JP2022000308A - TIG welding torch with constriction nozzle for spot welding - Google Patents

Abstract

To make it possible to set a position of a tungsten electrode rod at a prescribed position without requirement for a setting gauge and to set an arc length.SOLUTION: A TIG welding device comprises: a torch body 2; an electrode collet 4 which holds a tungsten electrode rod 3 connected to a cathode; a constriction nozzle 5 which concentrically supports the tungsten electrode rod 3, and has a gas passageway for ejecting a shield gas G toward a tip of the tungsten electrode rod 3; a conductive cylindrical earth connection metal fitting 7 which is connected to an anode; and a conductive cylindrical nozzle 8 for electrode which is so screwed to an outer peripheral surface of the earth connection metal fitting 7 as to be adjustably moved in an axial direction of the tungsten electrode rod 3, and surrounds the tip of the tungsten electrode rod 3 projecting from the constriction nozzle 5. In this welding device, a position, where the tip of the tungsten electrode rod 3 and an apical surface of the nozzle 8 for electrode are at the same position, is so made as to be a reference position of the nozzle 8 for electrode, and an arc length display part, which displays a movement amount of the nozzle 8 for electrode from the reference position and sets an arc length, is provided.SELECTED DRAWING: Figure 2

Description

The present invention is used for spot welding (temporarily welding) a metal plate (base material) such as a stainless steel plate, a steel plate, a copper plate, and an aluminum plate, and is particularly provided with a non-consumable tank's ten electrode. The present invention relates to a TIG welding torch with a narrowing nozzle for spot welding, which is an improvement of the TIG welding torch.

Generally, spot welding (temporary welding) is used when two metal plates are temporarily attached or when a very high bonding strength is not required at the joint of the metal plates, and spot welding (temporary attachment) is used. As the shape of the joint when performing welding), a lap joint, a butt joint, a square joint, an edge joint, a T joint and the like are used.

Conventionally, resistance welding has been widely used for spot welding in which two metal plates are overlapped. That is, in resistance welding, a portion where two metal plates are welded is sandwiched between electrodes, an appropriate pressing force is applied to the electrodes to pass an electric current, and the welded portion is melt-bonded by Joule heat.

However, the above-mentioned resistance welding is not suitable for spot welding (temporary welding) of a metal plate such as a copper plate or an aluminum plate having low electric resistance, and is not suitable for spot welding of a metal plate such as a copper plate or an aluminum plate. Laser welding using laser light from a laser head), plasma welding using a plasma welding torch (see, for example, Patent Document 1), TIG welding using a TIG welding torch (see, for example, Patent Documents 2 and 3). Is used.

However, when spot welding of a metal plate such as a copper plate or an aluminum plate having low electric resistance is performed by laser welding, plasma welding, or TIG welding, there are the following problems.

That is, the two metal plates to be spot welded must be consolidated by pressure. This is because if a gap is created between the two metal plates, the arc heat will not be transferred to both metal plates, resulting in incomplete bonding, and in the worst case, only the upper metal plate will melt and the two metal plates will melt. It may not be possible to join metal plates. Therefore, a presser jig for pressurizing and adhering the two metal plates is required, which deteriorates workability.

Further, it is necessary to keep the height (or position) of the laser beam emitting unit, the plasma welding torch or the TIG welding torch constant with respect to the metal plate to be spot welded. This is because if the height (or position) of the emission unit, the plasma welding torch or the TIG welding torch varies, the heat input density will not be constant and unstable penetration will occur. Therefore, a jig for keeping the height (or position) of the laser beam emitting unit, the plasma welding torch or the TIG welding torch constant with respect to the metal plate is required, and the workability is deteriorated.

Furthermore, when two metal plates are temporarily attached by spot welding in TIG welding using a TIG welding torch, butt joints, square joints, edge joints, T joints, lap joints, etc. are used as the shape of the joints. However, in order to perform good spot welding, it is necessary to pay attention to the following points.
(1) Set the aiming position so that the arc is surely transferred to the spot welded part.
(2) Keep the distance between the tungsten electrode rod and the metal plate constant so that the arc length is constant.
(3) Prevent a short circuit between the tungsten electrode rod and the metal plate.

However, in TIG welding using a TIG welding torch, the experience of the operator is required and the skill is required to determine the target position of spot welding, keep the arc length constant, and prevent short circuits. Since there are individual differences, there is a problem that good spot welding cannot be performed unless an expert is used.

Further, when the tungsten electrode rod and the metal plate are short-circuited, the tip of the tungsten electrode rod is consumed and the tungsten electrode rod must be polished, which causes a problem that workability is extremely deteriorated.

On the other hand, as TIG welding torch that solves the above-mentioned problems, the TIG welding torch with a narrowing nozzle for spot welding (international application number: PCT / JP2019 / 050305) developed by the present inventor and non-consumable developed by other companies are used. An arc spot welding torch equipped with a Tungsten electrode rod of the formula (see, for example, Patent Document 4 (FIG. 3)) is known.

That is, although the TIG welding torch with a narrowing nozzle and the torch for arc spot welding are not shown, a conductive tubular electrode nozzle and a conductive tubular support member are attached to the tip of the torch. It is attached so as to surround the tip of the tungsten electrode rod, and the target position of spot welding is easily determined by pressing the conductive electrode nozzle and support member against the welding point of the metal plate (base material) to make contact. It is possible to keep the arc length constant as well as to be able to do it.

