U.S. patent application number 12/916710 was filed with the patent office on 2011-02-24 for plug bypass valves and heat exchangers.
This patent application is currently assigned to Dana Canada Corporation. Invention is credited to Brian E. Cheadle, Yuri Peric, Gregory Merle Pineo.
Application Number | 20110042060 12/916710 |
Document ID | / |
Family ID | 41061738 |
Filed Date | 2011-02-24 |
United States Patent
Application |
20110042060 |
Kind Code |
A1 |
Pineo; Gregory Merle ; et
al. |
February 24, 2011 |
Plug Bypass Valves and Heat Exchangers
Abstract
A bypass valve for a heat exchanger including a plurality of
parallel tubular members comprises a housing having a hollow plug
portion adjacent to an actuator portion. The actuator comprises a
reciprocating plunger extending into the plug portion and a
solenoid having a central actuator shaft attached to the plunger,
wherein the actuator shaft extends upon energization of the
solenoid so that the plunger prevents bypass flow through the
valve. The valve also comprises a temperature sensor for sensing a
temperature of the fluid flowing through the heat exchanger, the
temperature sensor being electrically coupled to the solenoid
through one or more conductors, wherein the temperature sensor is
located at the first end of the actuator shaft and the conductors
extend through the hollow interior of the actuator shaft to the
second end thereof.
Inventors: |
Pineo; Gregory Merle;
(Kleinburg, CA) ; Cheadle; Brian E.; (Brampton,
CA) ; Peric; Yuri; (Split, HR) |
Correspondence
Address: |
Marshall & Melhorn, LLC
Four SeaGate, 8th Floor
Toledo
OH
43604
US
|
Assignee: |
Dana Canada Corporation
Oakville
CA
|
Family ID: |
41061738 |
Appl. No.: |
12/916710 |
Filed: |
November 1, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12335024 |
Dec 15, 2008 |
7854256 |
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12916710 |
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11264494 |
Nov 1, 2005 |
7487826 |
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12335024 |
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09918082 |
Jul 30, 2001 |
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11264494 |
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Current U.S.
Class: |
165/297 ;
137/468 |
Current CPC
Class: |
F01M 5/00 20130101; F28D
2021/0089 20130101; F01M 5/007 20130101; F28F 27/02 20130101; G05D
23/1393 20130101; G05D 23/24 20130101; Y10T 137/7737 20150401; F28F
2250/06 20130101; F28D 1/0333 20130101; F28D 1/05358 20130101 |
Class at
Publication: |
165/297 ;
137/468 |
International
Class: |
F28F 27/02 20060101
F28F027/02; F16K 17/38 20060101 F16K017/38 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 26, 2001 |
CA |
2,354,217 |
Claims
1. A bypass valve for a heat exchanger including a plurality of
parallel tubular members having adjacent wall portions defining
flow openings in communication to form flow manifolds, the bypass
valve comprising: a housing having a hollow plug portion with
opposed plug walls defining inlet and outlet openings therein, the
plug walls being adapted to be sealingly mounted between selected
adjacent tubular member wall portions to allow fluid flow
respectively between said flow manifolds and said inlet and outlet
openings; the housing also having an actuator portion located
adjacent to the plug portion; an actuator releasably mounted in the
actuator portion and comprising a reciprocating plunger extending
into the plug portion and a solenoid having a central actuator
shaft attached to the plunger, wherein the actuator shaft extends
upon energization of the solenoid, so that the plunger blocks flow
between the inlet and outlet openings, wherein the actuator shaft
has a first end to which the plunger is attached, a second end, and
a hollow interior, and wherein the actuator further comprises bias
means for urging the actuator shaft to retract upon de-energization
of the solenoid so as to unblock flow between said inlet and outlet
openings; and a temperature sensor for sensing a temperature of the
fluid flowing through the heat exchanger, the temperature sensor
being electrically coupled to the solenoid through one or more
conductors, wherein the temperature sensor is located at the first
end of the actuator shaft and the one or more conductors extend
through the hollow interior of the actuator shaft to the second end
thereof.
2. A bypass valve according to claim 1, further comprising an
electrical control unit mounted in the housing and electrically
connected between the temperature sensor and the solenoid for
controlling the movement of the plunger in accordance with the
temperature sensed by the temperature sensor.
3. A bypass valve according to claim 1, wherein the temperature
sensor is a thermistor mounted on the plunger.
4. A bypass valve according to claim 1, wherein the opposed plug
walls of the housing plug portion are flat, parallel side walls
defining said inlet and outlet openings.
5. A bypass valve according to claim 4, wherein said side walls are
spaced apart a predetermined distance so as to determine the
spacing between adjacent heat exchanger tubular members.
6. A heat exchanger comprising: a plurality of parallel, tubular
members having adjacent wall portions defining flow openings in
communication to form inlet and outlet manifolds for the flow of
fluid through the tubular members; and a bypass valve comprising a
housing having a hollow plug portion with opposed plug walls
defining inlet and outlet openings therein, the plug walls being
adapted to be sealingly mounted between selected adjacent tubular
member wall portions to allow fluid flow respectively between said
flow manifolds and said inlet and outlet openings; the housing also
having an actuator portion located adjacent to the plug portion; an
actuator releasably mounted in the actuator portion and comprising
a reciprocating plunger extending into the plug portion and a
solenoid having a central actuator shaft attached to the plunger,
wherein the actuator shaft extends upon energization of the
solenoid, so that the plunger blocks flow between the inlet and
outlet openings, wherein the actuator shaft has a first end to
which the plunger is attached, a second end, and a hollow interior,
and wherein the actuator further comprises bias means for urging
the actuator shaft to retract upon de-energization of the solenoid
so as to unblock flow between said inlet and outlet openings; and a
temperature sensor for sensing a temperature of the fluid flowing
through the heat exchanger, the temperature sensor being
electrically coupled to the solenoid through one or more
conductors, wherein the temperature sensor is located at the first
end of the actuator shaft and the one or more conductors extend
through the hollow interior of the actuator shaft to the second end
thereof.
7. A heat exchanger according to claim 6, wherein the bypass valve
further comprises an electrical control unit mounted in the housing
and electrically connected between the temperature sensor and the
solenoid for controlling the movement of the plunger in accordance
with the temperature sensed by the temperature sensor.
8. A heat exchanger according to claim 6, wherein the temperature
sensor is a thermistor mounted on the plunger.
9. A heat exchanger according to claim 6, wherein the tubular
members are formed of plate pairs having enlarged distal end
portions joined together to form said inlet and outlet manifolds,
said plug walls being spaced-apart flat, parallel side walls
defining said inlet and outlet openings and being joined to
adjacent enlarged distal end portions of the adjacent plate
pairs.
10. A heat exchanger according to claim 6, wherein said side walls
are spaced apart a predetermined distance so as to determine the
spacing between adjacent heat exchanger tubular members.
11. A bypass valve for a heat exchanger, comprising: (a) a housing
comprising: (i) a first opening and a second opening to permit
fluid to flow through the valve; (ii) a first valve chamber which
is arranged between the first and second openings and is in flow
communication with both the first and second openings; (iii) a
second valve chamber in flow communication with the first valve
chamber; (iv) a third opening in communication with the second
valve chamber; and (v) a valve port which is arranged between the
first and second valve chambers, wherein the second valve chamber
is arranged between the third opening and the valve port; and (b) a
temperature-responsive actuator mounted in the housing and
comprising: (i) a reciprocating sealing member extending into the
first valve chamber; (ii) a solenoid having a central actuator
shaft attached to the sealing member, wherein the actuator shaft
extends upon energization of the solenoid, so that the sealing
member seals the valve port and blocks flow between the first and
second valve chambers, wherein the actuator shaft has a first end
to which the sealing member is attached, a second end, and a hollow
interior; (iii) bias means for urging the actuator shaft to retract
upon de-energization of the solenoid so as to unblock flow between
said inlet and outlet openings; and (iv) a temperature sensor for
sensing a temperature of the fluid flowing through the valve, the
temperature sensor being electrically coupled to the solenoid
through one or more conductors, wherein the temperature sensor is
located at the first end of the actuator shaft and the one or more
conductors extend through the hollow interior of the actuator shaft
to the second end thereof.
12. A bypass valve according to claim 11, further comprising an
electrical control unit mounted in the housing and electrically
connected between the temperature sensor and the solenoid for
controlling the movement of the sealing member in accordance with
the temperature sensed by the temperature sensor.
13. A bypass valve according to claim 11, wherein the temperature
sensor is a thermistor mounted on the first end of the actuator
shaft.
14. The bypass valve according to claim 11, wherein the actuator
shaft and the first and second valve chambers are aligned along a
common axis, and wherein the biasing means comprises a coil spring
housed in the second valve chamber.
15. The bypass valve according to claim 11, wherein the housing
further comprises a fourth opening which is in flow communication
with the second valve chamber, and wherein the second valve chamber
is arranged between the third and fourth openings.
16. The bypass valve according to claim 11, wherein the housing
includes a valve cover which closes the first valve chamber and
which has a central opening through which the actuator shaft
extends, wherein the solenoid is mounted to the valve cover.
17. The bypass valve according to claim 12, wherein the second end
of the actuator shaft extends through the solenoid and is provided
with a plunger plate to which the electrical control unit is
mounted.
18. The bypass valve according to claim 12, wherein the housing
further comprises a control unit compartment in which electrical
control unit is housed.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S.
patent application Ser. No. 12/335,024 filed on Dec. 15, 2008;
which is a continuation-in-part of U.S. patent application Ser. No.
11/264,494, filed on Nov. 1, 2005, now U.S. Pat. No. 7,487,826,
which is a continuation of U.S. patent application Ser. No.
09/918,082, filed Jul. 30, 2001, now abandoned; all of which are
incorporated herein by reference in their entireties and from which
priority is claimed.
FIELD OF THE INVENTION
[0002] This invention relates to heat exchangers, and in
particular, to bypass valves for bypassing or short-circuiting flow
from the heat exchanger inlet to the heat exchanger outlet under
conditions where the heat transfer function of the heat exchanger
is not required or is only intermittently required.
BACKGROUND OF THE INVENTION
[0003] In certain applications, such as in the automotive industry,
heat exchangers are used to cool or heat certain fluids, such as
engine oil or transmission fluid or oil. In the case of
transmission fluid, for instance, a heat exchanger is usually used
to cool the transmission fluid. The heat exchanger is usually
located remote from the transmission and receives hot transmission
fluid from the transmission through supply tubing, cools it, and
delivers it back to the transmission again through return tubing.
However, when the transmission is cold, such as at start-up
conditions, the transmission oil is very viscous and does not flow
easily through the heat exchanger, if at all. In such cases, the
transmission can be starved of fluid and this may cause damage to
the transmission or at least erratic performance. Damage can also
be caused to the transmission if the quantity of fluid returned is
adequate, but is over-cooled by the heat exchanger due to low
ambient temperatures. In this case, water may accumulate in the
transmission fluid as a result of condensation (which normally
would be vaporized at higher temperatures) and this may cause
corrosion damage or transmission fluid degradation.
[0004] In order to overcome the cold flow starvation problem, it
has been proposed to insert a bypass valve between the supply and
return tubing to and from the heat exchanger. This bypass valve may
be temperature responsive so that it opens causing bypass flow when
the transmission fluid is cold, and it closes to prevent bypass
flow when the transmission fluid heats up to operating temperature.
An example of such a bypass valve is shown in U.S. Pat. No.
6,253,837 issued to Thomas F. Seiler et al. While this approach
works satisfactorily, the heat exchanger and bypass valve assembly
becomes quite large and includes fluid inlet and outlet tubing that
may not otherwise be required.
SUMMARY OF THE INVENTION
[0005] In the present invention, the bypass valve can be
incorporated as an integral part of the heat exchanger as a plug-in
item that can be located anywhere desired between the inlet and
outlet flow manifolds of the heat exchanger.
