LU500556B1

LU500556B1 - Condenser with receiver dryer

Info

Publication number: LU500556B1
Application number: LU500556A
Authority: LU
Inventors: Leszek Sikora; Roger Fourile; Remi Grunewald
Original assignee: Estra Automotive Systems Luxembourg S A R L
Priority date: 2021-08-19
Filing date: 2021-08-19
Publication date: 2023-02-20

Abstract

A heat exchanger, in particular a condenser, comprises a core with a plurality of heat exchanger tubes (16) extending between opposite manifolds (12, 14). A receiver dryer container (26) is connected to an adjacent manifold (12) by means of a connector (28) comprising a body (30) having a passageway (32) therein extending between a first opening (34) in a first face and a second opening (38) in a second face (40). The first face (36) is configured as an abutment face in contact with an outer surface of said peripheral wall of said container and comprises a protruding, locking lip (44) at least partially surrounding the first opening (34) and engaged in said aperture (26.3). The aperture (26.3) is defined by an edge region shaped to define an annular locking surface having a width greater than a wall thickness of said peripheral wall, the locking surface having an outwardly tapering profile. The locking lip (44) extends along the locking surface, such that the edge region of the aperture (26.3) is locked between the first face (36) and the locking lip (44).

Description

1 | U500556

CONDENSER WITH RECEIVER DRYER

FIELD OF THE INVENTION

The present invention generally relates to the field of heat exchangers. More specifically the invention relates to condensers provided with a receiver dryer.

BACKGROUND OF THE INVENTION

Heat exchangers such as condensers are used in refrigerating systems, in particular a vehicle air conditioning system. A condenser typically receives a fluid such as a refrigerant in a vapor phase, at a reasonably high temperature, and cools the vapor phase to transform it to a liquid phase. The condenser normally comprises a cooling core consisting of a plurality of parallel tubes and cooling fins, and two manifolds (generally known as header) fluidly connected with reciprocal ends of each tube. One type of condenser, often referred to as a multi- pass condenser, includes a plurality of baffles placed in one or both of the manifolds to direct the refrigerant through a plurality of flow paths. As the refrigerant flows in a back and forth pattern through the condenser, heat is transferred from the vapor phase of the refrigerant to condense to the liquid phase. The liquid phase continues to flow through the tubes of the condenser until it reaches an outlet where it is drawn off and used in the air conditioning system.

Itis also known to provide a receiver dryer for storage of excess refrigerant from the condenser and to remove any moisture from the refrigerant in the air conditioning system. A typical receiver dryer comprises a cylindrical container with a fluid inlet for receiving refrigerant from the condenser and at least one fluid outlet, for directing refrigerant back to the condenser. The receiver dryer also includes a quantity of desiccant material to remove moisture from the refrigerant.

The cylindrical dryer container is fluidly connected with one of the manifolds by means of connectors. The attachment of the receiver dryer to the manifold is somewhat challenging as it is desirable to have a connector that is robust, liquid tight, compact, easy to manufacture and to assemble. Furthermore, the desiccant material inside the dryer container is typically contained in an envelope which is rather fragile. Accordingly, the configuration of the connector should not put at risk the integrity of the desiccant material.

U.S. Patents Nos. 5,884,503 and 6,052,899 disclose such condensers fluidly connected with a cylindrical liquid tank by means of connectors.

OBJECT OF THE INVENTION

The object of the present invention is to provide an improved design of condenser with dryer receiver that allows a safe and simple assembly.

This object is achieved by a heat exchanger as claimed in claim 1.

