CN106378520A - High-current TIG welding gun capable of cooling cathodes - Google Patents

Abstract

The invention relates to argon tungsten arc welding torches, and discloses a high-current argon tungsten arc welding torch for cooling cathodes, which includes a central column and an outer cylinder whose lower end is connected to a gas cover, and the lower part of the central column is fixed with a tungsten electrode sleeve through a tungsten electrode sleeve. The top of the center column and the outer cylinder are fixedly connected to the tail cover, and the annular space between the center column and the outer tube forms an air passage connected to the air inlet hole on the tail cover; a center sleeve is welded outside the center column, and the gap between the center sleeve and the center column The annular space constitutes the return water cavity; the lower part of the return water cavity is connected to the hose, which passes through the air channel and communicates with the water inlet hole on the tail cover; the return water cavity is connected to the Tail cap exterior. In the invention, the cooling water is introduced into the welding torch, and the tungsten rod is strongly cooled, the current carrying capacity of the welding torch is greatly increased, and the area of the cathode area is greatly compressed, thereby increasing the penetration ability of the arc, making the welding torch have better penetration, and improving welding efficiency. Process stability, increased welding speed, significantly improved welding efficiency, and saved welding manufacturing costs.

Description

A high-current tungsten argon arc welding torch with cooled cathode

technical field

The invention relates to a tungsten argon arc welding torch, in particular to a TIG welding torch which improves the arc performance based on the cathode compression effect and effectively and directly water-cools the whole tungsten rod, which can improve the welding efficiency.

Background technique

Tungsten argon arc welding (TIG) is a high-quality welding process widely used in industrial production. However, since TIG welding uses a free arc as a heat source, the penetration depth is shallow, the welding speed is small, and the welding efficiency is very low. It is urgent to improve and optimize TIG welding.

Constraining the arc diameter improves arc performance. Restricting the arc diameter can increase the arc energy density and arc pressure, thereby significantly increasing the penetration depth, and finally greatly improving the welding efficiency. In order to achieve this goal, you can choose to compress the cathode. The principle is: the water-cooled tungsten electrode can take away the heat of the tungsten electrode, compress the high-temperature area, and thereby compress the electron emission area, that is, compress the cathode area, so that the root of the arc is concentrated on the tip of the tungsten electrode. The extremely small area; the current density increases, the magnetic compression effect of the arc itself is enhanced, and the size of the arc column can be compressed, thereby improving the thermal-mechanical characteristics of the arc.

Foreign researchers have applied the water-cooled compressed cathode theory to improve welding guns and arc characteristics. In 1997, CSIRO, an Australian research institution, invented the K-TIG welding method based on the water-cooled compressed cathode effect and a large welding current, and realized the perforation welding of 3-12mm thick titanium alloys, stainless steel and other low thermal conductivity materials. Due to the large welding penetration of this process, it can realize perforation welding or high-speed fusion welding for medium and thick plates, which greatly improves production efficiency. For the perforation welding of medium and thick plates, there is no need to open grooves, single-pass single-sided welding, double-sided forming; saving welding wire, greatly shortening the manufacturing time; reducing the heat-affected zone of the weld and the deformation of the workpiece. Subsequently, Dresden University of Technology in Germany, Date Gaoke Welding Co., Ltd. and Kjellberg Finsterwalde jointly carried out the design of the welding torch based on the cathode compression effect, and preliminarily studied the influence of the cathode compression effect on the arc shape; Perforation welding of low thermal conductivity materials is extended to high speed fusion welding of high thermal conductivity materials. Domestic research on K-TIG is less, Suzhou Huaweld Technology Co., Ltd. has initially studied K-TIG equipment, and carried out imitation research on welding torches. Taking the K-TIG welding torch as the research object, Zhang Ruihua of Lanzhou University of Technology established a three-dimensional finite element mathematical model of the arc according to the theory of magnetohydrodynamics. Temperature distribution, potential distribution, arc pressure and plasma velocity field distribution during current welding. The welding guns developed by the above teams are all based on the water-cooled compression cathode effect to compress the arc, which greatly improves the welding efficiency and reduces the production cost. The current carrying capacity of these two welding torches reaches 1000A, and the burning loss of the tungsten electrode is very small during the welding process; the water cooling method is to add a water-cooled copper sleeve outside the tungsten electrode, and indirectly water-cool the tungsten electrode. , there is still room for improvement in the water-cooled compression effect of the tungsten cathode area.

Contents of the invention

The present invention aims to solve the technical problem that the tungsten electrode part of the high-current welding torch is easily burned, and provides a high-current tungsten argon arc welding torch for cooling the cathode. The confinement effect of the arc increases the penetration ability of the arc, thereby welding thicker workpieces, further improving the welding stability, and expanding the process window of stable welding.

