U.S. patent application number 10/910896 was filed with the patent office on 2005-01-13 for heat-flux gage, manufacturing method and manufacturing device thereof.
This patent application is currently assigned to International Business Machines Corporation. Invention is credited to Choi, Jong Hak, Koo, Seong Wan, Lee, Yeol Hwa.
Application Number | 20050008062 10/910896 |
Document ID | / |
Family ID | 29208744 |
Filed Date | 2005-01-13 |
United States Patent
Application |
20050008062 |
Kind Code |
A1 |
Lee, Yeol Hwa ; et
al. |
January 13, 2005 |
Heat-flux gage, manufacturing method and manufacturing device
thereof
Abstract
A heat-flux gage, a manufacturing method and a manufacturing
device thereof which are improved from circular foil heat-flux gage
disposed in ASTM E511 comprise: a cylindrical body having a
receiving space therein, and a foil mounting hole on one end
thereof; a foil including a heat absorption surface, an inner
surface facing the heat absorption surface, and a radiant side
surface connecting the heat absorption surface and the inner
surface, wherein the inner surface faces toward the receiving space
and the radiant side surface is contacted to a side surface of the
foil mounting hole; a foil lead wire connected on a center of the
inner surface of the foil; a body lead wire connected to an
opposite end of the foil mounting hole on the cylindrical body; and
a filler filled in the inner receiving space, to prevent the foil
lead wire from being damaged by fixing the foil lead wire.
Inventors: |
Lee, Yeol Hwa; (Daejeon,
KR) ; Koo, Seong Wan; (Daejeon, KR) ; Choi,
Jong Hak; (Daejeon, KR) |
Correspondence
Address: |
SCULLY, SCOTT, MURPHY & PRESSER
400 Garden City Plaza
Garden City
NY
11530
US
|
Assignee: |
International Business Machines
Corporation
Armonk
NY
|
Family ID: |
29208744 |
Appl. No.: |
10/910896 |
Filed: |
August 4, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10910896 |
Aug 4, 2004 |
|
|
|
10395947 |
Mar 24, 2003 |
|
|
|
Current U.S.
Class: |
374/29 ;
374/E17.015 |
Current CPC
Class: |
G01K 17/20 20130101 |
Class at
Publication: |
374/029 |
International
Class: |
G01K 017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 19, 2002 |
KR |
21693/2002 |
Claims
1. A heat-flux gage comprising: a cylindrical body having a
receiving space therein, and a foil mounting hole on one end
thereof; a foil including a heat absorption surface, an inner
surface facing the heat absorption surface, and a radiant side
surface connecting the heat absorption surface and the inner
surface, wherein the inner surface faces toward the receiving space
and the radiant side surface is contacted to a side surface of the
foil mounting hole; a foil lead wire connected on a center of the
inner surface of the foil; a body lead wire connected to an
opposite end of the foil mounting hole on the cylindrical body; and
a filler filled in the inner receiving space.
2. The gage of claim 1, wherein the filler is made using a ceramic
material.
3. The gage of claim 1, wherein the foil is formed as a circular
plate.
4-11 (Cancelled)
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a heat-flux gage, a
manufacturing method thereof and a manufacturing device thereof,
and particularly, to a heat-flux gage which is improved from a
circular foil heat-flux gage disposed in ASTM (American Society for
Testing and Material) E511, a manufacturing method and a
manufacturing device thereof.
[0003] 2. Description of the Background Art
[0004] When a temperature difference is generated between metals of
difference kinds which are contacted to each other, an
electromotive force (emf) is generated due to thermoelectric
potential difference between the metals. And heat-flux gage means a
sensor for calculating heat-flux amount by multiplying the
electromotive force (emf) generated according to above principle by
compensating value of heat-flux after mounting the above assembly
of two kinds of metals on a heat source which will be measured.
[0005] FIG. 1 is a cross sectional view showing a construction and
a principle of the heat-flux gage disposed on ASTM E511-73.
