U.S. patent application number 12/537113 was filed with the patent office on 2009-11-26 for bonding of materials with induction heating.
This patent application is currently assigned to Inductotherm Corp.. Invention is credited to Maochang Cao, Oleg S. Fishman.
Application Number | 20090291320 12/537113 |
Document ID | / |
Family ID | 30115728 |
Filed Date | 2009-11-26 |
United States Patent
Application |
20090291320 |
Kind Code |
A1 |
Fishman; Oleg S. ; et
al. |
November 26, 2009 |
Bonding of Materials with Induction Heating
Abstract
An apparatus and process are provided for forming a two-metal
flat bonded article. A flat metal sheet in solid form is placed in
the indention of a heat resistant plate. A second heat resistant
plate is placed over the flat metal sheet in the indentation to
form a flat metal sheet enclosure. The flat metal sheet enclosure
is placed in a U-shaped inductor assembly embedded with a
solenoidal induction coil. Supply of alternating current to the
solenoidal induction coil inductively heats the flat metal sheet
after which the sheet is withdrawn from the inductor assembly. The
second heat resistant plate is removed and a bond metal in liquid
form is placed over the top surface of the flat metal sheet in the
indentation so that the two-metal flat bonded article is formed as
the bond metal solidifies.
Inventors: |
Fishman; Oleg S.; (Maple
Glen, PA) ; Cao; Maochang; (Mount Laurel,
NJ) |
Correspondence
Address: |
PHILIP O. POST;INDEL, INC.
PO BOX 157
RANCOCAS
NJ
08073
US
|
Assignee: |
Inductotherm Corp.
Rancocas
NJ
|
Family ID: |
30115728 |
Appl. No.: |
12/537113 |
Filed: |
August 6, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11735098 |
Apr 13, 2007 |
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12537113 |
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|
10615150 |
Jul 8, 2003 |
7205516 |
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11735098 |
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60394515 |
Jul 9, 2002 |
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Current U.S.
Class: |
428/615 ;
219/603 |
Current CPC
Class: |
Y10T 428/31678 20150401;
H05B 6/105 20130101; F16C 33/14 20130101; F16C 2223/32 20130101;
Y10T 428/12493 20150115 |
Class at
Publication: |
428/615 ;
219/603 |
International
Class: |
B32B 15/00 20060101
B32B015/00; B23K 13/01 20060101 B23K013/01 |
Claims
1. A method of bonding the adjacent sides of a pair of metal
sheets, the method comprising the steps of: seating a flat metal
sheet in solid form in an indentation in a first heat resistant
plate, the indentation having a perimeter substantially equal to
the perimeter of the flat metal sheet; seating a second heat
resistant plate over the first heat resistant plate containing the
flat metal sheet so that an interior protruding region of the
second heat resistant plate seats in the indentation in the first
heat resistant plate over the top surface of the flat metal sheet,
the combination of the second heat resistant plate seated over the
first heat resistant plate forming a flat metal sheet container;
inserting the flat metal sheet container into a side-entry interior
volume of a U-shaped inductor assembly having at least one
solenoidal induction coil embedded in the top and bottom of the
U-shaped inductor assembly, the side-entry interior volume having a
height substantially equal to the height of the flat metal sheet
container to press the interior protruding region of the second
heat resistant plate over the top surface of the flat metal sheet;
supplying alternating current to the at least one solenoidal
induction coil to inductively heat the flat metal sheet;
withdrawing the heated flat metal sheet container from the
side-entry interior volume of the U-shaped inductor assembly;
removing the second heat resistant plate from the first heat
resistant plate; placing a bond metal in liquid form over the top
surface of the flat metal sheet; and bonding the bond metal to the
top surface of the flat metal sheet as it solidifies.
2. Apparatus for bonding the adjacent sides of two metal sheets
together, the apparatus comprising: a U-shaped inductor assembly
having a side opening into the interior volume of the U-shaped
inductor assembly; at least one solenoidal induction coil embedded
in at least the top and bottom of the U-shaped inductor assembly;
at least one alternating current power supply connected to the at
least one solenoidal induction coil; and a flat metal sheet
containment enclosure comprising a first and second heat resistant
plate, the first heat resistant plate having an indentation with
sufficient height for at least seating the flat metal sheet in
solid form in the indentation and a bonding metal in liquid form
over the flat metal sheet, the second heat resistant plate having
an interior protruding region, the interior protruding region
removably insertable into the indentation to a depth sufficient to
touch the top surface of the first metal sheet when seated in the
indentation, the interior volume of the U-shaped inductor assembly
having a height substantially equal to the height of the
combination of the first and second heat resistant plates when the
interior protruding region of the second heat resistant plate is
inserted into the indentation of the first heat resistant
plate.
