Note: Descriptions are shown in the official language in which they were submitted.
CA 02906646 2015-10-01
FRAGMENT DETECTION METHOD AND APPARATUS
BACKGROUND
[0001I Disclosed is a method and apparatus for detecting machined substrate
fragments within one or
more internal chambers of a machined metal component, and more particularly,
the use of non-destructive
thermography for the detection of machined substrate fragments.
[0002] Non-destructive thermography for defect detection is generally known in
the art. U.S. Pat. No.
4,996,426 discloses an apparatus for subsurface flaw detection of a
continuously moving working piece,
specifically, a rolled, worked metallic sheet. Heat is applied to a bottom
surface of the workpiece causing
thermal flow from the bottom to a top surface. Low thermal conductivity
defects within the workpiece,
including foreign material inclusions and subsurface cracks, cause thermal
lines to flow around the defect
creating low temperature areas on the top surface. An IR-detection device
captures a thermal image of the
top surface, wherein low temperature areas on the thermal image correlate with
subsurface defects within
the workpiece.
[00031 U.S. 8,581,975 and U.S. 5,834,661 disclose the detection of subsurface
defects using
thermography. U.S. 8,581,975 discloses a method and apparatus in which an
induction coil applies heat
to a powder-metallic component to cause a thermal increase flow through the
body of the component and
heat the component substantially uniformly throughout the component body. An
IR-detection device
creates a thermal image of the component following induction heating and
subsurface inclusions, such as
foreign metallic compounds, appear as different colors within the thermal
image. U.S. 5,834,661
discloses a method wherein one side of a component is placed near a
thermoplate and an opposing side is
placed near a vacuum. As heat flows from the heated side to the vacuum side as
the component cools, an
IR-detection device captures a transient thermal image of the component.
Subsurface inclusions appear as
temperature/color varations within the transient thennal image.
100041 Similarly, U.S. 2013/0261989 and U.S. 5,654,977 disclose methods of
detecting subsurface
defects at varying depths, such as foreign metal inclusions and subsurface
laminations, using transient
thermal imaging techniques.
[00051 The referenced apparatuses and methods detect defects such as foreign
material and subsurface
defects. Many of these disclosed apparatuses and methods detect subsurface
defects. However, these
disclosed methods and apparatuses, as well as others that are well known in
the art, rely on a difference in
material substance between the defect and the component substrate in order in
order to effectively locate
such defects using thermography techniques. In typical machining applications,
machined substrate
fragments, which fragments are composed of the same material substance as the
component itself, are
removed from the machined component body. These substrate fragments may be
resident in one or more
internal chambers of a machined component following a machining operation,
which, if left undetected,
1
can create component malfunctions following the installation and/or use of the
machined component. It is
an object of the disclosed method and apparatus to overcome these shortcomings
in the art.
BRIEF SUMMARY
100061 In one aspect, there is provided a method of inspecting a machined
metal component in an
ambient environment following a machining operation for detecting machined
substrate fragments resident
in the at least one internal chamber in a machined metal component, wherein
the machined metal component
includes a component body, the component body having an outer surface, and an
interior region, the interior
region having at least one internal chamber, the method comprising the steps
of: a) providing a profile of the
machined metal component that has been subjected to a least one machining
operation wherein the at least
one internal chamber defined in the metal component communicates with at least
one aperture defined in the
outer surface of the component body providing open exposure of the at least
one internal chamber to the
ambient surrounding environment; b) identifying one or more points defined on
the outer surface, the one or
more points each corresponding with an aperture communicating with one or more
internal chambers; c)
moving a heating element configured to deliver a pulse of hot air to the one
or more points defined on the
outer surface and applying a pulse of hot air sequentially to the one or more
points defined on the outer
surface for a time interval at each of the one or more points, wherein the
pulse of hot air is applied to each of
the one or more points defined on the outer surface sequentially following the
expiration of the time interval
at each location, the application of hot air sufficient in temperature and
duration to cause a fragment
temperature elevation in at least one machined substrate fragment separated
from the component body
during the machining operation present in the at least one internal chamber
following the machining
operation, and a component temperature elevation in the machined metal
component, wherein the fragment
temperature elevation has a fragment temperature elevation rate and the
component temperature elevation
has a component temperature elevation rate and wherein the fragment
temperature elevation rate is greater
than the component temperature elevation rate, wherein the at least one
machined substrate fragment is
composed of the same material substance as the machined metal component and
was removed from the
machined metal component during the machining operation; d) producing a
thermal image of temperature
distribution of the outer surface of the machined metal component following
the application of heat the pulse
of hot air for the time interval at each one of the one or more points; and e)
detecting one or more heat
elevation points within the thermal image of the temperature distribution of
the outer surface, the heat
elevation points indicating the presence of at least one machined substrate
fragment resident within one or
more internal chambers of the machined metal component following the machining
operation.
[0007] In some embodiments, the profile may be an open cross-sectional
profile of the machined metal
component.
[0008] In some embodiments, the theimal image of temperature distribution
is a real-time transient
image.
[0009] In another aspect there is provided an apparatus for inspecting a
machined metal component
following a machining operation, the machined metal component comprising a
component body having at
2
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least one internal chamber, the internal chamber communicating with at least
one aperture defined on an
outer surface of the component body, comprising: a) heating element configured
to apply a pulse of hot air
to at least one section of an outer surface of the machined metal component;
b) a positioning element
configured to move the heating element along one or more axes to one or more
points relative to the at least
one section of the outer surface, wherein the at least one section of the
outer surface correspond to the at
least one aperture communicating with the internal chamber; c) a controller
mechanism, the controller
mechanism operably connected to the positioning element and the heating
element to permit selective
control of the application of the pulse of hot air to the aperture defined on
the outer surface and the
positioning of the heating element relative to the aperture defined in the
outer surface; d) a thermal detection
device, wherein the thermal detection device is an infrared (ER) detector and
is positioned to detect an IR
radiation signal emitted from the at least one section of the outer surface;
e) a signal processor, operably
connected to the theimal detection device to receive and process the detected
IR radiation signal; and f) a
visual output device operatively connected to the signal processor for
receiving the processed IR radiation
signal and displaying a thermal image of the IR radiation signal emitted from
the section of the outer
surface.
[0010] In some embodiments, the apparatus may further include a housing
having an outer wall
defining an inner chamber, the inner chamber containing the IR detection
device, the positioning means and
the heating means. The housing may include a drawer configured to receive and
retain the machined metal
component, the drawer being configured for movement from an outer loading
position wherein at least a
portion of the drawer is outside of the inner chamber to allow loading of the
machined metal component, and
an inner inspection position wherein the drawer is inside of the inner
chamber. In some embodiments, the
drawer may include locking means for selectively locking and unlocking the
drawer within the inner
chamber when the drawer is in the inner inspection position. The apparatus may
further include a sensor
mechanism, the sensor mechanism detecting when the drawer is in the inner
inspection position, the sensor
operably connected to the controller mechanism to permit activation of the
heating means and positioning
means when the drawer is in the inner inspection position.
