bnp-b2365(eng)b.pdf - 第272页
5. Spindle Adjustment 5 - 27 5-3-2 Adjusting the acceleration/deceleration operation (1) Calculating the theoretical acceleration/deceler ation time Each theoretical acceleration/decelerati on time is calculated for each…
5. Spindle Adjustment
5 - 26
5-3 Adjustment procedures for each control
5-3-1 Basic adjustments
(1) Items to check during trial operation
[1] Directly couple the motor and machine, and check the control status during m achine run-in.
[2] Check that the command speed and actual speed match.
If the speeds do not match, check spindle parameters again.
(Especially check SP017, SP034, SP040 and SP257 to SP384.)
[3] Check the NC parameters Slimit1 to 4, Smax 1 to 4, and Smini.
[4] Is the rotation smooth?
[5] Is there any abnormal noise?
[6] Are there any abnormal odors?
[7] Has the bearing temperatu re risen abnormally?
(2) Adjusting the spindle rotation speed
The rotation speed is received as digital signals from the NC, and thus does not need to be
adjusted. If the spindle rotation speed does not match the commanded value due to a dimensional
error, such as the pulley diameter, adjust the parameters with the following method.
[1] Set the spindle specification parameter slimit.
Slimit = SP017 × (deceleration rate between motor and spindle)
[2] Set the S command to half of the maximum spindle rotation speed, and then measure the
spindle rotation speed.
If the speeds do not match, change the Slimit value in small increments until the speed
matches.
[3] Set the S command to the maximum spindle rotation speed, and check whether the spindle
rotation speed matches.
[4] In machines involving gear changeover, etc., change the gears, and then adjust with steps [1]
to [3] above.
5. Spindle Adjustment
5 - 27
5-3-2 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 this calculatio n 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/decel eration operation, the motor
can output at 120% of the short-time rating. Thus, the
motor output Po in the constant output range during
acceleration/deceleration follows the expression below.
Po = (Short-time rated output) × 1.2 [W]
(b) Total load inertia: J
all
The inertia of the total load which is accelerated and decelerated follows the expression below.
J
all
= (Motor inertia) + (motor shaft conversion load inertia) [ kg•m
2
] (Caution 1)
The acceleration/deceleration time until the rotation speed "N" to be required is calculated for
each motor output range as shown below, using the values obtained in (a) and (b).
(c) Acceleration/deceleration time for constant torque range: t1···0 to N [r/min ] (0≤N≤N1)
(For N>N1, apply N=N1 and also calculate t2 or t3.)
1.097 x 10
-2
x J
all
x N1 x N
t1 =
Po
[s] (Caution 1)
(d) Acceleration/deceleration time for constant output range: t2···N1 to N [r/min] (N1<N≤N2)
(For N>N2, apply N=N2 and also calculate t3.)
1.097 x 10
-2
x J
all
x (N
2
- N1
2
)
t2 =
2 x Po
[s] (Caution 1)
(e) Acceleration/deceleration time in deceleration output range: t3···N2 to N [r/min]
(N2<N≤N3)
1.097 x 10
-2
x J
all
x (N
3
- N2
3
)
t3 =
3 x Po x N2
[s] (Caution 1)
Based on the above expression s, the acceleration/deceleration time: t from 0 to N3 [r/min] is:
t = t1 + t2 + t3 [s] (Caution 2)
CAUTION
1. Note that the inertia (J) is a quarter of "GD
2
".
Ex.) When "GD
2
" is 0.2 [kg･m
2
], the inertia is "0.2 ÷ 4 = 0.05 [kg･m
2
]".
2. If the AC input power voltage to the power supply is low, or if the input
power impedance is high, the accelerati on/deceleration time may be long.
(Especially, the acceleration/decele rati on time of the deceleration output
range may be long.)
Output [W]
Output characteristics for
acceleration/deceleration
0
N1
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
5. Spindle Adjustment
5 - 28
[Calculation example]
Calculate the acceleration/deceleration time from 0 to
10000[r/min] for an spindle motor having the output
characteristics shown on the right when the motor inertia is
0.059 [kg･m
2
], and when the motor shaft conversi on load
inertia is 0.2 [kg
•m
2
].
Po = (Short-time rated output) x 1.2
= 5500 x 1.2 = 6600 [W]
J
all
= (Motor inertia) + (load inertia)
= 0.0148 + 0.05 =0.0648 [kg･m
2
]
1.097 x 10
-2
x J
all
x N1
2
1.097 x 10
-2
x 0.0648 x 1500
2
t1 =
Po
=
6600
= 0.242 [s]
1.097 x 10
-2
x J
all
x (N2
2
- N1
2
) 1.097 x 10
-2
x 0.0648 x (6000
2
- 1500
2
)
t2 =
2×Po
=
2×6600
= 1.818 [s]
1.097 x 10
-2
x J
all
x (N3
3
- N2
3
) 1.097 x 10
-2
x 0.0648 x (10000
3
- 6000
3
)
t3 =
3 x Po x N2
=
3 x 6600 x 6000
= 4.691 [s]
Thus,
t = t1 + t2 + t3 = 0.242 + 1.818 + 4.691 = 6.751 [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]
Spindle motor characteristics
2.8