[0006] According to one aspect of the invention, there is provided
a bypass valve for a heat exchanger including a plurality of
parallel, tubular members having adjacent wall portions defining
flow openings in communication to form flow manifolds. The bypass
valve comprises a housing having a hollow plug portion with opposed
plug walls defining inlet and outlet openings therein, the plug
walls being adapted to be sealingly mounted between selected
adjacent tubular member wall portions to allow fluid flow
respectively between the flow manifolds and the inlet and outlet
openings. The housing also has an actuator portion located adjacent
to the plug portion. Also, an actuator is releasably mounted in the
actuator portion and has a reciprocating plunger extending into the
plug portion to block and unblock flow between the inlet and outlet
openings.
[0007] According to another aspect of the invention, there is
provided a heat exchanger comprising a plurality of parallel,
tubular members having adjacent wall portions defining flow
openings in communication to form inlet and outlet manifolds for
the flow of fluid through the tubular members. A bypass valve
includes a housing having a hollow plug portion with opposed plug
walls defining inlet and outlet openings therein, the plug walls
being sealingly mounted between selected adjacent tubular member
wall portions to allow fluid flow respectively between the flow
manifolds and the inlet and outlet openings. The housing also has
an actuator portion located adjacent to the plug portion. Also, an
actuator is releasably mounted in the actuator portion and has a
reciprocating plunger extending into the plug portion to block and
unblock flow between the inlet and outlet openings.
[0008] According to yet another aspect of the invention, there is
provided a bypass valve for a heat exchanger including a plurality
of parallel tubular members having adjacent wall portions defining
flow openings in communication to form flow manifolds. The bypass
valve comprises a housing having a hollow plug portion with opposed
plug walls defining inlet and outlet openings therein. The plug
walls are adapted to be sealingly mounted between selected adjacent
tubular member wall portions to allow fluid flow respectively
between said flow manifolds and said inlet and outlet openings. The
housing also has an actuator portion located adjacent to the plug
portion. An actuator is releasably mounted in the actuator portion
and comprises a reciprocating plunger extending into the plug
portion and a solenoid having a central actuator shaft attached to
the plunger. The actuator shaft extends upon energization of the
solenoid, so that the plunger blocks flow between the inlet and
outlet openings. The actuator shaft has a first end to which the
plunger is attached, a second end, and a hollow interior, and the
actuator further comprises bias means for urging the actuator shaft
to retract upon de-energization of the solenoid so as to unblock
flow between said inlet and outlet openings. A temperature sensor
is provided for sensing a temperature of the fluid flowing through
the heat exchanger. The temperature sensor is electrically coupled
to the solenoid through one or more conductors, wherein the
temperature sensor is located at the first end of the actuator
shaft and the one or more conductors extend through the hollow
interior of the actuator shaft to the second end thereof.
[0009] According to yet another aspect of the invention, there is
provided a heat exchanger comprising a plurality of parallel,
tubular members having adjacent wall portions defining flow
openings in communication to form inlet and outlet manifolds for
the flow of fluid through the tubular members, wherein the heat
exchanger includes a bypass valve according to the invention.
[0010] According to yet another aspect of the invention, there is
provided a bypass valve for a heat exchanger. The bypass valve
comprises a housing and a temperature-responsive actuator mounted
in the housing. The housing comprises a first opening and a second
opening to permit fluid to flow through the valve; a first valve
chamber which is arranged between the first and second openings and
is in flow communication with both the first and second openings; a
second valve chamber in flow communication with the first valve
chamber; a third opening in communication with the second valve
chamber; and a valve port which is arranged between the first and
second valve chambers, wherein the second valve chamber is arranged
between the third opening and the valve port. The
temperature-responsive actuator comprises a reciprocating sealing
member extending into the first valve chamber; a solenoid having a
central actuator shaft attached to the sealing member, wherein the
actuator shaft extends upon energization of the solenoid, so that
the sealing member seals the valve port and blocks flow between the
first and second valve chambers, wherein the actuator shaft has a
first end to which the sealing member is attached, a second end,
and a hollow interior; bias means for urging the actuator shaft to
retract upon de-energization of the solenoid so as to unblock flow
between said inlet and outlet openings; and a temperature sensor
for sensing a temperature of the fluid flowing through the valve,
the temperature sensor being electrically coupled to the solenoid
through one or more conductors, wherein the temperature sensor is
located at the first end of the actuator shaft and the one or more
conductors extend through the hollow interior of the actuator shaft
to the second end thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Preferred embodiments of the invention will now be described
by way of example, with reference to the accompanying drawings, in
which:
[0012] FIG. 1 is an elevational view of a heat exchanger having a
preferred embodiment of a bypass valve according to the present
invention mounted therein;
[0013] FIG. 2 is an enlarged view of the portion of FIG. 1
indicated by circle 2;
[0014] FIG. 3 is a perspective view, partly broken away of the
bypass valve of FIG. 2 shown in the closed position;
[0015] FIG. 4 is a perspective view similar to FIG. 3 but showing
the bypass valve in the open position;
[0016] FIG. 5 is an elevational view similar to FIG. 2, but showing
another preferred embodiment of a bypass valve according to the
present invention, the valve being shown partially in
cross-section;
[0017] FIG. 6 is an elevational view similar to FIG. 2, showing yet
another preferred embodiment of a bypass valve according to the
present invention, the valve being shown in cross-section and in
the closed position;
[0018] FIG. 7 is an elevational view similar to FIG. 6, but showing
the bypass valve of FIG. 6 in the open position;
[0019] FIG. 8 is a schematic view of a heat exchanger having
multiple passes and more than one bypass valve;
[0020] FIG. 9 is an elevational view of a portion of another
preferred embodiment of a heat exchanger and bypass valve according
to the present invention;
[0021] FIG. 10 is an elevational view similar to FIG. 2, partly in
cross section, showing yet another preferred embodiment of a bypass
valve according to the present invention, with the valve being in
the open position;
[0022] FIG. 11 is an elevational view similar to FIG. 10, but
showing the bypass valve of FIG. 10 in the closed position;
[0023] FIG. 12 is a schematic view of a heat exchange circuit
including a heat exchanger and a four-port bypass valve according
to the present invention;
[0024] FIG. 13 is a schematic view of a heat exchange circuit
including a heat exchanger and a three-port bypass valve according
to the present invention;
[0025] FIG. 14 is a cross-section along line 14-14 of FIG. 12
showing the four-port bypass valve in the open position;
[0026] FIG. 15 is a cross-sectional view similar to FIG. 14, but
showing the four-port bypass valve of FIG. 14 in the closed
position;
[0027] FIG. 16 is a cross-section along line 16-16 of FIG. 13
showing the three-port bypass valve in the open position;
[0028] FIG. 17 is a cross-sectional view similar to FIG. 16, but
showing the three-port bypass valve of FIG. 14 in the closed
position; and
[0029] FIG. 18 is a cross-sectional view of a four-port bypass
valve according to another embodiment of the present invention.