[0011] In some embodiments, the positioning means may move the heating
means within a single plane
located at a predetermined height relative to the outer surface.
[0012] In some embodiments, the positioning means may include one or more
servo-actuated linear
sliders and the heating means may be mounted to the one or more servo-actuated
linear sliders for
movement. In some embodiments, the one or more servo-actuated linear sliders
may include an X-axis linear
slider for moving the heating means within an X-axis within a single plane and
a Y-axis linear slider for
moving the heating means within a Y-axis within a single plane.
[0013] In some embodiments, the apparatus may further include a component
movement mechanism,
the component movement mechanism allowing for selective displacement of the
machined metal component
relative to the heating means to allow for heating of various sections of the
machined component. The
component movement mechanism may comprise a rotational mechanism, the
rotational mechanism rotating
the machined metal component relative to the heating means. In some
embodiments, the rotational
CA 2906646 2018-03-27 3
=
mechanism may comprise one or more pneumatic cylinders, the pneumatic
cylinders may be releasably
securable to the machined metal component.
[0014/0018] In another aspect, there is provided a method of inspecting a
machined metal component in
a surrounding ambient environment, the machined metal component defining a
component body, the
component body having an outer surface, and an interior region, the interior
region having at least one
internal chamber, for detecting machined substrate fragments resident in the
at least one internal chamber,
the internal chamber communicating with at least one aperture defined on a
surface of the machined metal
component, the method comprising the steps of: providing an apparatus for
inspecting a machined
component, the apparatus including: a heating element configured to apply a
pulse of hot air to at least a
section of one aperture defined on the component surface of the machined metal
component and
communicating with the internal chamber; a positioning element configured to
move the heating element
along one or more points of the heating element relative to the aperture
defined on the outer surface; a
controller mechanism, the controller mechanism operably connected to the
positioning means and heating
means to permit selective control of the application of a pulse of hot air to
the aperture defined in the outer
surface and the positioning of the heating element relative to the outer
surface; an lR detection device,
positioned to detect an IR radiation signal emitted from the section of the
component surface; a signal
processor, operably connected to the IR detection device to receive and
process the detected IR radiation
signal; and a visual output device operatively connected to the signal
processor for receiving the processed
IR radiation signal and displaying a thermal image of the IR radiation signal
emitted from the section of the
component surface; providing a profile of the machined component wherein the
at least one internal
chamber communicates with at least one aperture defined in the outer surface
providing open exposure of
the at least one internal chamber to the ambient surrounding environment;
identifying one or more points
defined in the outer surface, the one or more points each corresponding with
an aperture communicating
with one or more internal chambers; moving the heating element configured to
deliver the pulse of hot air to
the one or more points defined on the outer surface and applying a pulse of
hot air sequentially to the one or
more points defined on the outer surface for a time interval at each of the
one or more points, wherein the
pulse of hot air is applied to each of the one or more points defined on the
outer surface sequentially
following the expiration of the time interval for each location, the
application of heat sufficient in
temperature and duration to cause a fragment temperature elevation in at least
one machined metal fragment
present in the at least one internal chamber and a component temperature
elevation in the machined metal
component, wherein fragment temperature elevation has a fragment temperature
elevation rate and the
component temperature elevation has a component temperature elevation rate and
wherein the fragment
temperature elevation rate is greater than the component elevation rate;
producing a thermal image of
temperature distribution of the component surface of the machined metal
component following the
application of the pulse of hot air for the predetermined amount of time at
each of the one or more points;
and detecting one or more heat elevation points within the thermal image of
the temperature distribution
output of the component surface, the heat elevation points indicating the
presence of at least one machined
substrate fragment within one of the one or more internal chambers of the
machined metal component.
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BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0019] To easily identify the discussion of any particular element or act, the
most significant digit or
digits in a reference number refer to the figure number in which that element
is first introduced.
[0020] FIG. I illustrates a routine for detecting machined substrate fragments
resident in the at least one
internal chamber in accordance with one embodiment.
[0021] FIG. 2 illustrates a routine for detecting machined substrate fragments
resident in the at least one
internal chamber in accordance with one embodiment.
[0022] FIG. 3 is a picture of a sample machined metal component to be
inspected in accordance with
one embodiment.
[0023] FIG. 4 is a picture of a sample machined metal component with various
locations identified on
an open cross-sectional profile to be inspected in accordance with one
embodiment.
[0024] FIG. 5 is a picture of a sample machined metal component with a
machined substrate fragment
residing in an internal chamber to be inspected in accordance with one
embodiment.
[0025] FIG. 6 is a picture of a sample machined metal component with a
machined substrate fragment
= residing in an internal chamber to be inspected in accordance with one
embodiment.
[0026] FIG. 7 illustrates a perspective view of the inspection apparatus in
accordance with one
embodiment.
[0027] FIG. 8 illustrates a perspective view of the inspection apparatus with
a machined metal
component loaded for inspection in accordance with one embodiment.
[0028] FIG. 9 illustrates a perspective view of the inspection apparatus with
a machined metal
component loaded for inspection and the apparatus in the inner inspection
position in accordance with one
embodiment.
[0029] FIG. 10 illustrates a front view of the inspection apparatus with a
machined metal component
loaded for inspection and the apparatus in the inner inspection position in
accordance with one
embodiment.
[0030] FIG. 11 illustrates a perspective view of the inspection apparatus with
outer wall removed and
the apparatus in the inner inspection position in accordance with one
embodiment.
[0031] FIG, 12 illustrates a top view of the inspection apparatus with the
apparatus in the outer loading
position in accordance with one embodiment.
[0032] FIG. 13 illustrates a side view of the inspection apparatus with outer
wall removed and the
apparatus in the inner inspection position in accordance with one embodiment.
[0033] FIG. 14 illustrates a top view of the inspection apparatus with the
apparatus in the inner
inspection position in accordance with one embodiment.
[0034] FIG. 15 illustrates a perspective view of the inspection apparatus with
outer wall removed and
the apparatus in the inner inspection position during inspection in accordance
with one embodiment of the
apparatus and method.
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=
[0035] FIG. 16 illustrates an enlarged view of the apparatus and method of
FIG. 15.
[0036] FIG. 17 illustrates a perspective view of the inspection apparatus with
outer wall removed and
the apparatus in the inner inspection position during inspection in accordance
with one embodiment of the
apparatus and method.
[0037] FIG. 18 illustrates an enlarged view of the apparatus and method of
FIG. 17.