3. The apparatus of claim 2 wherein the first and second heat
resistant plates are formed from a ceramic composition.
4. A two-metal flat bonded article formed from a process comprising
the steps of: seating a flat metal sheet in solid form in an
indentation in a first heat resistant plate, the indentation having
a perimeter substantially equal to the perimeter of the flat metal
sheet; seating a second heat resistant plate over the first heat
resistant plate containing the flat metal sheet so that an interior
protruding region of the second heat resistant plate seats in the
indentation in the first heat resistant plate over the top surface
of the first flat metal sheet, the combination of the second heat
resistant plate seated over the first heat resistant plate forming
a flat metal sheet container; inserting the flat metal sheet
container into a side-entry interior volume of a U-shaped inductor
assembly having at least one solenoidal induction coil embedded in
the top and bottom of the U-shaped inductor assembly, the
side-entry interior volume having a height substantially equal to
the height of the flat metal sheet container; supplying alternating
current to the at least one solenoidal induction coil to
inductively heat the first flat metal sheet; withdrawing the first
flat metal sheet container from the side-entry interior volume of
the U-shaped inductor assembly; removing the second heat resistant
plate from the first heat resistant plate; placing a second metal
in liquid form over the top surface of the first flat metal sheet;
and bonding the bond metal to the top surface of the flat metal
sheet as it solidifies.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of application
Ser. No. 11/735,098, filed Apr. 13, 2007, which is a divisional
application of application Ser. No. 10/615,150, filed Jul. 8, 2003,
now U.S. Pat. No. 7,205,516, which claims the benefit of U.S.
Provisional Application No. 60/394,515, filed Jul. 9, 2002, all of
which are hereby incorporated herein by reference in their
entireties.
FIELD OF THE INVENTION
[0002] The present invention relates to the use of magnetic
induction heating of a material to bond multiple materials
together.
BACKGROUND OF THE INVENTION
[0003] Bonded materials are used in many applications. For example,
a slide bearing may be formed from a bonded composition that
consists of a metal backing plate and a bearing surface material
that is bonded to the plate. The bearing surface material may be a
metal composition such as a copper or an aluminum alloy. Slide
bearings are linear or rotary in form. Linear slide bearings are in
sheet form, whereas rotary slide bearings are in cylindrical or
half-cylindrical form. Half-cylindrical slide bearings are used in
pairs for applications such as journal bearings in internal
combustion engines.
[0004] One method of producing slide bearings involves a continuous
process line wherein the feedstock for the metal backing plate is a
continuous roll of sheet steel. The continuous roll of sheet steel
is fed through heat treating furnaces and further conditioned
before the bearing surface material is applied to it. Raised edge
lips are formed on the longitudinal edges of the continuous sheet
and the bearing surface material, in a liquid form, such as a
molten copper or aluminum alloy, is poured onto the sheet. The
molten alloy solidifies and is bonded to the sheet, and can be
quench treated. Subsequent milling controls the thickness of the
bearing surface material. The sheet is cut into desired sizes for
slide bearing applications. For rotary slide bearings, the cut
pieces are further formed into a cylindrical shape. Economically,
the process must operate as an uninterrupted line process, since
stopping the line and restarting the line involves a substantial
effort in repeatedly bringing the line's furnaces to operating
temperature. Therefore there exists the need for a method of
bonding metals in a batch process for applications such as slide
bearings.
BRIEF SUMMARY OF THE INVENTION
[0005] In one aspect, the present invention is an apparatus for,
and method of, producing a bonded pair of metal sheets. A flat
metal sheet is seated in solid form in an indentation in a first
heat resistant plate. The indentation has a perimeter substantially
equal to the perimeter of the flat metal sheet. A second heat
resistant plate is seated over the first heat resistant plate that
contains the flat metal sheet so that an interior protruding region
of the second heat resistant plate seats in the indentation in the
first heat resistant plate over the top surface of the flat metal
sheet, with the combination of the second heat resistant plate
seated over the first heat resistant plate forming a flat metal
sheet container. The flat metal sheet container is inserted into a
side-entry interior volume of a U-shaped inductor assembly having
at least one solenoidal induction coil embedded in the top and
bottom of the U-shaped inductor assembly. The side-entry interior
volume has a height substantially equal to the height of the flat
metal sheet container to press the interior protruding region of
the second heat resistant plate over the top surface of the flat
metal sheet. Alternating current is supplied to the at least one
solenoidal induction coil to inductively heat the flat metal sheet.
