U.S. patent application number 10/533867 was filed with the patent office on 2006-06-15 for collecting tank, heat exchanger and coolant circuit.
This patent application is currently assigned to BEHR GmbH & CO. KG. Invention is credited to Martin Kaspar, Kurt Molt.
Application Number | 20060123836 10/533867 |
Document ID | / |
Family ID | 32115317 |
Filed Date | 2006-06-15 |
United States Patent
Application |
20060123836 |
Kind Code |
A1 |
Kaspar; Martin ; et
al. |
June 15, 2006 |
Collecting tank, heat exchanger and coolant circuit
Abstract
The invention relates to a collecting tank (43) comprising an
elastically deformable drain plug (44), to a heat exchanger (1) and
to a coolant circuit.
Inventors: |
Kaspar; Martin; (Esslingen,
DE) ; Molt; Kurt; (Bietigheim-Bissingen, DE) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
BEHR GmbH & CO. KG
Stuttgart
DE
|
Family ID: |
32115317 |
Appl. No.: |
10/533867 |
Filed: |
October 22, 2003 |
PCT Filed: |
October 22, 2003 |
PCT NO: |
PCT/EP03/11692 |
371 Date: |
October 14, 2005 |
Current U.S.
Class: |
62/509 ;
62/474 |
Current CPC
Class: |
F28F 2220/00 20130101;
F25B 43/006 20130101; F25B 2500/01 20130101; F25B 2339/0441
20130101; F25B 2400/162 20130101; F25B 39/04 20130101 |
Class at
Publication: |
062/509 ;
062/474 |
International
Class: |
F25B 43/00 20060101
F25B043/00; F25B 39/04 20060101 F25B039/04 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 5, 2002 |
DE |
102 51 777.0 |
Claims
1. A collecting tank for a heat exchange medium, having a housing,
in which a replaceable drier and/or filter device can be
accommodated, the housing having an aperture that can be closed by
a removable plug and sealed by a sealing means, characterized in
that the plug is elastically deformable.
2. The collecting tank as claimed in claim 1, characterized in that
the plug is composed of plastic.
3. The collecting tank as claimed in claim 2, characterized in that
the plug has a shielding element against the heat exchange
medium.
4. The collecting tank as claimed in claim 3, characterized in that
the shielding element takes the form of a coating, in particular a
metalized or enamel coating.
5. The collecting tank as claimed in claim 1, characterized in that
the sealing means comprises at least one sealing ring of an
elastomer material, such as rubber or Teflon.
6. The collecting tank as claimed in claim 1, characterized in that
the plug is integrally formed with the sealing means, the sealing
means in particular being molded onto the plug.
7. The collecting tank as claimed in claim 1, characterized in that
the plug can be held in the aperture by a retainer ring.
8. The collecting tank as claimed in claim 1, characterized in that
the aperture has a circular cross-section and the plug is basically
of hollow cylindrical design, the hollow cylinder being open on the
side facing the interior of the housing.
9. The collecting tank as claimed in claim 1, characterized in that
the housing takes the form of a tube with one open end, the plug
being received in the open tube end.
10. The collecting tank as claimed in claim 1, characterized in
that the heat exchange medium is a refrigerant and the collecting
tank is an integral part of a coolant circuit, in particular for a
motor vehicle air conditioning system.
11. A heat exchanger, in particular a condenser, having tubes, fins
and two head pieces, characterized in that the heat exchanger has a
collecting tank as claimed in claim 1.
12. A coolant circuit of an air conditioning system, in particular
for a motor vehicle, having a compression element, a first heat
exchanger, an expansion element, a second heat exchanger and a
collecting tank, characterized in that the collecting tank is
designed according to claim 1.
Description
[0001] The invention relates to a collecting tank having a drain
plug, and to a heat exchanger and a coolant circuit.
[0002] Heat exchange media as in the coolant circuits of air
conditioning systems, for example, are often led through collecting
tanks thereby serving, on the one hand, to equalize the pressure,
and on the other possibly ensuring the complete condensation of any
refrigerant. In addition, a heat exchange medium in such a
collecting tank may have particles removed by means of a filter
device and any water removed by means of a drier device. In order
to design such a filter and/or drier device so that it can be
replaced for maintenance purposes, it is necessary to provide the
collecting tank with a reversibly closeable aperture, through which
the filter and/or drier device can be removed from the collecting
tank.