In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

A high-current tungsten argon arc welding torch for cooling the cathode, comprising a central column and an outer cylinder coaxially arranged outside the central column, a tungsten rod is fixed at the center of the lower part of the central column through a tungsten sleeve, and the lower end of the outer cylinder is connected with a Air cover; the top of the central column and the outer cylinder are fixedly connected to the tail cover, and the tail cover seals the air passage formed by the annular space between the central column and the outer cylinder from the top, and the air The channel communicates with the air intake hole that runs through the tail cover; a central sleeve is installed on the outside of the central column, and the upper and lower ends of the central sleeve are respectively welded and fixed to the central column, so that the The annular space between the central sleeve and the central column constitutes a return water cavity; the lower part of the return water cavity is respectively connected to two hoses through two through holes preset at the bottom of the central sleeve, and the two The hose passes through the air channel and communicates with the two water inlet holes passing through the tail cap respectively; The water outlet holes in the center column are connected, and the water outlet holes pass through the tail cap and lead to the outside of the tail cap.

Wherein, the tail cap, the center column, the center sleeve, and the tungsten pole sleeve are all made of copper.

The beneficial effects of the present invention are:

The high-current argon tungsten arc welding torch of the present invention improves the design of the torch, and the cooling water is introduced into the torch through double water inlet holes to directly and strongly cool the tungsten rod as a whole, which can more effectively take away the heat of the tungsten rod and greatly increase the welding torch. At the same time, it can greatly compress the area of the cathode area, compress the arc cathode area to the very small area of the tip of the tungsten rod, and achieve stronger compression of the arc column, thereby increasing the penetration ability of the arc and making the welding torch have better performance. Penetration, improve the stability of the welding process, increase the welding speed, significantly improve the welding efficiency, and save welding manufacturing costs.

Description of drawings

Fig. 1 is the first cross-sectional schematic view of the high current argon tungsten arc welding torch provided by the present invention;

Fig. 2 is a second cross-sectional schematic view of the high-current argon tungsten arc welding torch provided by the present invention.

In the figure: 1: the first water inlet; 2: the first welding point; 3: the tail cover; 4: the second welding point; 5: the center column; 6: the third welding point; 7: the center sleeve; 8: The first hose; 9: return water cavity; 10: outer sleeve; 11: air channel; 12: gas cover; 13: tungsten sleeve; 14: fourth welding point; 15: tungsten rod; 16: first Two hoses; 17: fifth welding point; 18: second water inlet hole; 19: water outlet hole; 20: sixth welding point; 21: seventh welding point; 22: air inlet hole.

detailed description

In order to further understand the content, characteristics and effects of the present invention, the following examples are given, and detailed descriptions are as follows in conjunction with the accompanying drawings:

As shown in Figures 1 and 2, this embodiment provides a high-current argon tungsten arc welding torch for cooling the cathode, which is mainly designed for a welding torch with a current carrying capacity of up to 1000A, including a tail cover 3 and a first water inlet hole 1. Second water inlet hole 18, air inlet hole 22, water outlet hole 19, outer sleeve 10, air cover 12, center column 5, center sleeve 7, return water cavity 9, air channel 11, first hose 8. The second hose 16, the tungsten pole cover 13, and the tungsten pole 15. Wherein, the tail cover 3, the central column 5, the central sleeve 7, and the tungsten pole sleeve 13 are all made of copper, and the tungsten pole 15 is made of tungsten.

Including the tail cap 3 arranged on the top of the welding torch. The tail cover 3 is equipped with a first water inlet 1 and a second water inlet 18 arranged symmetrically. The water pipe is formed, the water inlet pipe forming the first water inlet hole 1 is welded and fixed to the top of the tail cover 3 through the first welding point 2, and the water inlet pipe forming the second water inlet hole 18 is welded and fixed to the top of the tail cover 3 through the fifth welding point 17 . Air intake hole 22 is also equipped on the tail cover 3, and air intake hole 22 is formed by the air intake pipe that is installed in tail cover 3 vertically through, and the air intake pipe that forms air intake hole 22 is welded with tail cover 3 top by the 7th welding point 21 fixed.

The lower part of the tail cap 3 is provided with an external thread, and is threadedly connected with the outer sleeve 10 through the external thread. The lower part of the outer sleeve 10 is provided with an external thread, and is threadedly connected with the air cover 12 through the external thread. A central column 5 is coaxially arranged inside the outer sleeve 10, the bottom end of the central column 5 is flush with the gas cover 12, and the top end of the central column 5 extends to the outside through the tail cover 3, and passes through the sixth upper and lower welding points respectively. 20 and the second welding point 4 are welded to the top and bottom of the tail cap 3 respectively.

A central sleeve 7 is sheathed outside the central column 5 , the upper end of the central sleeve 7 is welded to the central column 5 through the third welding point 6 , and the lower end of the central sleeve 7 is welded to the central column 5 through the fourth welding point 14 . An annulus is provided between the central sleeve 7 and the central column 5 , and the annulus part forms a return water cavity 9 . The annular space between the central sleeve 7 and the outer sleeve 10 forms an air channel 11 , and the bottom end of the air inlet hole 22 communicates with the air channel 11 . A first hose 8 and a second hose 16 are arranged in the air passage 11, and the upper ends of the first hose 8 and the second hose 16 are respectively connected with the bottom ends of the first water inlet 1 and the second water inlet 18, The bottom ends of the first hose 8 and the second hose 16 are respectively connected to two preset through holes at the lower end of the central sleeve 7 , so as to communicate with the return water cavity 9 . The top of the center column 5 is provided with a water outlet hole 19, the lower end of the water outlet hole 19 communicates with the return water cavity 9 through two water guide holes, and the upper end of the water outlet hole 19 passes through the tail cover 3 to the outside of the tail cover 3.

The tungsten electrode sleeve 13 is set on the outside of the tungsten electrode rod 15, and is fixedly connected with the tungsten electrode rod 15 by compression to form an electrode head. The upper part of the tungsten pole sleeve 13 is provided with a certain length of external thread, through which the external thread is screwed into the interior of the central column 5 and fixedly connected with the central column 5 . During installation, the upper half of the tungsten pole sleeve 13 is divided into two lobes, and the tungsten pole 15 is clamped in the middle. The tungsten pole sleeve 13 is rotated into the inner wall thread of the central column 5. As the screwing depth increases, the two lobes of the tungsten pole sleeve 13 gradually Tighten up and clamp the tungsten rod 15.

When the welding torch of the present invention is in use, cooling water flows into the return water between the center sleeve 7 and the center column 5 through the first hose 8 and the second hose 16 from the first water inlet 1 and the second water inlet 18 respectively. The cavity 9 flows out from the water outlet hole 19 in the middle of the central column 5 after cooling the tungsten rod 15 as a whole. During the cooling process, the cooling water cools the parts that flow through it, especially the forced cooling of the tungsten rod 15 as a whole, so that the high-temperature area at the end of the tungsten rod 15 shrinks, that is, the cathode area is forcibly shrunk, the root of the arc is restrained, and the root of the arc is increased. The current density, the magnetic compression effect of the arc itself is enhanced, and the size of the arc column is compressed, thereby improving the thermal-mechanical characteristics of the arc. The welding torch can adjust the degree of cathode compression by changing the velocity of the water flow, so as to obtain arc columns with different degrees of compression, and can better adapt to welding of different materials. At the same time, the shielding gas enters the gas channel 11 formed between the outer sleeve 10 and the central sleeve 7 from the air inlet 22, and then enters the shielding gas cover 12 to protect the tungsten electrode, the arc and the molten pool.

Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative and not restrictive. Those of ordinary skill in the art Under the enlightenment of the present invention, without departing from the gist of the invention and the scope of protection of the claims, personnel can also make specific changes in many forms, and these all belong to the protection scope of the present invention.

Claims (2)

1. A high-current argon tungsten arc welding torch for cooling the cathode is characterized in that it comprises a central column and an outer cylinder coaxially arranged outside the central column, and the center of the lower part of the central column is fixed with a tungsten pole rod through a tungsten pole sleeve , the lower end of the outer cylinder is connected with an air cover; the center column and the top end of the outer cylinder are fixedly connected to the tail cap, and the tail cap seals the air formed by the annulus between the center column and the outer cylinder from the top. The air passage is closed, and the air passage communicates with the air intake hole that runs through the tail cover; a central sleeve is installed on the outside of the central column, and the upper and lower ends of the central sleeve are respectively welded and fixed to the center. column, so that the annular space between the central sleeve and the central column forms a return water cavity; the lower part of the return water cavity is respectively connected to two through holes preset at the bottom of the central sleeve. Two hoses, two hoses pass through the air channel and respectively communicate with the two water inlet holes passing through the tail cover; the upper part of the return water cavity passes through the The water guide hole communicates with the water outlet hole arranged in the central column, and the water outlet hole passes through the tail cap and leads to the outside of the tail cap. 2. The one according to claim 1, characterized in that, the tail cap, the central column, the central sleeve, and the tungsten pole sleeve are all made of copper.