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Examines the part is the numerical control engine bed
servosystem important constituent, it plays is examining each control
axis the displacement and the speed role, it the signal which examines
feeds back, constitution closed-loop system. The survey way may
divide into the direct survey and the indirect survey: The
direct survey is uses the straight line examination part survey to the
engine bed straight line displacement, the direct survey commonly used
examination part generally includes: Straight line induction
synchromesh, measurement diffraction grating, magnetism ruler laser
interferometer. The indirect survey is uses the reforming
examination part survey to the engine bed straight line displacement,
the indirect survey commonly used examination part generally includes:
Pulse encoder, rotary transformer, circle induction synchromesh,
round diffraction grating and round magnetism grid.
When the engine bed appears the following breakdown phenomenon,
should consider whether is by examines the part the breakdown to
cause:
1. mechanical oscillationses (add/decelerate time):
(1) the pulse encoder appears the breakdown, this time inspects
on the speed unit the feedback line 端子 voltage whether does drop
in some several voltages, if has the drop to indicate the pulse
encoder is not good, replaces the encoder.
(2) the pulse encoder cross shaft coupling possibly damages,
causes 轴转?with speed not synchronization which examines,
replaces the shaft coupling.
(3) the speed-voltage generator appears the breakdown, the
repair, the replacement measures fast machine.
2. mechanical storms walk (speeding car):
In inspects position control unit and in the speed control unit
situation, should inspect:
(1) pulse encoder wiring is whether wrong, inspects the encoder
wiring whether is the regeneration, A and B whether meets instead.
(2) pulse encoder shaft coupling whether does damage, replaces
the shaft coupling.
(3) inspects the speed-voltage generator 端子 whether meets
counter- and the excitation holding wire whether meets wrong.
3. main axles cannot the direction detection or the direction
detection do not arrive:
In the inspection direction detection control circuit
establishment and the adjustment, the inspection direction detection
board, at the same time which the main axle control printed wiring
board adjusts, should inspect the position sensor (encoder) isn't
whether good, this time measures the encoder output wave shape, normal
profile as follows:
4. coordinate axes vibrate give:
In inspection electric motor coil whether short-circuits, the
machinery enters for the guide screw with the electrical machinery
connection whether good, in inspection entire servosystem whether
stable situation, inspection pulse code whether good, the shaft
coupling does join whether steady reliable, measured fast machine is
whether reliable.
5. NC reports to the police because of the program error,
reporting to the police which the operation mistake causes. If
FAUNUC 6ME system NC reports to the police 090.091. Appears NC
to report to the police, has the possibility is the main circuit
breakdown and enters for the speed too lowly causes. At the same
time, but also has the possibility is:
(1) the pulse encoder is not good.
(2) the pulse encoder supply voltage too is low, (this time
adjusts supply voltage 15V, causes main circuit board + the 5V 端子
on voltage value in 4.95 - 5.10V).
(3) has not input the pulse encoder a revolution of signal but
not to be able normally to carry out the reference point to return.
6. servosystems newspaper alarm signal: If FAUNUC the 6ME
system servo reports to the police: 416th, 426, 436, 446, 456.
The SIEMENS 880 systems servos report to the police: 1,364
SIEMENS 8 systems servos report to the police: 114th, 104 and so
on. When appears like reports the alarm signal, has the
possibility is:
(1) the axis pulse encoder feedback signal broken line,
short-circuits with the signal loses, measures A with the
oscilloscope, a B revolution of signal.
(2) the encoder interior is polluted, too dirty, the signal is
unable correctly to receive.
My factory existing numerical control equipment 15, among,
Simens 8 systems processings center, Simens 880 systems processings
center two, numerical control cutter four, IRB2000 welding robot
three, CNCJ a 800X8100 numerical control folds bender, FAUNUC 6
systems processings center, ordinary numerical control lathe three,
use first YBM-90N from 91 years the Simens 8 systems processings
center to start until now, appears the breakdown from the use process
to look, examines the breakdown which the part appears to account for
the very great proportion: Under makes an analysis on several
typical breakdowns.
Breakdown one: The pulse encoder light electrophorus
division, causes the work table localization not to permit.