DETAILED DESCRIPTION
[0030] Referring first to FIGS. 1 and 2, a heat exchanger is
generally indicated by reference numeral 10, and a preferred
embodiment of a bypass valve according to the present invention is
generally indicated by reference numeral 12. Heat exchanger 10 is
formed of a plurality of parallel, spaced-apart, tubular members 14
preferably with enlarged distal end portions 16 that have adjacent
wall portions 17 defining flow openings (not shown) in
communication. Tubular members 14 are preferably formed of mating
plate pairs with transversely protruding cupped end portions to
form these enlarged end portions 16 that also together form flow
manifolds 19 and 21. However, tubular members 14 could be formed of
tubes with separate joined enlarged end portions 16, if desired.
Alternatively, tubular members of uniform width or thickness could
be used, in which case tubular spacers could be used between the
tube ends in place of enlarged distal end portions 16. If it is not
necessary to space tubular members 14 apart transversely, then such
spacers would not be required. Yet another possibility would be to
use transversely orientated tubular manifolds 19 and 21 attached in
communication with the ends of tubular members 14. For the purpose
of this disclosure, the term "distal end portions" is intended to
include all of the above-mentioned tube member communicating wall
structures. Corrugated cooling fins 18 are located between the
tubular members 14 where the tubular members 14 are spaced apart
transversely.
[0031] In the heat exchangers shown in FIGS. 1 and 2, the tubular
members 14 are formed into two upper and lower groups separated by
central back-to-back dimpled plates 20 having offset end portions
22, 24. As seen best in FIG. 2, the space between offset end
portions 22, 24 provides a location where bypass valve 12 can be
plugged into heat exchanger 10. Bypass valve 12 includes a hollow
plug portion 26 located in this space, and which will be described
in further detail below.
[0032] As mentioned above, the enlarged distal end portions 16 have
transverse openings therethrough (not shown), so that the distal
end portions 16 located above bypass valve 12 are all in
communication and form either an inlet or an outlet manifold 19
depending on the direction in which fluid is to flow through heat
exchanger 10. Similarly, the enlarged distal end portions 16
located below bypass valve 12 are all in communication and form a
respective outlet or inlet manifold 21. As seen best in FIG. 1, an
inlet or outlet fitting 28 communicates with the enlarged distal
end portions below it and an inlet or outlet fitting 30
communicates with the enlarged distal end portions above it. So,
for example, fluid entering inlet fitting 28 travels from right to
left as shown in FIG. 1 through all of the tubular members 14
located above dimpled plates 20, to a similar left hand manifold
formed by enlarged distal end portions 32, and then downwardly
through a cross-over fitting 34 into a left hand manifold in the
lower section of heat exchanger 10 formed by enlarged distal end
portions 32, and then back to the right end and out through outlet
fitting 30. Heat exchanger 10 is thus called a two-pass heat
exchanger and can have any number of tubular members 14 above or
below the dimpled plates 20. In fact, there could just be one
tubular member 14 above or below dimpled plates 20, as illustrated
in the embodiment shown in FIG. 9 and as described further
below.
[0033] Heat exchanger 10 also has upper and lower dimpled plates
36. Suitable mounting brackets 40 are attached to dimpled plates 36
as are the inlet and outlet fittings 28, 30.
[0034] Referring next to FIGS. 3 and 4, bypass valve 12 includes a
housing 42 having a hollow plug portion 26 with spaced-apart,
opposed, flat, parallel plug side walls 43 defining transversely
located inlet and outlet openings 44, 46 formed therein for the
flow of fluid through plug portion 26 when valve 12 is in the open
position as shown in FIG. 4. Plug walls 43 are sealingly mounted
between selected adjacent tubular member wall portions 17 of the
enlarged distal end portions 16 of tubular members 14. The distal
end portions 16 have flat mating surfaces. The offset end portions
22 mate flush against their adjacent distal end portion flat
surfaces and the flat housing side walls 43 mate flush against the
flat offset end portions 22. However, housing side or plug walls 43
would mate flush against the flat portions of distal end portions
16, if dimpled plates 22 were not used in heat exchanger 10. This
mounting allows bypass fluid flow directly between selected distal
end portions 16, or respectively between the flow manifolds 19 and
21 and the inlet and outlet openings 44 and 46, or between the
inlet and outlet fittings 28, 30 when bypass valve 12 is open.
Bypass valve side or plug walls 43 are spaced apart a predetermined
distance so as to determine the spacing between adjacent heat
exchanger tubular members, especially if dimpled plates 20 are not
used.
[0035] Bypass valve housing 42 also has an actuator portion 48
located adjacent to and communicating with plug portion 26. A
temperature responsive actuator 50 is located in housing 42.
Actuator 50 has a central shaft 52 attached to a removable closure
54 located remote from plug portion 26. Removable closure 54 has an
O-ring seal 56 and is held in position by a split pin 58 passing
through openings 60 in housing actuator portion 40 and a through
hole 62 in closure 54.
[0036] Temperature responsive actuator 50 has a reciprocating
barrel portion 64 which forms a plunger slidably located in housing
plug portion 26 to block and unblock flow between inlet and outlet
openings 44, 46. A spring 66 is located in housing actuator portion
48 and bears against an annular shoulder 68 on barrel 64 to act as
bias means to urge the actuator 50 to retract so that barrel or
plunger 64 unblocks the flow of fluid through inlet and outlet
openings 44, 46 of bypass valve 12, when the actuator is not
extended due to temperature, as described next below.
[0037] Temperature responsive actuator 50 is sometimes referred to
as a thermal motor and it is a piston and cylinder type device.
