Unic URW295CUR, Workshop Manual

Page: 73 / 155

Bolt
Tele2
Pipe for cord reel
Spool
Seletor valve ass’y
Check valve 2
１
４
－１
How oil flows when tele1 is extended
Pressure oil opens the check valve in the counter-balance valve to
enter the cylinder rod of t
ele1 and lows through the slide pipe to
reach the check valve 1 of selector valve ass’y.
The tele2 has been fully retracted at the time and the bolt opens the
check valve 1 of selector valve ass’y via spool which leads the pressure
oil to the extension side.
Simultaneously, oil in the retraction side of tele1 lows through the
dual cylinder in the rod to return to the tank.
This allows the tele1 to extend.
Since the check valve 2 of selector valve ass’y is closed at the time,
pressure oil will not lows in the tele2.
Also, oil in the retraction side of tele2 will not lows in the tele1 as
the tele2 has been fully retracted so that the tele2 will not be actuated.
And the tele3 also will not be actuated according to the same
reasons as in the tele2.
14-１
5-Section Boom (Triple Cylinder) Operation
(1) When Telescoping Cylinder1 extends
1 ４
. TELESCOPING CYLINDER
After the set-screw is tightened with LOCTITE #2701
applied hit with a punch at 2 places on the
circumference and leave it as it is for 1 hour.
Rod
Check
valve
Pressure Oil To Tank
Slide pipe
Piston
Apply"LOCTITE #638".
Check valve 1
Counter-balance
valve
Tele1
Tele2
Tele3
Counter-balance
valve
Courtesy of Machine.Market