Welders.

By Admin | Tools
24 April 2016
Welders

Speed, efficiency and durability - these are the main advantages that allowed it to be widely distributed not only in industry but also in everyday life.

Arc is one of the leading places among the different types of fusion welding.It occurs due to arc between the electrode and the base metal, and is supported by DC or AC.Under the influence of applied energy at the edges of the metal parts to be welded is melted and mixed with the other edge of the liquid metal forming the weld puddle, which cools, crystallizes and forms the weld.As a result of the elementary particles of metal welded parts closer together so that between them they begin to act interatomic bonds, providing the mechanical strength of the connection.All operations on the ignition of the arc, keeping the length and displacement along the seam welder manually.Arc welding is performed as a consumable and non-consumable electrode in the forward or reverse polarity.

Since welding machine is needed for domestic use, it is recommended to lim
it the range of compact portable model that can be used in apartments, garages, or from those that the market offers.

for welding metals by means of an electric current created a number of instruments:
  • welding transformers;
  • inverters;
  • systems for arc welding;
  • Machines for the resistance spot welding;
  • welding rectifiers;
  • welding generators (welders);
  • welding machines.

However, they can be grouped into three main groups.

Welding generators

These are complex electromechanical devices, which are integrated on a common basis of an internal combustion engine with the necessary systems to ensure its operation and powerful generator with its electronic systems and control devices.The essence of his work is simple.The mechanical energy of the flywheel generator is converted to DC electric current to the indicators maintain a stable welding arc.Such welding generators called welding applications.If the functions of the engine performs a single-phase or three-phase electric motor, such a device is called a welding inverter.Subsequent stabilization, adjustment of a constant electric current and to supply it by wire to the metal parts of the heating occurs and the connection.

welders have a unique, peculiar only to them feature.Due to the fact that electricity produces the generator, this device can be used in places where electricity is not yet done.The main disadvantage of it - extremely cumbersome, heavy and difficult to maintain.Because of this demand for welding generators used in everyday life, low, and their use is very limited.

Welding transformers

This is the most simple, cheap and common units of all intended for manual arc welding.Appointment welding transformers - conversion of electrical current, its regulation and the power of the welding arc.A simplified circuit diagram is at them.At the core, the magnetic core made of a special transformer steel, placed two coils - primary and secondary.In the simplest devices both are fixed.In a more advanced one coil fixed statically, and the second moved relatively to the first along the core.It is this movement and adjustment of the current is carried out.

Welding machine VME140 Alternating current passing through the primary winding of the transformer, magnetises the core, creating in it the variable magnetic flux crossing the secondary winding turns, it induces an alternating current in the undervoltage.
believed that cell phones capable of providing the current more than 300 A - a professional transformers up to 300 A - semi.

are commercially available and welding machines made on the basis of the welding transformer.Their peculiarity is that metal welding electrodes is carried out not, as a special wire that comes automatically on the sleeve to the point of welding.On the same sleeve simultaneously with the wire supplied and carbon dioxide.Thus, the welding process itself is in a gaseous medium.The seam is obtained when the semi-automatic welding and even more protected from corrosion than other types of welding.In addition, with the help of such devices can be jewelry welding very thin metal.This is why semi providing weld metal in the carbonate environment and people called & lt; & gt ;, kislushkami have been applied in the repair of vehicles.

positive features of welding transformers - simple structure, and consequently, its reliability, ease of maintenance and low price.Negative with respect to the welding rectifier is considerable weight and larger dimensions.The most significant drawback of the welding transformer is that the welding is done with alternating current, which adversely affects the quality of the weld.Besides, there are difficulties in retaining the optimal arc during operation.This is most obvious for beginners without the necessary skills and experience.

Welding rectifiers are power supply consisting of a transformer with a control device and a block of semiconductor rectifiers.The principle of its operation is based on a constant diet of the arc current flowing through the secondary circuit and rectified unit selenium or silicon rectifiers.To obtain the desired characteristics of these devices are often equipped with additional ballast.The arc in these devices is very stable, do not interrupt.This allows you to produce high quality welds, even without any initial skills.

Another notable feature of the exhibit Welders DC.When staffing of the additional equipment they can weld cast iron and even non-ferrous metals.

very promising high frequency welding machines - inverters.The high-frequency component can significantly increase the efficiency of the power supply to reduce its size and weight.In addition, devices with higher frequencies provide good processing properties and a wide range of regulation.Doug have a very stable and smooth weld.
acquainted with the features of various types of welding machines, you can proceed to the selection of the desired unit.

proposed the following method of choosing the welding machine.First, you must answer the questions and then give preference to one or another model.

which network the device is connected?The choice begins with clarification site power: single-phase 220 V or three-phase 380 V. For home use device is more suitable to the single-phase 220-240 V. If the shop has a three-phase current, you can buy the device with unified power 220/380 V or three-phaseNetwork 380 W.

What metal will have to deal?If this iron or non-ferrous metals, electric welding need DC if the job is connected with the car or if the corrosion resistance of welds to increased requirements, it is necessary to select a semi-automatic welding.If the cook will have only a black metal, you can do the welding transformer.

Metal how thick to cook?From a given metal thickness depends welder power (different amperage), and consequently also its price.This question is an unambiguous answer can not be.The fact that the diameter of the electrode, as current, is selected, considering the thickness of the base metal, but not only.These parameters also depend on the position in which the welding is performed, and on the type of compound and form edges of other welding conditions.Pretty sure it can be found in the worksheets that are in the technical documentation of the device.But the approximate ratio of the thickness of the welded parts, electrode diameter, and values ​​of current can be taken from the table:

Metal thickness, mm Diameter, mm Current, A
1 - 2 16 25 - 50
2 - 3 2 40 - 80
2 - 3 2,5 60 - 100
3 - 4 3 80 - 160
4 - 6 4 120 - 200
6 - 8 5 180 - 250
10 - 24 5 - 6 220 - 320
30 - 60 6 - 8 300 - 400


Experienced welders necessary amperage (I) is determined experimentally on the stability of the arc.If no such skill, it can be calculated using formulas.For the most common diameters (D) of the electrodes (3-6 mm): I = (20 + 6D) D;electrode diameter less than 3 mm: I = 30 D. To weld seams ceiling current should be 10-20% less than at the lower position of the seam.The depth of penetration when welding with alternating current by 15-20% smaller than the welding current constant.

Furthermore, the welding current is also affected by its polarity.Thus, DC welding with reverse polarity, the cathode and anode are reversed, the penetration depth is increased to 40%.

expectancy What works?If you have to work long, is to acquire the welding machine with power reserves to not operate it for a long time at peak loads, or double-cooled or other features, allows you to perform the task.Thus, the apparatus can select the optimum digital parameters, but where the coils are made of copper.It will cost a bit more expensive than its counterpart with aluminum windings, but warm at the same loads would be weaker.

What weight unit is acceptable?If you plan to frequent movement of the welder, working at heights, better to stay at a small and light