The heated flat metal sheet container is withdrawn from the
side-entry interior volume of the U-shaped inductor assembly. The
second heat resistant plate is removed from the first heat
resistant plate and a bonding metal in liquid form is placed over
the top surface of the flat metal sheet, after which the bonding
metal is allowed to bond to the flat metal sheet as it
solidifies.
[0006] These and other aspects of the invention are set forth in
this specification and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The figures, in conjunction with the specification and
claims, illustrate one or more non-limiting modes of practicing the
invention. The invention is not limited to the illustrated layout
and content of the figures in the drawings.
[0008] FIG. 1 is an isometric view of one example of an apparatus
of the present invention for bonding materials with induction
heating.
[0009] FIG. 2 is an isometric view illustrating one example of an
arrangement of induction coils for the apparatus shown in FIG.
1.
[0010] FIG. 3 is a front elevational view of the apparatus shown in
FIG. 1.
[0011] FIG. 4 is a side elevational view of the apparatus shown in
FIG. 1.
[0012] FIG. 5 is a top view of the apparatus shown in FIG. 1,
further illustrating the arrangement of induction coils shown in
FIG. 2.
[0013] FIGS. 6(a), 6(b) and 6(c) illustrate another example of the
present invention for bonding materials with induction heating.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring now to the drawings, wherein like numerals
indicate like elements, there is shown in FIG. 1 through FIG. 5,
one example of apparatus 10 of the present invention for bonding of
materials with induction heating. Apparatus 10 includes first
induction heating plate 12, frame 14 and second induction heating
plate 16. First and second induction heating plates 12 and 16, and
frame 14, are formed from a heat resistant, non-electrically
conductive material, such as a ceramic composition. First plate
induction coil 18 is disposed in first induction heating plate 12;
frame induction coil 20 is disposed in frame 14; and second plate
induction coil 22 is disposed in second induction heating plate 16.
When a castable material, such as a ceramic composition, is used
for the heating plates and frames, the coils may be embedded in the
heating plates and frame during the casting process.
[0015] The induction coils are arranged to form a transverse
induction coil assembly for inductively heating an electrically
conductive sheet 90 placed between the first induction heating
plate, and the combination of the frame and second induction
heating plate when the second induction heating plate is inserted
into the frame. While the sheet is generally referred to as a metal
sheet, any electrically conductive material may be used. The
particular arrangement of coils shown in the figures illustrates
one non-limiting example of transverse flux coil arrangements that
can be used in the present invention. The illustrated induction
coils may be fluid (liquid or gas) cooled by circulation of a
cooling fluid, such as water, through hollow induction coils or
separate cooling coils in the heating plates and frame. In some
examples of the invention, an induction coil may not be necessary
in frame 14.
[0016] Metal sheet 90 is placed upon the top surface of first
induction heating plate 12. The dimensions of metal sheet 90 are
such that when frame 14 is placed over the top surface of first
induction heating plate 12, the perimeter of the metal sheet will
extend beyond the interior open space in frame 14 to establish a
metal sheet contact surface around the metal sheet's perimeter that
is sandwiched between the top surface of the first induction
heating plate 12 and the bottom surface of frame 14.
[0017] With metal sheet 90 positioned on the surface of first
induction heating plate 12, as described above, frame 14 and second
induction heating plate 16 are placed over the top surface of the
first induction heating plate 12 and the metal sheet. The interior
open space in frame 14 is sized to allow the fitting of second
induction heating plate 16 so that the bottom surface of the second
induction heating plate 16 makes contact with metal sheet 90. With
the frame and second induction heating plate placed over metal
sheet 90, suitable ac current is supplied from one or more power
sources to first plate induction coil 18, frame induction coil 20,
and second plate induction coil 22. The magnetic field created by
ac current flow in the first plate induction coil 18 inductively
penetrates and heats into the facing side of metal sheet 90,
whereas the magnetic fields created by ac current flow in the frame
induction coil and second plate induction coil inductively
penetrate and heat into the opposing side of the metal sheet. As
best illustrated in FIG. 5, the orthogonal orientation of the first
plate induction coil to the combination of the frame and second
plate induction coils provides a crisscross induction heating
pattern that enhances uniform heat penetration of the sheet.
