5
2022 and ERT9 series Pneudraulic Installation Tools (HK1021)
PUll STROKE
When tool is connected to the air supply, the air
pressure holds the throttle valve in the up (RETURn)
position; air pressure is directed to the top of the air
piston, keeping it down. When the trigger is pressed,
the throttle valve moves down to the PUll position,
and pressurized air is directed to the bottom of the
air piston, causing it to move upward. The air above
the air piston is exhausted and directed through the
center of the throttle valve and out the bottom of
the tool (
through the muffler
).
As the hydraulic piston rod moves upward, a column
of pressurized
fluid is forced into head, which
moves the pull piston rearward. The attached nose
assembly moves with the pull piston to start fastener
installation.
RETURn STROKE
When fastener installation is completed, the trigger
is released. Air pressure, with the assistance of a
spring, sends the throttle valve to the up (RETURn)
position. Pressurized air is re-directed to the top
of the air piston (see above), causing it and the
hydraulic piston rod to move downward.
The air from below the piston is exhausted through
the bottom of the tool. The piston and hydraulic
piston rod move downward, hydraulic pressure is
reversed, and the pull piston is returned forward.
Principle of Operation
