Tadano TT-800XXL1, Service Manual

Page: 111 / 267

G-1 G-1
Telescoping System
2
WG02-026 1 E
2. Description of telescoping system
(Refer to the circuit diagram in Chapter Z.)
IWG02-0260E0 1
Sheave at the head of the telescoping cylinder
Adjuster and sheave on the head of the 2nd boom section
Sheave at the rear end of
the 3rd boom section.
Sheave at the rear end of
the 3rd boom section
Sheave at the rear end of
the top boom section.
Fix at the rear end of the top boom section.
4th boom section extension wire
Top boom section extension/
4th boom section retraction wire
Top boom section retraction wire
Fix at the rear end of the 4th boom section.
Fix at the rear end of the 2nd boom section.
Fold at the rear end the 3rd boom section.
Sheave at the head of the 4th boom section
Fix at the head of the 4th boom section.
Fix at the head of
the 2nd boom section.
2. 1 Extension circuit
Telescoping mode I
(The 2nd boom section extends first.)
1 . When the boom telescoping lever (linked to the
remote control valve) is operated to the extension
side, pilot pressure is led to the hydraulic pilot
control valve, shifting the telescoping control valve
to extension side and delivering the pressurized
oil from the hydraulic pump to the selector valve.
2. The pressurized oil is sent to the No. 1
telescoping cylinder, making the 2nd boom
section extend.
3. After the 2nd boom section is fully extended,
press the next section extension switch while
keeping the boom telescoping lever operated. The
hydraulic valve will be energized, the pressurized
oil will be sent to the No. 2 telescoping cylinder
and the 3rd boom section will extend.
4. In this case, you need not keep pressing the next
section extension switch when the No. 2
telescoping cylinder extends slightly because the
boom full retraction switch is shifted and the
solenoid self-holding circuit for the hydraulic valve
is established.
5. The 4th and top boom sections are extended by
the wire-rope mechanism linked to the No. 2
telescoping cylinder.
Telescoping mode II
(The 3rd through top boom sections extend first.)
1 . When the boom telescoping lever (linked to the
remote control valve) is operated to the extension
side, pilot pressure is led to the hydraulic pilot
control valve, shifting the telescoping control valve
to extension side and delivering the pressurized
oil from the hydraulic pump to the selector valve.
2. The pressurized oil is sent to the No. 2
telescoping cylinder, making the 3rd boom section
extend.
3. The 4th and top boom sections are extended by
the wire-rope mechanism linked to the No. 2
telescoping cylinder.