Jitsukaisho 61-182677 Japanese Patent No. 5602974 Japanese Patent No. 5887445 Japanese Unexamined Patent Publication No. 2014-100734

However, the above-mentioned TIG welding torch with a narrowing nozzle and the arc spot welding torch still have problems to be solved.

That is, in the TIG welding torch with a narrowing nozzle and the torch for arc spot welding, it is necessary to change the arc length depending on the magnitude of the welding current. In this case, the tip of the tungsten electrode rod is conductive using a setting gauge. It is necessary to adjust the position of the tungsten electrode rod so as to be in a predetermined position from the tip of the electrode nozzle or the support member, and it is extremely troublesome to set the position of the tungsten electrode rod in the predetermined position.

Further, there is a problem that a setting gauge is required to set the position of the tungsten electrode rod at a predetermined position.

The present invention has been made in view of such problems, and an object thereof is that when the arc length is changed depending on the magnitude of the welding current, a setting gauge is not required and the position of the tungsten electrode rod is set to a predetermined position. It is an object of the present invention to provide a TIG welding torch with a narrowing nozzle for spot welding, which can be easily set and the arc length can be set with one touch.

In order to achieve the above object, the TIG welding torch with a constriction nozzle for spot welding according to the present invention is detachably attached to the torch body and the torch body to hold a tungsten electrode rod connected to the cathode, and at the same time. It is provided at the tip of the electrode collet and the electrode collet through which the shield gas passes, and supports the tungsten electrode rods concentrically to form a gas passage through which the shield gas flows between the electrode collet and the tungsten electrode rod. A narrowing nozzle that ejects shield gas toward the tip of the rod, a conductive tubular ground connection fitting that is provided at the tip of the torch body and is connected to the anode via a ground cable, and a ground connection fitting. It is screwed to the outer peripheral surface of the tungsten electrode rod so as to be movable and adjustable in the axial direction, and the tip portion is formed in a constricted shape and has conductivity surrounding the tip portion of the tungsten electrode rod protruding from the constriction nozzle. A tubular electrode nozzle is provided, and the pitch of the male screw formed on the outer peripheral surface of the ground connection fitting is the same as the pitch of the female screw formed on the inner peripheral surface of the electrode nozzle and screwed into the male screw. The outer peripheral surface of the ground connection fitting and the outer peripheral surface of the electrode nozzle are formed at a predetermined pitch and the position where the tip of the tungsten electrode rod and the tip surface of the electrode nozzle are at the same position as the reference position of the electrode nozzle. Is characterized by providing an arc length display unit for displaying the amount of movement of the electrode nozzle from the reference position and setting the arc length.

It is preferable to interpose an O-ring that provides a resistance to stop the rotation of the electrode nozzle between the outer peripheral surface of the ground connection fitting and the inner peripheral surface of the electrode nozzle.

The arc length display unit is provided on the outer peripheral surface of the ground connection fitting and has a scale indicating the amount of movement of the electrode nozzle from the reference position and is provided on the outer peripheral surface of the electrode nozzle to rotate the electrode nozzle from the reference position. It is preferable to have a reference mark indicating the scale when the scale is formed.

The electrode nozzle is divided into upper and lower parts, and has a conductive tubular nozzle body screwed onto the outer peripheral surface of the ground connection fitting so as to be movable and adjustable in the axial direction of the tungsten electrode rod, and the nozzle body. It is preferable that the tip portion is detachably provided and the tip portion is provided with a conductive tubular nozzle tip formed in a constricted shape.

It is preferable to form a V-shaped positioning groove formed on the tip surface of the nozzle tip along the radial direction of the nozzle tip and fitted to the corner portion of the square joint.

It is preferable to form an opposed positioning surface that contacts the corner of the T joint in a surface contact state on the outer peripheral surface of the tip of the nozzle tip.

It is preferable that the electrode nozzle is formed with a gas vent port for allowing the shield gas in the electrode nozzle to escape to the outside.

The TIG welding torch with a constriction nozzle for spot welding according to the present invention is configured so that the electrode nozzle in contact with the metal plate to be spot welded can be moved and adjusted in the axial direction of the tungsten electrode rod, and the amount of movement of the electrode nozzle can be adjusted. Since it is equipped with an arc length display such as a scale to display, when changing the arc length depending on the magnitude of the welding current, it is only necessary to rotate the electrode nozzle to see the arc length display, and no setting gauge is required. The position of the Tung electrode rod can be easily set to a predetermined position, and the arc length can be set with one touch.

It is a front view of the TIG welding torch with a constriction nozzle for spot welding which concerns on embodiment of this invention. It is also a vertical sectional front view of a TIG welding torch with a narrowing nozzle. It is also an enlarged vertical sectional front view of a main part of a TIG welding torch with a narrowing nozzle. FIG. 3 is a cross-sectional view taken along the line aa of FIG. It is an enlarged longitudinal front view of the electrode collet used for the TIG welding torch with a constriction nozzle. A narrowing nozzle used for a TIG welding torch with a narrowing nozzle is shown, (A) is an enlarged front view of the narrowing nozzle, (B) is an enlarged longitudinal front view of the narrowing nozzle, and (C) is an enlarged cross-sectional view of the narrowing nozzle. Another example of the electrode nozzle used for the TIG welding torch with a narrowing nozzle is shown, and is an enlarged vertical sectional view of the electrode nozzle used when the current is 80A to 200A (for medium current and large current). Another example of the electrode nozzle used for the TIG welding torch with a narrowing nozzle is shown, which is used when spot welding a square joint. (A) is an enlarged vertical sectional view of the electrode nozzle, and (B) is. It is an enlarged bottom view of the nozzle for an electrode. Another example of the electrode nozzle used for the TIG welding torch with a narrowing nozzle is shown, which is used when spot welding a T joint. (A) is an enlarged vertical sectional view of the electrode nozzle, and (B) is. An enlarged side view of the electrode nozzle and (C) is an enlarged bottom view of the electrode nozzle.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 6 show a TIG welding torch 1 with a narrowing nozzle for spot welding according to an embodiment of the present invention, and the TIG welding torch 1 with a narrowing nozzle has two sheets such as a stainless steel plate, a steel plate, a copper plate, and an aluminum plate. It is used for spot welding (temporary welding) of the metal plate W (hereinafter referred to as base metal W), and when the arc length is changed depending on the magnitude of the welding current, the arc length can be set with one touch. This is what I did. When the two base materials W are temporarily attached by spot welding (temporary welding), a butt joint, a square joint, an edge joint, a T joint, a lap joint, or the like is used as the shape of the joint.

