time of welding is provided.
Can be prevented from adhering to the top plate 21 formed of expensive quartz glass or the like. In addition, with such a configuration, the plume 36 is provided with the protective glass 2 instead of the top plate 21.
2, the protective glass 22 can be formed of the inexpensive material as described above, so that frequent replacement does not increase the cost much.

However, when a certain amount of plume 36 adheres to the protective glass 22 as described above, the transmittance decreases, and melting and breakage occur. Therefore, by providing the shielding disks 27 and 28 having the through holes 31 and 32 through which the laser beam 35 only passes as described above, the plume 36 generated during welding is prevented from reaching the protective glass 22 as much as possible. Can be. As shown, the shielding disk 27,
It is effective to install a plurality of 28, but the number is arbitrary. The effect of shielding the plume 36 can be enhanced by bringing the shielding disk 28 as close to the sealing plate 26 as possible.

With this configuration, the top plate 21 made of expensive quartz glass or the like can be used for a long time. Note that, as described above, the protective glass 2
In addition to using the shielding discs 27 and 28 in combination, only one of them can be used alone.

As a heat source for welding, it is preferable to use the laser beam 35 as described above, and specifically, a carbon dioxide laser, a YAG laser, a semiconductor laser, or the like can be used. Further, a light beam from a xenon lamp used as a general light beam heating device can be used. In addition, the light ray here is
This concept includes not only visible light but also other wavelength ranges, such as infrared rays.

The present invention is not only applied to the above-described vacuum insulated container, but also has a wide light-transmitting property for forming a vacuum atmosphere with light from a non-vacuum atmosphere, that is, a vacuum atmosphere. The present invention can be applied to anything for heating and welding a workpiece by irradiating the workpiece inside the vacuum atmosphere by passing through a wall and introducing the workpiece into the vacuum atmosphere.

[0031]

As described above, according to the present invention, a light beam is transmitted through a wall portion constituting a vacuum chamber having a light transmitting property, and the transmitted light beam is irradiated on a workpiece in a vacuum atmosphere to perform welding. In the welding device, on the workpiece side than the wall portion, to prevent a plume generated from a molten substance from reaching the wall portion, a light-transmitting protective body is provided, In place of the above-described protective body, a shield having a hole for allowing light to pass therethrough and capable of preventing a plume generated from a molten substance from reaching the wall is provided. In order to weld the workpiece inside the vacuum atmosphere by passing the light beam through the translucent wall and introducing the inside of the vacuum atmosphere, a device such as a light source in the vacuum atmosphere, that is, a large scale for welding. Dress It is not necessary to install a pipe, so that welding in a vacuum atmosphere can be easily performed. In addition, when the welding is performed in such a manner, a plume that is an updraft of metal vapor or the like is generated. The protective body or the shield having the hole can prevent the plume from reaching the light-transmitting wall and reducing the light-transmitting property of the wall.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic configuration of a welding device according to an embodiment of the present invention.

FIG. 2 is a plan view of a gear portion in FIG.

FIG. 3 is a plan view of a portion of a shielding disk in FIG. 1;

[Explanation of symbols]

 14 Exhaust port 21 Top plate 22 Protective glass 26 Sealing plate 27 Shielding disk 28 Shielding disk 35 Laser beam

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B23K 101: 12 B23K 101: 12 101: 36 101: 36 103: 04 103: 04 (72) Inventor Hiroshi Yamazaki 1-1-1, Hama, Amagasaki-shi, Hyogo F-term in Kubota Technology Development Laboratory Co., Ltd. (Reference) 4B002 BA22 CA23 CA32 CA43 4E068 CG05 CJ09 DA07 DB01 5H029 AJ14 AK05 AL13 CJ05 CJ28 CJ30 DJ02 EJ01

Claims (3)

[Claims] 1. A welding apparatus for transmitting a light beam to a wall portion having a light transmitting property and constituting a vacuum chamber, and irradiating a workpiece in a vacuum atmosphere with the transmitted light beam to perform welding. A welding apparatus, further comprising: a light-transmitting protective body for preventing a plume generated from a molten substance from reaching the wall portion on a workpiece side. 2. A welding apparatus which has a light transmitting property and transmits light to a wall constituting a vacuum chamber, and irradiates the transmitted light to a workpiece in a vacuum atmosphere to perform welding. A welder having a hole on the workpiece side for allowing light rays to pass therethrough and capable of preventing a plume generated from a molten substance from reaching the wall. 3. The welding apparatus according to claim 2, wherein the shield is movable so that the hole moves along the path of the light beam.