Tungsten electrode bending device and method for nuclear fuel rod argon arc welding

Abstract

The invention belongs to the technical field of nuclear fuel manufacturing, and particularly relates to a tungsten electrode bending device and method for nuclear fuel rod argon arc welding. Comprising a fixed electrode, a movable electrode, a fixed-length check block and a resistance butt welding machine, and the fixed electrode, the movable electrode and the fixed-length check block are installed on the resistance butt welding machine. The tungsten electrode heating device has the beneficial effects that the tungsten electrode is heated conveniently and rapidly by adopting the means that the heating device which is standardized and convenient to use is adopted for heating the tungsten electrode. And the bending length is determined through the fixed-length check block, and the effect of rapidly determining the bending size is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear fuel manufacturing, and in particular relates to a tungsten electrode bending device and method for argon arc welding of nuclear fuel rods. Background Art

[0002] In some special occasions of nuclear fuel manufacturing, internal welds need to be welded, and the straight tungsten electrode cannot enter these welding areas. For this purpose, the development of bent tungsten electrodes was carried out.

[0003] The patent application with application number 202011609676.2 provides a method for bending the tungsten electrode. This method uses argon arc for continuous heating and gradually applies force to bend the tungsten electrode. However, this method requires the operator to have strong skills and be able to control the degree of heating and the bending force. In addition, because it requires the use of tools such as argon arc welding guns and gas cylinders, the operation is relatively cumbersome.

[0004] The utility model patent with patent number CN 203695814 U also controls the bending angle of the tungsten electrode through a simple mold, but it also uses argon arc for continuous heating and shaping, which is inconvenient to operate.

[0005] The utility model with patent number CN 215697106 U provides a dedicated heating power source, which is bent by a handle after heating. The bending process still requires manual intervention and requires certain skills. Summary of the invention

[0006] The purpose of the present invention is to provide a tungsten electrode bending device and method for argon arc welding of nuclear fuel rods, which can solve the problem of fast fixed-length bending of 1.0 mm tungsten electrode.

[0007] The technical solution of the present invention is as follows: a tungsten electrode bending device for argon arc welding of nuclear fuel rods, comprising a fixed electrode, a movable electrode, a fixed-length stopper and a resistance butt welding machine, wherein the fixed electrode, the movable electrode and the fixed-length stopper are installed on the resistance butt welding machine.

[0008] The resistance butt welding machine is composed of a welding transformer box, a base, a fixed electrode mounting seat and its accessory parts, a movable electrode mounting seat and its accessory parts, and a screw connector.

[0009] The resistance butt welding machine comprises a fixed electrode mounting seat, a top wheel, an adjusting bolt, a fixing plate, a movable electrode mounting seat, a nut, a welding transformer box, a current adjusting handle, a start welding button, a fixed electrode mounting arm, a movable electrode mounting arm, a substrate, a movable clamping jaw seat guide rail, a ball, a screw, a spring, a spring fixing end, a button mounting plate, a fixed electrode copper conductive belt, a movable electrode copper conductive belt, and a wire; the substrate is welded by two upper plates with step surfaces, a hollow cavity and a lower plate with a central opening, and the lower plate of the substrate is connected to the welding transformer box; the fixed electrode copper conductive belt of the fixed electrode mounting seat and the movable electrode copper conductive belt of the movable electrode mounting seat pass through the inside of the hollow cavity of the substrate; there is a mounting hole for the fixed electrode mounting seat on the upper plate surface of the substrate, and the fixed electrode seat is installed by screws; the lower part of the step surface of the upper plate of the substrate is used to install the movable clamping jaw seat guide rail, and the movable clamping jaw seat guide rail is fixed to the upper plate of the substrate by screws; the fixed electrode mounting seat is a cast aluminum cavity, and the fixed electrode mounting arm is welded on the upper part of the fixed electrode mounting seat.

[0010] The fixed electrode is installed on the fixed electrode installation arm.

[0011] The fixed electrode is made of beryllium cobalt copper with good electrical and thermal conductivity. Its installation edge is a right angle. The edge of the welding machine fixed electrode installation arm is used as the positioning reference. A tungsten electrode socket is processed inside it, and the tungsten electrode to be processed passes through the hole.