[0003] A collecting tank of this type is described in DE 100 39 260
A1 of the present applicant. Inside, the collecting tank described
accommodates a drier, which for maintenance purposes can be changed
by way of an aperture that can be closed by a removable cover. The
cover in this case takes the form of a cylindrical plug and is
axially displaceable and sealed in a corresponding cylindrical bore
of the collecting tank. In addition, this plug is fixed by a
retainer ring, the retainer ring being secured to prevent its
release by a locking offset bearing on the plug. The plug is at the
same time pressed axially outwards against the retainer ring by an
excess pressure acting on said plug, as is present inside the
collecting tank during operation. To open, the plug must be pressed
inwards when the collecting tank is unpressurized, so that the
retainer ring is released and can be removed, following which the
plug can also be removed from the collecting tank.
[0004] The bore is sealed by way of two sealing rings, which are
each arranged in an annular groove in the plug and are pressed into
the annular grooves by introducing the plug into the collecting
tank. In order to obtain an adequate sealing effect, the outside
dimensions of the plug must on the one hand be matched precisely to
the inside dimensions of the bore. On the other hand, the plug must
be composed of the same material as the collecting tank, in order
to prevent a diminishing sealing effect during operation of the
collecting tank, since different materials are possibly subjected
to different degrees of thermal expansion owing to the naturally
occurring temperature fluctuations of the heat exchange medium.
These restrictions on both the shape and the material of the plug
have a disadvantageous impact on the manufacture of such a
collecting tank.
[0005] Since the known collecting tank is composed of aluminum, the
plug is also made of aluminum. The strength of this material means
that it is possible to make the plug hollow, in order to save
weight and material costs, without having to accept a reduction in
the dimensional stability of the plug.
[0006] The object of the present invention is to provide a
collecting tank, a heat exchanger and/or a coolant circuit, in
which simplified and/or inexpensive manufacture and possibly an
improved sealing effect can be achieved.
[0007] This object is achieved by a collecting tank having the
features of claim 1, by a heat exchanger having the features of
claim 9 and by a coolant circuit having the features of claim
10.
[0008] According to Claim 1 a collecting tank for a heat exchange
medium comprises a housing, in which a drier and/or filter device
can be accommodated. The housing is provided with an aperture,
which can be closed by a removable plug and through which the drier
and/or filter device can be received into and removed from the
housing, so that the drier and/or filter device is of replaceable
design. For this purpose the housing aperture can be closed by a
removable plug and sealed by a sealing means. The sealing means may
be one or more sealing rings, which is/are composed of an elastomer
material such as rubber or Teflon.
[0009] The object of the invention is advantageously achieved in
that the plug is elastically deformable. Whilst the collecting tank
is in operation the plug can thereby be deformed by an internal
pressure in such a way that the plug is pressed against an edge of
the housing aperture by the sealing means. This ensures the desired
sealing even when the plug, simply by virtue of its dimensions,
would be incapable of exerting sufficient pressure on the sealing
means, which may be the case, for example, due to an inaccurate
production dimension or to different degrees of thermal expansion
of the plug and the housing.
[0010] In the context of the invention the term elastically
deformable plug is taken to mean a plug which due to the
application of a pressure inside the collecting tank modifies its
shape in such a way that the sealing means is subjected to a force.
An ordinary operating pressure for heat exchange media such as
refrigerant in air conditioning systems, for example, is already
sufficient for this purpose. In this sense a solid aluminum plug,
for example, possesses no elastic deformability.
[0011] The elastic deformability of the plug can be achieved on the
one hand by a suitable plug geometry. The plug has a recess, for
example, with a thin wall in such a way that the wall can be
pressed against an edge of the housing aperture by means of a
pressurized heat exchange medium present inside the recess. The
plug is preferably designed basically as a hollow cylinder with an
open end towards the interior of the housing, the aperture having a
circular cross-section. The heat exchange medium then presses the
cylinder wall radially towards an edge of the aperture, with the
result that the sealing means, preferably a sealing ring, is
uniformly compressed, achieving an effective sealing action. The
structure of the collecting tank is particularly simplified if the
housing is designed as a tube having an open end. The aperture is
then formed by the open tube end, into which the plug can be
received.