SUMMARY OF THE INVENTION

The present invention relates to a heat exchanger comprising: a core with a plurality of heat exchanger tubes for carrying a coolant fluid, the core extending between two opposite manifolds to which the tubes are fluidly connected and which define inlet and outlet cavities; and a container having a peripheral wall extending along a length axis, adjacent to one of the manifolds and connected thereto by means of at least one connector which provides a fluid communication between an aperture formed in a lateral wall of the container and an opening in the adjacent manifold;

According to the invention, the connector includes: a body having a passageway therein extending between a first opening in a first face and a second opening in a second face, wherein the first and second openings are in alignment with the aperture and manifold opening, respectively; wherein the first face is configured as an abutment face in contact with an outer surface of the peripheral wall of the container and comprises a protruding, locking lip at least partially surrounding the first opening and engaged in the aperture; wherein the aperture is defined by an edge region formed the peripheral wall, which is shaped such as to define an annular locking surface having a width

3 | U500556 greater than a wall thickness of the peripheral wall, the locking surface having an outwardly tapering profile; and wherein the aperture surrounds the protruding lip, and the locking lip extends along the locking surface, such that the edge region of the aperture is locked between the first face and the locking lip.

The present invention exploits a particular configuration between the aperture in the container and the connector in order to improve the locking (or binding or interlock) between the two components. More specifically, the aperture is formed by a shaped edge region (i.e. by shaping the peripheral wall at the aperture) defining an annular locking surface having an outward taper (towards the exterior of the container) against which the protruding lip extends and is preferably applied. The shaping of the edge region can be realized by any appropriate means by which the size of the locking surface can be increased beyond the nominal thickness of the peripheral wall, e.g. machining and/or plastic deformation. As a result, the aperture edge region is bracketed between the connector first face and the lip, and hence locked in place. In practice, the protruding lip is deformed from an initial configuration, by outwardly bending the lip so that it is applied against the locking surface. This plastic deformation of the locking lip is typically achieved by a clinching process. The design increases the clinching area and provides a positive lock on the connector so that it cannot pull out.

The present invention has been particularly developed for application to the field of refrigeration systems, where the heat exchanger is a condenser and the container is configured as a receiver dryer (i.e. forming a storage reservoir with desiccant material). However, the inventive concept can be used for other applications where it is desirable to have a container attached to a heat exchanger manifold and fluidly connected therewith.

Advantageously, the protruding lip extends along the edge region without protruding beyond an internal surface of the container peripheral wall. This is of particular interest for application to condensers where the container holds a volume of desiccant material, the absence of protruding elements avoiding damaging the desiccant material.

The present connector used to connect the manifold opening to the container aperture may be referred to as manifold connector or manifold coupler.

In embodiments, the aperture of in the peripheral wall is formed such that the edge region presents a chamfer. Accordingly, the annular locking surface is defined by a chamfered edge. The width of the chamfered edge, measured from the inner surface to the outer surface of the peripheral wall, is greater than the wall thickness of the peripheral wall. The locking lip is, upon assembly, plastically deformed (in particular clinched) to extend along, and preferably against, the annular locking surface.

A satisfactory size increase of the locking surface is obtained with such chamfered edge. The chamfer edge may have a chamfer angle lying between 20° and 50°, preferably between 30° and 40°.

In alternative embodiments, the edge region may be obtained by shaping the peripheral wall at the aperture into an outwardly protruding collar, an inner surface of which defines the annular locking surface. The use of an outward collar is relevant for relatively thin walled containers. The outward collar may have a generally frusto-conical cross-section based on a cone angle of between 40 and 100°, preferably between 60 and 80°.

In practice, one may select the chamfered edge design for containers having a peripheral wall with a thickness of at least 1.3 mm, in particular above 1.5 or 1.8 mm, and more. The outward collar design is preferred for containers with a wall thickness of less than 1.3 mm.

Advantageously, the first face of the connector has a curvature corresponding to the outer surface of the peripheral wall.

Preferably, the body includes two lateral wings extending the first face on opposite sides of the first opening

These features allow increasing the contact surface and hence the bonding strength upon brazing of the heat exchanger.

In embodiments, the protruding lip is bent against the chamfer by plastic deformation, in particular by clinching. Preferably, the protruding lip is a continuous circular lip.