The TIG welding torch 1 with a narrowing nozzle has a torch body 2 and an electrode collet 4 that is detachably attached to the torch body 2 and holds a tungsten electrode rod 3 connected to a cathode and allows a shield gas G to pass through. Provided at the tip of the electrode collet 4, the tungsten electrode rods 3 are concentrically supported to form a gas passage 5c through which the shield gas G flows between the tungsten electrode rods 3 and the gas passages 5c to the tungsten electrode rods 3. A narrowing nozzle 5 that ejects the shield gas G toward the tip of the torch body 2, and a conductive tubular ground connection fitting 7 that is provided at the tip of the torch body 2 and is connected to the anode via the ground cable 6. , The outer peripheral surface of the ground connection fitting 7 is screwed so as to be movable and adjustable in the axial direction of the tungsten electrode rod 3 (longitudinal direction of the tungsten electrode rod 3). A tubular electrode nozzle 8 having conductivity surrounding the tip of the tungsten electrode rod 3 protruding from 5 is provided, and the pitch of the male screws 7b formed on the outer peripheral surface of the ground connection fitting 7 and the electrode nozzle 8 are provided. The pitch of the female screw 8c formed on the inner peripheral surface of the ground connection fitting 7 and screwed into the male screw 7b of the ground connection fitting 7 is formed to the same predetermined pitch, and the tip of the tungsten electrode rod 3 and the tip surface of the electrode nozzle 8 are formed. Is the reference position of the electrode nozzle 8 at the same position, and the arc length display that displays the amount of movement of the electrode nozzle 8 from the reference position on the outer peripheral surface of the ground connection fitting 7 and the outer peripheral surface of the electrode nozzle 8. The unit 9 is provided, and the electrode nozzle 8 is rotated to set the arc length by the arc length display unit 9.

As shown in FIG. 2, the torch body 2 has a tubular lower torch body 2A made of synthetic resin (for example, MC nylon (registered trademark)) having a small diameter on the tip side (lower end side) and a tip. A tubular upper torch body 2B made of synthetic resin (for example, MC nylon (registered trademark)) in which a portion (lower end portion) is fitted to a recess formed on the upper end surface of the lower torch body 2A via an O-ring 10. A tubular cover body 11 made of synthetic resin (for example, polycarbonate) having excellent insulating properties is fitted on the outer peripheral surface of the upper torch body 2B.

As shown in FIGS. 2, 3 and 5, the electrode collet 4 is detachably inserted into the cylindrical lower torch body 2A, and a female screw 4a is attached to the inner peripheral surface of the base end portion (inner peripheral surface of the upper end portion). It is detachably inserted into the formed conductive brass (or copper) tubular nozzle fitting 4A and the cylindrical upper torch body 2B, and expands radially toward the tip (lower end). A collet chuck portion 4b having a small diameter that can be freely adjusted is formed, and a male screw 4c that is freely screwed into the female screw 4a of the nozzle fitting 4A in the axial direction is formed on the outer peripheral surface of the collet chuck portion 4b. A conductive brass (or copper) cylindrical connecting collet 4B is provided, and a shield gas G supplied from a gas hose 13 connected to the base end of the connecting collet 4B via a hose joint 12 is provided. It flows sequentially in the connection collet 4B and the nozzle fitting 4A.

The inner diameter of the connecting collet 4B of the electrode collet 4 and the inner diameter of the nozzle fitting 4A are formed to be larger than the outer diameter of the tungsten electrode rod 3, and the inner peripheral surface of the connecting collet 4B and the outer peripheral surface of the tungsten electrode rod 3 are formed. An annular passage through which the shield gas G flows is formed between the surface, the inner peripheral surface of the nozzle fitting 4A, and the outer peripheral surface of the tungsten electrode rod 3.

Further, a female screw 4d to which the narrowing nozzle 5 is detachably screwed is formed on the inner peripheral surface of the tip portion (inner peripheral surface of the lower end portion) of the nozzle mounting tool 4A, and the inner peripheral surface of the intermediate portion of the nozzle mounting tool 4A is formed. A first tapered surface 4e whose diameter is gradually reduced toward the tip end side of the nozzle mounting tool 4A is formed.

Further, as shown in FIG. 5, a plurality of split grooves 4f through which the shield gas G can flow are formed in the collet chuck portion 4b of the connecting collet 4B, and the split grooves 4f are formed at the base end portion of the collet chuck portion 4b. A through hole 4g is formed which communicates with each other to facilitate the reduction of the diameter of the collet chuck portion 4b.

