8 Operation
8.4.3 Holding Brakes
8-12
8.4.3
Holding Brakes
A holding brake is a brake used to hold the position of the movable part of the machine when the SERVO-
PACK is turned OFF so that movable part does not move due to gravity or external forces. Holding brakes are
built into servomotors with brakes.
The holding brake is used in the following cases.
There is a delay in the braking operation. Set the following ON/OFF timing.
∗
1.
The operation delay time of the brake depends on the model. For details, refer to
Brake Operation Delay Time
shown
in the following page.
∗
2.
Allow a period of 50 ms or more after the brake signal (/BK) is turned ON until the speed reference is input.
∗
3.
Use Pn506, Pn507, and Pn508 to set the timing of when the brake will be activated and when the servomotor power
will be turned OFF.
Note: The above operation delay time is an example when the power supply is turned ON and OFF on the DC side.
The holding brake release time and holding brake operating time depend on the discharge circuit that is used.
Always confirm the operation delay time on the actual equipment before actual operation.
• The brake built into the servomotor with brakes is a de-energization brake, which is
used only to hold and cannot be used for braking. Use the holding brake only to hold
a stopped motor.
• The servomotor power should not continue to be ON when activating the brake.
Brake Operation Delay Time
Model
Voltage
Brake Release Time (ms)
Brake Applied Time (ms)
SGMGV-05 to 20
24 VDC,
90 VDC
100
80
SGMGV-30, -44
170
100 (24 VDC), 80 (90 VDC)
SGMGV-55, -75
170
80
Servomotor
.
Vertical Shaft
Holding brake
.
Shaft with External Force Applied
Movable part of machine
Holding brake
Movable part of
machine
Servomotor
External
force
Prevents the movable part (table)
from moving due to external force.
Prevents the
movable part from
moving due to its
own weight when the
power is OFF.
OFF
OFF
OFF
Brake release
OFF
OFF
ON
ON
ON
*1
*2
0V
*1
*3
OFF
Servomotor power
Servo ON signal (/S-ON)
Brake signal (/BK1, /BK2)
Brake contact part (lining)
Position/speed reference
Motor speed