The peripheral wall of the container may typically have a cylindrical shape, in particular with a circular cross-section.

In embodiments, the second face is configured as an abutment face in contact with the lateral side of the manifold and comprises protruding tab segments at least partially surrounding the second opening and engaged in a respective manifold opening.

In embodiment, the second face is configured similarly to the first face, i.e. it is configured as an abutment face in contact with an outer surface of the peripheral wall of the manifold and comprises a further protruding, locking lip at least partially surrounding the second opening and engaged in the manifold opening. The manifold opening is defined by an edge region shaped to define an annular locking surface having a width greater than a wall thickness of the manifold wall, the locking surface having an outwardly tapering profile. The manifold opening surrounds the further locking lip, the locking lip extending along the locking surface such that the edge region of the manifold opening is locked between the second face and the further locking lip.

In embodiments, the first and second faces of the connector are brazed to the outer surface of the container and manifold, thereby providing a fluid tight communication between the latter.

According to another aspect, the invention relates to a method of manufacturing a heat exchanger as claimed in claim 14.

Embodiments of the inventive heat exchanger and method are recited in the appended dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1: is a front view of an embodiment of condenser with receiver dryer;

Figure 2: is a perspective view of the receiver dryer container;

Figure 3: is a part exploded view showing the side of the condenser with one manifold, two connectors and the receiver dryer;

Figure 4: is a detail view showing a connector fixed to the receiver dryer;

Figure 5: a) and b) are perspective views of the connector, form opposite sides;

Figure 6: is a cross-section view through the connector positioned onto the receiver dryer, before clinching (intermediate configuration);

Figure 7: is cross-section view through the connector assembled to the receiver dryer, after clinching;

Figure 8: is a sketch illustrating the tooling for forming the aperture in the receiver dryer container; and.

Figure 9: are cross-section views corresponding to another embodiment, with the connector positioned onto the receiver dryer, (a) before clinching and (b) after clinching.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings and in particular to Fig. 1, one embodiment of a condenser 10, according to the present invention, is shown for an air conditioning system (not shown) in a motor vehicle (not shown). However, condenser 10 may be used as a heat exchanger in other applications besides motor vehicles.

The condenser 10 includes a pair of generally vertical, parallel first and second manifolds 12, 14 (also referred to as header or tank), spaced apart a predetermined distance. The condenser 10 also includes a plurality of generally parallel, flat tubes 16 extending between the manifolds 12, 14 and conducting fluid, namely such as a refrigerant between them. This assembly of tubes 16 is also referred to as core. The manifolds 12, 14 define an internal cavity for the refrigerant and have a plurality of slits (not shown) through which the tubes 16 are engaged and attached in a fluid-tight manner.

7 | U500556

The condenser 10 includes a fluid inlet 18 for directing the fluid into the condenser 10 formed in the manifold 12 and a fluid outlet for directing the fluid out of the condenser 10 formed in manifold 14. An inlet connector 20 is coupled to fluid inlet 18 and a block connector 22 assembled to manifold 14 (thus hiding the fluid outlet).

Condenser 10 is of the multipass type. The manifolds 12, 14 include a plurality of baffles to direct the refrigerant through a plurality of flow paths, whereby the refrigerant flows in a back and forth pattern through the condenser. As illustrated, the condenser inlet and outlet are located in the same manifold 14 (right hand side in Fig.1).

Conventionally, the condenser 10 also includes a plurality of convoluted or serpentine fins (not shown) disposed between the tubes 16 and attached to an exterior of each of the tubes 16. The fins serve as a means for conducting heat away from the tubes 16 while providing additional surface area for convective heat transfer by air flowing over the condenser.

The condenser, namely the tubes and manifolds, are generally made from aluminum alloy. In use, the refrigerant enters into manifold 14 of condenser 10 through inlet 18, flows in a back and forth pattern through the condenser (i.e. from one manifold to the other), to exit condenser 10 via its outlet at block connector 22.