[0012] The fixed-length stopper is connected to the fixed electrode through a screw, and has an outer shape of a rectangular parallelepiped with a notch, wherein the notch is the tungsten electrode extension positioning surface.

[0013] The fixed-length stopper is made of beryllium cobalt copper.

[0014] The movable electrode mounting seat is a cast aluminum cavity, ball mounting grooves are provided at the lower parts of both sides of the movable electrode mounting seat, and movable electrode mounting arms are welded to the upper part of the movable electrode mounting seat.

[0015] The movable electrode is mounted on a movable electrode mounting arm of a movable electrode mounting seat.

[0016] The movable electrode is made of beryllium cobalt copper, and a corner thereof in contact with the fixed electrode is a double-step structure.

[0017] A tungsten electrode bending method for argon arc welding of nuclear fuel rods comprises the following steps:

[0018] Step 1: Before bending, adjust the top wheel through the handle so that the movable electrode is pushed away a certain distance along with the movable electrode mounting arm, and level the fixed-length stopper so that it contacts the movable electrode;

[0019] Step 2: Insert the tungsten electrode through the oblique hole inside the fixed electrode, contact and position it with the blocking surface of the fixed-length stopper, and slightly push the movable electrode to make the fixed-length stopper fall;

[0020] Step 3: Loosen and rotate the top wheel handle to move the movable electrode toward the fixed electrode until it contacts the tungsten electrode and applies pre-pressure to it;

[0021] Step 4: Start the resistance welding machine. The current passes through the movable electrode, tungsten electrode, and fixed electrode in sequence, quickly softening the tungsten electrode but not yet reaching its melting point. The tungsten electrode deforms under the pressure of the movable electrode and bends around the corner point of the fixed electrode to the required angle.

[0022] The beneficial effects of the present invention are: by adopting a standardized and easy-to-use heating device to heat the tungsten electrode, convenient and rapid heating of the tungsten electrode is achieved. By using a method of determining the bending length by a fixed-length stopper, the effect of quickly determining the bending size is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the application of bending tungsten electrode;

[0024] Figure 2 A top view of a tungsten electrode bending device for argon arc welding of nuclear fuel rods provided by the present invention;

[0025] Figure 3 This is a rear view of a tungsten electrode bending device for argon arc welding of nuclear fuel rods provided by the present invention;

[0026] Figure 4 is a cross-sectional view of the substrate;

[0027] Figure 5 It is a schematic diagram of assembling the fixed electrode mounting seat and the movable electrode mounting seat with the substrate;

[0028] Figure 6 It is a schematic diagram of the inner cavity structure of the fixed electrode mounting seat and the movable electrode mounting seat.

[0029] In the figure: 1 tungsten electrode, 2 fixed electrode, 3 movable electrode, 4 fixed length block, 5 fixed electrode mounting seat, 6 top wheel, 7 adjustment bolt, 8 fixing plate, 9 movable electrode mounting seat, 10 nut, 11 welding transformer box, 12 current adjustment handle, 13 welding start button, 14 fixed electrode mounting arm, 15 movable electrode mounting arm, 16 base, 17 movable jaw seat guide rail, 18 ball, 19 screw, 20 spring, 21 spring fixed end, 22 end chamber, 23 button mounting plate, 24 fixed electrode copper conductive belt, 25 movable electrode copper conductive belt, 26 wire. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Tungsten electrodes are relatively hard and are mostly made using powder metallurgy. Bending at room temperature usually causes the tungsten electrodes to break, so the tungsten electrodes usually need to be heated before bending. Heating is usually done by arc welding, which is relatively complicated.

[0032] The present invention utilizes the resistance heat generated by a resistance butt welding machine, adopts special-shaped electrodes and a positioning device, and develops a bending process to achieve a fast and convenient bending effect.

[0033] like Figure 2 As shown, a tungsten electrode bending device for argon arc welding of nuclear fuel rods includes a fixed electrode 2, a movable electrode 3, a fixed-length stopper 4 and a resistance butt welding machine, and the fixed electrode 2, the movable electrode 3 and the fixed-length stopper 4 are installed on the resistance butt welding machine.

[0034] The resistance butt welding machine is a carrier used in the present invention and is an existing finished product.

[0035] The resistance butt welding machine is composed of a welding transformer box 11, a base 16, a fixed electrode mounting seat 5 and its accessories, a movable electrode mounting seat 9 and its accessories, and screws and other connectors. Specifically, it includes a fixed electrode mounting seat 5, a top wheel 6, an adjustment bolt 7, a fixing plate 8, a movable electrode mounting seat 9, a nut 10, a welding transformer box 11, a current adjustment handle 12, a start welding button 13, a fixed electrode mounting arm 14, a movable electrode mounting arm 15, a base 16, a movable jaw seat guide rail 17, a ball 18, a screw 19, a spring 20, a spring fixed end 21, a button mounting plate 23, a fixed electrode copper conductive belt 24, a movable electrode copper conductive belt 25, and a wire 26. The base 16 is made of cast aluminum and is welded by two upper plates with stepped surfaces, a hollow cavity and a lower plate with an opening in the center. The lower plate of the base 16 is connected to the welding transformer box 11 by bolts; the fixed electrode copper conductive belt 24 of the fixed electrode mounting seat 5 and the movable electrode copper conductive belt 25 of the movable electrode mounting seat 9 pass through the hollow cavity of the base 16. There are mounting holes for the fixed electrode mounting seat 5 on the upper plate surface of the base 16, and the fixed electrode seat 5 is installed by screws. The lower part of the stepped surface of the upper plate of the base 16 is used to install the movable jaw seat guide rail 17, and the movable jaw seat guide rail 17 is fixed to the upper plate of the base 16 by screws.

[0036] The fixed electrode mounting seat 5 is a cast aluminum cavity. A fixed electrode mounting arm 14 is welded on the upper part of the fixed electrode mounting seat 5. The top wheel 6 and the fixed electrode 2 are mounted on the fixed electrode mounting arm 14 by screws. The fixed electrode copper conductive strip 24 from the transformer secondary side of the welding transformer box 11 is connected to the lower part of the fixed electrode mounting seat 5 by screws.

[0037] A movable electrode mounting arm 15 is welded on the upper part of the movable electrode mounting seat 9, and a movable electrode is mounted on the movable electrode mounting arm by screws. A fixing plate 8 is mounted on the side of the movable electrode mounting arm 15 by screws, and an adjusting bolt 7 is fixed on the upper part of the fixing plate 8 by threaded connection. Guide grooves are provided on both sides of the lower part of the movable electrode mounting seat 9, and a ball bearing is filled between the movable jaw seat guide rail 17 to slide. The bottom surface of the movable electrode mounting seat 9 is connected to the movable electrode copper conductive belt 25 from the secondary side of the transformer box 11 welded by screws.

[0038] The internal cavity of the fixed electrode mounting seat 5 includes two chambers. The end chamber 22 is mainly used to accommodate the start button 13 and the wire 26. There are two holes on the chamber partition, one hole is used to pass the wire between the substrate 16 and the start button 13, and the other hole is used to install the spring fixed end 21. The movable electrode mounting seat 9 and the fixed electrode mounting seat 5 are connected and reset by a spring 20. One end of the spring is connected to the inner wall of the end cavity 22 of the fixed electrode mounting seat 5 through the spring fixed end 21, and the other end is connected to the end of the movable electrode mounting seat 9 through a screw with a hole 19 and locked by a nut 10. The start button 13 is connected to the primary circuit of the transformer through the wire 26.

[0039] The fixed electrode 2 is made of beryllium cobalt copper with good electrical and thermal conductivity. Its mounting edges are processed into right angles to facilitate good positioning with the edges of the fixed electrode mounting arm 14 of the welding machine. A tungsten electrode plug hole is processed inside it, and the tungsten electrode 1 to be processed can pass through the hole. The fixed-length stopper 4 is made of beryllium cobalt copper and is connected to the fixed electrode 2 by screws. The shape is a rectangular parallelepiped with a notch, and the notch is the tungsten electrode extension positioning surface.