Further, as shown in FIGS. 2, 3 and 5, a second tapered surface 4h that engages with the first tapered surface 4e of the nozzle fitting 4A is formed at the tip of the collet chuck portion 4b of the connecting collet 4B. There is. Therefore, when the collet chuck portion 4b of the connecting collet 4B is screwed into the nozzle mounting tool 4A, the second tapered surface 4h formed on the collet chuck portion 4b of the connecting collet 4B becomes the first tapered surface 4e of the nozzle mounting tool 4A. Engagement is performed, the collet chuck portion 4b of the connecting collet 4B is tightened in a direction of diameter reduction, and the tungsten electrode rod 3 inserted into the electrode collet 4 is sandwiched and fixed by the inner peripheral surface of the tip portion of the collet chuck portion 4b.

At this time, the groove width of the split groove 4f of the collet chuck portion 4b is set to such a dimension that a gap through which the shield gas G can flow is formed even if the collet chuck portion 4b is tightened to narrow the groove width. Therefore, the shield gas G that has passed through the split groove 4f of the collet chuck portion 4b passes through the annular passage formed between the inner peripheral surface of the nozzle fitting 4A and the outer peripheral surface of the tungsten electrode rod 3 and is narrowed to the nozzle 5. It will be possible to distribute to the inside. Further, since the through hole 4g communicating with the split groove 4f is formed at the base end portion of the collet chuck portion 4b, the collet chuck portion 4b can be easily and easily tightened in the direction of diameter reduction, and the collet chuck portion 4b Will firmly pinch and fix the tungsten electrode rod 3 with a small force.

An L-shaped torch cable bar 14 formed of a copper plate is attached to the upper end of the connection collet 4B of the electrode collet 4, and the torch cable bar 14 is torched via a cable set screw 15. The terminal 16a of the cable 16 is connected and fixed. The torch cable 16 is connected to a cathode terminal of a power supply control unit (not shown). Therefore, the tungsten electrode rod 3 inserted into the electrode collet 4 is connected to the cathode of the power supply control unit (not shown) via the electrode collet 4 and the torch cable bar 14.

The narrowing nozzle 5 is arranged on the outer periphery of the tip of the tungsten electrode rod 3 so that the tip of the tungsten electrode rod 3 protrudes and supports the tungsten electrode rod 3 concentrically, and gas is provided between the narrowing nozzle 5 and the tungsten electrode rod 3. The passage 5c is formed and the shield gas G is injected from the gas passage 5c around the tip of the tungsten electrode rod 3 at high speed.

That is, the narrowing nozzle 5 is formed in a tubular body by a metal member (for example, molybdenum or copper), and as shown in FIGS. 2 to 4 and 6, a tungsten electrode is formed around the tip of the tungsten electrode rod 3. A tubular narrowing nozzle body 5a arranged concentrically with the rod 3 and a protrusion formed on the inner peripheral surface of the narrowing nozzle body 5a at predetermined intervals in the circumferential direction, and the tungsten electrode rod 3 is formed on the narrowing nozzle body 5a. A shield gas formed between a plurality of positioning ridges 5b along the longitudinal direction of the squeezing nozzle body 5a held at the center position of the squeezing nozzle body 5a and extending parallel to the longitudinal direction of the squeezing nozzle body 5a. It is provided with a plurality of groove-shaped gas passages 5c through which G flows, and on the outer peripheral surface of the base end portion of the narrowing nozzle main body 5a (the upper end portion of the narrowing nozzle main body 5a shown in FIG. 3), the inside of the tip portion of the nozzle fitting 4A is provided. A male screw 5d that is detachably screwed to the female screw 4d formed on the peripheral surface is formed.

Further, as shown in FIG. 4, the positioning ridges 5b and the groove-shaped gas passages 5c are arranged on the inner peripheral surface of the narrowing nozzle main body 5a at equal angles in the circumferential direction, respectively, and the narrowing nozzle main body 5a. The shield gas G can be evenly flowed around the tip of the tungsten electrode rod 3 from the tip opening.

The ground connection fitting 7 is formed of conductive oxygen-free copper in a cylindrical shape having a flange portion 7a, and is fitted and fixed to the outer peripheral surface of the small diameter portion of the lower torch body 2A.

Further, the ground connection fitting 7 is provided with a terminal stopper 17 for connecting the terminal 6a of the ground cable 6 to the ground connection fitting 7. The terminal stopper 17 is composed of a machine screw screwed to the flange portion 7a of the ground connection fitting 7 via a washer 18. Further, the ground cable 6 is connected to the anode terminal of the power supply control unit (not shown). Although not shown, the terminal stopper 17 may be a terminal stopper composed of a headless screw screwed to the ground connection fitting 7 and a nut screwed into the headless screw.

Further, a male screw 7b to which the electrode nozzle 8 is detachably screwed is formed on the outer peripheral surface of the intermediate portion of the ground connection fitting 7, and between the male screw 7b and the flange portion 7a of the ground connection fitting 7. An O-ring 19 that provides a resistance to stop the rotation of the electrode nozzle 8 is fitted on the outer peripheral surface of the ground connection fitting 7.

The electrode nozzle 8 has a tip portion formed of a conductive metal material into a tubular shape having a constricted tip, and is divided into upper and lower parts so that the tip end side (lower end portion side) has a different shape. It can be replaced with a variety of joint shapes (butt joints, square joints, edge joints, T joints, lap joints, etc.).

