Semi-automatic arc welding
For arc welding with consumable electrode distinguish automatic and semiautomatic welding. The boundary between them is rather vague. Actually what has been achieved to date, usually does not go beyond the partial mechanization of the welding process, which includes two basic operations, starting electrode in an arc as it is melting and moving arc welding line. If both operations are mechanized, the process is considered automatic if it is only a supply of electrodes, the semi-automatic. Automatic welding is not always feasible and appropriate. It is beneficial to the mass and the mass production of products with a long enough straight and circular stitches. A huge number of welded products does not meet these requirements, and a large amount of work performed manual welding. For a long time, along with machine guns set up a simplified adaptation, in varying degrees, reduce the amount of manual work. In connection with this great development was semi-automatic welding hose. Automatic hose semiautomatic mechanism similar to conventional arc machines with electric drive, pushing the wire electrode from the Bay area in an arc through a flexible hose and holder for the tip. The length of flexible hose can be up to 5 m welder, holding the tip, manually move it along the seam.
Originally intended for hose semiautomatic welding arc open bare electrode wire diameter of 4-5 mm. The work was carried out at low welding currents. Because of significant wire diameter hose was heavy, not flexible enough, inconvenient to use. Small currents do not permit Lyali significantly improve welding productivity over manual welding, so the hose semiautomatic, although they were known, could not find application. creation of nearly a suitable hose semiautomatic facilitated the transition to a process for submerged arc welding electrode wire of small diameter not exceeding 2 - 2,5 mm. Application of flux allowed to increase the welding current, arc stability and improved dramatically increased the productivity of welding. With decreasing wire diameter decreased weight and increased hose flexibility. Apparatus for semiautomatic welding hose type PH-5, developed at the Institute of Electric them. Paton, is shown in the figure above. electrode wire diameter of 1.6-2 mm, including those twisted, located in a box or drawer 1, feed mechanism 2 is pushed through a flexible hose 3 to the holder 4, which is in the hand welder. The welding current is supplied to the holder through a flexible hose from the welding transformer 5 with choke. Includes equipment and electric measuring instruments installed in the hardware box 6. Feeding mechanism works on the principle of a constant feed rate of electrode wire. Submission is a three-phase AC induction motor current capacity of 0.1 kW through a worm, and two pairs of cylindrical gears. Wire feed speed change gears rearrangement within the 80-600 m / h Through a flexible hose welding current is supplied to the holder and the electrode wire is fed into the zone of the arc. to pass a special electrode wire inside the flexible hose is a flexible steel wire helix is separated from the current-carrying part of the hose sdoem isolation. On top of the spiral are flexible copper wires, which enters the welding current. In the two wires laid insulated conductors for control circuits. Live parts protected cotton braided and solid rubber insulation 6. The normal length of 3.5 m hose ends hose holder-tip. Mounted on a holder funnel-hopper for the flux and the button to activate the mechanism and semiautomatic welding current. The electrode wires, having a flexible hose goes to the tip and forwarded to the zone of the arc. welding current to the conductors of flexible hose goes into the holder and the friction of the metal mouthpiece end of the electrode wire is directed into the zone of the arc. Universal holder LH-5 to the semi-automatic hose (Fig.) consists of isolated from other parts of the curved tubular mouthpiece 1, the funnel for 2 flux with the flap handle 3 and 4, inside which are mounted start button and attach the hose to the holder. The support crutch 5 or fix a special nozzle and the workpiece rasstoyaniemezhdu mouthpiece and allow you to copy the configuration of the joint. There are a set of special holders for semiautomatic welding in confined spaces, obvarki pipes and flanges, etc. The flux for welding of manually filled into the funnel holder. semiautomatic welding is normally alternating current, but sometimes at a constant current, for example when working in the field, when welding thin metal, etc., is designed for semi-automatic wire diameter of 2 mm, and the current 200-650 and welding speed (movement of the arc along the seam) 15 40 m / h Can be used with 1.6 mm diameter wire at currents of 150-450 and the wire diameter and 1.2 mm at currents of 100-170 A. In spite of the relatively low welding currents, the hose MIG turns deep melting of base metal (up to 10 - 12 mm ), which provides the ability to weld metal is not only small but also large thicknesses. A considerable depth of melting due to high current density. hose semiautomatic are often more profitable automatic and manual welding. They are suitable for welding of metal with a thickness of 2-3 mm to the largest thicknesses encountered in practice, for all types of welding of butt joints - single or bilateral, with or without bevel edge bevel, fillet welds in lap joints and T-rail, as well as slash seams. Semi-automatic hose can be performed not only continuous, but interrupted sutures, and they are successfully applied in the factory and in field conditions outdoors, such as welding joints of pipelines, the construction of metal construction, skeletons of tall buildings, etc. The difference between automatic and semiautomatic hose is rather arbitrary. By installing stationary and moving the holder of semiautomatic underneath the product straight or rotating it, get an arc machine. There hose machines, wire them out of the hose is not supplied in the manual holder, and a compact samohodnuyu welding head, moving along the line of welding.
See also:
Automatic Arc Welding
Automatic ADS
Machines with a Constant Feed Rate of Electrode
Flux Equipment
Settings for Automatic Arc Welding
Automatic Submerged Arc Welding Introduction
Fluxes for Automatic Arc Welding
Processed Fluxes
Ceramic Fused Fluxes
Semi-Automatic Arc Welding
Arc Welding with Flux Cored Wire
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