U.S. patent application number 13/382811 was filed with the patent office on 2012-05-03 for cooling system for a combustion engine.
This patent application is currently assigned to ILLINOIS TOOL WORKS INC.. Invention is credited to Carsten Heldberg.
Application Number | 20120103577 13/382811 |
Document ID | / |
Family ID | 42985403 |
Filed Date | 2012-05-03 |
United States Patent
Application |
20120103577 |
Kind Code |
A1 |
Heldberg; Carsten |
May 3, 2012 |
COOLING SYSTEM FOR A COMBUSTION ENGINE
Abstract
The invention relates to a cooling system for a combustion
engine, comprising an inlet for cooling fluid, which is connectable
to cooling channels of the combustion engine, and an outlet for
cooling fluid, which is also connectable to the cooling channels of
the combustion engine, a pump for pumping the cooling fluid through
the inlet and outlet, a cooler for cooling the cooling fluid, which
is connected to the outlet, on the one hand, and the inlet, on the
other hand, and a bypass line, which connects the outlet to the
inlet without passing through the cooler, and a valve assembly
comprising a valve element and an actuation device for actuating
the valve element, characterized in that the valve element is
arranged in the outlet and comprises at least three fluid
connections, wherein a first fluid connection is connected to a
section of the outlet coming from a cooling fluid discharge of the
combustion engine, a second fluid connection is connected to a
section of the outlet leading to the cooler and a third fluid
connection is connected to the bypass line leading to the inlet,
and the actuation device comprises an expansion element, which is
arranged in the inlet downstream of the connection of the bypass
line to the inlet, and with which expansion element the valve
element is actuatable such that the first fluid connection is
connected to the second and/or third fluid connection.
Inventors: |
Heldberg; Carsten;
(Kirchlinteln, DE) |
Assignee: |
ILLINOIS TOOL WORKS INC.
Glenview
IL
|
Family ID: |
42985403 |
Appl. No.: |
13/382811 |
Filed: |
June 23, 2010 |
PCT Filed: |
June 23, 2010 |
PCT NO: |
PCT/US10/39583 |
371 Date: |
January 6, 2012 |
Current U.S.
Class: |
165/121 |
Current CPC
Class: |
F01P 7/16 20130101 |
Class at
Publication: |
165/121 |
International
Class: |
F28F 13/00 20060101
F28F013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 8, 2009 |
DE |
102009032647.2 |
Claims
1. A cooling system for a combustion engine, comprising an inlet
for cooling fluid, which is connectable to cooling channels of the
combustion engine, and an outlet for cooling fluid, which is also
connectable to the cooling channels of the combustion engine, a
pump for pumping the cooling fluid through the inlet and outlet, a
cooler for cooling the cooling fluid, which is connected to the
outlet the one hand and the inlet on the other hand, and a bypass
line, which connects the outlet to the inlet without passing
through the cooler, and a valve assembly comprising a valve element
and an actuation device for actuating the valve element
characterized in that the valve element is arranged in the outlet
and comprises at least three fluid connections, wherein a first
fluid connection is connected to a section of the outlet coming
from a cooling fluid discharge of the combustion engine a second
fluid connection is connected to a section of the outlet leading to
the cooler and a third fluid connection is connected to the bypass
line leading to the inlet, and the actuation device comprises an
expansion element, which is arranged in the inlet downstream of the
connection of the bypass line to the inlet, and with which
expansion element the valve element is actuatable such that the
first fluid connection is connected to the second and/or third
fluid connection.
2. The cooling system as claimed in claim 1, characterized in that
the valve element comprises a ball valve, which is rotatably
supported in a valve housing, wherein the valve housing comprises
the at least three fluid connections, wherein the ball valve
comprises at least two openings, and wherein the ball valve is
rotatable in the valve housing by the expansion element such that
the first fluid connection is connected to the second and/or third
fluid connection through the openings of the valve element.
3. The cooling system as claimed in claim 1, characterized in that
the valve element comprises a disk valve, which comprises at least
one fluid tight disk, whose position is actuatable by the expansion
element such that the first fluid connection is connected to the
second and/or third fluid connection.
4. The cooling system as claimed in claim 1, characterized in that
the expansion element is an expanding wax element.
5. The cooling system according to claim 1, characterized in that
the expansion element actuates the valve element via an actuation
rod which is in operative connection with a return spring.
6. The cooling system as claimed in claim 1, characterized in that
the pump is arranged in the inlet downstream of the connection of
the bypass line to the inlet.