That is, as shown in FIGS. 2 and 3, the electrode nozzle 8 is divided into upper and lower parts, and is screwed onto the outer peripheral surface of the ground connection fitting 7 so as to be movable in the axial direction of the brass electrode rod 3 for comparison. It is detachably attached to the tubular nozzle body 8A made of an inexpensive conductive material (for example, brass) and the tip (lower end) of the nozzle body 8A, with the tip (lower end) first. It includes a tubular nozzle tip 8B formed of a constricted and conductive material (eg, brass or oxygen-free copper).

Further, the nozzle body 8A and the nozzle tip 8B are a female screw 8a formed on the inner peripheral surface of the tip portion of the nozzle body 8A and a male screw formed on the outer peripheral surface of the base end portion of the nozzle tip 8B and screwed onto the female screw 8a. It is removable from the 8b, and the nozzle tip 8B can be replaced with a nozzle tip 8B having a different shape.

Further, the nozzle body 8A is formed to have a larger diameter than the nozzle tip 8B, and is detachably screwed on the inner peripheral surface of the base end portion of the nozzle body 8A with a male screw 7b formed on the outer peripheral surface of the ground connection fitting 7. A female screw 8c to be combined is formed. The pitch of the male screw 7b formed on the outer peripheral surface of the ground connection fitting 7 and the pitch of the female screw 8c formed on the inner peripheral surface of the base end portion of the nozzle body 8A are formed to be the same predetermined pitch. In the present embodiment, the pitch of the male screw 7b of the ground connection fitting 7 and the pitch of the female screw 8c of the nozzle body 8A screwed to the male screw 7b are set to 1.0 mm, and the electrode nozzle 8 is 1. When rotated, the electrode nozzle 8 moves 1.0 mm in the axial direction of the tungsten electrode rod 3.

Further, a plurality of shield gas G formed in the peripheral wall of the tip portion of the nozzle body 8A at predetermined intervals in the circumferential direction and allowing the shield gas G in the electrode nozzle 8 to escape to the outside together with the metal vapor generated from the molten pool. A hole-shaped gas vent 8d is formed. The number, shape, size, etc. of the hole-shaped gas vents 8d can allow the shield gas G in the electrode nozzle 8 to escape to the outside and prevent the shield gas G in the electrode nozzle 8 from turbulent flow. It is set so that the metal vapor generated from the molten pool in the electrode nozzle 8 can be discharged to the outside in a good and reliable manner. In the present embodiment, the nozzle body 8A is formed with four hole-shaped gas vents 8d at 90 degree intervals along the circumferential direction.

Further, the nozzle tip 8B is formed to have a smaller diameter than the nozzle body 8A, and the nozzle diameter (inner diameter of the tip opening of the nozzle tip 8B) is formed to a predetermined inner diameter depending on the magnitude of the welding current. For example, when the welding current is a small current (about 10A to 80A), the nozzle diameter is set to 0.7mm, 1.0mm or 2.0mm, and the welding current is a medium current to a large current (about 80A to 200A). ), The nozzle diameter is set to 3.0 mm, 4.0 mm or 5.0 mm.

The electrode nozzle 8 is arranged concentrically with the tip of the tungsten electrode rod 3 protruding from the tip of the narrowing nozzle 5 when attached to the outer peripheral surface of the ground connection fitting 7, and the tip of the narrowing nozzle 5 is formed. It surrounds the tip of the tungsten electrode rod 3 protruding from the surface.

Further, when the electrode nozzle 8 is attached to the outer peripheral surface of the ground connection fitting 7, an O-ring interposed between the outer peripheral surface of the ground connection fitting 7 and the inner peripheral surface of the nozzle body 8A of the electrode nozzle 8 is provided. A resistance is given to the electrode nozzle 8 by 19, so that the electrode nozzle 8 is prevented from inadvertently rotating and moving in the axial direction of the tungsten electrode rod 3.

Further, the electrode nozzle 8 has a position where the tip of the tungsten electrode rod 3 and the tip surface of the electrode nozzle 8 are at the same position as the reference position of the electrode nozzle 8, and the outer peripheral surface of the ground connection fitting 7 and the electrode are used. An arc length display unit 9 for displaying the amount of movement of the electrode nozzle 8 from the reference position is provided on the outer peripheral surface of the nozzle 8, and the arc length can be set by the arc length display unit 9 by rotating the electrode nozzle 8. It has become like.

The arc length display unit 9 is provided on the outer peripheral surface of the ground connection fitting 7, has a scale 9a indicating the amount of movement of the electrode nozzle 8 from the reference position, and is provided on the outer peripheral surface of the electrode nozzle 8 to indicate the electrode nozzle. A reference mark 9b that points to the scale 9a when the 8 is rotated is provided, and the scale 9a and the reference mark 9b can display the amount of movement of the electrode nozzle 8 from the reference position and set the arc length. It has become.

As shown in FIG. 1, the scale 9a is provided on the outer peripheral surface of the ground connection fitting 7 over the entire circumference, and a sheet or a sticker on which the scale 9a is printed is attached to the outer peripheral surface of the ground connection fitting 7. It is formed. In the present embodiment, the scale 9a is provided with ten thick wires and ten thin wires alternately to divide the outer peripheral surface of the ground connection fitting 7 into 20 equal parts. It means that the electrode rod 3 moves by 0.1 mm in the axial direction. The scale 9a may be formed directly on the outer peripheral surface of the ground connection fitting 7.

The reference mark 9b is formed by attaching a sheet or a sticker on which a triangular black mark is printed to the outer peripheral surface of the nozzle body 8A of the electrode nozzle 8. In the present embodiment, when the electrode nozzle 8 is at the reference position (the position where the tip of the tungsten electrode rod 3 and the tip surface of the electrode nozzle 8 are at the same position), the reference mark 9b is at the zero position of the scale 9a (the position where the tip surface is the same). It is set to point to the thick line that displays the position of zero). The reference mark 9b may be formed directly on the outer peripheral surface of the nozzle body 8A.