[0006] As shown therein, a general heat-flux gage has a structure
that a circular foil 1 formed by a thermocouple constantan is
coupled to a cylindrical body 2 formed by an oxygen-free
high-conductivity copper (OFHC).
[0007] The heat-flux gage is to generate electromotive force (emf)
of mV unit, which is a linear function of the heat-flux, and uses
above material because non-linear movement is shown in case that
other metal compound is used.
[0008] Two thermocouple junctions are formed on the circular foil
1, one is a heat emission portion coupled to the cylindrical body
2, and the other is a junction with a lead wire 3 connected to a
center part thereof.
[0009] The lead wire 3 is installed in order to transport a signal
from the heat-flux gage to a readout device, and the lead wire 3 is
fabricated by twisting a thin leading wire of copper material. The
lead wire 3 is generally coated by TFE-fluorocarbon, and protected
by a braid overwrap covered by the TFE-fluorocarbon. The lead wire
is divided into anode and cathode by colors, and generally, black
color is used for the cathode side.
[0010] The operation of the heat-flux gage is sensitively affected
by surface status, and therefore, a coating by a thin layer of
metallic or non-metallic material is generally formed on the
surface of the heat-flux gage.
[0011] In case that radiant energy is measured, a high-emissive
coating is used. It is ideal that the above coating has a diffuse
absorbing surface. The diffuse coating is a coating not to change
absorption rate by changing incident angle when radiating is
generated on the coating.
[0012] Also, the ideal coating should have no change in the
absorption rate according to the changes of wavelengths, and it is
defined as "gray body". Some coatings approach to the ideal status,
however, most coatings have differences from the ideal status.
[0013] A metallic coating having low emissivity formed by highly
polished gold and nickel is used in a certain case which requires
reflection of radiant heat, since the above coating reduces the
sensitivity of the gage. The gold coating causes a phenomenon that
the output of the heat-flux gage becomes non-linear shape due to
rapid change on the thermal conductivity of the gold according to
the temperature change.
[0014] Hereinafter, principles of measuring heat-flux by the
heat-flux gage will be described as follows.
[0015] In case that the heat-flux gage is exposed to the heat
source, the heat-flux absorbed by the circular foil 1 moves toward
the cylindrical body 2 in radial direction, and difference of
equilibrium temperature between the center portion of the circular
foil and the cylindrical body 2 is generated rapidly. An
equilibrium thermoelectric potential (E) between the center portion
of the circular foil 1 and the cylindrical body 2 is changed in
proportion to heat-flux (q) absorbed into the foil as following
equation.
[0016] Q=KE
[0017] Herein, K is a proportional factor set by an experimental
result.
[0018] Therefore, in case that an appropriate K value is set
through the experiment, emf generated on the circular foil 1 and
the cylindrical body 2 respectively can be measured by the foil
lead wire 3 and a body lead wire 4 to obtain the thermoelectric
potential (E) value, and the heat-flux can be measured by above
equation.
[0019] In order to measure precisely, the temperature should be in
a range of 50.about.450.degree. F. (-45.about.235.degree. C.). In
case that the temperature is out of above range, compensation by
the change of physical property of the constantan foil is not made,
and therefore, the gage does not show the linear movement due to
the thermoelectric output any more.
[0020] In addition, an idea for fabricating the heat-flux gage has
been required since the heat-flux gage should be fabricated very
finely in order to obtain precise measured value using the
heat-flux gage of above structure.
[0021] Especially, the junction of the circular foil 1 and the
cylindrical body 2 makes the heat sink, and therefore, another
material such as adhesive can not be added thereto. Therefore, the
above components should be coupled in a force fit assembly. Thus,
an idea for fabrication method of the heat-flux gage by which the
above assembling process can be performed simply and finely has
been desperately required.
[0022] Also, the foil lead wire 3 connected electrically to the
circular foil 1 is in a structure that the lead wire is coupled on
a plane, and therefore, coupling force therebetween is weak. Thus,
a user should be careful when he/she uses the heat-flux gage.
