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Weldability:
The machine is capable of welding a wide range of materials, Tin
sheets, Black and TFS sheets (after proper edge cleaning) with thickness
ranging from 0.2 to 0.4 mm and body diameters ranging from 52 to
300 mm and body height upto 450 mm depending on the lower arm size.
Intermediate Electrode:
Use of electrolytic copper wire as an intermediate electrode between
weld wheel and tin sheet, avoids deposition of molten tin on weld
wheels and ensures consistent, quality weld without frequent cleaning
of wheels.
Welding Arms:
Upper arm made out of high tensile brass is common for complete
range of can diameters and is actuated by a hydropneumatic-damping
cylinder to avoid initial impact on contact with lower weld wheel
and to maintain constant welding force. Lower arm is complete with
carriage guide rail, Z-bar, weld wheel etc. Three standard sizes
of lower arms are available. Any one size of arm will be provided
with machine, other sizes will be available at extra cost.
Weld whels & Z-bars:
Antifriction, mercury contact weld wheels made out of special copper
alloy & Z-bars made out of wear resistant material are available
in three standard sizes i.e. 52, 65 and 100 size suitable for respective
arms. These wears out parts are available as spares off the shelf.
Standard overlap provided on Z-bar is 4 mm.
Carriage:
Carriage assembly with built-in pneumatic clamping and limit switches
for low/high current initiation, auto cut off and frame contract
is mounted on antifriction bearings and can be adjusted for different
can lengths easily. Different sizes of carriages are available to
match each size of arm. Movement of carriage is actuated by automatic
fly-start system to maintain normal welding speed from the start.
Electronic Control:
High precision fully solid state welder control incorporating thyristors
permits uniform weld quality. Two-stage heat control unit controls
the intensity of weld current at the beginning of weld cycle at
desired low levels. Current control is through transformer taps
and potentiometers.
Operation and work cycle:
Once the welding parameters like current, pressure, speed, carriage
positioning, high /low heat and cut-off limit switch setting is
over, operator must feed a pre-rolled sheet into the carriage and
Z-bar, pushing it lightly against frame contact actuators.
On actuation of frame contact limit switches all further operations
take place automatically.
- Rolled body is clamped at the rear with pneumatic clamps.
- Upper welding roller comes down making contract with lower weld
wheel and welding pressure is developed between wheels by hydropneumatic
clamping cylinder and spring.
- Once the correct welding force is generated, the switch fitted
on cylinder actuates wire feed system.
- The carriage is pushed forward at the start of operation by
means of fly-start mechanism.
- Initially reduced current is applied for a pre-determined length
and thereafter-full welding current is provided. The weld initiation
with reduced current and change over to full current is done automatically
by welder control.
- At the end of weld, the current is cut-off, wire, feed system
stops and upper weld wheel goes up automatically.
- The job can be taken out after clamps are released and carriage
is pulled back by spring balancer making machine ready for next
cycle.
Provision is also made for foot switch initiation in place of frame
contact to initiate weld cycle.
Easy Maintenance:
Open side mounting of weld wheels, with easy accessibility to every
working part along with use of highly reliable, high quality parts
like solenoid valves, bearing, weld wheels, etc. reduce the need
and frequency of maintenance.
A class 'F' insulated welding transformer and other specially built
assemblies like drive unit, wire reservoir, control system allow
24 hour continuous operation of machine.
Service Facilities: (to be provided by customer)
Compresses Air:
Minimum pressure 5.6 Kg./cm sq.
Cooling Water:
10 LPM @ 3 kg/cm sq. pressure and 18 degrees C for welding arm cooling.
10 LPM @ 3 kg/cm sq. pressure and 30 degrees C for thyristor cooling
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