JP2535284C - - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a gas element such as vacuum or gas or a fluid element such as water, oil or alcohol.
Regarding a welding device to seal in a container, particularly after exhausting air from a metal container and maintaining its internal pressure at a constant degree of vacuum, or after filling the container with the fluid element,
The present invention relates to a welding device for hermetically sealed containers in which an open end of a container is closed with an end plug, and finally the end plug and the container are projection-welded with a movable electrode and a fixed electrode. 2. Description of the Related Art Conventionally, when manufacturing sealed containers such as a vacuum sealed container of a heat pipe, a fluid sealed container of a shock absorber, a gas sealed container of a nuclear fuel rod, etc., generally, the side on which the container is sealed is generally manufactured. After evacuating from the open end and reducing the internal pressure to a desired degree of vacuum, a gas or fluid element is supplied into the container, and then the sealing portion is heated, and the brazing material is melted and completely sealed or sealed. A portion is heat-sealed, and the container is sealed by means such as arc welding and spot welding. However, in the above-described method for sealing a container, in the case of a heat pipe, since the end of the container is crushed, a fluid pressure element is transmitted to the crushed portion. It is a major factor in lowering energy efficiency. In addition, a sealing method using a brazing material such as a shock absorber or a sealing method by arc welding requires empirical rules and skill, and it is difficult to automate with good productivity. In the method of spot welding the gas-filled containers of nuclear fuel rods by spot welding, the shape and size of the work are limited to some extent, and the electrodes are generally energized in the compression direction of the welded article. In addition, thin-walled pipes are used for hermetically sealed containers, and in many cases, the diameter, thickness and length of the pipes vary widely, and when the projection shape uses the end face of a thin-walled pipe, it is suitable for a wide range of welding conditions. Since it is necessary to take measures and the welding work is also performed in an environment under certain conditions, it has been desired to commercialize the equipment according to the conditions. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a welding device for sealed containers which can automate the sealing by welding the sealed container, improve efficiency, reduce cost, and improve welding quality. It is assumed that. [0004] In order to solve the above-mentioned problems, a sealed container welding apparatus according to the present invention holds an end plug to be welded and a container so as to face each other on a pressurized center line. A movable-side electrode and a fixed-side electrode, a drive source for moving the movable-side electrode to the fixed-side electrode and positioning the work at a predetermined position, a pressurizing cylinder for the movable-side electrode, and a welding power source connected between the two electrodes And a pressurized chamber attached to the tip of the fixed side electrode and airtightly holding a butt welding area between the end plug and the container. The movable side electrode and the fixed side electrode each have a chuck made of a conductive member at the tip. And a chuck driving actuator in which the piston rod moves concentrically on the rod, and a chuck holder is mounted on the tip of the piston rod of the chuck driving actuator. The chuck holder is concentrically overlapped with the chuck, and is configured to perform a work holding and opening / closing operation when the chuck is opened by a piston movement of the chuck driving actuator. [0005] [act] According to the welding apparatus of sealing containers of the present invention, electrodes facing each other in pressing center line
Then, clamp the end plug to be welded and the container respectively, and then attach one end
Pressurizing gas or fluid attached to the tip of the other electrode by advancing the electrode to the other electrode
Insert a stopper into the interior of the chamber, and a slight gap formed between the stopper and the end face of the container.
A butt weld area containing
After filling the container with gas or fluid, one of the electrodes is advanced to project the end plug and the container.
Seal the mating end, and then apply the necessary pressure and welding current to this
The vessel can be sealed. Therefore, it is not necessary to crush one open end of the pipe-shaped container, and the product can be manufactured while keeping its original shape. In the case of a heat pipe, the energy efficiency can be increased to the tip of the pipe. In addition, since the container and the end plug can be joined by projection welding , the positioning accuracy of the work can be easily obtained, and automation can be easily promoted, thereby improving productivity, reducing costs, and improving welding quality. be able to. Furthermore, in the welding device for sealed containers of the present invention, a chuck driving actuator which is coaxial with a drive shaft of a pressurizing cylinder is incorporated in a chuck mechanism which also serves as a clamp electrode as a movable electrode and a fixed electrode. In addition, it is possible to select a cylinder-incorporating method having a simple shape, so that a compact design structure can be achieved, and the entire welding machine can be shortened. In addition, the projection welding of the container and the end plug can be performed smoothly, reliably, and easily. [0006] The embodiment of the welding apparatus of sealed containers of the embodiment of the present invention will be described with reference to FIG. FIG. 1 is an assembly view showing the entire resistance welding apparatus when a gas-filled container of a nuclear fuel rod is sealed, FIG. 2 is a plan view thereof, and FIG. 3 is an enlarged sectional view showing a main part of an electrode in FIG. is there. In this apparatus, an end plug W1 shown in FIG. 3 which is a component of a nuclear fuel element and a pipe-shaped container W2 are clamped by respective electrodes, and air in the container is exhausted from a butt end to be joined. After supplying He gas, a predetermined pressure is applied between both electrodes, a welding current is passed between the electrodes, and the projection is performed by Joule heat generated by the specific resistance of the end plug and the container and the contact resistance at the butt surface. It is to be welded. [0010] Reference numeral 1 in FIG . 1 denotes a mount on which the main body of the welding machine is mounted, reference numeral 2 in FIGS. 1, 2 and 3 denotes a movable-side electrode, and reference numeral 3 denotes a fixed-side electrode. The movable electrode 2 is configured as follows. That is, the chuck 4 made of a conductive member that clamps the end plug W1 at the tip is attached to the screw hole 6 provided at the tip of the chuck rod 5, and the chuck driving actuator 7 is mounted on the outer periphery of the chuck rod 5. And a chuck holder 9 attached to the tip of the piston rod 8 with a bolt B1 via a secondary conductor 29 insulated by an insulating material 16 is attached to the chuck 4 in a concentric manner. They are fitted concentrically. The chuck 4 is formed with a plurality of slits (not shown) for applying a spring force in order to securely grip the end plug W 1, and the outer periphery of the chuck 4 has a taper provided on the inner periphery of the chuck holder 9. A wedge surface b is formed to be engaged with the wedge surface b. A component force of the thrust of the actuator 7 acting on the wedge surface b acts in a direction perpendicular to the axial center of the chuck 4 so that the inner surface of the chuck 4 is formed. Is tightly attached to the end plug W1. Accordingly, since the opening and closing operation of the chuck 4 when holding and opening the workpiece is performed by the piston movement of the actuator 7, it is possible to prevent generation of a moment on the chuck rod 5 which is a welding pressurizing shaft. In the chuck holder 9, a linear bush 1 having a guide rod 11 parallel to the chuck rod 5 provided on a head flange on the actuator 7 side as a rotation preventing mechanism.
