Heat treating
line, Izard Irwin
International Ltd. Wellsford,
New Zealand |
|
Izard Irwin is a manufacturer of precision
Tungsten tip saw blades, demand was up and despite
both the Wellsford and Rotorua plants working to full
capacity a new heat treating line had to be installed
to increase production. Saw blades used for
industrial purposes are heat treated by cycling
through molten sodium chloride baths. High
temperatures mean that cranes are used to transport
saw blades between baths. Izard Irwin had already
encountered problems with previous cranes, dropping
saw blades due to jerky motion. What was required was
smooth, precise and most importantly quick operation. PDL's
microdrive Elite was chosen to control both the
vertical and horizontal axis of the crane. By
utilising the Elite's flexible ramp rate minimal
disturbance is caused to the blades as they are
transported. By operating the vertical and horizontal
axis at the same time a sloping profile is maintained,
saving time and increasing productivity.
The
drives receive a 4-20mA speed signal from a PLC. By
scaling the analogue input into the drives the motors
controlling the crane can be run over-speed, again
increasing productivity. When the crane is approaching
its preset co-ordinates, the addition of position
feedback to the PLC, modulates the operation of the
drive in creep mode , and further accuracy is
attained. |