[0040] The top wheel 6 is installed on the fixed electrode mounting seat 5, and is installed eccentrically. The top wheel can be rotated around the mounting screw through the handle thereon. Due to its eccentricity, the adjusting bolt 7 will be tightened or loosened during rotation, thereby changing the distance between the fixed electrode 2 and the movable electrode 3.

[0041] The movable electrode 3 is made of beryllium cobalt copper, and its appearance design is similar to that of the fixed electrode 2. The corner thereof in contact with the fixed electrode is designed to be double-stepped, so as to obtain the fulcrum and bending stroke for bending the tungsten electrode.

[0042] The adjusting bolt 7 is locked on the fixing plate 8 by means of double nuts, and the fixing plate 8 is fixed on the movable electrode mounting seat 9 by means of screws.

[0043] The welding transformer box 11 contains a welding transformer. The current adjustment handle 12 thereon can change the transformation ratio of the transformer, thereby changing the output current.

[0044] A tungsten electrode bending method for argon arc welding of nuclear fuel rods comprises the following steps:

[0045] Before bending, adjust the top wheel 6 through the handle so that the movable electrode 3 is pushed open a certain distance along with the movable electrode mounting arm 15, and the rotatable block 4 is leveled to make it contact with the movable electrode. Insert the tungsten electrode 1 through the internal inclined hole of the fixed electrode 2, just contact and position with the blocking surface of the fixed-length block 4, slightly push the movable electrode to make the rotatable block 4 fall; slowly loosen the handle of the rotating top wheel 6, so that the movable electrode 3 moves toward the fixed electrode 2 until it contacts the tungsten electrode 1 and applies pre-pressure to it; press the start button 13, and a low voltage and high current pass through instantly. The current passes through the path of the movable electrode 3, the tungsten electrode 1, and the fixed electrode 2 in sequence, quickly softening the tungsten electrode but not reaching its melting point. The tungsten electrode 1 deforms under the pressure of the movable electrode 3 and bends to the required angle around the corner point of the fixed electrode. The welding current can be controlled by the current adjustment handle 12, the clamping force of the movable electrode can be adjusted by rotating the nut 10, and the length of the short side of the tungsten electrode bending can be controlled by changing the size of the rotatable block 4 to meet different bending requirements. These parameters do not need to be adjusted at ordinary times, so the operation is convenient.

[0046] The device can be used to conveniently bend 1.0mm thoriated tungsten electrodes with a bending length of 4-5mm and an angle of 90°, with good results. However, the principle of the device is also applicable to the bending needs of tungsten electrodes of other sizes and types. By using similar electrodes, replacing the rotatable block design, and selecting a butt welding machine with appropriate power, the bending function of other types of tungsten electrodes can be achieved.

[0047] Example

[0048] A fuel rod has an inner ring weld that needs to be welded, but because the weld is inside the rod, a bent tungsten electrode is required for welding.

[0049] The bending steps of this method are:

[0050] 1. Adjust the push wheel to push the movable electrode away for a certain distance along with the movable electrode mounting arm, and level the fixed-length stopper so that it contacts the movable electrode.

[0051] 2. Insert the tungsten electrode into the fixed electrode and determine the length of the short side of the bend by the fixed-length stopper.

[0052] 3. Release the fixed-length stopper to allow the movable electrode to contact the tungsten electrode.

[0053] 4. Start the butt welding machine and turn on the power for bending.

Claims

1. A tungsten electrode bending device for argon arc welding of nuclear fuel rods, characterized in that: The invention comprises a fixed electrode, a movable electrode, a fixed-length stopper and a resistance butt welding machine, wherein the fixed electrode, the movable electrode and the fixed-length stopper are installed on the resistance butt welding machine.

2. A tungsten electrode bending device for argon arc welding of nuclear fuel rods as claimed in claim 1, characterized in that: The resistance butt welding machine is composed of a welding transformer box, a base, a fixed electrode mounting seat and its accessory parts, a movable electrode mounting seat and its accessory parts, and a screw connector.

