|
|
 |
 |
 |
|
Crack detection
on highly-stressed rollers- a new ibg application for aerospace |
|
A- A closeup of the probe
disk on this two-channel system shows that probes can be easily
adjusted to the different diameters of the parts.
B - Typical roller bearing part
|
 |
|
Highly-stressed bearings for aeronautical jet engines must have
flawless rollers. ibg has developed a system for 100% testing of
these rollers. Flaws as small as 50 microns deep by 80 microns long
are reliably detected! The new system has been certified for in-line
testing by a major manufacturer of commercial and military jet
turbines.
The system incorporates two-channel eddydector®
instrumentation and an eddyscan®
H2/30 rotating scanner for non-contacting testing. Crack
inspection can be on rollers with diameters of 5.0-26.0mm and
lengths of 5.0-32.0mm. Running at a maximum of 75mm/ sec, the system
cycles at a maximum of 204 parts/min.
The eddydector® crack
detection instrument uses two test channels with two probes on a
probe disk which can be adjusted to the different diameters of the
rollers parts. Friction wheels guide the test parts at a constant
speed, as they pass end-to-end through the eddyscan® unit,
from which individual OK and non-OK rollers are each forwarded to a
separate soft conveyor belt. Special provisions are made for extra
gentle handling of the parts on both feeding and discharge of tested
parts. Change parts and maintenance parts are kept in
compartmentalized drawers below the test instrument.
This application was interesting to ibg because it extended our
bearing testing experience with the specialized aviation/aerospace
market.
Instrument on X-Y slide
detects cracks
and pores on ID bore surfaces
A new
configuration of eddyscan® H designed for in-line high-speed
crack and pore detection is mounted on an X-Y slide for testing I.D.
bore surfaces. The system involves high-precision automatic
alignment of the bore axis for scanning. A ball bearing probe
guidance gently centers the probe precisely in the cylinder bore
hole. As soon as the rotating probe is introduced into the
cylindrical bore hole, it can test an entire cylinder liner I.D.
bore surface in seconds.
A version of this versatile semi-automatic test system can test
cylinder liners in engine blocks with three, four or six cylinders
(another version can test six, eight and 12 cylinders). It is
mobile, and can be moved quickly from the lab to the production
floor, and can be integrated into the engine block processing line.
The rotating probe (above cylinder) is on an X-Y slide for
positioning before it is automatically introduced into each cylinder
bore hole for scanning the entire surface.
Crack detection system
for cylinder liners tests
entire inner and outer diameters An ibg system for testing cylinder
liners for cracks on the whole I.D. and O.D. of the part has been
developed using a 3-channel eddydector®
instrument. It scans a 90mm O.D. and 86mm I.D. (of 132mm length)
in nine seconds, which allows production at 400 parts/hour. |
 |
 |
|
Once scanned, OK parts are
forwarded to the next processing step on the upper chute, while
non-OK parts occupy the lower chute. |
The entire inner and outer
surface of a liner such as shown . (right) is scanned by three
crack detection probes. |
|
The liners are clamped and put into
rotation (at 900 rpm) and two probes do the scanning for surface
flaws on the O.D., while a third scans the I.D. The liners are
gently separated as they enter the system and are passed singly to
the test and discharge stations. OK parts are forwarded to the next
processing step on one level, while non-OK parts are diverted to a
lower chute.
Like many automatic crack test systems, this one replaces magnetic
particle visual inspections |
|
Detection of
very small pores and cracks on camshaft lobes solved by new ibg
developments
Reliable detection of very small
pores and cracks on camshaft lobes is difficult, due to the complex
shapes of these parts. Any solution useful as an in-line test system
must be capable of testing all the lobes and journals automatically
at production rates, so that there can be 100% testing in-line to
guarantee zero defects from pores and cracks.
Responding to several automotive customers, ibg NDT Systems has
recently developed solutions to this problem using eddy current
methodology. Involving a combination of both special probe designs
and instrument capabilities, the new ibg capability provides
reliable detection of very small pores and cracks on camshaft lobes
and journals. In the most difficult case in scanning the lobe
surface areas, the negative effects caused by their highly variable
shapes are canceled out quite effectively. And, like all ibg
solutions, the method is easily incorporated into our production
line test systems.
Pores as small as 0.4 mm are reliably detected, as are small cracks
and small chips at edges of the lobes and journals. |
 |
 |
|
Chart
shows indications from 0.6 mm on lobe "A" vs. good surface area,
"B." Signal to noise ratio is better than 10:1. |
Example case showing probes guided
precisely by double-bearing ceramic shoes and use of eight test
channels. |
|
Software program for grade verification on
bars, tubing and shapes
A software program by ibg facilitates
grade verification on bars, tubing and other shapes with eddy
current. The system is faster than the conventional spark test or
chemical analysis, and can be used for 100% testing to find and
eliminate wrong alloy bars mixed in with good ones.
