
PROGRAMMING
B–63534EN/02
19. HIGH SPEED CUTTING FUNCTIONS
521
From the effect of gravity and friction, torque for acceleration/deceleration
is different on each condition, such as acceleration, deceleration or plus move
(up), minus move (down).
The following example is for the vertical axis and gravity and friction torque
are assumed as follows.
Torque of gravity : 20 (Nm)
Torque of friction : 10 (Nm)
Because these value are different on each machine, it is necessary to observe
the output torque on the actual machine for deciding acceleration pattern
The conditions are the same as the previous example.
Motor speed at rapid traverse : 3000 (min
–1
)
Ball screw pitch : 16 (mm)
Inertia : The machine inertia is to be 2.0
times higher than that of the rotor.
Rotor inertia : 0.0099 (Kgm
2
)
Maximum torque : 100 (Nm) Speed: 0 to 2000 (min
–1
)
Torque at rapid traverse : 79 (Nm) Speed: 3000 (min
–1
)
Minimum torque : 58 (Nm) Speed: 4000 (min
–1
)
(1) In case of plus move (up) and acceleration
Because torque of Gravity and friction work against the output torque of
motor, the torque for acceleration/deceleration is as follows.
Maximum torque : 70(=100–20–10) (Nm)
Speed: 0 to 2000 (min
–1
)
Torque at rapid traverse : 49(=79–20–10) (Nm)
Speed: 3000 (min
–1
)
Minimum torque : 28(=58–20–10) (Nm)
Speed: 4000 (min
–1
)
0
20
40
60
80
0 1000 2000 3000 4000
Speed(min
–1
)
P0 P1
P5
Torque(Nm)
Fig.19.10(g) Torque for Acc/Dec in case of + move and acceleration
D Examples of setting if
the acceleration pattern
differs depending on
whether acceleration or
deceleration is in
progress and whether
the movement is in the
minus or plus direction