Mitsubishi Electric Melservo MR-J3- 350B4, Инструкция по эксплуатации

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13. SERVO AMPLIFIERS WITH A LARGE CAPACITY (30k TO 55kW)
13.8.3 Dynamic brake characteristics
Fig. 13.2 shows the pattern in which the servo motor comes to a stop when the dynamic brake is operated. Use
Equation 13.1 to calculate an approximate coasting distance to a stop. The dynamic brake time constant
varies with the servo motor and machine operation speeds. (Refer to Fig. 13.3. Please contact us for the servo
motor not indicated.)
t
e
Forced stop (EM1)
Machine speed
Time constant
Time
OFF
ON
V
0
Fig 13.2 Dynamic Brake Operation Diagram
L
max
=
⎭
⎬
⎫
⎩
⎨
⎧
⎟
⎠
⎞
⎜
⎝
⎛
+ + ⋅
M
L
e
J
J
1 t
60
Vo
τ
··················································································································· (13.1)
L
max
: Maximum coasting distance ·········································································································· [mm]
V
0
: Machine rapid feed rate ······························································································ [mm/min][in/min]
J
M
: Servo motor inertial moment ······················································································ [kg cm
2
][oz in
2
]
J
L
: Load inertia moment converted into equivalent value on servo motor shaft ·············· [kg cm
2
][oz in
2
]
: Brake time constant ·························································································································· [s]
t
e
: Delay time of control section ············································································································ [s]
For 7kW or less servo, there is internal relay delay time of about 30ms. For 11k to 22kW servo, there
is delay time of about 100ms caused by a delay of the external relay and a delay of the magnetic
contactor built in the external dynamic brake.
40
35
30
25
20
15
10
5
0
200 600 1000
0
1200
Speed [r/min]
HA-LP30K1
HA-LP37K1
400 800
T
im
e c
on
sta
nt
[m
s]
40
35
30
25
20
15
10
5
0
200 600 1000
0
1200
Speed [r/min]
400 800
T
im
e c
on
sta
nt
[m
s]
HA-LP30K14
HA-LP37K14
HA-LP25K14
HA-LP1000r/min series