[0038] FIG. 19 illustrates a perspective view of the inspection apparatus with
outer wall removed and
the apparatus in the inner inspection position during inspection in accordance
with one embodiment of the
apparatus and method.
[0039] FIG. 20 illustrates an enlarged view of the apparatus and method of
FIG. 19.
[0040] FIG. 21 is a picture of a visual output device in accordance with one
embodiment.
[0041] FIG. 22 is a picture of a visual output device displaying a thermal
image of the machined metal
component during inspection in accordance with one embodiment of the apparatus
and method.
DETAILED DESCRIPTION
[0042] The process as disclosed herein is predicated on the unexpected
discovery that transient thermal
changes applied to a machined metal component can be employed to detect and
locate machining debris
lodged in interior channels defined on the machined metal component. The
process as disclosed herein
has particular efficacy when used to detect machining debris that is composed
of metal material derived
from the machine metal component; i.e. metal fines and the like.
[0043] In some embodiments, the thermal image is produced as the temperature
of the outer surface and
the at least one machined substrate fragment begins cooling to the temperature
of the ambient surrounding
environment following the heating step.
[0044] In some embodiments, producing the thermal image may include directing
an IR detection
device at the outer surface of the machined metal component to detect an IR
radiation signal emitted from
the outer surface, processing the IR radiation signal with a signal processor
operably connected to the IR
detection device and producing and outputting the thermal image from the IR
radiation signal on a visual
output device operatively connected to the signal processor. Processing the IR
radiation signal with a
signal processor may further include formatting the signal with a low-pass
size filter to remove heat
elevation points smaller than a predetermined minimum size from the thermal
image. Processing the IR
radiation signal with a signal processor may further include formatting the
signal with a high-pass size
filter to remove heat elevation points larger than a predetermined maximum
size from the thermal image.
[0045] In some embodiments, the disclosed method may further include
calculating at least one
temperature difference value between the temperature of the at least one heat
elevation points and the
component temperature elevation. Processing the IR radiation signal with a
signal processor may further
include formatting the signal with a low-pass temperature filter to remove
heat elevation points
corresponding with the temperature difference value being smaller than a
predetermined minimum
temperature difference value from the thermal image. In some embodiments,
processing the IR radiation
CA 02906646 2015-10-01
signal with a signal processor may further include formatting the signal with
a high-pass temperature filter
to remove heat elevation points corresponding with the temperature difference
value being larger than a
predetermined maximum temperature difference value from the thermal image.
[0046] In some embodiments, the IR detection device may include an IR camera.
[0047] In some embodiments, the signal processor may be a computer and the
output device may be a
computer screen operably connected to the computer. The computer may be
configured to process the IR
radiation signal and output the IR radiation signal in the form of a color-
temperature map thermal image
on the computer screen. In some embodiments, the color-temperature map thermal
image may be
configured to display colors corresponding with pre-defined temperatures
across the thermal image of the
outer surface of the machined metal component.
[0048] In some embodiments, the heat elevation points appear as a different
color from surrounding
areas of the outer surface within the color-temperature map thermal image.
[0049] In some embodiments, the machined metal component may include a metal
or a metallic alloy.
[0050] The machined substrate fragment may be substantially surrounded by
ambient air within the
internal chamber. The machined substrate fragment may constitute a metallic
chip separated from the
machined component body during the machining process.
[0051] In some embodiments, the heat elevation points may include a positive
temperature gradient
between the heat elevation points and the surrounding outer surface, the
positive temperature gradient
corresponding with the presence of a machined substrate fragment
[0052] In the process disclosed herein, the target machined metal component
inspection method as
disclosed herein includes the step of providing a profile the machined metal
component as in reference
numeral 1 in Figure 1. The machined metal component is typically one which is
prepared for subsequent
processing and/or assembly. Suitable metal parts will be configured to include
a component body having
at least one internal chamber defined therein. The at least one internal
chamber can be defined in the
component body by any suitable method including, but not limited to, casting,
machining and the like. In
the method disclosed the machined metal component may be a component part of a
final mechanical part
or mechanism that can be assembled in later subsequent post inspection steps
to produce a final assembled
component. The machined metal component can be a profile or other suitable sub-
device. In certain
applications, the profile can be an open cross-sectional profile across the
machined metal component. The
machined metal component under inspection by the process disclosed can have at
least one internal
chamber that communicated with at least one aperture defined in the outer
surface of the machined metal
component thereby providing open exposure of the at least one internal chamber
to the ambient
surrounding environment. One non-limiting example is depicted in Fig. 3 and is
discussed in greater
detail subsequently.
[0053] The method also includes a step of applying heat 2 to a least a section
of the outer surface of the
machined metal part component under inspection. The application step 2
proceeds for an interval and at a
temperature sufficient to cause a fragment temperature elevation in at least
one machined substrate
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=
= fragment present in the at least one internal chamber. The heat
application step 2 also causes a component
temperature elevation in the machined metal component. The heat application
step 2 provides a fragment
temperature elevation having a fragment temperature elevation value and a
component temperature
elevation having a component temperature elevation value in which the fragment
temperature elevation
value is greater than the component temperature elevation value. Following the
application step 2, the
method also includes the steps of producing a thermal image of temperature
distribution 3 and detecting
one of more heat elevation points within the thermal image 4. As the fragment
temperature elevation
value is greater than the component temperature elevation value, the heat
elevation points indicate the
presence of at least one machined substrate fragment within one or more
internal chambers of the
machined metal component.
[0054] Producing a thermal image 3 may include the steps of directing an IR
detection device at the
outer surface of the machined metal component 5, processing the IR radiation
signal captured by the IR
detection device with a signal processor operably connected to the IR
detection device 6, and outputting a
thermal image from the IR radiation signal on a visual output device 7. The
method also includes a step
in which the difference between the fragment temperature elevation value and
the component temperature
elevation value is detected and located relative to the machined metal
component. In certain embodiments
of the process disclosed, the detection and location is accomplished by the
production of a thermal image
of temperature distribution of the outer surface of the machined metal
component. The producing step 3
occurs after the heat application step 2.
[0055] Once the differences in fragment temperature elevation values and
machined metal component
have been ascertained, the method includes detecting one or more heat
elevation points within the thermal
image of the temperature distribution of the outer surface of the machined
metal component as at
reference numeral 8. The elevation points are indicative of the presence of at
least one machined substrate
fragment present within one or more internal chambers of the machined metal
component. Where desired,
the temperature elevation points can be detected with a suitable infrared
detection device.