The program is based on ibg
Preventive Multi-Frequency Testing method, which involves
calibration with a known OK material. Using the program, readings
are carried out continuously along the material length at up to
eight different test frequencies. Each unit is tested several times,
using a broad band of up to eight frequencies. Discrete variations
in eddy current flow patterns (due to discontinuities from
straightening, forming, sizing, etc.) may be ignored with a
selectable percentage, defining how frequently the material must
meet criteria along its length in order to pass. This selectivity
greatly increases reliability and reduces false rejects
| TOL |
FRQ |
FKT |
|
| A |
25.0 Hz |
2.0 |
-AAAAAAAAAAAAAAAAAAAAAAAA |
| B |
63.0 Hz |
2.0 |
-BBBBBBBBBBBBBBBBBBBBBBBBBB |
| C |
160 Hz |
2.0 |
CCCCCCCCCCCCCCCCCCCCCCCCC |
| D |
400 Hz |
2.0 |
DDDDDDDDDDDDDDDDDDDDDDDDD |
| E |
1.00 kHz |
2.0 |
EEEEEEEEEEEEEEEEEEEEEEEEEEEEEE |
| F |
2.50 kHz |
2.0 |
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF |
| G |
8 00 kHz |
2 0 |
GGGGGGGGGGGGGGGGGGGGGGGGG |
| H |
25.0 kHz |
2.0 |
HHHHHHHHHHHHHHHHHHHHHHHHHH |
|
Decision "O.K."
|
Decision "NOT O.K."
|
| TOt |
FM |
FKT |
|
| A |
25.0 Hz |
2.0 |
-AAAAAAAAAAAAAAAAAAAAAAAA |
| B |
63.0 Hz |
2.0 |
-BBBBBBBBBBBBBBBBBBBBBBBBBB |
| C |
160 H2 |
2.0 |
CCCCCCCCCCCCCCCCCCCCCCCCC |
| D |
400 HZ |
2.0 |
DDDDDDDDDDDDDDDDDDDDDDDDD |
| E |
1.00 kHz |
2.0 |
EEEEEEEEEEEEEEEEEEEEEEEEEEEEEE |
| F |
2.50 kHz |
2.0 |
FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF |
| G |
8.00 kHz |
2.0 |
GGGGGGGGGGGGGGGGGGGGGGGGG |
| H |
25.0 kHz |
2.0 |
HHHHHHHHHHHHHHHHHHHHHHHHHH |
|
| |
|
|
|
by Bill Buschur
General Manager |
|
NDTalk |
|
Spring Seminars/Workshops
successful, will be continued in 2003; Quality Show in Novi |
|
ibg held well-attended, informativeSeminars/Workshops in early Spring this year, concen-trating on
locations in theGreat Lakes states and Ontario, Canada.
Based
on the favorable reactions to these presentations, more are
planned for next year. These technical presentations will be
held in the southeast section of the country, covering topics of
material properties testing and crack testing. Actual examples
will be discussed, in addition to the presentation of some
theory and guidelines for effective testing. If you work in this
area, be on the alert for announcements of upcoming seminars
during the 2003 Spring season.
In this issue of TEST Patterns, ibg you will find different
applications of crack testing-on rollers, cylinder liners and
cam shafts-as well as news of an eddyscan®
H instrument mounted on a X-Y slide.
Meanwhile, back in
Michigan, ibg will be exhibiting in the Quality
|
|
New video shows a
variety of tests
for cracks and pores |
|
A new videotape available
from ibg learly depicts three different applications of
crack testing, as well as applications for heat treat and
hardness patterns.
Cylinder liners of cast iron for
a manufacturer of diesel engines are tested for cracks,
porosity and heat treatment. The entire I.D. bore surface
and end face are scanned for cracks and pores. And the
induction hardened I.D. bore is tested at multiple locations
for hardness, case depth and hardness pattern runout. Both
the testing and feeding operations are shown. In addition,
close-ups of defects detected by the system are included in
the visuals.
Planetary pins with soft ends are tested for cracks
on the cylindrical surface area and for hardness, case depth
and hardness pattern run-out. The test rate is 7,200 parts
per hour.
Cylinder liners also are covered in another sequence,
showing testing for I.D. and O.D. cracks and porosity on the
O.D. and I.D. surface areas. This section also shows
close-ups of flaws detected by the testing.
Rocker pins for engine timing chains tested for heat
treatment are the subject of another section of the video.
This system displays a twin sorter, with a test rate of
7,200 parts per hour.
The video is available for presentation at your plant on
request. Inquiries should be made to Bill Buschur at ibg (call 248-476-9490).
Expo
Detroit in Novi on June 12-13. Novi is a suburb of Detroit,
northwest of the city, adjacent to Interstate 96.
In addition, we welcome a new organization to the ibg
team: Radiatronics, with Neil Breslow covering a number of
mid-America states, including Missouri, Nebraska, Kansas,
Colorado, Wyoming and New Mexico, as well as Arkansas in the
South.
|
|
20793 Farmington Road
Farmington Hills, Ml 48336
248 478-9490
Fax: 248 478-9491
www.ibgndt.com
E-Mail:
sales@ibgndt.com |
|
|