Barrel or plunger 64 is filled with a thermal sensitive material,
such as wax, that expands and contracts, causing the actuator to
extend axially upon being heated to a predetermined temperature and
to retract upon being cooled below this predetermined temperature.
Where bypass valve 12 is used in conjunction with an automotive
transmission fluid or oil cooler, this predetermined temperature is
about 80 degrees Celsius, which is the temperature of the fluid
from the transmission when bypass flow is no longer required.
[0038] Referring next to FIG. 5, another preferred embodiment of a
bypass valve according to the present invention is generally
indicated by reference numeral 70. Bypass valve 70 is similar to
bypass valve 12 except that a sliding plate 72 bears against
central shaft 52 and a spring 74 is located in housing actuator
portion 48 to urge central shaft 52 toward the housing plug portion
26. Spring 74 absorbs any pressure spikes or peaks that may occur
in the inlet and outlet manifolds of heat exchanger 10. A notch 76
is formed in barrel 64 to allow the fluid to act against the end of
barrel 64 and provide this pressure relief even when bypass valve
70 is closed. A bleed hole through plunger or barrel 64
communicating with inlet opening 44 could also be used in place of
notch 76 for this purpose. Otherwise, bypass valve 70 is
substantially the same as bypass valve 12.
[0039] Referring next to FIGS. 6 and 7, another preferred
embodiment of a bypass valve according to the present invention is
generally indicated by reference numeral 80. In bypass valve 80,
the temperature responsive actuator 50 includes a solenoid having a
solenoid coil 82 and a central actuator shaft 84 attached to a
plunger 86. Plunger 86 also has a notch or bleed hole 76 to provide
pressure spike relief when valve 80 is closed. Actuator shaft 84
extends upon energization of solenoid coil 82, so that plunger 86
blocks flow between the housing inlet and outlet openings 44, 46. A
spring 88 located in housing plug portion 26 bears against plunger
86 to act as bias means for urging the actuator shaft 84 to retract
when solenoid coil 82 is de-energized.
[0040] A temperature sensor 90 is attached to plunger 86 and is in
the form of a thermistor electrically coupled to solenoid coil 82
for actuation of the solenoid coil when the temperature of the
fluid going through heat exchanger 10 reaches a predetermined
temperature. Temperature sensor 90 could be located elsewhere in
bypass valve 80, or even elsewhere in heat exchanger 10.
Preferably, temperature sensor 90 is electrically connected to an
electrical control unit 92 mounted in housing actuator portion 48.
Electrical control unit 92 is in turn electrically connected to
solenoid coil 82 for controlling the movement of plunger 86 in
accordance with the temperature sensed by temperature sensor 90. In
this way, the opening of bypass valve 80 could be controlled to
provide variable opening, rather than a simple on or off, but the
latter is also possible.
[0041] Referring next to FIG. 8, a heat exchanger 100 is shown
schematically and it is like two heat exchangers 10 of FIG. 1
mounted in series. Two bypass valves 102, 104 are used to provide
thermal modulation of the fluid flowing through the heat exchanger
100. Bypass valve 102 may have a predetermined temperature set
point or activation temperature, and bypass valve 104 may have a
somewhat higher temperature set point or activation temperature.
Heat exchanger 100 is a four pass heat exchanger having four groups
or stacks 106, 108, 110 and 112 of tubular members.
[0042] Where both bypass valves 102 and 104 are open, such as
during cold flow operation, there is full fluid bypass from inlet
fitting 28 to outlet fitting 30. Where bypass valve 102 is closed
and valve 104 is open, such as during warm up or an interim
temperature of fluid flowing through heat exchanger 100, there
would be fluid flow through the top two passes 106 and 108 of heat
exchanger 100, but passes 110 and 112 would be bypassed through
bypass valve 104. Where the fluid reaches its hot operating
temperature, both bypass valves 102 and 104 would close giving flow
through all four passes 106, 108, 110 and 112 and no bypass flow at
all. Additional multiples of passes and bypass valves could be used
in a single heat exchanger as well. Any of the types of bypass
valves described above could be used in heat exchanger 100.
[0043] Referring next to FIG. 9, other preferred embodiments of a
heat exchanger 113 and a bypass valve 115 are shown. In bypass
valve 115, inlet and outlet openings 44, 46 are formed in opposed
plug walls 114, 116 and this shows that inlet and outlet openings
44, 46 can be located anywhere in plug portion 26 as long as one of
these openings is blocked when valve 115 is closed. Otherwise,
bypass valve 115 is substantially similar to or can incorporate the
features of the bypass valves 12, 70 and 80 described above. In the
embodiment of FIG. 9, plate 36 (which preferably is dimpled but may
be flat) and a bottom plate 118 (which may also be dimpled or
flat), together form a tubular member 120 which is one of the
tubular members that make up heat exchanger 113. Tubular member 120
is actually a bypass channel and has flow openings 122 that
communicate with the flow openings in the adjacent enlarged distal
end portions 16 of adjacent tubular member 14, and as such forms
part of the inlet and outlet manifolds of heat exchanger 113.
Instead of tubular member 120, a regular tubular member 14 could be
used in heat exchanger 113, if desired. This would produce a full
flood or single pass heat exchanger. Tubular members 14 may or may
not have turbulizers in them or be made of dimpled plates, but the
bottom tubular member 120 likely would not be turbulized or have
other types of flow augmentation, such as dimples.
[0044] In the assembly of heat exchangers 10, 100 and 113, the
various components, such as the tubular members 14 or 120 and fins
18 are stacked together along with dimpled plates 20, if desired,
and upper and lower dimpled plates 36. Mounting plates or brackets
40 and inlet and outlet fittings 28, 30 can be preassembled to
upper and lower dimpled plates 36 or assembled along with all of
the other components. The housing 42 of the preferred bypass valve
12, 70, 80 or 115 (without any other bypass valve components) is
then placed in the desired location in the heat exchanger and the
entire assembly is brazed together in a brazing furnace. It will be
appreciated that in the preferred embodiments, aluminum or a
brazing-clad aluminum is used for most of the parts of the heat
exchangers, so that all of the parts can be brazed together in a
brazing furnace. After this assembly is cooled, the desired
actuator components of the bypass valves are inserted into housing
42 and the removable closures 54 are secured in position with split
pins 58.