[0056] As seen in the exemplary embodiment of Figure 3, the machined metal
component 10 comprises
standard transmission component valve body, which valve body would be
implemented for use in high
performance engine transmissions. The machined metal component 10 of the
exemplary embodiment is
cast from cast iron. This valve body of the exemplary embodiment controls the
shifting process in
automatic transmissions. The valve body of the exemplary embodiment contains a
one or more internal
chambers 12, through which an automotive hydraulic system would push
pressurized hydraulic fluid in
order to activate and deactivate appropriate clutches and band servos to
control up and down shifting of
gears. As such, it is important that such internal chambers 12 remain clear
from debris, including
substrate debris post-machining, in order to ensure smooth and effective
transfer of hydraulic fluid
through the internal chambers 12. Presence of substrate fragments within the
internal chambers 12 can
cause sub-optimal performance and in worst cases scenario transmission
failure.
[0057] The profile 20 of the exemplary embodiment of Figure 3 is an open cross-
sectional profile
having a number of open apertures 18 defined on the outer surface 14. The one
or more internal chambers
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12 communicate with one or more apertures 18 defined in the outer surface 14
providing open exposure to
the interior region 16 of the machined component body 22 and open exposure of
one or more internal
chambers 12 to the ambient surrounding environment. In the exemplary
embodiment illustrated in Figure
3, one or more internal chambers 12 comprise gear valves of varying shapes and
depths within the interior
region 16 of the machined metal component 10.
10058] As seen in the embodiment of Figure 4, the heating step 2 may comprise
the step of applying
heat either simultaneously or consecutively in a predetermined sequence to a
plurality of locations defined
on the outer surface 14 of the machined metal component 10. The heating means
70 may apply heat for a
predeteimined amount of time to each of the plurality of locations. Heat can
be applied to each of the
locations defined on the outer surface 14 for a suitable defined interval. The
heat application interval
associated with each location can be the same or can be varied depending on
factors such as localized
mass, the specific architecture details present in the location, etc. Where
sequential heating is employed,
it is contemplated that heating at a specific location will commence after the
expiration of the
predetermined amount of time at the prior location. It is also contemplated
that the heating step can occur
in a combination of sequential positions.
10059] Referring to the exemplary embodiment of Figure 4, heat may be applied
sequentially to each of
the positions I - IX for the following predetermined amount of time at each
position:
3 seconds
seconds
3 seconds
IV 3 seconds
V 4 seconds
VI 3 seconds
VII 3 seconds
VIII - 3 seconds
IX 2 seconds
100601 Heating interval variation can be determined based on depth and
intricacy of the one or more
internal chambers 12 at each position. It is also contemplated that the
heating interval can be varied based
on details such as potential size of machined substrate fragment 24 to be
detected for any specific
application. In some applications, particularly small machined substrate
fragments 24 may be lodged
deeply within intricate chambers, and accordingly, the application of heat
must be sustained for longer
duration in order to create a sufficient fragment temperature elevation to
ensure that the machined
substrate fragment will create a heat elevation point in the thermal image
following heating.
100611 Referring to the exemplary embodiment of Figure 4, specifications for
this exemplary
embodiment require detection of any machined substrate fragment having minimum
size of 2millimeter X
2millimeter surface area. Accordingly, the specific parameters of the heat
application step of the method
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disclosed herein have been calibrated with the above referenced time durations
at each position I - IX, the
details of which will be discussed below. Given the depth and intricacy of the
one or more internal
chambers 12 at each location I - IX, and the minimum size requirements for
detection of machined
substrate fragments, these predetermined time values at each location I - IX
ensure that adequate heat has
been applied to induce sufficient fiugment temperature elevation for any
machined substrate fragments
positioned within any of the one or more internal chambers 12 at each
position. The duration of the
application of heat interval per specific position based on fragment detection
specification can be deduced
by the skilled artisan based upon the teachings contained with in this
disclosure. Similarly, specific
heating intervals associated with specific locations in the machined metal
component can be deduced by
the skilled artisan based upon the present disclosure.
100621 As seen in Figure 5 and Figure 6, the machined substrate fragment may
comprise any substrate
fragment that is substantially surrounded by ambient air within the one or
more internal chambers 12.
Figure 6 illustrates a machined substrate fragment comprising a metallic chip
26 resident within one or
more internal chambers 12. Following machining of the machined metal component
10, such metallic chip
26 separated from the machined component body 22 during the machining process
and may become
lodged within one or more internal chambers 12 of the machined component body
22. Such metallic chips
can cause significant damage if left undetected and the machined metal
component 10 is installed in the
final product (in this exemplary embodiment, the final product being an
automobile).
100631 However, as seen in the embodiment of Figure 5, the machined substrate
fragment may
comprise any substrate fragment that is substantially surrounded by ambient
air within the one or more
internal chambers 12. The machined substrate fragment 24 illustrated in Figure
5 is attached to and
extends outward from the machined component body 22 within the one or more
internal chambers 12. As
discussed in detail below, based on optimization of the application of heat by
the heating means 70, in
order to apply heat sufficient in temperature and duration to cause a greater
fragment temperature
elevation rate than the component temperature elevation rate, as well as the
sensitivity of the IR detection
device 66 and the signal processor 54, the disclosed method can detect
machined substrate fragments of
various sizes and shapes. A skilled artisan applying the teachings disclosed
herein could detect machined
substrate fragments of any shape or size by optimizing resolution as well as
the field of view of the IR.
detection device 66. For example, the IR detection device 66 can be focused on
a much smaller area,
thereby creating a thermal image with far greater resolution (pixels per
millimeter) thereby permitting
detection of machined substrate fragments 24 of far smaller sizes.
100641 Referring to the embodiment of Figure 7 and Figure 8, the apparatus 28
of the exemplary
embodiment may comprise a housing 40 having an outer wall 52 defining an inner
chamber 30. The
apparatus 28 may further comprise a drawer 38, the drawer 38 being configured
to receive and retain the
machined metal component 10. Figure 8 illustrates the drawer 38 in the outer
loading position 36, wherein
at least a portion of the drawer 38 is outside of the inner chamber 30. The
outer loading position 36 allows
for loading of the machined metal component 10 into the drawer 38 for
inspection. Loading can either be
manually completed by a user, or automated using automated means, such as a
loading robot.
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[0065] The drawer 38 may also comprise a drawer frame 44. Referring to Figure
7 and Figure 8, the
drawer frame 44 receives and retains the machined metal component 10. As seen
in Figure 7 and Figure 8,
the machined metal component 10 is loaded into the drawer frame 44 of the
drawer 38 in order to secure
the machined metal component 10 for inspection.
[0066] The apparatus 28 comprises a controller mechanism 32 operably connected
to the positioning
means 68 and the heating means 70 (illustrated in Figure 11). The apparatus 28
may also comprise a
signal processor 54, the signal processor 54 operably connected to the IR
detection device 66 (illustrated
in Figure 11) to receive and process a detected IR radiation signal from the
machined metal component
10.