SUMMARY OF THE INVENTION
[0023] To achieve the object of the present invention, as embodied
and broadly described herein, there is provided a heat-flux gage
comprising: a cylindrical body having a receiving space therein,
and a foil mounting hole on one end thereof; a foil including a
heat absorption surface, an inner surface facing the heat
absorption surface, and a radiant side surface connecting the heat
absorption surface and the inner surface wherein the inner surface
faces toward the receiving space and the radiant side surface
contacts to a side surface of the foil mounting hole; a foil lead
wire connected to a center of the inner surface of the foil; a body
lead wire connected to opposite end of the foil mounting hole on
the cylindrical body; and a filler filled in the inner receiving
space.
[0024] Therefore, the foil lead wire is fixed firmly by the filler,
and thereby, escape of the foil lead wire from the foil can be
prevented.
[0025] Herein, it is desirable that the filler is ceramic material,
because the heat-flux gage according to the present invention is
used at high temperature and the ceramic material is strong for the
heat.
[0026] Also, it is effective that the foil is formed as a circular
plate. When the foil is formed as a circle, it is easy to analyze a
result since the shape of the foil is formed as symmetric.
[0027] To achieve the object of the present invention, there is
provided a method for fabricating a heat-flux gage comprising: a
step of disposing a cylindrical body having a receiving space
therein, and a foil mounting hole on one end thereof; a step of
disposing a foil including a heat absorption surface, an inner
surface facing the heat absorption surface, and a radiant side
surface connecting the heat absorption surface and the inner
surface; a foil welding step for point welding a foil lead wire on
a center of inner surface of the foil; a body welding step for
point welding a body lead wire on an opposite end of an end on
which the foil mounting hole is formed; a assembly fixture
inserting step for inserting an assembly fixture having a foil lead
wire hole therein into the receiving space of the cylindrical body;
and a foil assembly step for inserting the foil lead wire through
the foil lead wire hole of the assembly fixture and for assembling
the circular foil into the foil mounting hole in a force fitting
method.
[0028] Therefore, the foil lead wire is protected by the assembly
fixture, and thereby, damages of the foil lead wire or of the
coupling portion of the foil lead wire and the inner surface during
the force fitting process can be prevented.
[0029] Also, it is desirable that the above method further
comprises: a step of separating the assembly fixture from the
receiving space of the cylindrical body; and a filing step for
filling a filler in the receiving space of the cylindrical body,
after the foil assembly step.
[0030] In addition, the filling step is to fill the filler of
ceramic material, and it is desirable that the method further
comprises a heating and hardening step for heating the heat-flux
gage assembly consisting of the foil and the cylindrical body after
the filling step.
[0031] Also, it is desirable that the method further comprises a
cutting step for micro-cutting the front surface of the heat-flux
gage assembly after the heating and hardening step.
[0032] In addition, it is desirable that the method further
comprises a acid cleaning step for cleaning the surface of the
heat-flux gage assembly with acid; and a washing step for washing
the surface of the acid-cleaned heat-flux gage assembly, after the
cutting step.
[0033] Further, it is effective that the method further comprises a
coating step for forming a non-reflective coating film on an
exposed surface of the circular foil, after the washing step.
[0034] On the other hand, to achieve the object of the present
invention, there is provided an assembly fixture comprising: a
support portion; a protruded portion which is protruded from the
support portion to be inserted into the receiving space of the
cylindrical body; and a lead wire hole formed on center portion in
the protruded portion so that a foil lead wire can be penetrated
therethrough.
[0035] The foregoing and other objects, features, aspects and
advantages of the present invention will become more apparent from
the following detailed description of the present invention when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The accompanying drawings, which are included to provide a
further understanding of the invention and are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and together with the description serve to explain
the principles of the invention.