Description
[0001] The invention relates to a cooling system for a combustion
engine, comprising an inlet for cooling fluid, which is connectable
to cooling channels of the combustion engine, and an outlet for
cooling fluid, which is also connectable to the cooling channels of
the combustion engine, a pump for pumping the cooling fluid through
the inlet and outlet, a cooler for cooling the cooling fluid, which
is connected to the outlet on the one hand and the inlet on the
other hand, and a bypass line, which connects the outlet to the
inlet without passing through the cooler, and a valve assembly
comprising a valve element and an actuation device for actuating
the valve element.
[0002] In cooling systems of this kind, a pump pumps the coolant,
e.g. a water/glycol mixture, via the engine block and the cylinder
head of the combustion engine and then via a cooler back into the
engine block and cylinder head. Another known practice in this
context is to provide a bypass line, by means of which the cooling
fluid coming from the engine block and/or cylinder block in the
cold starting phase of the engine is passed directly back into the
inlet to the engine block and/or cylinder head without passing
through the cooler. A cooling system of this kind is known from DE
103 51 852 A1, for example. In this arrangement, a valve assembly
comprising a valve element and an actuation device is provided on
the discharge side of the combustion engine. The individual flows
of cooling fluid can be divided up in the desired manner with just
one valve assembly through appropriate actuation of the valve
element. An expansion element arranged within the valve ball of a
valve element designed as a ball valve, for example, can be
provided for the actuation of the valve element, for example. The
expansion element is in heat conducting contact with the cooling
fluid and expands and contracts with heating and cooling, and in
this way automatically actuates the valve element as a
thermostat.
[0003] One disadvantage of the position of the valve assembly on
the discharge side is that the expansion element is exposed to a
change in the temperature of the cooling fluid and hence the
thermostatic regulation effected by the expansion element takes
effect only when the cooling fluid has already flowed through the
engine block and the cylinder block. Regulation is therefore
subject to a delay and the cold starting phase of the combustion
engine is extended in an undesirable way. Another known practice is
to arrange valve assemblies of this kind on the side on which
cooling fluid is admitted. However, the disadvantage with such an
arrangement is that the cooler and, in particular, the cooling
hoses are immediately subjected to the full pressure of the cooling
fluid when the engine is cold started. This can lead to damage in
the cooling hoses, especially in the winter months.
[0004] Taking as a starting point the prior art that has been
explained, it is the underlying object of the invention to provide
a cooling system of the type stated at the outset which, on the one
hand, allows rapid regulation and, on the other hand, reliably
prevents damage to the cooling system.
[0005] The invention achieves this object through the subject
matter of claim 1. Advantageous embodiments can be found in the
dependent claims, the description and the figures.
[0006] For a cooling system of the type stated at the outset, the
invention achieves the object by virtue of the fact that the valve
element is arranged in the outlet and comprises at least three
fluid connections, wherein a first fluid connection is connected to
a section of the outlet coming from a cooling fluid discharge of
the combustion engine, a second fluid connection is connected to a
section of the outlet leading to the cooler and a third fluid
connection is connected to the bypass line leading to the inlet,
and that the actuation device comprises an expansion element, which
is arranged in the inlet downstream of the connection of the bypass
line to the inlet, and with which expansion element the valve
element is actuatable such that the first fluid connection is
connected to the second and/or third fluid connection.
[0007] The combustion engine can be the combustion engine of a
motor vehicle, in particular. In this context, the cooling channels
can pass through the engine block and/or the cylinder head of the
combustion engine. The cooling fluid discharge and the cooling
fluid entry of the combustion engine are the inlet and outlet
respectively of the cooling channels. The cooling fluid can be a
water/glycol mixture, which is a known option. The pump pumps the
cooling fluid through the cooling system in a manner which is
likewise known, i.e. in particular from the inlet line, through the
cooling channels of the engine, into the outlet line and, depending
on the position of the valve, through the cooler or the bypass. It
is of course also possible for more than one cooler to be provided.
The flow of cooling fluid passed to the cooler can also pass
through an oil/water heat exchanger and/or be fed to a motor
vehicle heating system in winter operation.
[0008] Via the bypass, cooling fluid coming from the engine can be
fed directly, i.e. without passing through elements that cool the
fluid, in particular a cooler, back to the inlet from the outlet in
a manner known per se. This is desired if the engine has not yet
reached operating temperature and the intention is that it should
heat up to the operating temperature as quickly as possible. In
this state, the cooling fluid is not supposed to be cooled by a
cooler or similar.
