Structure And Stability Of The Lift Truck - Komatsu AX20 Operation & Maintenance Manual

15. STRUCTURE AND STABILITY OF THE LIFT TRUCK

15. STRUCTURE AND STABILITY OF THE LIFT TRUCK
TO PREVENT LIFT TRUCK FROM TIPPING
To operate the lift truck safely, it is important to understand the structure and stability of the lift truck.
A forklift truck consists basically of the lifting mechanism (the forks and
mast) at the front and the lift truck itself (with tires) at the rear.
The front wheels of the lift truck act as the fulcrum, and the center of gravity
of the lift truck and center of gravity of the load are kept in balance.
The relationship between the position of the center of gravity of the lift truck
and the center of gravity of the load is extremely important for maintaining
the safety of the lift truck.
The loads carried by forklift trucks come in various shapes (and
weights) from boxes to planks and long objects. To judge the
stability of the lift truck, it is important to distinguish the position of
the center of gravity for loads of various shapes.
The stability of the lift truck is determined by the position of the
combined center of gravity resulting from the combination of the
centers of gravity of the lift truck and the load.
When the lift truck is carrying no load, the center of gravity remains
as it is, but when the lift truck is loaded, the combined center of
gravity becomes the combination of the centers of gravity of both the
lift truck and the load.
The position of the center of gravity of the load changes according to
whether the mast is tilted forward or back or whether the mast is
raised or lowered.
The position of the combined center of gravity of the lift truck is
governed by the following factors:
• Size, weight, shape of load
• Lifting height
• Tilting angle of mast
• Inflation pressure of tires
• Acceleration, deceleration, turning radius
• Condition of road surface, angle of road
• Type of attachments
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STRUCTURE OF LIFT TRUCK
CENTER OF GRAVITY OF LOAD
CENTER OF GRAVITY AND STABILITY