[0037] In the drawings:
[0038] FIG. 1 is a cross-sectional view showing a structure and a
principle of a conventional heat-flux gage;
[0039] FIG. 2 is a longitudinal cross-sectional view showing a
structure of a heat-flux gage according to the present
invention;
[0040] FIG. 3 through FIG. 6 are showing manufacturing processes of
the heat-flux gage according to the present invention,
[0041] FIG. 3 is a longitudinal cross sectional view illustrating
foil welding step;
[0042] FIG. 4 is a longitudinal cross-sectional view illustrating
body welding step;
[0043] FIG. 5 is a longitudinal cross-sectional view illustrating
assembly fixture mounting process and foil assembly step;
[0044] FIG. 6 is a longitudinal cross-sectional view illustrating
filling step; and
[0045] FIG. 7 is a longitudinal cross-sectional view showing a
structure of the assembly fixture of the heat-flux gage according
to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings.
[0047] FIG. 2 is a longitudinal cross-sectional view showing a
structure of a heat-flux gage according to the present invention,
FIG. 3 through FIG. 6 are views showing manufacturing process of
the heat-flux gage according to the present invention, FIG. 3
through FIG. 6 are showing manufacturing processes of the heat-flux
gage according to the present invention, wherein FIG. 3 is a
longitudinal cross sectional view illustrating foil welding step;
FIG. 4 is a longitudinal cross-sectional view illustrating body
welding step; FIG. 5 is a longitudinal cross-sectional view
illustrating assembly fixture mounting step and foil assembly step;
FIG. 6 is a longitudinal cross-sectional view illustrating filling
step; and FIG. 7 is a longitudinal cross-sectional view showing a
structure of the assembly fixture of the heat-flux gage according
to the present invention.
[0048] As shown therein, the heat-flux gage according to the
present invention comprises: a cylindrical body 2 having a
receiving space 22 therein and a foil mounting hole 21 on one end
thereof; a foil 1 mounted on the cylindrical body 2; a foil lead
wire 3 connected to the foil 1; a body lead wire 4 connected to the
cylindrical body 2; and a filler 5 filled in the inner receiving
space 22.
[0049] The cylindrical body 1 is formed as a cylinder, and
comprises the receiving space 22 formed therein, the foil mounting
hole 21 formed on one side thereof, and a lead wire coupling
portion 23 formed by cutting some part of the opposite end of the
foil mounting hole 21.
[0050] The foil 1 is formed as a circular plate, and comprises a
heat absorption surface 1a, an inner surface 1b facing the heat
absorption surface 1a; and a radiant side surface 1c connecting the
heat absorption surface 1a and the inner surface 1b. Also, the
inner surface 1b of the foil 1 faces toward the receiving space 22,
and the radiant side surface 1c is coupled to be contacted with a
side surface of the foil mounting hole 21.
[0051] The foil lead wire 3 is connected to a center of the inner
surface 1b of the foil, and the body lead wire 4 is connected to
the lead wire coupling portion 23 of the cylindrical body 1.
[0052] The filler 5 is made with ceramic material which is
resistant for the heat, since the heat-flux gage according to the
present invention is used at high temperature status.
[0053] In the present invention, the inner receiving space 22 of
the cylindrical body 2 is filled with the filler 5.
[0054] That is, the foil lead wire 3 is electrically connected to
the inner surface 1b of the circular foil 1, and after that, the
filler is filled around the lead wire 3, and therefore, the foil
lead wire 3 firmly coupled to the foil and can not be escaped from
the circular foil 1.
[0055] On the other hand, a manufacturing method for the heat-flux
gage according to the present invention comprises: a foil welding
step for point welding the foil lead wire 3 on the inner surface 1b
of the circular foil 1 (FIG. 3); a body welding step for point
welding the body lead wire 4 on the lead wire coupling portion 23
of the cylindrical body 2, on which the mounting portion 21 of the
circular foil is mounted, having the receiving space 22 therein
(FIG. 4); an assembly fixture 6 inserting step for inserting an
assembly fixture 6 having a foil lead wire hole 61 formed on center
portion thereof into the receiving space 22 of the cylindrical body
(FIG. 5); and a foil assembling step for inserting the foil lead
wire 3 through the foil lead wire hole 61 of the assembly fixture
and assembling the circular foil 1 into the mounting portion 21 of
the cylindrical body in force fitting method.