As shown in FIG. 1, a torch switch 20 is provided on the outer peripheral surface of the torch body 2 of the TIG welding torch with a narrowing nozzle, and the torch switch 20 is provided with a power supply control unit via a switch cable (not shown). It is connected to (not shown).

Further, the power supply control unit (not shown) supplies the shield gas G to the TIG welding torch 1 with a narrowing nozzle according to the operation of the torch switch 20, and applies a voltage for a predetermined time after the flow of the shield gas G stabilizes. It is controlled to generate an arc (arc plasma). Further, the current value and time for spot welding are determined by the material of the base metal W, the plate thickness, and the like.

Further, the nozzle diameter of the electrode nozzle 8 (inner diameter of the tip opening of the nozzle tip 8B) is determined according to the magnitude of the welding current, and by changing the welding current and the nozzle diameter of the electrode nozzle 8, the molten pool is formed. The size (outer diameter) of the nozzle can be adjusted.

FIG. 7 shows another example of the electrode nozzle 8 used in the TIG welding torch 1 with a narrowing nozzle, and the electrode nozzle 87 is used when the welding current is a medium current to a large current (about 80A to 200A). It is attached to the ground connection fitting 7 and is detachably attached to the nozzle body 8A formed in a tubular shape by a conductive material (for example, copper) and the tip portion of the nozzle body 8A, and the tip portion is first. It is provided with a tubular nozzle tip 8B formed of a constricted and conductive material (for example, chromium copper or oxygen-free copper), and only the nozzle tip 8B is replaced with a nozzle tip 8B having a different shape. It was done.

That is, as shown in FIG. 7, the nozzle tip 8B has an inner diameter of the tip opening larger than the inner diameter of the tip opening of the nozzle tip 8B shown in FIGS. 2 and 3, and has a shape and structure of other parts. Is formed in the same shape and structure as the nozzle tip 8B shown in FIGS. 2 and 3. In the present embodiment, the inner diameter of the tip opening of the nozzle tip 8B is set to 3.0 mm, 4.0 mm or 5.0 mm. The nozzle body 8A shown in FIG. 7 is the same as the nozzle body 8A shown in FIGS. 2 and 3, and the same parts / members are designated by the same reference numbers.

FIG. 8 shows still another example of the electrode nozzle 8 used in the TIG welding torch with a narrowing nozzle, and the electrode nozzle 8 is used for spot welding of a square joint and is attached to the ground connection fitting 7. The nozzle body 8A is formed in a tubular shape from a conductive material (for example, copper) and is detachably attached to the tip of the nozzle body 8A, and the tip is formed in a constricted shape to provide conductivity. It is provided with a tubular nozzle tip 8B made of a material (for example, chrome copper or oxygen-free copper), and only the nozzle tip 8B is replaced with a nozzle tip 8B having a different shape.

That is, as shown in FIG. 8, the nozzle tip 8B has a V-shaped positioning groove 8e fitted to the corner of the square joint formed on the tip surface of the nozzle tip 8B along the radial direction of the nozzle tip 8B. The shape and structure of the other parts are the same as those of the nozzle tip 8B shown in FIGS. 2 and 3. The nozzle body 8A shown in FIG. 8 is the same as the nozzle body 8A shown in FIGS. 2 and 3, and the same parts / members are designated by the same reference numbers.

FIG. 9 shows still another example of the electrode nozzle 8 used in the TIG welding torch with a narrowing nozzle, and the electrode nozzle 8 is used for spot welding at the corner of the T joint, and the ground connection fitting 7 is used. The nozzle body 8A, which is attached to the nozzle body and is formed in a tubular shape by a conductive material (for example, copper), is detachably attached to the tip of the nozzle body 8A, and the tip is formed in a constricted shape. It is provided with a tubular nozzle tip 8B made of a conductive material (for example, chrome copper or oxygen-free copper), and only the nozzle tip 8B is replaced with a nozzle tip 8B having a different shape.

That is, as shown in FIG. 9, the nozzle tip 8B has an opposed positioning surface 8f formed on the outer peripheral surface of the tip portion of the nozzle tip 8B so as to be in contact with the corner portion of the T joint in a surface contact state. The shape and structure of the portion is the same as that of the nozzle tip 8B shown in FIGS. 2 and 3. The nozzle body 8A shown in FIG. 9 is the same as the nozzle body 8A shown in FIGS. 2 and 3, and the same parts / members are designated by the same reference numbers.

Therefore, a case where two base materials W butted against each other by spot welding using the TIG welding torch with a narrowing nozzle shown in FIG. 1 will be described.

First, the distance (arc length) between the tip of the tungsten electrode rod 3 and the tip surface of the electrode nozzle 8 is set according to the magnitude of the welding current.

That is, the reference mark 9b of the arc length display unit 9 is set to the zero position of the scale 9a with the electrode nozzle 8 at the reference position (the position where the tip of the tungsten electrode rod 3 and the tip surface of the electrode nozzle 8 are at the same position). After aligning with (thick line indicating the position of zero), the electrode nozzle 8 is rotated according to the magnitude of the welding current, and the electrode nozzle 8 is moved in the axial direction of the tungsten electrode rod 3 to display the arc length. 9 sets the arc length (distance between the tip of the tungsten electrode rod 3 and the tip surface of the electrode nozzle 8) to a predetermined value (for example, 0.2 mm to 0.5 mm).

After the arc length is set to a predetermined value, the tip surface of the electrode nozzle 8 is brought into contact with the spot welded portion of the base metal W having two butted pieces in a surface contact state.

At this time, the welding conditions such as the welding current, the flow rate of the shield gas G, the type of the shield gas G, and the welding time are set to the optimum conditions according to the material of the base material W, the plate thickness, and the like. Further, the tungsten electrode rod 3 is used as a cathode, and the electrode nozzle 8 is used as an anode. Therefore, the position where the electrode nozzle 8 of the base material W comes into contact is grounded.

After the electrode nozzle 8 is brought into contact with the base material W, the torch switch 20 is pressed. Then, the shield gas G is supplied to the TIG welding torch 1 with a narrowing nozzle, and a voltage is applied between the tungsten electrode rod 3 and the base material W after the flow of the shield gas G is stabilized. Then, an arc (arc plasma) is generated between the tip of the tungsten electrode rod 3 and the base material W in the atmosphere of the shield gas G for a predetermined time. As a result, a part of the base metal W is melted, and spot welding is performed on the base metal W.

The shield gas G supplied from the gas hose 13 to the TIG welding torch with a narrowing nozzle flows down in the electrode collet 4 and flows into the gas passage 5c of the narrowing nozzle 5.

The shield gas G flowing into the gas passage 5c increases its speed to become a high-speed gas, and is ejected linearly around the arc from the tip opening of the narrowing nozzle 5.

The shield gas G ejected from the narrowing nozzle 5 flows around the tip of the tungsten electrode rod 3 and flows into the space inside the electrode nozzle 8, and then has a hole shape formed in the nozzle body 8A of the electrode nozzle 8. It is discharged to the outside from the degassing port 8d of.

In the TIG welding torch 1 with a narrowing nozzle described above, the electrode nozzle 8 can be moved and adjusted in the axial direction of the tungsten electrode rod 3, and the arc length display unit 9 such as a scale 9a that displays the movement amount of the electrode nozzle 8 is displayed. Therefore, when the arc length is changed depending on the magnitude of the welding current, it is only necessary to rotate the electrode nozzle 8 to see the arc length display unit 9, and the setting gauge becomes unnecessary and the tungsten electrode rod 3 is provided. The position of can be easily set to a predetermined position, and the arc length can be set with one touch.

Further, in the TIG welding torch 1 with a narrowing nozzle, the electrode nozzle 8 is divided into a tubular nozzle body 8A and a tubular nozzle tip 8B, and the nozzle tip 8B is detachably attached to and detachable from the nozzle body 8A. Therefore, only the nozzle tip 8B can be replaced with a different shape, and various joint shapes can be supported. For example, opposed positioning in which the nozzle tip 8B is in contact with the corners of the nozzle tip 8B and the T joint shown in FIG. 8 having a V-shaped positioning groove 8e in which the nozzle tip 8B is fitted to the corner of the square joint in a surface contact state. By replacing with the nozzle tip 8B shown in FIG. 9 having the surface 8f formed, spot welding of a square joint or a T joint can be performed reliably and easily.

Further, since the TIG welding torch 1 with a narrowing nozzle has the ground cable 6 connected to the ground connection fitting 7, even when the electrode nozzle 8 is replaced or only the nozzle tip 8B is replaced, the ground is grounded. The operation of connecting and disconnecting the cable 6 becomes unnecessary.

Further, in the TIG welding torch 1 with a narrowed nozzle, the nozzle body 8A and the nozzle tip 8B are made of another material having conductivity, for example, the nozzle body 8A is made of relatively inexpensive brass and the nozzle tip 8B is made of chrome copper. Since it is made of oxygen-free copper, the cost can be reduced as compared with the case where the entire electrode nozzle 8 is made of copper.

Further, since the TIG welding torch 1 with a narrowing nozzle uses the tungsten electrode rod 3 as a cathode and the electrode nozzle 8 as an anode, the tip of the electrode nozzle 8 having a narrowed tip is brought into contact with the base material W. Spot welding (temporary welding) can be performed in this state, and the target position of spot welding can be easily determined.

Further, in the TIG welding torch 1 with a narrowing nozzle, the distance between the tip of the tungsten electrode rod 3 and the tip of the electrode nozzle 8 is constant, so that the arc length can be kept constant.

Further, in the TIG welding torch 1 with a narrowing nozzle, since the tip of the tungsten electrode rod 3 is covered with the electrode nozzle 8, the short-circuit phenomenon between the tungsten electrode rod 3 and the base metal W can be eliminated, and the arc is performed during welding. And the shield gas G are not affected by the wind, and the arc light can be minimized to leak to the outside, so that the worker can directly see the intense light from the arc, and it can be applied to the eyes and skin. Welding work can be performed safely without being exposed to harmful ultraviolet rays or infrared rays. Moreover, since the shield gas G is flowing in the electrode nozzle 8, it is possible to prevent the tungsten electrode rod 3 from being oxidized by oxygen.

Further, since the TIG welding torch 1 with a narrowing nozzle is provided with a narrowing nozzle 5 that supports the tungsten electrode rods 3 concentrically and allows the shield gas G to flow around the tungsten electrode rods 3 at high speed, the tungsten electrode rods 3 are provided with a narrowing nozzles 5. The tungsten electrode rod 3 can be accurately and surely set in a predetermined position at the time of replacement.