[0067] In the embodiment of Figure 7 to Figure 10, the controller mechanism 32
and the signal
processor 54 may be housed within a control shelf 46, the control shelf having
a left shelf door 48 and a
right shelf door 50 opening up to an enclosed shelf space (not illustrated)
within the control shelf 46.
[0068] The controller mechanism 32 may comprise a standard programmable logic
controller, such as a
standard Allen Bradley programmable logic controller. A person skilled in the
art would appreciate that
any similar control apparatus that could serve the same function would be an
adequate controller
mechanism 32. As discussed in detail below, the signal processor 54 may
comprise a standard computer
equipped with commercially available thermal image processing software. Both
the programmable logic
controller and the computer of the embodiment of Figure 7 to Figure 10 could
be housed within the
control shelf 46, which control shelf 46 could be attached to the outer wall
52 of the housing 40.
[0069] The apparatus 28 may further comprise a visual output device 34, the
visual output device 34
being operatively connected to the signal processor 54 for receiving the
processed IR radiation signal and
displaying a thermal image of the IR radiation signal emitted from the section
of the outer surface 14. In
the exemplary embodiment of Figure 7 to Figure 10, the visual output device 34
may comprise a standard
computer monitor screen connected to the signal processor 54 computer housed
within the control shelf
46, and as illustrated in Figure 7 and Figure 8, may be disposed upon the left
shelf door 48 of the control
shelf 46.
[0070] Referring to Figure 9 and Figure 10, once the machined metal component
10 is loaded into the
drawer 38, the drawer 38 is configured for movement from the outer loading
position 36 (as seen in
Figure 7 and Figure 8) to the inner inspection position 58. In the inner
inspection position 58, the drawer
38, with the machined metal component 10 received and retained therein, is
inside of the inner chamber
30 of the housing 40. In the embodiment of Figure 9 and Figure 10, the
apparatus 28 may further
comprise a sensor mechanism 56. The sensor mechanism 56 detects when the
drawer 38 is in the inner
inspection position 58. Once in the inner inspection position 58, the sensor
mechanism 56 is operably
connected to the controller mechanism 32 such that the sensor mechanism 56
signals to the controller
mechanism 32 to permit automatic activation of the heating means 70 and the
positioning means 68, in
order to begin the inspection process.
[0071] Referring to Figure 10, the apparatus 28 may further comprise locking
means 60 for selectively
locking and unlocking the drawer 38 within the inner chamber 30 when the
drawer 38 is in the inner
CA 02906646 2015-10-01
inspection position 58. The locking means 60 can comprise any locking means
known in the art, such as
bolt-lock system. Additionally, the locking means 60 may comprise a
pneumatically activated bolt-lock
system, which bolt-lock system can be automatically locked and unlocked by the
controller mechanism 32
before and after the completion of the inspection process respectively. This
controller mechanism 32
activated/de-activated locking prevents a user from moving the drawer 38 from
the inner inspection
position 58 to the outer loading position 36 prior to completion of the
inspection process, thereby
preventing user error and/or injury to a user.
[0072] Figure 11 illustrates the apparatus 28 with outer wall 52 of the
housing 40 removed along with
the control shelf 46. As seen in the exemplary embodiment of Figure 11, the
inner chamber 30 may
contain the IR detection device 66, the positioning means 68 and the heating
means 70. From a practical
perspective, this allows the operation of the apparatus 28 to take place
entirely within the inner chamber
30 of the housing 40, in order to mitigate against user injuries and/or user
error.
100731 The drawer 38 may slide along a drawer frame railing 64 in order to
move from the outer
loading position 36 to the inner inspection position 58.
[0074] In the exemplary embodiment of Figure 11, the IR detection device 66 is
positioned above the
machined metal component 10 and the drawer 38 and aimed downward towards the
machined metal
component 10 during the inspection process. A skilled artisan would appreciate
that the IR detection
device 66 can be positioned anywhere sufficient to allow the IR detection
device 66 to detect an IR
radiation signal emitted from the machined metal component 10. Positioning of
the rft detection device 66
will depend on a number of factors, including without limitation the
capabilities of the specific IR
detection device 66 implemented, the ability to acquire an unobstructed view
of the machined metal
component 10 and the amount of precision required in capturing an adequate IR
radiation signal, factors
which are well within the purview and control of a skilled artisan.
[0075] Similarly, the heating means 70 and the positioning means 68 are
positioned above the
machined metal component 10 and the drawer 38 when the drawer 38 is in the
inner inspection position
58. It would be within the capability of a skilled artisan to position the
heating means 70 and the
positioning means 68 as required in order to optimize the necessary
application of heat in a variety of
specific circumstances and the scope of the disclosed method and apparatus
should not be limited to the
exemplary positioning. The heating means 70 and the positioning means 68 can
be secured in position to
the housing 40 using any means known in the art, such as the mounting bar 62
used in the embodiment of
Figure 11.
[0076] Referring to Figure 12, a user may load the machined metal component 10
into the drawer 38
for inspection when the drawer 38 is in the outer loading position 36. The
drawer 38 of the embodiment of
Figure 12 comprises a drawer frame 44, which drawer frame 44 is a fixture
configured to receive and
retain the machined metal component 10. The drawer frame 44 may further
comprise a pair of drawer
frame securing tabs 80, which tabs can be manually shifted into place by a
user for further secure the
machined metal component 10 within the drawer frame 44. Alternatively, the
drawer frame securing tabs
80 may comprise hydraulic tabs that can be controlled by the controller
mechanism 32 in order to
11
CA 02906646 2015-10-01
automatically shift the drawer frame securing tabs 80 into position upon
placing the machined metal
component 10 within the drawer frame 44. This mechanism has the added benefit
of ensuring that the
machined metal component 10 is correctly placed into the drawer frame 44,
given that the controller
mechanism 32 can be configured to activate the drawer frame securing tabs 80
when the machined metal
component 10 is correctly positioned within the drawer frame 44. Furthermore,
this can also prevent the
machined metal component 10 from being released from the drawer frame 44 until
completion of
inspection, as the controller mechanism 32 can be configured to release the
drawer frame securing tabs 80
only upon completion of an inspection cycle.
[0077] The apparatus 28 may also comprise a component movement mechanism 42,
the component
movement mechanism 42 allowing for selective displacement of the of the
machined metal component 10
relative to the heating means 70 to allow for heating of various sections of
the machined metal component
10. The component movement mechanism 42 could comprise any number of
mechanisms known in the
art, including automated movement mechanisms such as servo-actuated or
hydraulic actuated movers.