[0045] Having described preferred embodiments of the invention, it
will be appreciated that various modifications can be made to the
structures described above. For example, instead of using a thermal
motor or solenoid type actuator for the bypass valves, other
devices could be used as well, such as a bi-metallic helix to move
the barrel or plunger of the valve. The tubular members can also
have other shapes or configurations as well.
[0046] From the above, it will be appreciated that the bypass
valves of the present invention are in the form of plugs that can
be plugged in at any desired location in the heat exchanger with a
simple rearrangement of the location of some components. The bypass
valve housings actually act as a form of baffle plate to
intermittently block flow between manifold portions of the heat
exchangers. In fact, the bypass valves could be plugged in anywhere
in the heat exchangers where it is desired to have bypass flow
between the plate pairs or tubes. The bypass valve housings are
brazed in place along with all of the other heat exchanger
components. The actual valve elements in the actuators are then
removably or releasably located in the bypass valve housings to
complete the assembly. No external tubing or peripheral components
are required to make the actuator valves active.
[0047] FIGS. 10 and 11 illustrate a plug bypass valve 150 according
to another embodiment of the invention. Valve 150 shares a number
of common characteristics with the plug bypass valve 80 shown in
FIGS. 6 and 7, and like components thereof are identified by like
reference numerals. Bypass valve 150 includes a temperature
responsive actuator 50 including a solenoid having a solenoid coil
82 and a central actuator shaft 84 attached to plunger 86. When the
solenoid 82 is energized, the actuator shaft 84 is extended so as
to move the plunger 86 into blocking relation with the housing
inlet and outlet openings 44, 46 as shown in FIG. 11. When the
solenoid 82 is de-energized, spring 88 urges the actuator shaft 84
to retract, thereby causing the plunger 86 to move out of blocking
relation with openings 44, 46, thereby opening the valve as shown
in FIG. 10.
[0048] Temperature sensor 90, preferably in the form of a
thermistor, is attached to plunger 86 and/or the actuator shaft 84
for actuation of the solenoid coil 82 when the temperature of the
fluid going through heat exchanger 10 reaches a predetermined
temperature. Preferably, the temperature sensor 90 is electrically
connected to an electrical control unit 92 mounted in housing
actuator portion 48. More preferably, the sensor 90 is connected to
the electrical control unit 92 by a pair of electrical conductors
or leads 152, 154 which extend between sensor 90 and control unit
92 through the hollow interior 156 of actuator shaft 84.
[0049] In the embodiment shown in FIGS. 10 and 11, the electrical
control unit 92 includes a circuit board 158 and is mounted to a
solenoid plunger plate 160 having a central aperture in which one
end of actuator shaft 84 is received. The sensor leads 152, 154 are
connected to the circuit board 158 of control unit 92, as are the
power supply leads 162, 164. The power supply leads 162, 164 extend
through the housing 42 to a power supply (not shown). In the
embodiment shown in the drawings, the power supply leads 162, 164
extend through the removable closure 54 of housing 42, although
this is not necessarily the case. The power supply leads 162, 164
may instead extend through the side wall of actuator portion 48 of
housing 42, or inbetween the actuator portion 48 and the removable
closure 54. The electrical control unit 92 permits the opening of
valve 150 to be controlled in order to provide variable opening,
although simple on or off opening is also possible.
[0050] In operation, the temperature sensor 90 continuously
monitors the temperature of the fluid flowing through heat
exchanger 10. When the valve 150 is open as in FIG. 10, there is
bypass flow through the valve 150, with the temperature sensor 90
communicating with the fluid as it flows through the valve 150 from
inlet opening 44 to outlet opening 46. This is the low temperature
configuration of valve 150, i.e. where the temperature of the fluid
is below a predetermined temperature.
[0051] Once the fluid in heat exchanger 10 reaches the
predetermined temperature, the increased temperature is sensed by
the temperature sensor 90 and is communicated to the electrical
control unit 92 through leads 152. The electrical control unit 92
in turn causes the solenoid coil 82 to become energized with power
supplied through power supply leads 162, 164. When the solenoid is
energized, the hollow actuator shaft 84 is extended to the closed
position shown in FIG. 11 so that plunger 86 blocks flow between
the housing inlet and outlet openings 44, 46, thereby preventing
bypass flow and causing the fluid to flow through the tubular
members 14 of heat exchanger 10. This is the high temperature
configuration of valve 150, and in this configuration the
temperature sensor 90 communicates with the fluid in heat exchanger
10 through notch or bleed hole 76.
[0052] When the temperature signal communicated to the control unit
92 indicates that the temperature of the fluid in heat exchanger 10
has dropped below the predetermined temperature, the electrical
control unit 92 causes the solenoid coil 82 to become de-energized,
and the plunger 86 and actuator shaft 84 are then pushed by spring
88 back to the open position shown in FIG. 10, in which the plunger
86 no longer blocks flow between the inlet and outlet openings 44,
46 so as to permit bypass flow.
[0053] The above description describes simple on/off operation of
valve 150. It will however be appreciated that the operation of
valve 150 could instead be controlled to provide variable opening.
For example, once the temperature of the fluid reaches a first
predetermined temperature, the actuator shaft could be partially
extended so that the plunger 86 moves from the fully open position
as shown in FIG. 10 to a position at which it partially blocks the
inlet and outlet openings 44, 46 (inbetween the positions shown in
FIGS. 10 and 11), thereby reducing but not stopping the bypass flow
through the heat exchanger 10. Once the temperature reaches a
second predetermined temperature, higher than the first
predetermined temperature, the plunger 86 is fully extended to the
closed position shown in FIG. 11, and the inlet and outlet openings
44, 46 are completely blocked.