0 and attached to the tip of the piston rod 8. The pressurizing cylinder 12 required for welding pressurization uses air as a driving source, and a response between the chuck rod 5 of the chuck 4 and the piston shaft 13 of the pressurizing cylinder 12 when the electrode is pressurized. In order to improve the performance, a follow-up spring 14 and a load cell 15 for monitoring a pressing force are incorporated on a bear-in guide. The movable electrode 2 having the unit structure as described above is fixed to a linear guide rail 19 fixed on a movable base 18 which moves the linear guide rail 17 of the gantry 1 by a positioning hydraulic cylinder (not shown). And moves so as to face one fixed-side electrode 3. The fixed-side electrode 3 is mounted on a movable base 21 that shifts along a bearing guide rail 20 on the gantry 1 arranged in a direction perpendicular to the center line of the pressure, that is, perpendicular to the plane of FIG. ing. [0013] chucking structure of the fixed-side electrode 3 is basically the same as the movable side electrode 2 described above. That is, a chuck 4 'made of a conductive member for clamping the container W2 is attached to a screw hole 6' provided at the tip of a chuck rod 5 ', and the chuck rod 5' is hollow, and a container A movement-adjustable backup rod 22 for backing up the rear part of W2 is provided. [0014] 'tubular piston rod 8' of the chuck driving actuator 7 'have been fitted concentrically on the outer periphery of the piston rod 8' the chuck rod 5 are insulated by an insulating material 16 'at the tip of the A chuck holder 9 'attached by bolts B2 via a secondary conductor 29' is fitted and attached concentrically to the chuck 4 '. The chuck 4 'is formed with a plurality of slits (not shown) for applying a spring force in order to securely grip the end plug W1, and the outer periphery of the chuck 4' is formed on the inner periphery of the chuck holder 9 '. A wedge surface b engaging with the provided tapered pressing surface a is formed, and a component force of the thrust of the actuator 7 ′ acting on the wedge surface b acts in a direction perpendicular to the axis of the chuck 4 ′. The inner surface of the chuck 4 'is tightly fastened to the outer periphery of the container W2. Therefore, the opening and closing operation of the chuck 4 'when holding and opening the work is performed by the piston movement of the actuator 7'.
It is possible to prevent a moment from being generated on the chuck rod 5 'which is a welding pressurizing shaft. In the chuck holder 9 ', a guide rod 11' parallel to the chuck rod 5 'is passed through a linear bush 10' provided on a head flange on the actuator 7 'side as a rotation preventing mechanism, and a piston rod 8' is provided. It is attached to the tip of. The fixed side electrode 3 can be shifted in a direction perpendicular to the pressing center line,
In the case of a short work, it can be set and removed from the direction of the movable electrode 2. At the tip of the chuck holder 9 ′ of the fixed electrode 3, a pressure chamber 23 is provided with an insulating material 16.
The chamber 23 and the chuck holder 9 '
An O-ring 24 is inserted between the front end of the housing and the airtightness. An O-ring 27 for hermetically sealing around the end plug W1 is fitted into the through hole 26 of the seal portion 25 into which the end plug W1 is inserted. The pressurizing chamber 23 has a volume surrounding an area where the end plug W1 and the end face of the container W2 meet at a small distance, and this volume exhausts air to the outside. There is provided a passage 28 which also serves as a suction port for keeping the internal pressure of the container W2 constant, and a supply port for supplying He gas into the container W2 after being evacuated. The part of the sealing portion 25 into which the end plug W1 is inserted can be changed according to the thickness of the end plug W1. [0019] Each of the chuck 4, 4 of the movable electrode 2 and the fixed-side electrode 3 ', consideration has been made which can be replaced by the thickness of the various work. The replacement method is the chuck holder 9,
Remove connection bolts B1, B2 with secondary conductors 29, 29 'to which 9' is attached,
The chucks 4 and 4 'are removed from the chuck rods 5 and 5', and the chuck having a different thickness is replaced. The secondary conductors 29 and 29 'connect the movable-side electrode 2 and the fixed-side electrode 3 to respective terminals of a welding transformer (not shown), and have a power supply function for supplying power to the electrode portion when moving such as work positioning. It has a moving function that moves with the electrode part and an insulating seal function that penetrates the gantry. A flexible ounce copper plate (flexible plate) is used for parts that require the moving function, and a penetrating part that requires a sealing function is used for Copper round bars are used. [0021] 'protruding margin e from, e' the chucks 4 and 4 of the container W2 of the end plug W1 and the fixed-side electrode 3 of the movable electrode 2 setter is omitted in the drawing, generally gauge bar May be inserted from the front surfaces of the opposing electrodes 2 and 3 to determine the position by abutting the gauge bar, or electrically detect and determine the protrusion allowances e and e 'using a sensor. Can be used selectively. The following in FIGS. 4-10 the operation sequence of the welding device of the above configuration. The air pressure of the pressurizing cylinder 12, the chuck driving actuator 7, the shift cylinder, etc. of the resistance welding apparatus shown in FIGS. 1 and 2, and the hydraulic pressure of the positioning hydraulic cylinder are applied to the respective return-side working chambers, and are moved. The side electrode 2 is separated from the fixed side electrode 3 and each chuck 4
, 4 'are opened, and all the drive units are returned to their original positions to stand by. Next, insert the container W2 as shown in FIG. 4 the chuck 4 'of the fixed electrode 3.
