Mitsubishi Electric MELDAS MDS-B-SVJ2 Series, Технические характеристики и инструкция по эксплуатации

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Chapter 11 Selection
11-13
(2) For an unbalance axis
The regenerative energy differs in the upward stop and downward stop for an unbalance axis. A
constant regeneration state results during downward movement if the unbalance torque is the
same as or larger than the friction torque.
Regeneration energy
A regeneration state only occurs when deceleration torque (downward torque) is generated.
ERU = 5.24
×
10
−
5
·
η
· Tdu · N · td
−
Ec (J) ........................................................................... (11-8)
Upward stop
η
: Motor reverse efficiency
Tdu : Upward stop deceleration torque (N·m)
N : Motor speed (r/min)
td : Deceleration time (time constant) (msec)
Ec : Amplifier charging energy (J)
A regeneration state occurs even during constant rate feed when the upward torque Ts during dropping
is generated.
Calculated so that Ts = 0 when Ts is downward.
ERD =
2
π
·
η
· Ts · L
Δ
S
+ 5.24
×
10
−
5
·
η
· Tdd · N · td
−
Ec (J) ....................................... (11-9)
Downward stop
η
: Motor reverse efficiency
Ts : Upward torque during dropping (N·m)
L : Constant rate travel (mm)
Δ
S : Travel per motor rotation (mm)
Tdd : Downward stop deceleration torque (N·m)
N : Motor speed (r/min)
td : Deceleration time (time constant) (msec)
Ec : Amplifier charging energy (J)
One return is assumed to be one cycle, and the regeneration energy per cycle (ER) is obtained using
expression (11-10).
ER = ERU + ERD (J) .................................................... (11-10)
A return operation is executed for a time constant of 50msec for 200mm. The operation is executed at
F20000 in a machine tool vertical axis driven by an HC52 motor. The regenerative energy per return
operation is obtained at this time.
Note the following :
Travel per upward motor rotation : 10mm
Upward stop deceleration torque : 5N·m
Downward stop deceleration torque : 8N·m
Upward torque during downward movement : 0.5N·m
Using expression (11-8), the upward stop regeneration energy ERU is as follows :
ERU = 5.24
×
10
−
5
×
0.85
×
5
×
2000
×
50
−
11 = 11.3 (J)
The acceleration/deceleration distance required to accelerate at the 50msec acceleration/ deceleration
time constant to 20000mm/min. is as follows:
20000
×
50
2
×
60
×
1000
= 8.3 (mm)
Therefore, the constant speed travel is 183.4mm.
The downward stop regeneration energy ERD is obtained using the following expression (11-9).
ERD =
2
π ×
0.85
×
0.5
×
183.4
10
+ 5.24
×
10
−
5
×
0.85
×
8
×
2000
×
50
−
11 = 73.6 (J)
Thus, the regeneration energy per return operation ER is as follows :
ER = 11.3 + 73.6 = 84.9 (J)
(Example)