Dynamic Brake Characteristics - Mitsubishi Electric MELSERVO-J2-Super Series Instruction Manual

14. CHARACTERISTICS

14.3 Dynamic brake characteristics

Fig. 14.3 shows the pattern in which the servo motor comes to a stop when the dynamic brake is operated.
Use Equation 14.2 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. 14.4)
Forced stop (EMG)
J
V
0
L
t
1
e
max
60
J
L : Maximum coasting distance .................................................................................................[mm][in]
max
V : Machine rapid feedrate ......................................................................................... [mm/min][in/min]
0
J : Servo motor inertial moment................................................................................. [kg cm
M
J : Load inertia moment converted into equivalent value on servo motor shaft..... [kg cm
L
: Brake time constant ........................................................................................................................ [s]
t : Delay time of control section........................................................................................................... [s]
e
(There is internal relay delay time of about 30ms.)
ON
OFF
V
Machine speed
Fig. 14.3 Dynamic brake operation diagram
L
....................................................................................................................... (14.2)
M
0
t
e
14 - 4
Time constant
Time
][oz in ]
2 2
][oz in ]
2 2