[0009] According to the invention, the valve element for
selectively connecting the first connection to the second and/or
third connection of the valve assembly is arranged in the outlet
and the expansion element is arranged in the inlet. The valve
element is connected to the inlet line on the upstream and
downstream side. The element is furthermore connected to the
bypass. The expansion element, which is arranged in the inlet, is
in heat conducting contact with the cooling fluid and is heated in
accordance with the temperature of the cooling fluid. During this
process, it expands and actuates the valve element accordingly. In
this way, automatic regulation of the flow of cooling fluid coming
from the engine through the cooler back into the inlet or, via the
bypass, directly into the inlet is accomplished as a function of
the temperature of the cooling fluid and hence of the enthne
temperature. Thus the valve assembly operates as a thermostat and,
in particular, it is possible to provide just one valve
assembly.
[0010] The expansion element actuates the valve element in such a
way that, below a limiting temperature, all of the cooling fluid
coming from the engine is initially routed back into the inlet via
the bypass line. As the expansion element heats up and hence
expands, the cooling fluid coming from the engine is initially
passed partially through the cooler and partially through the
bypass back into the inlet. Above a limiting temperature, all of
the cooling fluid coming from the engine is then passed through the
cooler under the control of the actuation device or valve element.
For the purpose of routing part of the fluid through the cooler and
the bypass, the first connection is connected partially to the
second connection and partially to the third connection. It is, of
course, also possible to provide for the possibility of setting the
valve element to a position in which flow from the first connection
to the second or third connection is shut off.
[0011] According to the invention, the valve element and the
actuation device are spatially separated. Since the valve element
is arranged on the side on which the cooling fluid is discharged
from the engine, the cooler and, in particular, the cooling water
hoses are, on the one hand, advantageously not exposed to the full
pressure of the fluid in the cold starting phase. Thus damage is
reliably prevented, especially in the cold winter months. Since, on
the other hand, the expansion element is arranged on the side on
which the cooling fluid is admitted to the engine, particularly
rapid and hence good regulation is achieved, especially in the cold
starting phase of the engine, since the temperature of the cooling
fluid is recorded by the expansion element even before it flows
through the engine block and/or cylinder head and is accordingly
taken into account immediately for regulation. Thus, according to
the invention, the respective advantages of positioning valve
assemblies on the admission and the discharge side are combined by
providing a discharge thermostat controlled by the admission
temperature of the cooling fluid.
[0012] According to a refinement, provision can be made for the
valve element to comprise a ball valve, which is rotatably
supported in a valve housing, wherein the valve housing comprises
the at least three fluid connections, wherein the ball valve
comprises at least two openings, and wherein the ball valve is
rotatable in the valve housing by the expansion element such that
the first fluid connection is connected to the second and/or third
fluid connection through the openings of the valve element. The
valve element can thus be a ball (segment) valve. With such ball
valves, particularly precise and, at the same time, robust control
is possible. In this arrangement, a hollow sphere (spherical
segment) is mounted in such a way that it can be rotated in the
housing by means of one or more suitable shafts. A rod or similar
connected to the expansion element engages on the valve ball,
eccentrically for example, to rotate the latter. However, it is
also conceivable that the valve element should comprise a disk
valve, which comprises at least one fluid tight disk, the position
of which is actuatable by the expansion element such that the first
fluid connection is connected to the second and/or third fluid
connection. In particular, the disk valve can comprise two disks,
each interrupting a link between two connections. For example, one
disk can be provided for the link between the first fluid
connection and the second fluid connection, and a second disk can
be provided for the link between the first fluid connection and the
third fluid connection. A flow of cooling fluid coming from the
first fluid connection can then be fed completely or partially to
the section of the outlet leading to the cooler and/or to the
bypass line by appropriate positioning of the disks. It is a simple
matter additionally to integrate a pressure relief valve into the
cooling system, if required.
[0013] According to a particularly practical refinement, the
expansion element can be an expanding wax element. Provision can
furthermore be made for the expansion element to actuate the valve
element via an actuation rod which is in operative connection with
a return spring. The actuation rod then engages on the valve
element against the spring force of the return spring and actuates
said element when there is a temperature-induced expansion or
contraction of the expansion element. If the expansion element does
not exert a sufficient force on the return spring, the spring can
relax and thereby actuate the valve element in such a way, for
example, that cooling fluid coming from the engine is routed
directly into the inlet via a bypass. However, it is also possible
that, when the spring is free of force, said spring actuates the
valve element in such a way that cooling fluid coming from the
engine is routed into the inlet through the cooler. As a result,
adequate cooling of the engine is ensured at all times if the
expansion element fails.