[0054] FIG. 12 illustrates a heat exchange circuit 170 including a
heat exchanger 172 and a preferred four-port bypass valve 174
according to the invention. Any type of heat exchanger can be used
with this embodiment of the present invention. A typical two pass
heat exchanger is shown in FIG. 12 and has a first manifold 176,
which could be an inlet or an outlet manifold, a return manifold
178 and a second manifold 180. A plurality of spaced-apart heat
exchange tubes 182, 184 are connected between the manifolds such
that, where first manifold 176 is an inlet manifold, fluid flows
from the inlet manifold 176 through tubes 182 into return manifold
178 where it reverses direction and comes back through tubes 184 to
the second manifold 180, which is now an outlet manifold. The flow
direction can be reversed so that second manifold 180 is the inlet
manifold and the first manifold 176 is the outlet manifold. It will
also be appreciated that heat exchanger 172 could be modified to
become a single pass heat exchanger with manifolds 176, 180 located
at respective ends of the heat exchanger.
[0055] Where first manifold 176 is an inlet manifold, it is formed
with an inlet opening 186 and an inlet conduit 188 is connected to
communicate with the inlet opening 186. In this arrangement, the
second manifold 20 is the outlet manifold, and is formed with an
outlet opening 190, and an outlet conduit 192 is connected to
communicate with the outlet opening 190. It will be appreciated,
however, that if the flow direction is reversed, the outlet conduit
192 becomes the inlet conduit and inlet conduit 188 becomes the
outlet conduit. Conduits 188, 192 are connected to inlet and outlet
ports of the bypass valve 174, as will be described further below.
Similarly, supply conduits 194, 196 are also connected to ports in
bypass valve 174, as will be described below. Supply conduits 194,
196 have end fittings 198, 200 for attachment to flow lines (not
shown). Where the heat exchanger 172 is used as a transmission oil
cooler, the end fittings 198, 200 can be hose barbs for attaching
rubber hoses between the transmission and heat exchange circuit
170. However, any type of end fittings 198, 200 can be used to suit
the type of conduits running to and from the heat exchange circuit
170. Bypass valve 174 is referred to as a four port bypass valve
because four conduits 188, 192, 194 and 196 are connected to the
bypass valve 174.
[0056] FIG. 13 is similar to FIG. 12 and similar reference numerals
have been used in FIG. 13 and subsequent figures to indicate
components that correspond to those of the embodiment shown in FIG.
12. However, the heat exchange circuit 202 of FIG. 13 has a
three-port bypass valve 204 which has a single conduit 205 through
which it communicates with conduits 188 and 196, the purpose of
which will be discussed below.
[0057] FIGS. 14 and 15 provide additional detail regarding the
structure of the four port bypass valve 174. Four port valve 174
has a valve housing 206 defining a valve chamber 208 therein. The
housing 206 has three main ports or openings 210, 212 and 214. Main
ports 210 and 212 are connected to conduits 192 and 194 (FIG. 12).
Main port 214, also referred to as a valve port, communicates with
two lower branch ports 216, 218 to which conduits 188 and 196 (FIG.
12) are connected, respectively.
[0058] The valve port 214 has a peripheral valve seat 220 facing
chamber 208, and a movable valve member 222 for opening and closing
the valve port 214.
[0059] The valve member 222 is in the form of an annular ring which
is slidably mounted proximate to a first end of a hollow valve
shaft 224. In the orientation of four port valve 174 shown in FIGS.
14 and 15, the first end of the valve shaft 224 is its lower end.
Movement of valve member 222 toward the first end of the valve
shaft 224 is limited by a retaining ring 226 received on the valve
shaft 224 proximate to its first end.
[0060] The valve 214 further comprises a valve cover 228 which is
sealed to the housing 206, for example by a gasket 230. The valve
cover 228 has a central apertured boss 232 through which the second
(upper) end of the valve shaft 224 extends. Spaced from the valve
member 222 toward the second end of valve shaft 224 are provided an
annular washer 234 slidably received on the valve shaft 224 and a
retaining ring 236 attached to the shaft 224 to limit movement of
the washer 234 toward the second end of the shaft 224. A coil
override spring 238 surrounds the valve shaft 224 and bears against
the washer 234 and the valve member 222 to urge them into
engagement with retaining rings 236, 226, respectively. A seal is
formed between the valve cover 228 and the valve shaft 224 by an
O-ring 240 which is provided in an annular groove 242 surrounding
the central aperture of the valve cover 228.
[0061] A return spring 244 is received in a bore 246 extending
between the valve chamber 208 and the branch ports 216, 218,
thereby providing communication between branch ports 216, 218 and
valve chamber 208 through the valve port 214. The bore 246 extends
into the bottom wall 248 of the housing 206, forming a circular
depression 250 therein. As shown in the drawings, the first end of
the valve shaft 224 extends partway into the bore 246. The coil
return spring 244 extends between the depression 250 in the bottom
wall 248 and the valve member 222 and urges the valve member out of
engagement with the valve seat 220, i.e. toward the open position
shown in FIG. 14.
[0062] A temperature sensor 252 is provided at the second end of
the valve shaft 224 for sensing the temperature of fluid flowing
through the branch ports 216, 218 and the bore 246. The temperature
sensor 252 may preferably be a thermistor. Temperature information
from the sensor 252 is communicated via a pair of sensor leads 254,
256 which extend through the hollow interior of the valve shaft 224
between its first and second ends. The sensor leads 254, 256 convey
temperature information from the sensor 252 to an electrical
control unit 258 which is housed in a control unit compartment 260.
The compartment 260 is housed inside a cap 262 which is secured to
valve cover 228 by any suitable means, such as set screws 264 as
illustrated in FIG. 14. The control unit 258 may preferably be
attached to a plunger plate 266 which is attached to the second end
of the valve shaft 224, and which has an upper surface on which the
control unit 258 is provided. The control unit 258 may preferably
include a circuit board 268 to which the temperature sensor leads
254, 256 and power supply leads 270, 272 are connected through
appropriate connectors 274, 276.
[0063] The control unit 258 controls the operation of a solenoid
278 having a central bore 280 through which the valve shaft 224
extends. The solenoid 278 may preferably be provided with studs
282, 284 through which it is secured to the valve cover 228. The
solenoid 278 may preferably have an annular depression 290 in its
upper surface into which a boss 288 of the plunger plate 266
extends. When the solenoid 278 becomes energized by the control
unit 258, the valve shaft 224 is caused to move downwardly relative
to the solenoid. Engagement of the plunger plate 266 and the
solenoid 278 provides a stop which limits the downward movement of
the shaft 224.