Reference sign 25 designates a receiver dryer unit (hereinafter also referred to as dryer) that is attached to manifold 12 (to the left in Fig. 1) and in fluid communication therewith, by means of manifold connectors 28, or herein simply connectors. The receiver dryer unit 26 allows for storage of excess refrigerant from the condenser 10 and removal of any moisture from the refrigerant.

The dryer 25 includes a container 26 of generally cylindrical shape having a cylindrical peripheral wall 26.1 extending along a length axis 26.4. In use, dryer container 26 is closed at both ends 26.2 and defines a storage volume, which contains desiccant material. As for the condenser 10, the container wall 26.1 is made of aluminum alloy. Two apertures 26.3 are provided in the peripheral wall

26.1 of the dryer, which serve as inlet and outlet for the refrigerant. In embodiments there could be more apertures 26.3.

Each of the apertures 26.3 is fluidly connected with a respective opening 12.1 in manifold 12 through a respective connector 28.

The connector 28 comprises a body 30 with a passageway 32 extending therethrough between a first opening 34 in a first face 36 of the body and a second opening 38 in an opposite, second face 40. These openings 34, 38 are designed to come in alignment with the aperture 26.3 in the container wall 26.1 and the opening 12.1 in the manifold 12, respectively.

The connector 28 is typically a metal block (preferably aluminum alloy) of rectangular or round cross section and the two opposite faces 36, 40 are configured as butting faces, for abutment and connection to the container peripheral wall 26.1 and manifold 12.

Referring more specifically to the first face 36, it is configured as a cylindrical butting face having a curvature corresponding to the outer curvature of peripheral wall 26.1. This butting face 36 is extended by two wings 42 extending laterally from the body 30. Reference sign 44 designates a cylindrical locking lip protruding from the first face and surrounding first opening 34.

Locking lip 44 has an outer diameter that initially corresponds (typically slightly smaller) to the inlet diameter of aperture 26.3, so that it can be introduced therein.

As can be seen from Fig.6, which shows an intermediate configuration, once lip 44 is inserted in aperture 26.3, the butting face 36 is in contact with the outer surface of the peripheral wall 26.1 and the edge 27 of aperture 26.3 closely surrounds cylindrical lip 44. The wings 42 overlap with the peripheral region of the aperture 26.3, in contact therewith.

It should be noted that the edge 27 of aperture 26.3 is inwardly chamfered. That is, the edge 27 does not follow a radius R of the container, but is slanted/beveled such that the edge profile tapers from the interior to exterior of the dryer container 26. The bevel angle is indicated a in Fig. 6. The bevel angle a is measured at the

9 | U500556 frontmost point of the edge 27 and represent the angle between a line 29 defining the chamfered surface and a line corresponding to a straight cut along radius R.

This edge 27 defines an annular locking surface 27.1 that, due to the chamfer, has, measured from the inner to outer surface of wall 26.1, a linear extent Wis greater than the wall thickness t of the peripheral wall 26.1.

In other words, this shaping of the edge region of aperture 26.3 forms the locking surface 27.1, which is extended (larger) compared to a straight cut of the edge, in particular with has a larger width Wis compared to a straight cut (with a width corresponding to wall thickness t). The chamfered edge 27 provides a positive locking surface which allows clinching the cylindrical lip 44 against this locking surface 27.1. As a result, the edge region of aperture 26.3 is blocked (bracketed) by the bent locking lip 44 and the first face 36. This is the configuration shown in

Fig. 7.

It may be noted that the locking lip 44, at the moment of assembly to the dryer 26, extends in a relatively straight manner, in axial continuation of passageway 32 (substantially parallel to axis 32.1), whereby the outer diameter of locking lip 44 is inferior to the diameter of aperture 26.3. In Fig.7, the lip 44 has been plastically outwardly deformed, by clinching. Lip 44 extends along and bears against chamfered edge 27. It should however be noticed that the lip 44 does not protrude inwardly beyond the inner surface 31 of peripheral wall 26.1. In particular, the free end of lip 44 may be flush with the inner surface 31 of peripheral wall 26.1. This avoids damaging fragile material located inside the container 26, e.g. desiccant material.