[0014] According to a further particularly practical refinement,
the pump can be arranged in the inlet downstream of the connection
of the bypass line to the inlet. The intake side of the pump is
thus downstream of the inflow from the bypass line. In particular,
the pump can be arranged substantially directly in front of the
cooling fluid entry of the combustion engine, i.e. the entry to the
system of cooling channels.
[0015] An illustrative embodiment of the invention is explained in
greater detail below with reference to the figures. In said
figures, which are schematic:
[0016] FIG. 1 shows a cooling system according to the invention in
accordance with a first illustrative embodiment, in a first
operating state.
[0017] FIG. 2 shows the cooling system from FIG. 1 in a second
operating state,
[0018] FIG. 3 shows a cooling system according to the invention in
accordance with a second illustrative embodiment, in a first
operating state, and
[0019] FIG. 4 shows the cooling system from FIG. 3 in a second
operating state.
[0020] Unless stated otherwise, identical reference signs refer to
identical objects in the figures. FIGS. 1 and 2 illustrate a
cooling system 10 according to the invention for a combustion
engine of a motor vehicle. For the sake of clarity, the only part
of the combustion engine shown is the engine block 12. Running
through the latter is a plurality of cooling channels (not shown in
the figures). Furthermore, a cylinder head of the combustion engine
(not shown) can likewise have such cooling channels. The cooling
system 10 has an inlet line 14, which is connected on the admission
side 16 of the engine block 12 to the cooling channels of the
latter and, where applicable, of the cylinder head. The cooling
system 10 furthermore has an outlet line 18, which, in the example
shown, comprises a first section 22, which starts from the
discharge side 20 of the engine block 12, said discharge side
likewise being connected to the cooling channels, and a second
section 24, which adjoins the first section 22. The second section
24 opens as a cooler feed into a cooler 26, in the present case the
main cooler, of the cooling system 10. The inlet 14 is connected to
the cooler 26 at the outlet of said cooler as a cooler return. In
the inlet 14, there is a pump 28 on the admission side 16 of the
engine block 12. In particular, the inlet 14 opens into the intake
side of the pump 28. The delivery side of the pump 28 is connected
to the cooling channels of the engine block 12 and/or of the
cylinder head. The pump 28 pumps cooling fluid, in the example
illustrated a water/glycol mixture, through the cooling system
10.
[0021] The cooling system 10 furthermore has a bypass line 30,
which connects the section 22 of the outlet 18 which starts from
the cooling water exit of the engine block 12 directly to the inlet
14, bypassing the cooler 26. The intake side of the pump 28 is thus
arranged downstream of the connection of the bypass line 30 to the
inlet 14. Between the section 22 of the outlet 18 which starts from
the discharge side 20 of the engine block 12 and the bypass line 30
and the section 24 of the outlet which leads to the cooler 26 there
is a valve element 32. In the illustrative embodiment shown in
FIGS. 1 and 2, the valve element 32 is a hollow spherical segment
arranged in a valve housing. The valve housing has three fluid
connections, a first connection being connected to section 22 of
the inlet, a second connection being connected to section 24 of the
inlet 18, and a third connection being connected to the bypass line
30. In the example shown, the hollow spherical segment has two
openings. It is rotatably mounted in the housing in a manner known
per se. Given appropriate arrangement of the openings of the valve
ball, it is possible by rotating the hollow spherical segment to
connect the first fluid connection of the housing to the second
and/or the third fluid connection.
[0022] FIG. 1 shows a position of the valve element 32 in which the
first connection is connected only to the third connection, while
the link to the second connection is shut off. This position is
adopted in the cold starting phase of the combustion engine. In
this position, cooling fluid pumped out of the inlet 14 through the
engine block 12 by the pump 28 thus flows through the first section
22 of the outlet 18 and, from there, flows in full through the
bypass line 30, bypassing the cooler 26, back into the inlet 14, as
illustrated schematically by the arrows 34 in FIG. 1. FIG. 2 shows
a different position of the valve element 32, in which the first
connection of the valve housing is connected only to the second
connection, while the link to the third connection is shut off. In
this position of the valve element 32, all of the cooling fluid
pumped out of the inlet 14 through the engine block 12 and into
section 22 of the outlet 18 by the pump 28 thus flows through the
section 24 of the outlet 18 which opens into the cooler 26, through
the cooler 26, and from there back into the inlet 14 and through
the engine block 12 etc. This is indicated by the arrows 36 in FIG.
