RU2564657C1 - Torch for arc gas-shield welding by consumable electrode - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to has-shield welding. Torch comprises casing with current conducting circuit for consumable electrode fitted axially therein and composed of wire, nozzle, casing cooling chamber, shield gas chamber with channels for its feed into channels and current-feed tip. Guide current conducting circuit consists of interconnected tubes of stainless steel, collet of brass with conical base with lengthwise cutout, contact inserts of steel 45 with HRC 40-49 and brass eccentric fitting coaxially screwed in said current-feed tip made of copper. Contact insert gas variable cross-section axial bore. Torch casing incorporates castle nut with orifices made in circle and composed of the chamber for shield gas splitting.

EFFECT: different sliding friction factors with positive potential of impedance, decreased wire springing, reliable current feed, rectilinear wire end spread without shift relative to weld axis.

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Description

The invention relates to techniques for the arc welding of circumferential welds with narrow cutting, namely, torches for arc welding with a consumable electrode in a protective gas environment with an increased welding speed.

Known a torch for arc welding by a consumable electrode in shielding gases, comprising a housing with a mouthpiece installed in it with a current-supplying tip and a nozzle with a replaceable sleeve fixed therein (A.S. SU No. 56120 A1. Torch for arc welding by a consumable electrode in protective gases " . - IPC: V23K 9/16).

The disadvantage of this torch for arc welding is that the holder mounted on the nozzle with internal longitudinal grooves in which the permanent magnets are installed creates structural complexity, increases the mass of the housing with the torch nozzle, and during operation creates inconvenience to service. When welding parts of different diameters with a consumable electrode having a diameter of 1.2 mm, a magnetic effect is created, as a result of which the welding arc deviates from the axis of the seam.

Known contact tip to the torches for electric arc welding, consisting of a body of the mouthpiece, in which there is a current-carrying element with a gap, where on its axis there is a channel for supplying a protective gas with a shape corresponding to two coaxial truncated cones with combined smaller bases and large directed in opposite directions bases (A.S. SU No. 967720 A2. “Contact tip to burners for electric arc welding” - IPC: V23K 9/16, V23K 9/12).

A disadvantage of a current-carrying tip made of copper, the sides of which are in contact with the mouthpiece and nozzle, coated with protective layers of mild steel with enamel, is a protective gas supply channel consisting of two truncated cones located in the center of the tip, and the wire is supplied through sinusoidal channels , which is the complexity of the design in manufacture.

Also known is a torch for arc welding in two concentric spiral shielding gas flows, containing a nozzle and a current-carrying tip located inside it with a nozzle fixed on it, as well as channels for supplying a protective gas, which are made in the form of screw screws located on the surface of the current-carrying mouthpiece and on the surface of the nozzle grooves with the same direction (AS SU No. 816717 A1. Torch for arc welding. - IPC: V23K 9/16).

The disadvantage of an arc welding torch is that in order to create the stability of the protective bell in the welding zone, the design of the current-supplying tip located in the nozzle has a complex configuration, which is laborious to manufacture. The gas flow rate and its volume, in the main stream between the spark plug and the nozzle, from the collector is regulated by means of a screw equipped with a conical throttle tail, which creates additional laboriousness in operation when welding parts into a ring groove.

Known a torch for arc welding by a consumable electrode in a shielding gas medium, comprising a housing, in the axial longitudinal opening of which there is a guide current supply path for the consumable electrode in the form of a wire, a nozzle, a chamber for cooling the housing, a chamber for protective gas with channels for its outflow into the nozzle and current-carrying tip (Welding in mechanical engineering. Handbook edited by Yu.N. Zorin. M., Mechanical Engineering, 1979, v. 4, p. 102-103, Fig. 13). This burner is taken as a prototype.

The disadvantage of the prototype is that the torch provides welding with a consumable electrode using wires with a diameter of 1.6-3 mm at currents up to 315 A using replaceable tips. When welding ring seams with figured cutting of a ring seam with a current-supplying tip for a wire with a diameter of 1.2 mm with spring-loaded properties when sliding into the guide current-supply path of the torch body for automatic welding in a protective gas environment by a water-cooled consumable electrode (GPA-315), it is not ensured alignment of the end of the consumable electrode and creates a deviation from the axis of the weld during welding, which degrades the stability of the arc with increasing spraying drops of the consumable electrode .