At this time, the protruding margin e 'from the chuck 4' is electrically detected by a gauge bar provided at a predetermined position or an arbitrary detector, and the chuck 4 'is stopped at the predetermined position, and at the same time, the chuck driving actuator 7' is operated. The chuck holder 9 'is advanced to press the pressing surface a of the holder 9' against the wedge surface b of the chuck 4 ', and the wedge action reduces the inner diameter of the chuck 4' in the axial direction of the container W2. As shown in FIG. 5, the container W2 is pressed against the outer periphery of the container W2 and clamped to hold the container W2. Next, insert the end plug W1 to the chuck 4 of the movable electrode 2, is electrically detected by the gauge bar or any detector provided protruding margin e of the end plug W1 in position,
The chuck 4 is stopped at a predetermined position, and at the same time, the chuck driving actuator 7 is actuated to advance the chuck holder 9 to press the pressing surface a of the holder 9 against the wedge surface b of the chuck 4. The inner diameter of the chuck 4 is reduced in the axial direction of W1, and pressed against the outer periphery of the end plug W1 as shown in FIG. 5 to clamp the end plug W1. Thus, the preparation for welding the opposing works on the pressing center line of the movable-side electrode 2 and the fixed-side electrode 3 is completed. Next, operate the hydraulic cylinders for positioning, to advance the movable side electrode 2 to a predetermined position, inserted in the pressure chamber 23 to the tip of the end plug W1 as shown in FIG. As a result, the butting area with a slight gap formed between the tip of the end plug W1 and the tip of the container W2 is hermetically surrounded by the pressure chamber 23. Then, vacuum evacuation is performed, and the air in the chamber 23 is exhausted from the passage 28, and is drawn within a few seconds until the pressure in the container W2 reaches a certain degree of vacuum. After evacuating like this,
He gas is supplied from the passage 28 into the chamber 23, and a certain amount of He gas is supplied into the container W2.
The gas is filled. The gas filling amount is determined by detecting the original pressure by a sensor. When the predetermined supply of He gas to the container W2 is completed, the pressurizing cylinder 12 is immediately activated by the signal, and the movable-side electrode 2 is advanced, and as shown in FIG.
A predetermined pressurizing force is generated at the abutting portion with the end face of No. 2 and then a welding current is supplied between the electrodes 2 and 3 for a certain period of time. Since the welding is performed in a sealed state in the pressure chamber 23, the welding quality is improved. [0027] After completion of the welding is operated chuck driving actuator 7 of the movable electrode 2 (see FIG. 2) on the return side, the end of the clamping force of the chuck 4 of the movable-side electrode 2 as shown in FIG. 8 At the same time as opening the stopper W1, the pressurizing cylinder 12 and the positioning hydraulic cylinder are operated to return, and the movable electrode 2 is returned to the original position as shown in FIG. Then, the chuck driving actuator 7 'of the fixed side electrode 3 is operated to the return side, and FIG.
The welded product can be taken out by opening the container W2 by the chuck 4 'as shown in FIG. And, it prepares for the next welding work. When the container W2 is short, the pressurizing cylinder 12 (see FIGS. 1 and 2) is lowered to its original position, the end plug W1 is set on the chuck 4, and the whole of the fixed electrode 3 is moved to the movable electrode 2. , The container W2 is set on the chuck 4 'from the direction of the movable electrode 2, and after the setting is completed, the fixed electrode 3 is shifted back to the original position. . When the container W2 is long, the end plug W1 is set in the same manner as in the case of the short container. Set to '. As can be seen from the above description, according to the welding device for hermetically sealed containers of the present invention, it is not necessary to crush one open end of the pipe-shaped container and always keep the original shape. It can be made into a product, and in the case of a heat pipe, energy efficiency can be increased up to the end of the pipe. Also, it can be joined by projection welding of container and end plug.
