SU1346372A1 - Arc welding torch - Google Patents

Description

If necessary, it can be easily replaced with a new one.

The tungsten insert 8 is mounted in the form of a cylinder having a working end in the form of a truncated cone. The non-working end of the insert 8, located in the cooling cavity 7, is made by FLAX. In one embodiment of the invention, the end of the insert 8 of the electrode 6, located in the cooling cavity 7, is made in the form of a cone, which is expedient when using inserts 8 of small diameters. The tungsten insert B is embedded inside the electrode 6 by an amount equal to 1.5-2 of its diameter. The insert (h) of a tungsten insert 8 made of copper electrode 6 is 1.1-1.5 times its diameter.

In the cooling cavity 7 of the copper electrode 6, a tube 9 is installed concentrically with it and in the immediate vicinity of the insert 8. gas housing 1.

The location of the non-working end of the tungsten insert in the cavity of the cooling electrode provides its direct cooling with a flowing fluid. This makes it possible to significantly increase the heat removal from the tungsten insert by eliminating the resistance to heat flow at the interface divided between the copper electrode and the tungsten insert.

Increasing the heat removal from the tungsten insert allows an increase in the allowable value of the welding current by 20-40% and, consequently, increase the performance of the torch as a whole. Direct cooling of the tungsten insert makes it possible to reduce the possibility of forming tungsten inclusions in the weld.

When a tungsten insert j smaller than 1.1 of its diameter is taken out, the arc begins to burn unstably when the polarity is changed due to the excessive cooling of the active end. When a Wolf-Frame insert is poured larger than 1.5 of its diameter, the temperature gradient along the length of the insert decreases, which reduces the permissible value of the welding current ,.

Heat removed from the insert by direct flushing

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five

D)

five

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five

Q

the non-working end with water and due to the heat sink through the side surface into copper, depends on the height of the tungsten insert buried inside the electrode. The smaller this height, the greater the temperature gradient along the length of the insert and the greater the share of heat removed from the working end of the insert due to the direct contact of the insert with the cooling gadfly. When increasing the depth of insertion-P: And in the copper electrode, the cooling efficiency of the working end decreases due to a decrease in temperature gradient along the length of the insert and also due to the fact that good contact of the copper electrode with the embedded part of the insert across its side surface a narrow annular zone of zach-cunk near the end of the electrode, having a height of about one millimeter),

In the ideal case, it is desirable “that this value approaches zero, but constructively such a solution is impossible.

Constructively, the magnitude of the penetration of a tungsten insert into a copper electrode should be at least 1p3 of the insert diameter, which is necessary for its reliable and tight fastening and reduction of electrical resistance in the contact between the electrode and the insert,

In order to adjust the free flow of the tungsten insert for the purpose of KOMneHi, its shortening due to the possible erosion of the working end can be increased to a value equal to two insert diameters. A further increase in burial leads to a decrease in cooling efficiency and durability of the tungsten insert.

Torch for spirit welding with non-floating electrode in a protective environment

gases works as follows.

one

In housing 1, channel 2 supplies

coolant, for example, water 5 which through cooled cavity D of housing 1 and tube 9 goes to the end of a tungsten insert B located in cavity 7 of copper electrode 6, and then through the gap between tube 9 and electrode 6j cavity 4 of housing 1 and channel 3 of housing is removed from the burner. Then through the channels of the housing 1 into the channels 12 between the nozzles 5 and the electrode 6, the protective gas is supplied. An iron is brought to the part to be welded, a current is switched on, an arc is excited and welding is performed.

Intensive cooling and restriction of the tungsten insert along the length provide a high temperature gradient along its axis, cause good cooling of the working end of the tungsten insert, prevent the formation of drops of liquid metal on it and. Falling them into the weld pool.

The maximum allowable value of the welding current for the proposed burner varies from 280 to 240 A with an increase in h from 3.3 to 4.5 mm (i.e. when the ratio of the magnitude of the burned out to the diameter of the tungsten insert h / dg from 1.1 to 1, five).

With a magnitude of 3.3 mm (h / dj 1f1), intensive cooling of the tungsten insert leads to supercooling of tungsten. In this case, the excitation and stability of the arc deteriorate, since the density of the thermionic emission current decreases as

the temperature of the tungsten cathode from 3500–4000 to a decrease from 1000 to 50 A / cm. With an arc diameter of 2 mm, the current in the arc decreases accordingly from 300 to 2 A, which is not enough to maintain the arc discharge. The dependence of the critical current on the magnitude of the electrode of the VI 30 type is outputted in a table.

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Compiled Editor L.Zaytseva Tehred M. Morgenthal

Order 1388

Circulation 895

VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5

Production and Publishing Combine Patent, Uzhgorod, st. Gagarin, 101

Proofreader L.Pilipenko Subscription

Claims (2)

The torch for arc welding with a non-consumable electrode in a shielding gas medium comprises a housing 1 having a channel 2 for supplying and a channel 3 for draining the coolant, a cooled cavity 4, communicating with the channels 2 by the inner surface of the nozzle and the outer surface of the electrode, characterized in that, in order to increase productivity by increasing the permissible value, welding current and improving the quality of welding by reducing the possibility of the formation of tungsten inclusions in the weld, the non-working end of the tungsten insert laid in the cooling cavity of the electrode, and the protrusion of the tungsten insert from the electrode is 1.1-1.5 of its diameter. 2. The burner according to claim 1, characterized in that the tungsten insert is buried inside the copper electrode by an amount equal to 1.5-2 diameters of the insert. and 3, and channels for supplying a _t- protective gas (not shown). A ceramic nozzle 5 is fixed on the housing 1, for example, by means of a thread. In the nozzle 5, concentric to it, a copper cylindrical electrode 6 with a cooling cavity 7 is installed. The electrode'6 is fixed in the housing 1 of the burner, for example, by means of a thread, while the cooling cavity 7 of the electrode 6 communicates with the cooled cavity 4 of the housing 1. The electrode 6 is made in the form of a cylindrical cup of copper, A tungsten insert 8 is installed on the working end of the electrode 6. To seal the cooling cavity 7 of the electrode 6, the tungsten insert 8 is minted (using a steel tubular embossing) into the copper electrode 6 around the circumference from the side of the working end of the electrode 6 and