2. The operating position shown in FIG. 2 is adopted when the
combustion engine has reached its operating temperature. The valve
element 32 can also adopt intermediate positions not shown in FIGS.
1 and 2 if the link between the first connection and hence section
22 of the outlet 18, on the one hand, and the second connection and
hence section 24 of the outlet 18 and the third connection and
hence the bypass line 30, on the other hand, are simultaneously and
each partially opened. In this state, therefore, part of the
cooling fluid flows through the cooler 26 and part through the
bypass line 30, directly back into the inlet 14, depending on the
position of the valve element 32.
[0023] In the example shown, the valve element 32 is actuated by
means of an expansion element 38, in the example shown an expanding
wax element 38, arranged in the inlet 14 downstream of the
connection of the bypass line 30 to the inlet 14. This is thus in
heat conducting contact with the cooling fluid flowing through the
inlet 14 and expands or contracts in accordance with the
temperature of the cooling fluid. The expansion element 38 is
connected to an actuation rod 40, in the present case a working pin
40, which is in turn in operative connection, at its end remote
from the expansion element 38, with a return spring 42 arranged in
the axial direction of the working pin 40. During movement of the
actuation rod 40 owing to an expansion or contraction of the
expansion element 38, the valve element 32, in the present case the
ball valve, is moved counter to the spring force of the return
spring 42 by way of a connecting rod 43 articulated on the
actuation rod 40, as is shown in FIGS. 1 and 2. Here, the expansion
element 38 is to a large extent contracted in FIG. 1 and to a large
extent expanded in FIG. 2. It can easily be seen that any desired
mixing ratios of the cooling fluid routed through the cooler 26, on
the one hand, and the bypass line 30, on the other hand, can be set
in an infinitely variable manner, in addition to the two positions
of the valve element 32 which are shown in FIGS. 1 and 2.
[0024] FIGS. 3 and 4 show a cooling system 10 according to the
invention in accordance with a second illustrative embodiment. FIG.
3 once again shows the operating position in the cold starting
phase of the combustion engine, while FIG. 4 shows the operating
position when the operating temperature of the combustion engine is
reached. The cooling system 10 shown in FIGS. 3 and 4 largely
corresponds to the cooling system shown in FIGS. 1 and 2. However,
it differs in the valve element from the cooling system 10 shown in
FIGS. 1 and 2. In FIGS. 3 and 4, a disk valve element 44 is
provided. In the example shown, the valve element 44 has two valve
disks 46, 48, which are arranged coaxially to one another on the
actuation rod 40 actuated by the expansion element 38. Upon
actuation of the actuation rod 40 by the expansion element 38, the
valve disks 46, 48 are thus moved in the axial direction of the
actuation rod 40 counter to the return force of a return spring
50.
[0025] In the operating position shown in FIG. 3, the expansion
element 38 is expanded to the minimum extent. In this position, the
link between the first fluid connection and the second fluid
connection is completely shut off, with the result that all the
cooling fluid pumped through the engine block 12 flows directly
back into the inlet 14 from the discharge side 20 of the engine
block 12 through the bypass line 30, as indicated by the arrows 34
in FIG. 3. In particular, the second valve disk 48 shuts off the
link to the section 24 of the outlet 18 which opens into the cooler
26. In the operating position shown in FIG. 4, the expansion
element 38 is, by contrast, expanded, with the result that the
first valve disk 46 of the valve element 44 shuts off the link
between the section 22 of the outlet 18 coming from the cooling
water discharge 20 of the engine block 12 and the bypass line 30,
with the result that all the cooling fluid pumped through the
engine block 12 flows back into the inlet 14 via section 24 of the
outlet 18 and the cooler 26, as indicated by the arrows 36 in FIG.
4.
[0026] In both illustrative embodiments, the return spring 42, 50
actuates the respective valve element 32, 44 in such a way when
free of force, i.e. when the expansion element 38 is not expanded,
as illustrated in both FIGS. 1 and 3, that all the cooling fluid
coming from the engine block 12 is passed back directly into the
inlet 14 through the bypass line 30. When the expansion element 38
is expanded, as shown in FIGS. 2 and 4, on the other hand, the
return spring 42, 50 is in each case compressed.
[0027] By means of the admission-side control, in accordance with
the invention, of the valve element arranged on the discharge side
by means of an expansion element, particularly rapid temperature
regulation with simultaneous reliable avoidance of damage,
especially to the cooling hoses, at low temperatures is
achieved.
* * * * *