MDS-C1-SPA Series INSTRUCTION MANUALib1500152(eng)a.pdf - 第122页
4. Spindle Adjustment 4 - 31 [Calculation example] Calculate the acceleration/deceleration time from 0 to 10000[r/min] for an SJ-V5.5-01 motor hav ing the output characteristics shown on t he right, when the motor shaft …
4. Spindle Adjustment
4 - 30
4-3-2 Adjusting the acceleration/deceleration operation
(1) Calculating the theoretical acceleration/deceleration time
Each theoretical acceleration/deceleration time is calculated
for each output range based on the spin dle motor output
characteristics as shown o n the right. Note that the load
torque (friction torque, etc.) is 0 in the calcul ation expression,
so the acceleration/deceleration time can be known as a
rough guide, but this calculation re sult differs from the
acceleration/deceleration time of the actual machine.
(a) Maximum motor output during
acceleration/deceleration: Po
During acceleration/deceleration, the motor can output at
120% of the short-time rating. Thus, the motor output Po
in the output range during acceleration/deceleration
follows the expression below.
Po = (Short-time rated output) × 1.2 [W]
(b) Total load GD
2
: GD
2
GD
2
of the total load which is accelerated and decelerated follows the expression below.
GD
2
= (Motor GD
2
) + (motor shaft conversion load GD
2
) [kg•m
2
] (Note 1)
The acceleration/deceleration time until the rotation speed "N" to be required is calculated for
each motor output range as shown below, usin g the values obtained in (a) and (b).
(c) Acceleration/deceleration time for constant torque range: t1···0→N [r/min] (0≤N≤N1)
(For N>N1, apply N=N1 and calculate t2 or t3.)
t1 =
1.03 × GD
2
× N1 × N
375 × Po
[s] (Note 1)
(d) Acceleration/deceleration time for constant output range: t2···N1→N [r/min] (N1≤N≤N2)
(For N>N2, apply N=N2 and calculate t3.)
t2 =
1.03 × GD
2
× (N
2
- N1
2
)
2 × 375 × Po
[s] (Note 1)
(e) Acceleration/deceleration time in deceleration output range: t3···N2→N [r/min]
(N2≤N≤N3)
t3 =
1.03 × GD
2
× (N
3
- N2
3
)
3 × 375 × Po × N2
[s] (Note 1)
Based on the above expressions, the acceleration/deceleration time: t from 0 to N3 [r/min] is:
t = t1 + t2 + t3 [s] (Note 2)
(Note 1) Note that "GD
2
" is four times the inertia（J）.
(Note 2) If the AC input power voltage to the power supply is low, or if the input power
impedance is high, the acceleration/deceleration time may be long. (Especially, the
acceleration/deceleration time of the deceleration output range ma y be long.)
Output [W]
Output characteristics for
acceleration/deceleration
0N1
N2
0
N3
Po
Rotation speed [r/min]
Short-time rating × 1.2
Constant
output range
Constant out
p
ut ran
g
e
Deceleration
range
4. Spindle Adjustment
4 - 31
[Calculation example]
Calculate the acceleration/deceleration time from 0 to 10000[r/min] for an SJ-V5.5-01 motor hav ing
the output characteristics shown on the right, when the motor shaft conversion load GD
2
is
0.2[kg
•m
2
].
Po = (Short-time rated output) × 1.2 = 5500 × 1.2 = 6600 [W]
GD
2
= (Motor GD
2
) + (load GD
2
) = 0.059 + 0.2 = 0.259 [kg•m
2
]
t1 =
1.03
×
GD
2
×
N1
2
375
×
Po
=
1.03 × 0.259 × 1500
2
375 × 6600
= 0.243 [s]
t2 =
1.03
×
GD
2
×
(N2
2
- N1
2
)
2
×
375
×
Po
=
1.03 × 0.259 × (6000
2
- 1500
2
)
2 × 375 × 6600
= 1.819 [s]
t3 =
1.03
×
GD
2
×
(N3
3
- N2
3
)
3
×
375
×
Po
×
N2
=
1.03 × 0.259 × (10000
3
- 6000
3
)
3 × 375 × 6600 × 6000
= 4.695 [s]
Thus,
t = t1 + t2 + t3 = 0.243 + 1.819 + 4.695 = 6.757 [s]
0 1500 6000
0
2.0
6.0
8.0
4.0
Output [kW]
10000
15-minute
rating
3.7
5.5
4.1
Continuous
rating
Rotation speed [r/min]
SJ-V5.5-01 output characteristics
2.8
4. Spindle Adjustment
4 - 32
(2) Measuring the acceleration/deceleration waveforms
Measure the acceleration/deceleration waveforms by using the spindle drive unit's D/A output
function and check if theoretical acceleration/de celeration time is within ±15%. Refer to "4-1 D/A
output specifications for spindle drive unit" for details on D/A output functions.
Phase current FB output can be measured by the waveform for either U or V phase FB.
When acceleration/deceleration time does not match the theoretical value (an error rate 15% or
more), check the following items.
[1] There may be an error in calculating load inertia for the motor axis conversion used when
calculating the theoretical acceleration/deceleration time. Check the load inertia again.
[2] When acceleration time is long and deceleration time is short, friction torque is thought to be
large. Check load meter value at the maximum speed (spindle monitor screen). If the load is
10% or more, friction torque is thought to be relatively large. Mechanical friction, such as
bearing friction or timing belt friction, is assumed to be large. Measure the acceleration/
deceleration time again following trial run.
[3] Even if the problems above are not found, when acceleration/deceleration time does not match,
there may be a possibility of using spindle motor and spindle drive unit that are not specified, or
using wrong parameters. Check the spindle motor type and spindle drive unit type again, as
well as the spindle parameter settings.
POINT
1. There are cases where acceleration/deceleration wa veforms chan ge dependin g
on the spindle temperature. Check the waveforms when the spindle temperature
is high (after continuous operation) and when it is low.
2. Conduct "3-3 Initial adjustment of spindle PLG" beforehand.
Speedometer output [V]
Acceleration/deceleration waveforms of spindle motor
0
4.0
2.5
1.0
U(V) phase current FB output [V]
Acceleration time: ta Deceleration time: td