[0078] In the exemplary embodiment of Figure 12, the component movement
mechanism 42 comprises
a rotational mechanism 76, which rotational mechanism 76 rotates the machined
metal component 10
relative to the heating means 70. The rotational mechanism 76 may comprise one
or more pneumatic
cylinders, and the rotational mechanism 76 of the embodiment of Figure 12
comprises a pair of pneumatic
cylinders 74 positioned on each side of and connected to the drawer frame 44.
The pneumatic cylinders 74
may be controlled by the controller mechanism 32, such that during the
inspection cycle, the controller
mechanism 32 may automatically cause the pneumatic cylinders 74 to rotate the
drawer frame 44 to allow
the heating means 70 to apply heat to various sections around the machined
metal component 10, and
thereafter allowing the IR detection device 66 to detect IR signals from each
of the respective sections
following heating.
[0079] Referring to the illustration of Figure 13, the IR detection device 66
of the exemplary
embodiment comprises an IR camera 82. The IR camera 82 of the exemplary
embodiment of Figure 13
comprises any standard IR camera, such as those manufactured by FLIR A65
Camera with 25mm lens
and 640 X 512 pixel output. In the embodiment of Figure 13, the IR camera 82
is positioned
approximately 4 feet above the machined metal component 10 when the machined
metal component 10 is
in the inner inspection position 58. Based on the specific capabilities of the
IR camera utilized, a skilled
artisan could position the IR camera 82 at any position that would allow the
IR camera 82 to adequately
capture an IR radiation signal from the machined metal component 10 following
heating.
[0080] The heating means 70 of the exemplary embodiment of Figure 13 comprises
a heat gun 94. In
the exemplary embodiment of Figure 13, the heat gun 94 comprises a standard
hot air gun capable of
producing pulses of hot air. The heat gun 94 implemented in the exemplary
embodiment of Figure 13 is a
standard Steinel HG 2000E. The heat gun 94 can be mounted to the positioning
means 68 using any
standard mounting mechanism known in the art, such as a basic mounting
bracket. A skilled artisan could
use any number of available heating means 70 known in the art capable of
creating a greater temperature
elevation rate in one or more machined substrate fragments located in the one
or more internal chambers
12
CA 02906646 2015-10-01
12 of the machined metal component 10 compared to the component temperature
elevation rate. This
could include any number of heat guns currently available, radiation heating
elements as well as other IR
heaters or other heating means in combination with air blowing means to
circulate heat through the one or
more internal chambers 12.
[0081] In the exemplary embodiment of Figure 13, the positioning means 68 move
the heating means
70 within a single plane 88 located at a predetermined height 90 relative to
the outer surface 14 of the
machined metal component 10. In the exemplary embodiment illustrated in Figure
13, the predetermined
height 90 of the single plane 88 is approximately 1.5 inches from the outer
surface 14 of the machined
metal component 10. A skilled artisan can position the heating means 70 at any
predetermined location
necessary, depending on the power of the heating means 70, the intricacy of
the internal chambers of the
machined metal component 10 and the detection requirements. Such modifications
would be within the
purview of a skilled artisan and the scope of the method and apparatus
disclosed herein should not be
limited to the positioning of the exemplary embodiment.
[0082] Figure 14 provides an overhead view of the exemplary embodiment, with
the machined metal
component 10 in the inner inspection position 58. As seen in Figure 14, the IR
camera 82 is positioned
above the machined metal component 10 in order to capture a thermal image of
the outer surface 14 of the
machined metal component 10 following the application of heat by the heating
means 70. The machined
metal component 10 is held in place in the drawer 38 by the drawer frame
securing tabs 80 in order
prevent movement of the machined metal component 10 during the inspection
process.
[00831 As seen in Figure 14, the heating means 70 is mounted to a positioning
means 68, which
positioning means 68 move the heating means 70 to various locations relative
to the outer surface 14 of
the machined metal component 10. One skilled in the art could readily
implement any number of
positioning means 68 well known in the art , including without limitation such
mechanisms as multi-axis
robots, one or more servo-actuated linear sliders or any form of manually
operated sliders. Accordingly,
the scope of the positioning means 68 would include any means that can move
the heating means 70 to
various locations relative to the outer surface 14 of the machined metal
component 10 and should not be
limited in scope to the specific means of the exemplary embodiment.
[0084] In the exemplary embodiment of Figure 14, the positioning means 68
comprises servo-actuated
linear sliders 86. The heat gun 94 is mounted to the servo-actuated linear
sliders 86 for movement relative
to the outer surface 14 of the machined metal component 10. Specifically, in
the exemplary embodiment
of Figure 14, the servo-actuated linear sliders 86 comprise a Y-axis linear
slider 84 and an X-axis linear
slider 98, which Y-axis linear slider 84 moves the heating means 70 along a Y-
axis 100 within the single
plane 88 (as illustrated in Figure 13) and which X-axis linear slider 98 moves
the heating means 70 along
an X-axis 102 within the single plane 88 (as illustrated Figure 13). In the
illustrated exemplary
embodiment of Figure 14, the X-axis linear slider 72 and Y-axis linear slider
84 comprise standard servo-
actuated linear sliders such as those produced by IAL Also, the heating means
70 could be mounted to a
multi-axis robot for movement in any number of directions.
13
CA 02906646 2015-10-01
100851 The controller mechanism 32, which in the exemplary embodiment
comprises a programmable
logic controller, is operably connected to the servo-actuated linear sliders
86, to allow a user to program
automatic movement of the heating means 70 to a plurality of different
positions along the Y-axis 100 and
the X-axis 102 within the single plane 88, to permit the Heating means 70 to
apply heat to a plurality of
locations defined on the outer surface of the machined metal component 10.
[0086] Figure 14 illustrates the heating means 70 in a rest position 104. When
in the rest position 104,
the heating means 70 is positioned outside of the direct view of the IR camera
82, thereby providing the
IR camera 82 with an unobstructed view of the outer surface 14 of the machined
metal component 10.
100871 Figures 11 to 16 illustrate the functioning of the embodiment of
apparatus 28 in accordance with
the method disclosed herein. Referring to Figure 4, Figure 15 and Figure 16,
after the machined metal
component 10 is loaded into inner inspection position 58, the controller
mechanism 32 causes the X-axis
linear slider 72 and Y-axis linear slider 84 to move the heat gun 94 from the
rest position 104 to a position
in the single plane 88 immediately above position I on the outer surface 14.
Once reaching position I, the
controller mechanism 32 will cause the heat gun 94 to apply a pulse of hot air
at a temperature of 600
degrees Celsius for a duration of three (3) seconds to position I on the outer
surface 14.
