Chapter D
Chapter D
Adjustment mode
171
W301-0411E
3.5 Function of Slow Stop
3.5.1 Elevation Slow Stop
The elevation slow stop functions with the stop positions by load moment ratio 100% stop, backward stability
stop, working range limit stop, elevating cylinder stroke end stop, and boom interference stop adopted as the
target stop angle. However, when multiple conditions are met, the control is implemented for the one having the
smallest allowable angle in relation to the stop angle. Then, a comparison is made between the obtained limit
value and the proportional valve characteristics value, and the Ao output value is determined.
The outline of stop angle calculation is described below.
- Load moment ratio 100% stop
Calculated by the AML task. The stop lower limit angle shall be the elevation angle of load radius that the
current hoist medium load (P Hook + Sling) becomes as the rated load.
- Working range limit stop
Set by the range limit function. Depending on the item that is set, different slow stop will be set either to
the raising direction or lowering direction. The items of slow stop to the elevation raising direction are the
elevation angle upper limit and lifting height limit. The items of slow stop to the elevation lowering direction
are the elevation angle lower limit and load radius limit.
However, with the lifting height limit and load radius limit, the value is used with which the elevation angle
is calculated in relation to the set value.
- Stroke end stop (Elevating cylinder)
The elevation angle, at which the elevation cylinder set with the by-models data (#16719) becomes to the
stroke end status, shall be the stop upper limit angle and lower limit angle.
- Boom interference stop
The elevation angle, at which an interference occurs between the engine hood cover and elevation
cylinder when the elevation is continued to be lowered above the engine hood cover set with the
by-models data (#12792), shall be the stop lower limit angle.
3.5.2 Swing Slow Stop
The swing slow stop functions while adopting the stop positions by working range limit stop, shift to lower
capacity at outrigger (O/R) slide beam differential extension, and boom interference stop as the target stop angle.
However, when multiple conditions are met, the control is implemented for the one having the smallest allowable
angle between the target stop angle and current swing angle. Then, after obtaining the limit value in relation to
the allowable angle according to each machine status (accelerator, inertia, swing speed) that is set with
by-models data based on the allowable angle, the Ao output value is determined.
The outline of stop angle calculation is described below.
- Working range limit stop
The swing angle set by the right swing limit or left swing limit shall be the stop swing angle.
- Shift to lower capacity at O/R slide beam differential extension
When a shift is made to the lower capacity at O/R slide beam differential extension, the stop swing angle
shall be the swing angle at which the capacity changes when the current hoist medium load is larger than
the rated capacity of shifting target.
The rated capacity is calculated by the AML task, but a lot of calculation items to exist and to require time,
only one O/R patterns capacity is calculated per every loop.
- Boom interference stop
The stop swing angle shall be the swing angle at which an interference occurs between the engine hood
cover and elevation cylinder when the swing is performed with low elevation angle (lower than the
elevation lower limit stored in the data) that is set with the by-models data (#12792).
- Swing free
The stop angle judgment shall be the same as the slow stop processing described above. Based on the
valve opening data set with by-models data (#1785 to 1797), the Ao output is performed.