[0064] Although not required, a coil spring 286 may be provided in
the control unit compartment 260. In the embodiment shown in FIGS.
14 and 15, one end of the coil spring engages the plunger plate
while the other end engages an internal boss 292 in the cap
262.
[0065] The operation of bypass valve 174 will now be described with
reference to FIGS. 12, 14 and 15. Heat exchange circuit 170 can be
operated with either conduit 194 or 196 being the inlet conduit,
the other one being the outlet conduit. Where conduit 194 is the
inlet conduit and receives transmission oil from the transmission
(not shown), this is referred to as "normal flow". In this case,
conduit 196 is the outlet conduit and returns the transmission oil
to the transmission. Where, on the other hand, the conduit 196 is
the inlet conduit receiving the transmission oil from the
transmission and conduit 194 is the outlet or return conduit for
delivering the oil back to the transmission, this configuration
referred to as "reverse flow".
[0066] Dealing first with the normal flow configuration, where the
temperature of the oil is lower than a predetermined temperature,
such as at engine start-up conditions, the oil may be too viscous
to flow through heat exchanger 172 and it is therefore necessary to
bypass the heat exchanger 172. Under these conditions, the valve
174 is in the open configuration with the solenoid 278 de-energized
as shown in FIG. 14. The hot transmission oil flowing through the
inlet conduit 194 enters the valve 174 through port 212, and enters
the valve chamber 208. The oil then flows through the open valve
port 214, passing through a gap between the valve element 222 and
the valve seat 220, into the bore 246 and then exits the valve 174
through the branch port 218. As the oil flows through bore 246 it
comes into contact with temperature sensor 252.
[0067] Once the sensor 252 detects that the oil temperature has
reached the predetermined temperature, and conveys this information
to the control unit 258, the control unit 258 energizes the
solenoid 278 which causes the valve shaft 224 to extend downwardly
until the valve element 222 is brought into sealed engagement with
the valve seat 220. In this configuration, shown in FIG. 15, the
valve port 214 is closed and bypass flow is prevented. Thus, when
the oil reaches the desired operating temperature, full flow is
occurring through heat exchanger 172 and bypass flow has been
discontinued.
[0068] With the valve 174 in the closed configuration shown in FIG.
15, the hot transmission oil flowing through inlet conduit 194
enters the valve 174 through port 212, flows through valve chamber
208 and exits the valve 174 through valve port 210. The hot oil
then flows through the conduit 192 and into the inlet manifold 180
of heat exchanger 172. The hot oil is cooled as it passes through
heat exchanger 172 and exits the heat exchanger 172 through outlet
conduit 188, which is connected to the outlet manifold 186. The
cooled oil flows then enters the valve 174 through branch port 216,
passes through bore 246 and exits the valve through branch port
218. The cooled oil then flows back to the transmission through
outlet conduit 196.
[0069] If the transmission oil returning to the transmission drops
below the predetermined temperature, the control unit 258
de-energizes the solenoid, thereby causing the return spring 244 to
lift the valve member out of engagement with the valve seat 220.
The oil is then permitted to bypass the heat exchanger 172 as
described above.
[0070] In the reverse flow configuration, conduit 196 becomes the
inlet conduit receiving hot oil from the transmission, and conduit
194 becomes the outlet conduit returning the cooled transmission
oil to the transmission. In the reverse configuration, the flow
through the valve 174 is the opposite of that described above,
whether the transmission oil is above or below the predetermined
temperature.
[0071] It will be appreciated that any pressure peaks that might
occur upon the closing of valve member 222 are attenuated or
modulated, because valve member 222 can lift off valve seat 220 by
such a pressure surge, since valve member 222 is urged into
position by coil spring 238 and is not solidly in engagement with
the valve seat 220. In other words, the coil spring 238 can absorb
pressure spikes in the inlet conduits 196, 188 so that they do not
travel back and adversely affect the transmission.
[0072] Another advantage of bypass valve 174 is that the
temperature sensor 252 is located such that it is in continuous
contact with oil flowing through the valve 174. Thus, the
temperature sensor can respond quickly to changes in the oil
temperature.
[0073] Referring next to FIGS. 13, 16 and 17, three-port bypass
valve 204 will now be described in detail. Bypass valve 204 is
similar to bypass valve 174 includes a number of components which
are either similar or identical to components of the four-port
bypass valve 174 described above. Similar reference numerals are
used to describe similar elements of valve 204 and detailed
description of these elements is omitted.
[0074] The principal difference between valve 204 and valve 174 is
that valve 204 has a valve housing 294 provided with a single
branch port 296 rather than a pair of branch ports 216, 218 as in
valve 174. The valve housing 294 is otherwise the same as the valve
housing 206 of valve 174. The single branch port 296 is connected
to conduits 188 and 196 through the conduit 205. The operation of
valve 204 is substantially the same as described above with
reference to valve 174, except that the transmission oil enters or
exits the valve 204 through the single branch port 296, depending
on whether the oil flow is in the normal or reverse direction.
[0075] In each of the valves illustrated in FIGS. 10 to 17, the
electrical control unit is attached to the valve shaft so that the
control unit and the valve shafts move together during operation of
the valve. FIG. 18 illustrates four-port bypass valve 298, similar
to valve 174 shown in FIG. 14, having an electrical control unit
300 which is spaced from the valve shaft and is housed in the
control unit compartment 260 which is separated from the remainder
of the valve 298 by an annular flange 302 extending inwardly from
the side wall of the cap 262. In this embodiment there is no spring
inside the cap 262. The remaining elements of valve 298 are
identical to the elements of valve 174 and are identified by like
reference numerals. Also, the operation of valve 298 is
substantially identical to the operation of valve 174. Therefore, a
detailed description of the elements of valve 298, and their
operation, are unnecessary.
[0076] As will be apparent to those skilled in the art in the light
of the foregoing disclosure, many alterations and modifications are
possible in the practice of this invention without departing from
the spirit or scope thereof. The foregoing description is of the
preferred embodiments and is by way of example only, and it is not
to limit the scope of the invention.
* * * * *