Therefore, the positioning accuracy of the work can be easily obtained, and automation can be easily promoted, so that productivity can be improved, cost can be reduced, and welding quality can be improved. Furthermore, in the welding device for sealed containers of the present invention, a chuck driving actuator which is coaxial with a drive shaft of a pressurizing cylinder is incorporated in a chuck mechanism which also serves as a clamp electrode as a movable electrode and a fixed electrode. In addition, it is possible to select a cylinder-incorporating method having a simple shape, so that a compact design structure that shortens the entire welding machine can be achieved. And the projection welding of the container and the end plug can be performed smoothly, reliably and easily.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an assembly drawing of the entire welding device for hermetically sealed containers of the present invention. FIG. 2 is a plan view of FIG. FIG. 3 is an enlarged sectional view showing a main part of an electrode of the welding device of FIG. 1; 4 to 10 are explanatory diagrams showing the operation sequence of the welding device of the present invention. [Description of Signs] 1 base 2 movable side electrode 3 fixed side electrode 4, 4 'chuck 5, 5' chuck rod 6, 6 'screw hole 7, 7' chuck driving actuator 8, 8 'piston rod 9, 9' Chuck holder 10, 10 'Linear bush 11, 11' Guide rod 12 Pressure cylinder 13 Piston shaft 14 Follow-up spring 15 Load cell 16, 16 ', 16 "Insulation material 17 Linear guide rail 18 Moving table 19 Linear guide rail 20 Bearing guide Rail 21 Moving table 22 Backup rod 23 Pressurizing chamber 24 O-ring 25 Seal part 26 Through hole 27 O-ring 28 Passage 29, 29 'Secondary conductor W1 End plug W2 Container a Pressing surface b Wedge surface e, e' Projecting allowance B1 , B2, B3 bolt

Claims (1)

Claims: 1. A movable electrode and a fixed electrode for holding an end plug to be welded and a container facing each other on a pressurized center line, and moving the movable electrode to the fixed electrode. A drive source for positioning the work at a predetermined position, a pressurizing cylinder for the movable-side electrode, a welding power source connected between the two electrodes, and a butt welding between the end plug attached to the tip of the fixed-side electrode and the container. A pressurizing chamber for keeping the area airtight; a chuck rod having a chuck made of a conductive member at its tip, and a chuck in which a piston rod moves concentrically on the rod, for the movable side electrode and the fixed side electrode. A driving actuator, and a chuck holder is attached to a tip of a piston rod of the chuck driving actuator, and the chuck holder overlaps the chuck concentrically,
A welding apparatus for hermetically sealed containers, wherein the work of holding the chuck and the opening and closing operation when the chuck is opened are performed by the piston movement of the chuck driving actuator. 2. A plurality of slits are formed in each of the chucks of the movable side electrode and the fixed side electrode so that a spring force is applied, and a taper-shaped chuck provided on the outer circumference of the chuck holder on the inner circumference of the chuck holder. A wedge surface that engages with the pressure surface is provided, and a component force of the thrust of the actuator acting on the wedge surface is applied in a direction perpendicular to the axis of each chuck, thereby tightening the end plug and the container on the inner surface of the chuck. 2. The welding device for hermetically sealed containers according to claim 1, wherein: 3. The sealed container according to claim 1, wherein a follow-up spring and a load cell for detecting a pressing force are incorporated between the pressurizing cylinder and an output shaft of the chuck holding the end plug. Kind of welding equipment. 4. The sealed container according to claim 1, wherein the chuck rod of the fixed-side electrode is hollow, and a back-up rod capable of adjusting movement is provided inside the chuck rod for backing up a rear portion of the container. Kind of welding equipment.