Breakdown phenomenon: Finnish VMC800 the SIMES 880
vertical processings centers work table for the double work table,
through exchanges the work table to complete two work pieces
processings, the work table depends on the mouse plate localization,
the mouse chain wheel division 360 teeth, each tooth correspondence
1° work table depends on the cylinder the vertical motion realization
work meeting and parting, draws the synchronized tooth profile belt
through the servo electrical machinery, drives the work table to
revolve through the pulse encoder examines the work table the degrees
rotation and the localization, the work table appears the localization
breakdown in 96 years in August, the work table cannot the correct
reference point, each time locates the mistake no matter is automatic
manually or all differs several angles, angle number of degree,
sometimes 1°, sometimes 2°, But work table if distinction
clockwise several angles like 30°, 60°, 90°, corresponding reverse
30°, 60°, 90° time, the localization is accurate, appears locates
wrong is late, CRT appears NC 228* to report to the police the
demonstration.
Fault analysis: Inquires 228* to report to the police the
content is: M19 chooses invalid, namely: M19 localization
procedure when movement has not completed, at that time we thought is
the M19 localization procedure and related NC MD has the mistake, but
the inspection routine and the data are normal, has the possibility
after the analysis is following several kind of reasons causes the
work table localization mistake: (1) the synchronized tooth
profile belt damage, causes the work table actual rotation with the
value not symbol which examines; (2) encoder shaft coupling
damage; (3) the metering circuit not good causes the
localization mistake.
Breakdown solution: According to the above reason, we to
the synchronized tooth profile belt and the encoder shaft coupling,
carry on the inspection, discovered all is normal, after removes the
above reason, we judge extremely have the possibility are the
breakdown which the metering circuit not good causes, this engine bed
is by RAC 2: 2-200 actuation module, the actuation exchange
servo electrical machinery constitutes the Sl axis, survey module is
composed the NC metering circuit by 6Fxl the l21-4BA with 1,024 pulses
photoelectricity pulse encoders, appears the breakdown when the work
table localization, inspects the work table to locate the PLC chart,
PLC on chart person board 4Al-C8 loses the person to select E9.3,
E9.4, E9.5, E9.6, E9.7 is the work table in revolves the joint
localization related spot, on output board 4Al-C5 A2.2, A2.3, A2.4,
A2.5, A2.6 is the corresponding output spot, inspects these spots, the
active status is normal, is unable the diagnosis reason from the PLC
chart, thereupon we inspect metering circuit module 6Fx1, 121-
4BA not reports to the police the demonstration to be normal.
Locates in the work table in the process, surveys the encoder
with the oscilloscope the feedback signal, determines the encoder to
appear the breakdown. Thereupon we dismantle the encoder,
dismantles its outer covering, discovered its light electrophorus is
away from greatly near with the under instruction diffraction grating,
revolves when had the friction, in the light electrophorus the circle
lightproof is partially rubbed has delimited a diaphanous ring, caused
to produce not the good pulse signal, after the replacement encoder
question solution, now considered initial reported to the police had
not demonstrated the metering circuit breakdown, was because the
encoder light electrophorus has not totally damagedded, was a random
fault, CNC is unable the real demonstration true to report to the
police the content, therefore the numerical control equipment reported
to the police certainly cannot the completely thorough explanation
breakdown reason, the need thoroughly carried on the analysis.
Breakdown two: The pulse encoder A signal wrongly causes
the axis movement to have the vibration.
Breakdown phenomenon: FAUNUC 6ME system two-sided
processing center 96 years in October X to has the vibration in the
movement process, and appears NC416 on CRT to report to the police.
Fault analysis: According to the breakdown phenomenon, we
analyze cause the breakdown reason possibly to have following several
kinds. (1) the speed control unit appears the breakdown;
(2) the position examination electric circuit is not good;
(3) the pulse encoder feedback electric cable segment and the
connection is not good; (4) the pulse encoder is not good;
(5) engine bed data is whether correct; (6) the servo
electrical machinery and measures the fast machine breakdown.
Breakdown solution: In view of reason which above
analyzes, to the speed control unit, the main circuit board, the pulse
encoder feedback electric cable connection and the segment carries on
the inspection, discovered all normal, the engine bed data is normal,
then withdraws the electric motor and the machine part, with 手转?the electric motor, observes 713 diagnoses conditions, 713 diagnoses
contents are: 713.3 is X axis pulse encoder feedback signal, if
the broken line, this is 1. 713.2 is X axis encoder feeds back a
revolution of signal. 713.1 is X axis pulse encoder B feedback
signal. 713.0 is X axis pulse encoder A feedback signal.
