Mitsubishi Electronics MR-J2S- CL Dynamic brake characteristics, Characteristics, 13

13. CHARACTERISTICS

13.3 Dynamic brake characteristics

Fig. 13.3 shows the pattern in which the servo motor comes to a stop when the dynamic brake is operated. Use Equation 13.2 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. 13.4)

Forced stop (EMG)	ON
	OFF

V0

Machine speed

te

Time constant

Time

					Fig. 13.3 Dynamic brake operation diagram
Lmax	V0	te	1	JL		(13.2)
	60				.......................................................................................................................
				JM
Lmax	: Maximum coasting distance					[mm][in]
V0	: Machine rapid feedrate					[mm/min][in/min]
J	: Servo motor inertial moment					[kg cm ][oz	in ]
M						2	2
	: Load inertia moment converted into equivalent value on servo motor shaft
J
L
	.................................................................................................................................					[kg cm2][oz in2]
	: Brake time constant						[s]
te	: Delay time of control section						[s]
	(There is internal relay delay time of about 30ms.)

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