[0088] Following completion of the three (3) second duration of hot air pulse
at position I, the
controller mechanism 32 can cause the heat gun 94 to move along the X-axis
linear slider 72 and Y-axis
linear slider 84 back to the rest position 104. The heat gun 94 will remain at
the rest position 104 for
sufficient time to allow the IR camera 82 to capture the IR signal from the
outer surface 14, which in the
exemplary embodiment is approximately two (2) seconds. While at the rest
position 104, the IR camera 82
will have unobstructed view of the outer surface 14 following the application
of heat to position I, and can
detect an IR radiation signal emitted from the outer surface 14 following the
application of heat.
[0089] Referring to Figure 4, Figure 17 and Figure 18, after completion of
heating and IR radiation
signal detection at the first position I, the controller mechanism 32 causes
the X-axis linear slider 72 and
Y-axis linear slider 84 to move the heat gun 94 from the rest position 104 to
a position in the single plane
88 immediately above position II on the component surface 108. Once reaching
position II, the controller
mechanism 32 will cause the heat gun 94 to apply a pulse of hot air at a
temperature of 600 degrees
Celsius for a duration of five (5) seconds to position II.
[0090] Following completion of the five (5) second duration of hot air pulse
at position II, the
controller mechanism 32 can cause the heat gun 94 to move along the X-axis
linear slider 72 and Y-axis
linear slider 84 back to the rest position 104. The heat gun 94 will remain at
the rest position 104 for
approximately two (2) seconds. While at the rest position 104, the IR camera
82 will have unobstructed
view of the outer surface 14 following the application of heat to position II,
and can detect an IR radiation
signal emitted from the outer surface 14 following the application of heat.
[0091] The controller mechanism 32 can cause automation of this cycle of
consecutive movement of
the heat gun 94 to each of the plurality of locations I - IX, causing the heat
gun 94 to apply heat at each
location for the requisite predetermined amount of time at each location and
then returning to the rest
position 104 to permit the IR camera 82 to detect an IR radiation signal
emitted from the outer surface 14
14
= CA 02906646 2015-10-01
= following the application of heat. This process will proceed
consecutively for each position I - IX, with
the controller causing the heat gun 94 to move sequentially from each location
to the next following the
predetermined amount of time at each location.
[0092] As illustrated in Figure 15 and Figure 16, after moving through each
position I - VIII, applying
heat for the predetermined amount of time at each location I - VIII and
detection of the IR radiation signal
at each location I - VIII, the controller mechanism 32 moves the heat gun 94
to the final location IX. The
controller mechanism 32 causes the heat gun 94 to apply a pulse of hot air for
two (2) seconds to the final
position IX. After completion of the two (2) second pulse of hot air, the
controller mechanism 32 will
cause the X-axis linear slider 72 and Y-axis linear slider 84 to move the heat
gun 94 to the rest position
104 to permit the IR camera 82 to detect the IR radiation signal following the
application of heat.
[0093] Optionally, the exemplary embodiment of Figures 11 to 16 may include a
pair of pneumatic
cylinders 74 connected to the drawer frame 44. The controller mechanism 32 can
automatically cause the
pneumatic cylinders 74 to rotate the drawer frame 44 and the machined metal
component 10 to allow for
the application of heat to other sections of the machined component body 22.
In the embodiment of Figure
20, following the application of heat at the final location IX and detection
of the emitted IR radiation
signal, the controller mechanism 32 may cause the pneumatic cylinders 74 to
rotate the machined metal
component 10 180 degrees to allow for the inspection method herein disclosed
to similarly be applied to
various locations on the opposing side (not illustrated) of the machined metal
component 10.
[0094] Figure 21 and Figure 22 illustrate the visual output device 34 of the
exemplary embodiment,
before and after the detection and outputting of the IR radiation signal in
the thermal image 116
respectively. In the exemplary embodiment, at the first location I prior to
the application of heat, the
machined component body 22 and machined substrate fragment 24 both had
temperature values of
approximately 27 degrees Celsius, which was approximately equal to the
temperature of the ambient
surrounding environment. At the first position I, the heat gun 94 applied a
sustained pulse of hot air for
three (3) seconds in duration. Immediately thereafter, the machined substrate
fragment 24 was
approximately 112 degrees Celsius in temperature and the outer surface 14 was
approximately 34 degrees
celsius in temperature. Given the large surface area, density, and weight of
the machined component body
22, it is expected that there will be a relatively small component temperature
elevation across the outer
surface 14. However, given that the machined substrate fragment 24 is much
smaller in size, with a
surface area substantially surrounded by air within the one or more internal
chambers 12, it is expected
that the fragment temperature elevation rate will be greater than the
component temperature elevation rate.
[0095] In the exemplary embodiment of Figure 22, producing the thermal image
116 comprises
directing the IR detection device 66 at the outer surface 14 of the machined
metal component 10 to detect
an IR radiation signal emitted from the outer surface 14, processing the IR
radiation signal with a signal
processor 54 operably connected to the IR detection device 66 and producing
and outputting the thermal
image 116 from the IR radiation signal on a visual output device 34
operatively connected to the signal
processor 54. In the exemplary embodiment, heat is applied at each
predetermined position I ¨ IX for the
predetermined amount of time. Following the application of heat at each
position I ¨ IX, the IR Camera
CA 02906646 2015-10-01
82 detects the IR radiation signal and the signal processor outputs a thermal
image 116. This process of
applying heat, detecting the IR radiation signal and outputting a thermal
image occurs at each
predetermined position I ¨ IX.
[0096] Illustrated in Figure 22 is the thermal image 116 created following
application of heat at the fifth
predetermined position V. Referring to Figure 22, the IR camera 82 detected
the IR radiation signal
shortly after the completion of heating at the fifth location V, the signal
processor 54 processed the IR
radiation signal and outputted the thermal image 116 on the visual output
device 34. The signal processor
54 of the exemplary embodiment of Figure 22 is a standard Windows based PC
operating standard image
processing software. In this exemplary embodiment, the software used is
VISIONPRO, produced by
Cognex Corporation. The visual output device 34 can be a standard computer
screen 110, and in the
exemplary embodiment, the visual output device 34 is a standard touch screen
HMI monitor.
[0097] The signal processor 54 is configured to process the 1R radiation
signal and output the IR
radiation signal in the form of a color-temperature map 112 thermal image 116
on the computer screen
110. The color-temperature map 112 thermal image 116 may be configured to
display colors
corresponding with pre-defined temperatures across the thermal image 116 of
the outer surface 14 of the
machined metal component 10. In the exemplary embodiment of Figure 22, given
that the surrounding
component temperature elevation 118 is approximately the same across the
entire outer surface 14 (i.e.
approximately 33 degrees Celsius) the majority of the thermal image 116
appears as a single color (the
color black in Figure 22) corresponding with approximately the same
temperature across the outer surface
14. In contrast, the heat elevation points 114 appear as a different color
from the surrounding areas of the
outer surface 14 within the color-temperature map 112 thermal image 116. As
illustrated in Figure 22, the
heat elevation points 114 appear as a shade of green. As the heat elevation
points 114 appear as a different
color, which color is configured to correspond with a specific temperature, in
the exemplary embodiment
of Figure 22 the heat elevation points 114 indicate the presence of at least
one machined substrate
fragment 24 within one or more internal chambers 12 of the machined metal
component 10.