713.2nd, 713.1, 713.0 normal time electric motors rotations
should be "0", "1" unceasingly changes, in the rotation electrically
operated machine-hour, discovered 713.0 signals only are "0" are
invariable "1", we use the oscilloscope examination pulse encoder A, B
and a revolution of signal, discovered the A signal is not normal,
therefore is not good through the above inspection decidable accent
axis pulse encoder, after replaces the new encoder, the breakdown
solution.
Breakdown three: The speed-voltage generator excitation
winding wire causes the control axis vibration breakdown.
Breakdown phenomenon: IRB2000 robot 98 years 10 introduces
which from Finland appear the breakdown, starts the robot, the robot
(seventh axis) on does not move in the guide rail, and has the intense
vibration, appears 5061407 on the controller and 509,237 reports to
the police.
Fault analysis: 50.061407 million reports to the police
the content is: (1) robot when seventh axis movement meets the
barrier; (2) actuates the electrical machinery overload, the
electromagnetism braking not to have the pine to open; (3)
actuates the electrical machinery through the electric current, but
cannot correctly commutate; (4) actuates the electrical
machinery not to pass the electric current. 509,237 reports to
the police the content is: The seventh axis speed-voltage
generator is not good, measured fast machine shuts.
Breakdown solution: And reports to the police the content
according to the breakdown phenomenon, we carry on the inspection to
the actuation system, actuates the electrical machinery for to
exchange the servo electrical machinery, the model is
NAC093A-O-WS-3-C/110-B-1, the actuation board is DSQC236B, this system
examination carries on the examination control for the speed-voltage
generator and the pulse encoder to the speed and the position, first
we inspect each tie cable the segment, the attachment and the
actuation board are all normal, then we inspect the strong electricity
electric circuit, has an electronic contact broken line after the
inspection discovery control actuation electrical machinery
electromagnetism braking time relay, after welds, restarts, the time
relay although works normally, but the electrical machinery still
could not move, reports to the police has not still eliminated,
Afterwards we withdraw the electrical machinery and the machine
part, only get on the brakes power source, with 手转?electrical
machinery, electrical machinery motionless, simultaneously surveys the
braking coil, discovered the coil 烧损, relieves after the repair
braking breakdown, 5061407 report to the police the elimination, but
509,237 reported to the police has not still eliminated, the robot
movement still had the vibration, thereupon we surveyed the
speed-voltage generator exciting winding, discovered the winding
broken line, because the winding wire was 0. 2mm, the line too thin
and is cut off quite several, the repair difficulty too in a big way,
the repair was hopeless, thereupon we to the ABB Corporation ordering,
after replaced the speed-voltage generator, the breakdown relieve.
Breakdown four: The pulse encoder the oil pollution,
causes the axis localization breakdown.
Breakdown phenomenon: SIEMENS 880 horizontal types
processings center work table 98 year in October in revolves in the
localization process to appear the breakdown, the outage, CRT appears
the newspaper alarm signal: 1,364 reports to the police the
content is 1,364 ORD 4B2 measuing System Dirty is the measurement
system is polluted.
Breakdown solution: Reports to the police the content
according to the breakdown, we first dismantle the examination line
board and the feedback electric cable attachment, cleans its dust and
the greasy dirt with the ethyl alcohol, starts the work table, the
breakdown has not eliminated, afterwards we dismantle the examination
work table position the pulse encoder, inside discovered has filled
the massive lubricating oil, originally has as soon as passes over the
encoder the compressed air air course, the compressed air can enter
the encoder the dust to blow out, plays the clean encoder role, these
lubricating oil are when ventilates by the air course, because the
compressed air is impure, comes in by the compressed air belt, we use
the gasoline to wash cleanly these greasy dirt, and the enhancement
compressed air quality, after reinstalls the good encoder,
Starts the work table, the breakdown elimination.
Breakdown five: The closed loop electric circuit
examination holding wire breaks off, causes the control axis movement
breakdown.