Referring to Fig.5 a), the second face 40 of connector 28 is also configured as an abutment face having a curvature corresponding to the outer surface of manifold 12. A plurality of protruding tabs 46, namely four, are arranged around the second opening 38, which are upon assembly engaged into a manifold opening 12.1.

Here tabs 46 are arcuate (following the opening curvature) and have conventional dimensions, that can be bent over the edge of opening 12.1, which edge is a rather straight edge. Upon clinching of the tabs 46, they protrude inside manifold 12.

10 | U500556

Alternatively, in a not shown embodiment, the second face 40 may be designed similarly to the first face 36 with a circular protruding locking lip, the manifold opening 12.1 being shaped similar to the aperture 26.3 in container to present a locking surface onto which the locking lip of the second surface can be clinched.

Connector 28 provides a fluid tight communication between manifold 12 and container 26. It may be noted here that the sealing is provided by the brazing operation (the assembled heat exchanger with connectors and dryer 25 is heated to the brazing temperature), whereby the first and second sides 36, 40 are brazed to the outer surfaces of the container 26 and manifold 40, respectively. The locking lip 44 and tabs 46 are mainly provided for the mechanical connection.

Fig.8 schematically illustrates the forming of the aperture 26.3 and chamfered edge in the receiver dryer 26. The aperture 26.3 is formed through peripheral wall 26.1 by punching using a cylindrical punching tool 50. Inside the cylindrical wall 26.1 is a chamfer mandrel 52 having a generally frustoconical shape, which is coaxial with punching tool 50 and configured to be able to receive the tip of punching tool 50. During manufacture, punching tool 50 and chamfer mandrel 52 are aligned. The punching tool 50 is actuated first (downwardly with reference to the figure orientation) to open the peripheral wall 26.1 and the chamfer mandrel 52 is then moved upward, along punching tool 50, to form the chamfered edge 27.

Figure 9 illustrates another embodiment of the invention, where the edge region of aperture 26.3 is shaped in order to define an outwardly extending annular collar 33. This collar 33 is formed by deforming the edge region of the aperture 26.3.

The collar 33 has an outer annular surface 33.1 and an inner annular surface 33.2. The inner annular surface 33.2 forms the annular locking surface, against which the locking lip 44 extends, in contact therewith. Annular collar 33 has a frustoconical profile.

As can be seen, the width Wis of annular locking surface 33.2 is greater than thickness t of peripheral wall 26.1.

In this embodiment, the first face 36 includes a groove 37 surrounding annular lip 44, in which the annular collar 33 is engaged.

Here, the orientation of the edge 27’ at the end of collar 33 is oriented to come into abutment with the flat bottom of groove 37.

Claims

1. A heat exchanger, in particular a condenser, comprising: a core with a plurality of heat exchanger tubes (16) for carrying a coolant fluid, the core extending between two opposite manifolds (12, 14) to which the tubes are fluidly connected and which define inlet and outlet cavities; a container (26) having a peripheral wall (26.1) extending along a length axis, adjacent to one of the manifolds and connected thereto by means of at least one connector (28) which provides a fluid communication between an aperture (26.3) formed in said peripheral wall of said container and an opening (12.1) in said manifold; characterized in that said connector (28) includes a body (30) having a passageway (32) therein extending between a first opening (34) in a first face and a second opening (38) in a second face (40), wherein said first and second openings are in alignment with said aperture and manifold opening, respectively; wherein said first face (36) is configured as an abutment face in contact with an outer surface of said peripheral wall of said container and comprises a protruding, locking lip (44) at least partially surrounding said first opening (34) and engaged in said aperture (26.3); wherein said aperture (26.3) is defined by an edge region shaped to define an annular locking surface having a width greater than a wall thickness (Wis) of said peripheral wall, said locking surface having an outwardly tapering profile; wherein said aperture (26.3) surrounds said locking lip (44), and said locking lip (44) extends along said locking surface, such that said edge region of said aperture (26.3) is locked between said first face (36) and said locking lip (44).

