Spot and projection welding machines-rocker arm-press type, Mechanical Engineering

Assignment Help:

Spot and projection welding machines

On the basis of the mechanical construction, resistance spot welding machines can be of four types viz. rocker arm, press, portable and multiple electrode machines. Usually projection welding machines are of press or multiple electrode type.

Rocker arm machines
: This is the simplest form of stationary machines. This machine consists of a frame that houses the transformer and tap switch vertically adjustable lower horizontal horn and an upper horn mounted in a rocker arm that is pivoted at the front top edge of the frame. This type of machine is available in the capacity range of 10 to 300 kVA (throat depths 300 mm to 1.2 m). For job shop work with short production runs, foot operated type rocker arm machines can be used. Air operated type rocker arm machines are used for short or medium production runs where minimum set up time is needed. Motor operated rocker arm machines will be suitable for long production runs.

Press type machines: They have an upper electrode and welding head that move vertically in a straight line. The capacity of these machines vary from 5 to 600 kVA (throat depths up to 1.2 m). Bench type models of this version are used for radio, instrumental, jewelry and dental work. They have throat depths of a few hundred millimeter and are rated below 5 kVA. Either manual, pneumatic or hydraulic controls can be used. Both spot and projection welding machines are available in this type.

Portable machines: They are otherwise called guns. The basic units of this type are:

  • Portable welding gun.
  • Electrical controls such as welding contactor and a sequence timer.
  • Welding transformer.
  • Secondary cables and hose needed to carry power between the transformer and the welding gun.

 

Welding force is applied by air or hydraulic cylinders. In these machines, secondary losses are high and so secondary voltage is two to four times the voltage of the transformers of the other type.

Multiple Electrode Machines: These are special purpose, custom built machines. These are economical in automobile industry. These are multiple transformer type machines. Each of these transformers will have two secondaries and two electrodes are connected to each secondary. This type is popular among projection welding machines.


Related Discussions:- Spot and projection welding machines-rocker arm-press type

Washing and drying a motorcycle, Washing and Drying a Motorcycle :  It is ...

Washing and Drying a Motorcycle :  It is important to wash and dry the motorcycle before servicing. It would ensure cleanliness during the service and would not allow any dust ent

Evaluate maximum shear stress, Evaluate maximum shear stress: Derive ...

Evaluate maximum shear stress: Derive equation subjected to combined bending and torsion for finding out maximum shear stress and its equivalent twisting moment.

Heat transfer situation, The aim of this project is for you to discover how...

The aim of this project is for you to discover how to use a spreadsheet to "model" a typical engineering problem, in this case a heat transfer situation. And to discover how this m

Friction, FRICTION: you have learnt laws of friction and problems invo...

FRICTION: you have learnt laws of friction and problems involving dry friction. The relative sliding motion of one body on another body is resisted by forces called as frictio

Simple bending or pure bending of beam, Q:   What is simple bending or pure...

Q:   What is simple bending or pure bending of beam?                                            Sol.: If portion of beam is subjected to the constant bending moment only and

Chemistry, Ask question #Minimum 100 whow to detect the presence of 2nd gro...

Ask question #Minimum 100 whow to detect the presence of 2nd group basic radicals ?ords accepted#

Plot velocity and pressure distributions reynolds numbers, The figure shows...

The figure shows a "square cavity flow". In this flow the cavity is filled with a fluid and the lid of the cavity moves with a constant velocity, while the other walls remain stati

Calculate the whole reaction at block, Calculate the whole reaction at bloc...

Calculate the whole reaction at block: A bar weighing 1 kg/m is bent at right angles into segments 0.60 m and 0.30 m long. It takes the position illustrated in Figure, while t

Main characteristics of couple - mechanics, Main characteristics of couple:...

Main characteristics of couple: Sol.: The main characteristics of couple 1. The algebraic sum of the forces, having the couple, is zero. 2. The algebraic sum of moment

MOTORSPORT VEHICLE CONSTRUCTION, MODIFICATIONS REQUIRE FOR A ROAD CAR TO EN...

MODIFICATIONS REQUIRE FOR A ROAD CAR TO ENTER A HILL CLIMB

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd