Mitsubishi Electronics MDS-D-SPJ3 ユーザーズマニュアル
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7 Selection
MITSUBISHI CNC
(a) Horizontal axis load torque
When operations [1] to [8] are for a horizontal axis, calculate so that the following torques are required in
each period.
Table 7-3 Load torques of horizontal axes
(b) Unbalance axis load torque
When operations [1] to [8] are for an unbalance axis, calculate so that the following torques are required in
each period. Note that the forward speed shall be an upward movement.
Table 7-4 Load torques of unbalance axes
Period
Load torque calculation method
Explanation
[1]
(Amount of acceleration torque) + (Kinetic friction torque)
Normally the acceleration/deceleration time con-
stant is calculated so that this torque is 80% of the
maximum torque of the motor.
stant is calculated so that this torque is 80% of the
maximum torque of the motor.
[2]
(Kinetic friction torque)
[3]
(Amount of deceleration torque) + (Kinetic friction torque)
The absolute value of the acceleration torque
amount is same as the one of the deceleration
torque amount. The signs for the amount of accel-
eration torque and amount of deceleration torque
are reversed.
amount is same as the one of the deceleration
torque amount. The signs for the amount of accel-
eration torque and amount of deceleration torque
are reversed.
[4]
(Static friction torque)
Calculate so that the static friction torque is always
required during a stop.
required during a stop.
[5]
- (Amount of acceleration torque) - (Kinetic friction torque)
The signs are reversed with period <1> when the
kinetic friction does not change according to move-
ment direction.
kinetic friction does not change according to move-
ment direction.
[6]
- (Kinetic friction torque)
The signs are reversed with period <2> when the
kinetic friction does not change according to move-
ment direction.
kinetic friction does not change according to move-
ment direction.
[7]
- (Amount of deceleration torque) - (Kinetic friction torque)
The signs are reversed with period <3> when the
kinetic friction does not change according to move-
ment direction.
kinetic friction does not change according to move-
ment direction.
[8]
- (Static friction torque)
Calculate so that the static friction torque is always
required during a stop.
required during a stop.
Period
Load torque calculation method
Explanation
[1]
(Amount of acceleration torque) + (Kinetic friction torque) +
(Unbalance torque)
(Unbalance torque)
Normally the acceleration/deceleration time con-
stant is calculated so that this torque is 80% of the
maximum torque of the motor.
stant is calculated so that this torque is 80% of the
maximum torque of the motor.
[2]
(Kinetic friction torque) + (Unbalance torque)
[3]
(Amount of deceleration torque) + (Kinetic friction torque) +
(Unbalance torque)
(Unbalance torque)
The absolute value of the acceleration torque
amount is same as the one of the deceleration
torque amount. The signs for the amount of acceler-
ation torque and amount of deceleration torque are
reversed.
amount is same as the one of the deceleration
torque amount. The signs for the amount of acceler-
ation torque and amount of deceleration torque are
reversed.
[4]
(Static friction torque) + (Unbalance torque)
The holding torque during a stop becomes fairly
large. (Upward stop)
large. (Upward stop)
[5]
- (Amount of acceleration torque) - (Kinetic friction torque)
+ (Unbalance torque)
+ (Unbalance torque)
[6]
- (Kinetic friction torque) + (Unbalance torque)
The generated torque may be in the reverse of the
movement direction, depending on the size of the
unbalance torque.
movement direction, depending on the size of the
unbalance torque.
[7]
- (Amount of deceleration torque) - (Kinetic friction torque)
+ (Unbalance torque)
+ (Unbalance torque)
[8]
- (Static friction torque) + (Unbalance torque)
The holding torque becomes smaller than the up-
ward stop. (Downward stop)
ward stop. (Downward stop)
During a stop, the static friction torque may constantly be applied. The static friction torque and
unbalance torque may be applied during an unbalance axis upward stop, and the torque during a stop
may become extremely large. Therefore, caution is advised.
POINT