Further, since the TIG welding torch 1 with a narrowing nozzle forms a hole-shaped gas vent 8d in the electrode nozzle 8 to allow the shield gas G in the electrode nozzle 8 to escape to the outside, the inside of the electrode nozzle 8 is formed. The gas turbulence can be prevented, and the metal vapor generated from the molten pool can be discharged to the outside together with the shield gas G from the slit-shaped groove-shaped gas vent 8d. As a result, the TIG welding torch 1 with a narrowing nozzle can prevent the metal vapor from reattaching / mixing with the molten metal, and can perform high-quality spot welding, and the metal vapor adheres to the tip of the tungsten electrode rod 3. This can be prevented and the life of the tungsten electrode rod 3 can be extended.

As described above, since the above-mentioned TIG welding torch 1 with a narrowing nozzle can exert the above-mentioned action and effect, even a beginner can easily and easily acquire the technique and is good spot welding (temporary welding). In addition to being able to improve workability, welding quality, and productivity can be improved.

In each of the above embodiments, the electrode nozzle 8 is divided into upper and lower parts to form a tubular nozzle body 8A and a tubular nozzle tip 8B, but in other embodiments, the electrode nozzle 8 is formed. The nozzle body 8A of 8 and the nozzle tip 8B may be integrally formed.

Further, in each of the above embodiments, a scale 9a indicating the amount of movement of the electrode nozzle 8 from the reference position is provided on the outer peripheral surface of the ground connection fitting 7, and the rotation of the electrode nozzle 8 is provided on the outer peripheral surface of the electrode nozzle 8. The reference mark 9b pointing to the scale 9a is provided when the scale 9a is formed, but in another embodiment, the scale 9a is provided on the outer peripheral surface of the electrode nozzle 8 and the reference mark 9b is provided on the outer peripheral surface of the ground connection fitting 7. May be.

1 is a TIG welding torch with a narrowing nozzle 2 is a torch body 3 is a tungsten electrode rod 4 is an electrode collet 5 is a narrowing nozzle 5c is a gas passage 7 is a ground connection fitting 7b is a male screw 8 is an electrode nozzle 8A is a nozzle body 8B is a nozzle Tip 8c is female screw 8d is gas vent 8e is positioning groove 8f is positioning surface 9 is arc length display 9a is scale 9b is reference mark 19 is O ring G is shield gas

Claims (7)

The torch body and the electrode collet that is detachably attached to and detachable from the torch body and is connected to the cathode, and the electrode collet that allows the shield gas to pass through, and the tungsten electrode rod that is provided at the tip of the electrode collet are concentric. A narrowing nozzle that ejects shield gas from the gas passage toward the tip of the tungsten electrode rod and a constriction nozzle that ejects the shield gas from the gas passage to the tip of the torch body while forming a gas passage through which the shield gas flows between the support and the tungsten electrode rod are provided at the tip of the torch body. A conductive tubular ground connection fitting that is connected to the anode via a ground cable, and an adjustable screw on the outer peripheral surface of the ground connection fitting that moves in the axial direction of the tungsten electrode rod, and the tip is first. A male screw formed on the outer peripheral surface of the ground connection fitting, which is formed in a constricted shape and is provided with a conductive tubular electrode nozzle that surrounds the tip of a tungsten electrode rod protruding from the constricted nozzle. The pitch and the pitch of the female screw formed on the inner peripheral surface of the electrode nozzle and screwed into the male screw are formed at the same predetermined pitch, and the tip of the tungsten electrode rod and the tip surface of the electrode nozzle are the same. The position to be the position is set as the reference position of the electrode nozzle, and the amount of movement of the electrode nozzle from the reference position is displayed on the outer peripheral surface of the ground connection fitting and the outer peripheral surface of the electrode nozzle to set the arc length. A TIG welding torch with a narrowing nozzle for spot welding, which is characterized by having an arc length display. The spot welding according to claim 1, wherein an O-ring that provides a resistance to stop the rotation of the electrode nozzle is interposed between the outer peripheral surface of the ground connection fitting and the inner peripheral surface of the electrode nozzle. TIG welding torch with narrowing nozzle. The arc length display unit is provided on the outer peripheral surface of the ground connection fitting and has a scale indicating the amount of movement of the electrode nozzle from the reference position, and is provided on the outer peripheral surface of the electrode nozzle to rotate the electrode nozzle from the reference position. The TIG welding torch with a narrowing nozzle for spot welding according to claim 1, wherein the TIG welding torch is provided with a reference mark indicating the scale when the scale is formed. The electrode nozzle is divided into upper and lower parts, and has a conductive tubular nozzle body screwed onto the outer peripheral surface of the ground connection fitting so as to be movable and adjustable in the axial direction of the tungsten electrode rod, and the nozzle body. The invention according to any one of claims 1 to 3, wherein the tip portion is detachably provided, and the tip portion is provided with a conductive tubular nozzle tip formed in a constricted shape. TIG welding torch with narrowing nozzle for spot welding. The spot according to claim 4, wherein a V-shaped positioning groove formed on the tip surface of the nozzle tip along the radial direction of the nozzle tip and fitted to the corner portion of the square joint is formed. TIG welding torch with constriction nozzle for welding. The TIG welding with a narrowing nozzle for spot welding according to claim 4, wherein an opposed positioning surface is formed on the outer peripheral surface of the tip of the nozzle tip so as to contact the corner of the T joint in a surface contact state. torch. The TIG welding torch with a narrowing nozzle for spot welding according to any one of claims 1 to 4, wherein the electrode nozzle is formed with a gas vent for releasing the shield gas in the electrode nozzle to the outside.

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