3. A tungsten electrode bending device for argon arc welding of nuclear fuel rods as claimed in claim 2, characterized in that: The resistance butt welding machine comprises a fixed electrode mounting seat, a top wheel, an adjusting bolt, a fixing plate, a movable electrode mounting seat, a nut, a welding transformer box, a current adjusting handle, a start welding button, a fixed electrode mounting arm, a movable electrode mounting arm, a substrate, a movable clamping jaw seat guide rail, a ball, a screw, a spring, a spring fixing end, a button mounting plate, a fixed electrode copper conductive belt, a movable electrode copper conductive belt, and a wire; the substrate is welded by two upper plates with step surfaces, a hollow cavity and a lower plate with a central opening, and the lower plate of the substrate is connected to the welding transformer box; the fixed electrode copper conductive belt of the fixed electrode mounting seat and the movable electrode copper conductive belt of the movable electrode mounting seat pass through the inside of the hollow cavity of the substrate; there is a mounting hole for the fixed electrode mounting seat on the upper plate surface of the substrate, and the fixed electrode seat is installed by screws; the lower part of the step surface of the upper plate of the substrate is used to install the movable clamping jaw seat guide rail, and the movable clamping jaw seat guide rail is fixed to the upper plate of the substrate by screws; the fixed electrode mounting seat is a cast aluminum cavity, and the fixed electrode mounting arm is welded on the upper part of the fixed electrode mounting seat.

4. A tungsten electrode bending device for argon arc welding of nuclear fuel rods as claimed in claim 3, characterized in that: The fixed electrode is installed on the fixed electrode installation arm.

5. A tungsten electrode bending device for argon arc welding of nuclear fuel rods as claimed in claim 3, characterized in that: The fixed electrode is made of beryllium cobalt copper with good electrical and thermal conductivity. Its installation edge is a right angle. The edge of the welding machine fixed electrode installation arm is used as the positioning reference. A tungsten electrode socket is processed inside it, and the tungsten electrode to be processed passes through the hole.

6. A tungsten electrode bending device for argon arc welding of nuclear fuel rods as claimed in claim 5, characterized in that: The fixed-length stopper is connected to the fixed electrode through a screw, and has an outer shape of a rectangular parallelepiped with a notch, wherein the notch is the tungsten electrode extension positioning surface.

7. A tungsten electrode bending device for argon arc welding of nuclear fuel rods as claimed in claim 6, characterized in that: The fixed-length stopper is made of beryllium cobalt copper.

8. A tungsten electrode bending device for argon arc welding of nuclear fuel rods as claimed in claim 3, characterized in that: The movable electrode mounting seat is a cast aluminum cavity, ball mounting grooves are provided at the lower parts of both sides of the movable electrode mounting seat, and movable electrode mounting arms are welded to the upper part of the movable electrode mounting seat.

9. A tungsten electrode bending device for argon arc welding of nuclear fuel rods as claimed in claim 8, characterized in that: On the movable electrode mounting arm of the movable electrode mounting seat.

10. A tungsten electrode bending method for argon arc welding of nuclear fuel rods, characterized in that: The steps include: Step 1: Before bending, adjust the top wheel through the handle so that the movable electrode is pushed away a certain distance along with the movable electrode mounting arm, and level the fixed-length stopper so that it contacts the movable electrode; Step 2: Insert the tungsten electrode through the oblique hole inside the fixed electrode, contact and position it with the blocking surface of the fixed-length stopper, and slightly push the movable electrode to make the fixed-length stopper fall; Step 3: Loosen and rotate the top wheel handle to move the movable electrode toward the fixed electrode until it contacts the tungsten electrode and applies pre-pressure to it; Step 4: Start the resistance welding machine. The current passes through the movable electrode, tungsten electrode, and fixed electrode in sequence, quickly softening the tungsten electrode but not yet reaching its melting point. The tungsten electrode deforms under the pressure of the movable electrode and bends around the corner point of the fixed electrode to the required angle.

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