The purpose of the invention is to improve the quality of welds when welding with a consumable electrode by ensuring the reliability of electrical contact between the current-carrying elements, ensuring the straightness of the free exit of the electrode to the butt groove without displacement in the zone of effective laminar flow of the protective gas.

This goal is achieved by the fact that in a torch for arc welding with a consumable electrode in a shielding gas medium containing a body, in the axial longitudinal opening of which there is a guide current-supply path for the consumable electrode in the form of a wire, a nozzle, a chamber for cooling the body, a protective gas chamber with channels for its outflow into the nozzle and the current-carrying tip, the current-conducting path consists of stainless steel tubes paired with each other, brass collets with a conical base, in which A longitudinal slot was made for a contact insert made of steel 45 with a hardness of HRC 40 ÷ 49 and a boot made of cadmium copper coaxially screwed into a current-carrying tip made of copper, while the contact insert was made with an axial hole of variable cross section, and the burner body was equipped with a castellated nut with holes around a circle made in the form of a chamber for deturbation of the protective gas.

The invention is illustrated:

FIG. 1 is a longitudinal section diagram of a device;

FIG. 2 - castellated nut made of copper, section AA in FIG. one;

FIG. 3 - contact insert made of steel 45 with a hardness of HRC 40 ÷ 49;

FIG. 4 - guide current supply path, section BB in FIG. four.

The diagram of a longitudinal section of the device shows:

1. burner body made of copper with an axial longitudinal hole;

2. a chamber for cooling the burner body;

3. a chamber for protective gas with channels;

4. contact insert made of steel 45 with a hardness of HRC 40 ÷ 49;

5. brass collets with conical base;

6. stainless steel tube;

7. copper inlet nut with hole;

8. union nut made of steel;

9. insulating sleeve;

10. brass ring;

11. castellated nut made of copper with holes;

12. a current-carrying tip made of copper;

13. boot made of cadmium copper;

14. copper nozzle;

15. current supply from a copper plate;

16. rollers of the gear mechanism of the welding installation.

The torch for arc welding with a consumable electrode in a shielding gas medium contains a housing 1 made of copper, in the axial longitudinal opening of which there is a guide current supply path for the consumable electrode in the form of a wire, a chamber 2 for cooling the housing from heating during thermal cycling of welding, a chamber 3 for protective gas with channels for its outflow into the nozzle 14. The guide current-supply path consists of stainless steel tubes 6 connected to each other, brass collets 5 with a conical base, contact insert 4 from steel 45 with t erdostyu HRC 40 ÷ 49 and boot 13 of cadmium copper. Contact insert 4 made of steel 45 with a hardness of HRC 40 ÷ 49, pressed into the longitudinal hole of the burner body 1, contains an axial hole of variable cross section with bevel angles α for sliding the melting electrode in the form of a wire and α ₁ at the end face for mating with brass collets 5 with conical base. With respect to the brass collet hole 5, a longitudinal slot is made along the length of the cone with an angle β, in the upper part of the collet 5 there is a chamfer angle α ₂ with access to the inner hole of the stainless steel tube 6, the tube 6 is screwed onto the brass collet 5 and coaxially mounted relative to contact insert 4 of steel 45 with a hardness of HRC 40 ÷ 49 using the receiving nut 7 of copper with a hole. A steel union nut 8 mounted on an insulating sleeve 9 is pressed into the lower part of the burner body 1, and a brass ring 10 is pressed into the insulating sleeve 9. A castellated nut 11 of copper is screwed onto the thread of the lower part of the housing 1 with holes around the circumference, made in the form of a chamber for deturbation of the protective gas. The castellated nut 11 is fixed by a copper lead 12 in which a boot 13 of cadmium copper is screwed. The copper nozzle 14 is fixed on the burner housing 1 with a steel union nut 8, the edge at the base of the nozzle is rounded off according to the inner diameter. The current lead 15 of the copper plate on the housing 1 of the torch provides a supply of welding current. The rollers 16 of the gearbox of the welding machine are designed to feed the wire into the hole of the receiving nut 7 of copper.