[0012] On the other hand it is possible to manufacture the plug
from an elastically deformable material. In this case also, the
plug is pressed against an edge of the housing aperture by the
pressure of the heat exchange medium, so that the sealing means is
compressed in order to achieve an improved sealing effect.
[0013] A combination of a suitable plug geometry with the selection
of an elastically deformable material is especially preferred. For
example, a hollow-cylindrical plastic plug is particularly
well-suited as removable closure for the collecting tank, since a
plastic affording sufficient elasticity for a deformability
according to the invention together with sufficient strength for
closing the collecting tank makes it an automatic choice. In order
to prevent the heat exchange medium permeating through the plug
material, the plug preferably has a shielding element. The
shielding element more preferably takes the form of a metalized
coating or enameled coating, which is applied at least to the side
of the plug facing the interior of the housing.
[0014] In a preferred embodiment the plug is integrally formed with
the sealing means, the resulting reduction in the number of
components serving to reduce the assembly cost of the collecting
tank. In the case of a plastic plug in particular, the sealing
means can be molded onto the plug with the result that an
especially simple one-piece plug design with the sealing means can
be achieved.
[0015] The plug is preferably secured to prevent it falling out of
the collecting tank, being held in the aperture by a retainer ring.
In particular, detachment of the retainer ring from any annular
groove provided in the edge of the housing aperture is prevented by
securing the retainer ring by means of a locking offset, which is
provided on the plug and which bears on the inside edge of the
retainer ring.
[0016] In an advantageous embodiment the collecting tank according
to the invention is inserted into a heat exchanger, having tubes,
fins and two head pieces, in such a way that a heat exchange medium
flowing through the heat exchanger flows previously, subsequently
or in the meantime through the collecting tank. In particular, the
heat exchanger here takes the form of a condenser, a drier then
most preferably being introduced into the collecting tank. Such
heat exchangers have been disclosed in DE 42 38 853 C2, which
hereby expressly forms part of the disclosure.
[0017] According to a further advantageous embodiment the
collecting tank according to the invention is inserted into a
coolant circuit of an air conditioning system having a compression
element, a first heat exchanger, an expansion element and a second
heat exchanger, in order to permit collecting of the refrigerant.
The collecting tank here in particular contains a drier for the
refrigerant. In particular the compression element is in this case
a compressor, the first heat exchanger is a condenser, the
expansion element is an expansion valve and the second heat
exchanger is an evaporator.
[0018] The invention will be explained in more detail below on the
basis of exemplary embodiments and with reference to the drawings,
in which
[0019] FIG. 1 shows a heat exchanger having a collecting tank
according to the invention and
[0020] FIG. 2 shows a detail of a collecting tank in
cross-section.
[0021] FIG. 1 represents a condenser (1) of a coolant circuit
(otherwise not shown) for an air conditioning system. It has a
tube-fin block (10) with tubes (11) and fins (12) arranged between
these. The tubes (11), which in this exemplary embodiment take the
form of flat tubes, open out into collecting pipes (13, 14) which
extend on both sides over the entire height of the tube-fin block
(10). A first collecting pipe (13) is provided with a feed
connection (15) for a gaseous refrigerant coming from a compression
element (not shown), such as a compressor, for example, and with an
outlet connection (16) for liquid refrigerant flowing to an
expansion element (likewise not shown), such as an expansion valve,
for example.
[0022] The two collecting pipes (13, 14) are subdivided by dividing
walls (17, 18, 19, 20), 21, 22, 26, 27) into head pieces (33, 24)
communicating with the connections (15, 16) and into intermediate
pieces (35, 36, 37, 38, 39, 40, 41, 42) in such a way that the
refrigerant from the head piece (33) to the intermediate piece (40)
and from the intermediate piece (42) to the head piece (34) in each
case describes a serpentine path through the condenser (1), the
flow cross-section being likewise reduced as cooling increases
accordingly with the diminishing volume of the gaseous and/or
liquid refrigerant. The collecting pipes (13, 14) are sealed
fluid-tight by end walls (28, 29, 30, 31).