Pressing the metal sheet between the first and second induction
heating plates prevents surface distortion of the sheet as it is
heated.
[0018] When metal sheet 90 has been inductively heated to a desired
temperature, second induction heating plate 16 is raised at least a
sufficient distance to allow pouring of a molten metal composition,
such as a copper or aluminum alloy, onto the top surface of the
heated metal sheet. The temperature of the metal sheet may be
sensed by one or more sensors, such as contact thermocouples
embedded in the first and/or second induction heating plates to
determine when the sheet has been heated to the desired
temperature. For example, if the metal sheet is steel, it is heated
to approximately 2,100.degree. F. for casting of a molten alloy,
such as bronze, onto its surface. While the term "molten metal" or
"molten alloy" is used, any liquid material capable of bonding with
the heated electrically conductive sheet may be used. Frame 14
remains in place to hold the metal sheet flat and to provide a dam
for the molten metal composition. The molten metal may be ported
through one or more openings in frame 14, or poured, into the
interior open space in frame 14 which was previously occupied by
the second induction heating plate. After pouring a quantity of
molten metal over the top surface of the metal sheet, the metal
will bond with the sheet as it cools. Alternatively, the metal can
be quenched by injecting a quench fluid or gas into the interior
open space in the frame over the top surface of the cooled molten
metal. The quench material may be ported through one or more
openings in frame 14, or poured, into the interior open space in
frame 14. The now solidified molten metal is bonded to the metal
sheet to form a bonded metal product, and frame 14 can be removed
from over the top surface of first induction heating plate 12. The
interior surface wall of frame 14 may be skewed towards its outer
wall in the region where the molten metal is poured to facilitate
removal of the frame. Additionally the same region of the wall may
be specially treated with a coating that will inhibit bonding of
the molten metal to the wall of the frame. By way of example, and
not limitation, a typical range of thickness of the metal sheet is
approximately 3.5 to 19 mm, and a typical range of thickness of the
cast metal on the metal sheet is approximately 2.5 to 5.0 mm.
Further working of the product can include milling for thickness
control of the product. If the product is used as slide bearings,
the product is appropriately cut to the desired dimensions. For
rotary slide bearings, the cut product is then worked to a
cylindrical shaped.
[0019] In an alternative embodiment of the invention, the top
surface of first induction heating plate 12, rather than being
flat, is indented for an area approximately equal to the surface
area of the bottom surface of second induction heating plate 16. In
this arrangement, after metal sheet 90 has been heated, the second
induction heating plate can be moved towards the metal sheet to
apply sufficient pressure on the heated sheet to force it into the
indentation in the first induction heating plate. In this example,
the frame does not generally provide a dam for the molten metal
composition that is poured over the top of the sheet since the
raised edges of the indented metal sheet and/or the walls of the
indentation will serve as a dam for the molten metal composition.
In this example of the invention, the frame serves as a means for
holding the metal sheet in place during induction heating and
molten metal pour after the sheet is pressed into the indentation
in the first induction heating plate.
[0020] In other examples of the invention longitudinal flux coils,
such as solenoidal coils, may be utilized. For example, as
illustrated in FIG. 6(a), solenoidal induction coil 21 is disposed
in inductor assembly 23. Metal sheet 90 is inserted into
indentation 25 in first heat resistant plate 13. Second heat
resistant plate 17 is placed over the first ceramic plate and the
enclosed metal sheet is inserted into inductor assembly 23 as shown
in FIG. 6(b) wherein it is inductively heated by a magnetic field
established when as current flows through coil 21. After the metal
sheet reaches the desired temperature, the enclosed metal sheet is
removed from the inductor assembly, and the second heat resistant
plate is removed, as shown in FIG. 6(c), so that the molten metal
can be poured over the metal sheet in the indentation.
[0021] The foregoing examples do not limit the scope of the
disclosed invention. The scope of the disclosed invention is
further set forth in the appended claims.
* * * * *