Breakdown phenomenon: The SIEMENS 8 systems horizontal
types processing center has in a time of work process, the engine bed
suddenly stops moving, CRT appears NC to report to the police 104,
shuts off the power source to restart, reports to the police the
elimination, the engine bed restores normally, however works soon,
also appears the above breakdown, so relapse.
Fault analysis and solution: Inquires NC 1O4 to report to
the police, the content is: X axis survey closed loop
电缆折断 short-circuits, the signal loses, not the correct
threshold signal not correct frequency code, this engine bed X, Y, the
Z three axle uses the diffraction grating ruler to move to the engine
bed carries on the position examination, carries on the reaction
control to form a closed-loop system.
And reports to the police according to the breakdown phenomenon,
we first inspect 读数?and the diffraction grating ruler, the
diffraction grating ruler seal good, inside pure, 读数?and the
diffraction grating ruler has not received the greasy dirt and the
dust pollution, and 读数?and the diffraction grating ruler is
normal, afterwards we inspect the differentiator amplifier and the
measuring circuit board, has not discovered the undesirable tendency
after the inspection, after passes through these work, we put with
emphasis in feed back on the electric cable, the survey feedback
端子, discovered 13 lines voltages are not steady, after the power
cut surveys 13 lines, discovered has a bigger resistance, after the
careful inspection, discovered this in X to has along with a guide
rail movement section to be going to break off, Resembles meets
must meets, creates the feedback value not to be steady, deviates its
actual value, causes the electrical machinery to fall out of step,
after to the broken line wiring, starts the engine bed again, the
breakdown elimination.
Breakdown six: The pulse encoder induces the light
electrophorus damage to cause the job finishing size error.
Breakdown phenomenon: CNC 862 numerical controls 20 lathes
X to cutting components when the size appears the error, achieved
0.30mm/250mm, CRT not reports to the police the demonstration.
Breakdown solution: This engine bed X, the Z axis for the
servo unit control direct current servo motor-driven, with the
photoelectricity pulse encoder took the position examination, creates
the finishing size error according to the analysis the reason
generally is: (1) X the bearing which connects to the ball
bearing guide screw and the nut vice- existence quite big gap or the
electrical machinery and the guide screw suffers injury, causes the
implementation travelling schedule with the size which examines to
appear the error; (2) the metering circuit is not good.
According to above analysis, after inspection discovery guide
screw and nut gap normal, the bearing also does not have the
undesirable tendency, the metering circuit electric cable segment and
the attachment is good, finally we use the oscilloscope to inspect the
encoder the examination signal, the profile are not normal.
Thereupon we dismantle the encoder, opens its outer covering,
discovered the light electrophorus lightproof are partial did not know
any reason appears three transparent spots to cause the examination
signal to appear the error, replaces the encoder, the question
solution, because CNC 862 systems from the diagnosis function is not
specially strong, therefore when appears such breakdown, engine bed
not engine off, also does not have NC to report to the police
demonstrated:
Also some several because examine the equipment failure which
the part not good creates, does not state in this 11 rows.
Examines the part is the component which one kind extremely
precise and is easy to suffer injury, certainly must pay attention
from following several aspects, carries on the correct use and
maintains the maintenance.
1. cannot receive the intense vibration and the friction in
order to avoid the damage code board, cannot receive the dust greasy
dirt the pollution, in order to avoid affects the normal signal the
output.
2. working conditions the ambient temperature cannot exceed the
allowed figure, the fixed supply voltage certainly must be satisfied,
in order to integrated circuit flat and thin piece normal work.
3. must guarantee the counter- 馈线resistance, the electric
capacity normalcy, the guarantee normal signal transmission.
4. prevented the external power supply, the noise jamming, needs
to guarantee the shield is good, in order to avoid influence feedback
signal.
5. installs the way to have to be correct, if the encoder
联接?must concentric align, prevented the axis surpasses the
permission the load-carrying capacity, guarantees its performance the
normalcy.
In brief, in the numerical control equipment breakdown, examines
the part the breakdown proportion is quite high, so long as the
correct use and strengthens the maintenance maintenance, to the
question which appears carries on the thorough analysis, certainly can
reduce the failure rate, and can rapidly solve the breakdown,
guarantees the equipment the normal operation.
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