[0023] Connected to the collecting pipe (14) is a collecting tank
(43), which serves for collecting the condensed refrigerant. The
housing (23) of the collecting tank (43) has an inlet aperture (24)
and an outlet aperture (25), which communicate with the
intermediate pieces (40) and (42) respectively of the collecting
pipe (14). Inside the housing (23) is a drier and filter device
(32), which can be removed from the housing (23). For this purpose
the tubular housing (23) is closed at one end by a removable plug
(44), so that the drier and filter device (32) can be replaced, for
maintenance purposes, for example, via the aperture (45).
[0024] FIG. 2 shows a more detailed, cross-sectional view of part
of a collecting tank (100) having a plug (110). The collecting tank
comprises a round tubular shaped housing (120), one end (130) of
which is open. The housing (120) has an inlet aperture (not
visible) and an outlet aperture (140) for a heat exchange medium
such as a refrigerant, for example. A connection to an adjoining
collecting pipe (150) with dividing and end walls (160, 170) is
made via an opening (180) in the collecting pipe (150), a raised
edge (190) of the aperture (180) engaging in the outlet aperture
(140) of the collecting tank (100).
[0025] In order to be able to replace a drier and filter device
(not shown), which can be inserted into the housing (120), the open
end (130) of the housing (120) is closed by the removable plug
(110), which has a cylindrical shape matched to the shape of the
housing. Two sealing rings (200, 210), which are accommodated in
circumferential annular grooves (220, 230) in the cylindrical wall
(240) of the hollow cylindrical plug (110), serve for sealing. A
retainer ring (260), which prevents the plug (110) from falling out
of the aperture (130), is accommodated in an annular groove (250)
in the edge of the aperture (130). The working principle of the
retainer ring (260) is described in detail in the aforementioned DE
100 39 260 A1, which hereby likewise expressly forms part of the
disclosure. Removal of the plug (110) from the housing (120) is
facilitated by a screw (now shown), which can be screwed into the
blind tapped hole (270), so that the plug (110) can be easily drawn
out of the aperture (130).
[0026] In order to achieve an improved sealing effect of the
sealing rings (200, 210), the plug (110) is made from an
elastically deformable plastic, with the result that the plug (110)
and in particular the wall (240) thereof is elastically deformable.
It should be noted that the deformability of the plug (110) is not
so pronounced as to jeopardize the closing action by means of the
retainer ring (260).
[0027] Whilst the collecting tank (100) is in operation the heat
exchange medium present inside the housing (120) thereof is under
pressure and from the cavity (280) of the hollow cylindrical plug
(110) exerts a force on the inside (290) of the wall (240) of the
plug (110). Owing to the elastic deformability of the plug material
the wall (240) then bends radially away from the cylinder axis
(300) towards the edge of the aperture (130), which in this
exemplary embodiment is represented by the tubular wall of the
housing (120). As a result the sealing rings (200, 210) in the
annular grooves (220, 230) are pressed against the housing (120)
and ensure a secure seal. Of essential importance is the fact that
the annular grooves (220, 230) with the sealing rings (200, 210)
are arranged precisely in an area of the wall (240) on a level with
the cavity (280), so that the force generated by the pressure of
the heat exchange medium and acting on the inside (290) of the wall
(240) is transmitted sufficiently to the sealing rings (200, 210).
In contrast to a cover area (310) of the hollow cylinder, the plug
(110) in the area of the wall (240) is relatively thin, in order to
further assist this transmission of force.
[0028] Even if the wall (240) possibly already bears on the inside
of the housing (120) without any internal pressure, the presence of
an excess pressure results in increased pressure on the sealing
rings (200, 210), since owing to the elastic deformability of the
material the plug wall (240) can only partially absorb the
aforementioned force, if at all, so that the force acts directly on
the sealing rings. An improved sealing effect is therefore possible
even under these circumstances.
[0029] Overall therefore, larger production tolerances on the
dimensions of the housing (120) and the plug (110) are just as
acceptable as relative variations in size between the housing (120)
and the plug (110) during operation of the collecting tank (100)
resulting from different degrees of thermal expansion, which may be
caused by temperature fluctuations of the heat exchange medium.
* * * * *