[0098] Given that the fragment temperature elevation rate is greater than the
component temperature
elevation rate, the heat elevation points 114 comprise a positive temperature
gradient between the heat
elevation points 114 and the surrounding outer surface 14. This positive
temperature gradient corresponds
with the presence of a machined substrate fragment 24.
[0099] In the exemplary embodiment of Figure 22, the IR camera 82 captures the
1R radiation signal at
a single point in time shortly after the completion of the heating process and
the thermal image 116 is
displayed as a color-temperature map 112 with specific colors corresponding
with specific temperatures
on the outer surface 14 at the point time when the IR radiation signal is
captured. However, given that the
machined substrate fragment 24 has a fragment temperature elevation rate that
is greater than the
component temperature elevation rate, in alternative embodiments the thermal
image of temperature
distribution may comprise a real-time transient image of temperature
distribution across the outer surface
14.
16
CA 02906646 2015-10-01
[00100] In the exemplary embodiment of Figure 22, immediately following the
application of heat, the
machined substrate fragment 24 was approximately 112 degrees Celsius in
temperature and the machined
component body 22 was approximately 34 degrees Celsius in temperature,
indicating that the fragment
temperature elevation rate was greater than the component temperature
elevation rate. Therefore, a real-
time transient image of temperature would also identify heat elevation points
114 corresponding with the
presence of machined substrate fragments. Similarly, the fragment temperature
cooling rate will also be
greater than the component temperature cooling rate. In the exemplary
embodiment of Figure 22, the
temperature of the machined substrate fragment 24 within approximately 6
seconds following the
application of heat had declined from approximately 112 degrees Celsius to
approximately 34 degrees
Celsius. As such the thermal image 116 may be produced as a real-time
transient image as the temperature
of the outer surface 14 and the at least one machined substrate fragment 24
begins cooling to the
temperature of the ambient surrounding environment following the heating step.
Such modifications to the
thermal image 116 can be carried out by a skilled artisan, and such a skilled
person would be able to
correlate heat elevation points 114 within the thermal image 116 to the
presence of machined substrate
fragment 24.
[00101] In accordance with the method herein described, the heat elevation
points 114 comprise a
positive temperature gradient between the heat elevation points 114 and the
and the surrounding
component temperature elevation 118. In accordance with the method herein
described, the positive
temperature gradient corresponds with the presence of a machined substrate
fragment 24 within the one or
more internal chambers 12 of the machined component body 22.
[00102] In some applications, one skilled in the art may wish to filter out
heat elevation points 114
smaller than a predetermined minimum size or greater than a predetermined
maximum size, as such heat
elevation points 114 may constitute 1R radiation signal noise, foreign
material inclusions within the
machined component body 22 that elevate in temperature at a greater rate than
the surrounding outer
surface 14, or other undesirable elements not requiring inspection.
[00103] In the exemplary embodiment of Figure 22, machined substrate fragments
24 smaller than 2
millimeters X 2 millimeters were considered negligible based on specifications
of the exemplary
embodiment. Fragments of such size can be correlated with a respective pixel
size within the thermal
image 116 of Figure 22; ; in the exemplary embodiment, a 2 millimeters X 2
millimeters fragment with
correspond with a size of approximately 10-20 pixels within the thermal image
116. As such, the method
may further comprise the steps of formatting the IR radiation signal with a
low-pass size filter to remove
heat elevation points smaller than a predetermined minimum size from the
thermal image. In the
exemplary embodiment, the low-pass size filter may remove heat elevation
points 114 smaller than the
corresponding pixel size within the thermal image 116, as such machined
substrate fragments 24 would be
negligible in size or such heat elevation points 114 may correspond with
inclusions that do not constitute
machined substrate fragments 24 within the one or more internal chambers 12.
The method may
optionally comprise the steps of formatting the signal with a high-pass size
filter to remove heat elevation
points larger than a predetermined maximum size from the thermal image.
17
CA 02906646 2015-10-01
= 1001041 As discussed above, in the exemplary embodiment of Figure 22, the
temperature difference
value between the machined substrate fragment 24 and the outer surface 14
immediately following the
application of heat is approximately 85-90 degrees Celsius. Foreign material
inclusions in the machined
component body 22 or other foreign materials may also absorb heat at different
temperatures than the
machined component body 22, thereby causing heat elevation points 114 to
appear in the thermal image
116 which do not correspond with the presence of machined substrate fragments
24.
[00105] Knowing the approximate fragment temperature elevation rate and the
standard difference in
temperature value between the machined substrate fragment 24 and the outer
surface 14 following the
application of heat, a skilled artisan may optimize the processing of the
thermal image to optionally
include the steps of calculating at least one temperature difference value
between the temperature of the at
least one heat elevation points and the component temperature elevation. The
signal processor may format
the IR radiation signal with a low-pass temperature filter to remove heat
elevation points corresponding
with the temperature difference value being smaller than a predetermined
minimum temperature
difference value from the thermal image. As such, one skilled in the art may
filter the thermal image 116
to remove heat elevation points 114 having temperatures that do not correspond
with machined substrate
fragments 24 resident within the one or more internal chambers 12. Similarly,
one skilled in the art may
optionally format the IR radiation signal with a high-pass temperature filter
to remove heat elevation
points corresponding with a temperature difference value being larger than a
predetermined maximum
temperature difference value from the thermal image.
1001061 The disclosed acts of optimizing the output format of the thermal
image 116 and/or filtering the
thermal image 116 can be deduced by the skilled artisan based upon the
teachings contained within this
disclosure. Through optimization, one skilled in the art can readily determine
the appropriate temperature
and duration for the application of heat in order to create the requisite
fragment temperature elevation rate.
Similarly, one skilled in the art can apply known color and filtering
techniques in order to ensure that heat
elevation points 114 appearing within the thermal image 116 correspond with
machined substrate
fragment 24 within the one or more internal chambers 12 of the machined
component body 22. Such
testing, IR. radiation signal detection and image processing techniques can be
deduced by the skilled
artisan based upon the teachings contained within this disclosure.
[00107] The foregoing embodiments are described in an illustrative sense.
Further features and sub-
combinations of aspects of the disclosed method and apparatus will be evident
to skilled artisans. All of
these features and sub-combinations are intended to be encompassed by the
following claims.
18