[0056] As shown in FIG. 7, the assembly fixture 6 comprises: a
support portion 62; a protruded portion 63 protruded from the
support portion 62 to be inserted into the receiving space of the
cylindrical body 2; and a lead wire hole 61 formed on the center
portion of the protruded portion 63 so that the lead wire 3 of the
circular foil 1 penetrates therethrough.
[0057] The manufacturing method according to the present invention
is characterized in using the assembly fixture 6 having the foil
lead wire hole 61 formed on center portion in the process of force
fitting the circular foil 1, on which the foil lead wire 3 is point
welded, into the cylindrical body 2.
[0058] Therefore, the assembly fixture 6 of above structure is
inserted into the inner receiving space 22 of the cylindrical body
2, and the circular foil 1 can be assembled into the foil mounting
portion 1 of the cylindrical body 2 in force fitting method using a
punch 7, etc., and therefore, the assembly can be made precisely
without damaging the foil lead wire 3.
[0059] The radiant side surface 1c of the circular foil 1 and the
junction of the cylindrical body 2 make a heat sink, and therefore,
another material such as the adhesive can not be added thereto.
Thus, the above components should be assembled in the force fitting
method, and the above process can be made easily and precisely
according to the present invention.
[0060] After the circular foil 1 is assembled into the cylindrical
body 2 in the force fitting method, the assembly fixture 6 is
separated from the receiving space 22 of the cylindrical body 2,
and then, the filler 5 is filled in the receiving space of the
cylindrical body 2.
[0061] Herein, it is desirable that the filler 5 is made with
ceramic material having heat resistance. Then, the filler of
ceramic material is filled in the receiving space of the
cylindrical body 2, and after that, the heat-flux gage assembly
consisting of the circular foil 1 and the cylindrical body 2 is
heated in order to harden the filler.
[0062] It is desirable that the heat-flux gage assembly is heated
one or more hours at 150.degree. C. in an oven, in order to harden
the assembly.
[0063] After cooling the gage assembly, the front surface of the
heat-flux gage assembly on which the circular foil 1 is mounted is
micro-cut. The precise surface treatment greatly affects to the
functions of the heat-flux gage.
[0064] The surface of the heat-flux gage is likely to have blots as
undergoing above processes, and therefore, the surface of the
heat-flux gage assembly is cleaned by acid and washed to maintain
the inherent surface status of metal.
[0065] Any cleaner can be used if it is used for maintaining the
surface status of metal, and the cleaning is made sufficiently
until the original color of the metal is shown, and then, the
heat-flux gage assembly is washed with flowing water, and
dried.
[0066] In order to measure the heat-flux precisely, the heat-flux
should not be reflected on the surface of the circular foil.
Therefore, in order to prevent the reflection, non-reflective
coating film is formed on the exposed surface of the circular
foil.
[0067] As described above, according to the present invention, the
filler is filled in the inner receiving space to fix the foil lead
wire firmly, and therefore, the foil lead wire is not escaped from
the inner surface of the foil easily.
[0068] Also, the assembly fixture is used when the foil is
assembled in the force fitting method, and therefore, the
assembling process can be performed precisely without damaging the
foil lead wire.
[0069] As the present invention may be embodied in several forms
without departing from the spirit or essential characteristics
thereof, it should also be understood that the above-described
embodiments are not limited by any of the details of the foregoing
description, unless otherwise specified, but rather should be
construed broadly within its spirit and scope as defined in the
appended claims, and therefore all changes and modifications that
fall within the metes and bounds of the claims, or equivalence of
such metes and bounds are therefore intended to be embraced by the
appended claims.
* * * * *