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Speciale Robotica e Sicurezza

PRECISION FLUID

CONTROLS

The control of the cooling of the welding pliers
electrodes with the UQS 7

KUKA robots in Augsburg are known worldwide for does not fow into the production environment, and
robot systems. It has large manufacturing facility with food the foor with the inherent dangers this may cause,
a hundred stand alone systems in an assembly hanger. resulting in possible production shutdown.
For high volume vehicle manufacture the robots must The UQS7 recognizes an absence of the fow, that
complete their tasks in a short time for example 30 there is a mistake in the process and switches off the
seconds, to undertake 40 spot welds. coolant inlet within a second, preventing further coolant
It is therefore really no wonder that KUKA works escaping. The use of magnetic shut off valves enable
constantly on the systems to fnd “split seconds” and the short response time of the UQS7 to provide a short
to realise time saving. turn-off time.
One factor is, to ensure even closing of the ‘welding Secondly time saving: Through a special software-
pliers electrodes’ which must meet the point of weld solution the start of the robots accelerate. If 0.2% of the
Ultrasonic fow switches with given contact force. This is achieved by either coolant fow is reached, the UQS 7 signals the robot
range 0.04….10 l/min. pneumatic or now most commonly using servo- control “coolant is present” to set the robot in place to
electronic adjustment. reach the position in production. The UQS7 checks the
Another is the cooling of the welding pliers electrodes correct fow before the
and the ambient coolant periphery on the robots. reached position. If it
The coolant at the welding pliers electrodes and the frst is so, the robot begins
part of the “welding head” is absolutely necessary to with the spot welding
dissipate the thermal load of the high currents and of and if not, it would be
the welding. stopped. This method
The copper electrodes used wear during operation, of approach results in
and require to be changed regularly. If the heat doesn’t seconds being saved
dissipate, the wear would be higher, commented Mr. during the production
Dr. Jacob. Therefore to reduce the heat between 6 to cycle.
8 liters of coolant fows by the welding pliers electrodes In addition to the
per minute. UQS7, Barksdale
The UQS 7 is installed into the cooling system to provides a complete Ultrasonic fow switches
with fast response time and
provide measurement and control of the cooling service unit to the compact solution
fuid. The factors that convinced KUKA to install the cooling periphery of
UQS7 were the ultrasonic sensor range used allowed the robot system.
measurement of fow from 0.04 to 10 litres per In the service unit, Barksdale has integrated an
minute. Also the compact construction, fast accumulator which collects the water content of the
response time, remote monitoring of coolant piping system, when maintenance for the cooling
fow and the ability for customised programming system or replacement of the welding electrodes is
were positive arguments. required.
There are further possibilities to enhance and The accumulator is a special development of Barksdale
optimise the cooling circuit with the new UQS7 for which patent has been applied; this allows the
from Barksdale, these concern security, time collection of water, and avoids any air bubbles in the
saving and attendance. reflling process of the cooling periphery.
In the quest to save seconds and maintain security,
We like to begin with the security: It is possible Barksdale assists the machine manufacturer with his
that during the production the welding pliers fexible products and its ability to be a system deliverer.
electrodes may become dislodged and are The destination is the solution of the problems to the
hanging on a work piece or on a machine as it is advantage of the user.
coming to the welding station.
This is rare, and it is critical to ensure coolant www.precisionfuid.it

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