The device operates as follows.

When you turn on the installation, the rollers 16 of the gear mechanism of the welding installation provide the supply of the melting electrode in the form of a wire with a given speed into the torch. The wire passes through the hole of the receiving nut 7 of copper with sliding and is pushed into the guide current-supply path. A directing current-conducting path installed in the axial longitudinal hole of the burner body 1 ensures the direction of the wire into the welding zone and consists of stainless steel tubes 6 connected to each other, brass collets 5 with a conical base, in which a longitudinal slot is made, of the contact insert 4 of steel 45 with hardness HRC 40 ÷ 49 and boot 13 made of cadmium copper.

To ensure cooling of the burner body 1, a chamber 2 and a nozzle 14 made of copper are made, and the nozzle 14 is fixed to the burner body 1 with a steel union nut 8 mounted on an insulating sleeve 9 into which a brass ring 10 is pressed. Shielding gas enters the chamber 3 with channels, which through the opening of the burner body 1 enters the cavity bounded by a castellated nut 11 of copper. The castellated nut 11 is made with holes around the circumference, which are necessary for the shielding gas to exit into the welding zone and create optimal conditions for the laminar flow of its flow, the stability of the bell in the volume of the nozzle 14 when flowing around the surface of a boot 13 of cadmium copper, coaxially screwed into the lead-in tip 12 of copper. When the rotation mechanism of the welded unit is turned on, with a welding speed, a welding current is generated, which is supplied through a current supply 15 from a copper plate on the burner body 1, passes through a current supply path to a boot 13 of cadmium copper with a wire installed in the hole into the welding zone. The contact insert 4 is made of steel 45 with a hardness of HRC 40 ÷ 49, pressed into the longitudinal hole of the burner body 1, has an axial hole of variable cross section with bevel angles α for sliding the wire and α ₁ at the end face for mating with brass collet 5 made of conical base, in which is made a longitudinal slot, and in the upper part of the collet 5 there is a chamfer with an angle α ₂ , with access to the inner hole of the tube 6 made of stainless steel.

The use of contact insert 4 of steel 45 with a hardness of HRC 40 ÷ 49 allows to reduce the abrasive breakdown of the hole of the boot 13 of cadmium copper, thereby increasing its service life, and also provides a constant current supply to the free take-off of the wire, its straightness and jet melting of the melting electrode at a constant welding speed with a “pinch effect”.

The internal chamfers of the guide current path allow you to guide and center the wire relative to the axis of the torch. When sliding the wire provides a temperature coefficient of friction of sliding relative to its elements, increasing the electrical resistivity, which reduces the springing and hardening of the wire, increasing the reliability of the electrical contact, as well as the stability of the current supply on the free reach of the wire.

When providing a laminar flow of protective gas in the weld zone, on a straight wire exit through the boot 13 of cadmium copper during the destruction of the jumper using the "pinch effect", a short welding arc with a diameter of "wire-drop" and a weld pool of a small volume of the weld, providing small-drop jet melting of the melting electrode, reducing spatter and creating a constant area of metal deposition with a constant gain of the weld.

The proposed torch for arc welding with a consumable electrode in a shielding gas environment allows automatic welding of both circular welds of different pipe diameters with cutting edges for welding with a cross section of 5 mm, and longitudinal welds of sheet materials made of structural steels and aluminum alloys.

Claims (1)

A torch for arc welding with a consumable electrode in a shielding gas medium, comprising a housing, in the axial longitudinal opening of which there is a guide current supply path for the consumable electrode in the form of a wire, a nozzle, a chamber for cooling the body, a protective gas chamber with channels for its outflow into the nozzle and the current supply a tip, characterized in that the guide current-carrying path consists of stainless steel tubes connected to each other, brass collets with a conical base, in which a longitudinal I cut a contact insert made of steel 45 with a hardness of HRC 40 ÷ 49 and a boot made of cadmium copper coaxially screwed into a current-carrying tip made of copper, while the contact insert is made with an axial hole of variable cross section, and the burner body is equipped with a castellated nut with holes a circle made in the form of a chamber for deturbation of the protective gas.

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