Kubota KX101-3a, Workshop Manual

Page: 49 / 206

II - 38
WSM Minor Change II Service Engineering Section
4. Concrete behavior at the start-point setting
T
s
:standard knob angle to start S/P
T
a
:Machine A knob angle to start S/P before set-up.
T
b
:Machine B knob angle to start S/P before set-up.
Set-up target is to start attachment (thumb cylinder) at the constant same knob control angle, T
s
. As
shown in above Fig., machine A starts at T
a
, machine B at T
b
.
In order to get both machines start at T
s
, controller outputs the PWM current by adding the difference a
i
or by subtracting the difference b
i
to machine A and B respectively.
Start point set-up is to test the difference a
i
, b
i
and input their data to the controller. So that the control-
ler can calculate and output the required amount PWM current to start the attachment at the same
knob control angle T
s
.
Why set-up at engine Max. rpm?
For safety purpose, start-up point is earlier at engine Max. speed than at idle speed.
Pilot secondary pressure
Machine B
Standard
Machine A
Ps
θ
b
θ
s
θ
a
Knob control angle:
θ
PWM input
to the solenoid valve
(mA)
L,
full stroke R,
full stroke
difference a
i
l
l
difference b
i
]
Pilot Secondary pressure current