2. The heat exchanger according to claim 1, wherein said annular locking surface (27.3) is defined by a chamfered edge.

3. The heat exchanger according to claim 2, wherein a width of said chamfered edge, measured from the inner surface to the outer surface of said peripheral wall, is greater than the wall thickness of said peripheral wall; and said locking lip extends along, and preferably against, said annular locking surface.

4. The heat exchanger according to claim 2 or 3, wherein said chamfer edge has a chamfer angle lying between 20° and 50°, preferably between 30° and

40°.

5. The heat exchanger according to claim 1, wherein said edge region comprises an outwardly protruding collar (33), an inner surface (33.2) of which defines said annular locking surface.

6. The heat exchanger according to any one of the preceding claims, wherein said locking lip extends along said annular locking surface without protruding beyond the inner surface of said peripheral wall.

7. The heat exchanger according to any one of the preceding claims, wherein said first face (36) has a curvature corresponding to said outer surface of said peripheral wall.

8. The heat exchanger according to any one of the preceding claims, wherein said body (30) includes two lateral wings (42) extending said first face on opposite sides of said first opening (34).

9 The heat exchanger according to any one of the preceding claims, wherein said protruding lip (44) is bent against said chamfer by plastic deformation, in particular by clinching.

10. The heat exchanger according to any one of the preceding claims, wherein said protruding lip (44) is a continuous circular lip.

11. The heat exchanger according to any one of the preceding claims, wherein said peripheral wall (26.1) is cylindrically shaped, in particular with a circular cross-section.

12. The heat exchanger according to any one of the preceding claims, wherein said second face (40) is configured as an abutment face in contact with said lateral side of said manifold (14) and comprises protruding tab segments (46)

at least partially surrounding said second opening (38) and engaged in a respective manifold opening.

13. The heat exchanger according to any one of claims 1 to 11, wherein the second face is configured as an abutment face in contact with an outer surface of the peripheral wall of the manifold and comprises a further protruding, locking lip at least partially surrounding the second opening and engaged in the manifold opening; the manifold opening is defined by an edge region shaped to define an annular locking surface having a width greater than a wall thickness of the manifold wall, the locking surface having an outwardly tapering profile; the manifold opening surrounds the further locking lip, the latter extending along the locking surface such that the edge region of the manifold opening is locked between the second face and the further locking lip.

14. The heat exchanger according to any one of the preceding claims, wherein said heat-exchanger is a condenser (10) and said container is configured as a receiver-dryer (25) containing desiccant material, said container containing at least a further aperture, by which it is fluidly connected with said adjacent manifold by means of a further connector.

15. A method of manufacturing a heat exchanger comprising: providing a heat-exchanger comprising a core with a plurality of heat exchanger tubes for carrying a coolant fluid, the core extending between two opposite manifolds to which the tubes are fluidly connected and which define inlet and outlet cavities; forming an aperture in a peripheral wall of a container such that it is delimited by an edge region defining an annular locking surface having a width greater than a wall thickness of said peripheral wall, said locking surface having an outwardly tapering profile; fluidly connecting said container to one of said manifolds by means of a connector which provides a fluid communication between said aperture and an opening in said manifold, wherein said connector comprises a body having

15 | U500556 a passageway therein extending between a first opening in a first face and a second opening in a second face, wherein said first and second openings are in alignment with said aperture and manifold opening, respectively, said first face being configured as an abutment face in contact with said lateral side of said container and comprising a protruding, locking lip at least partially surrounding said first opening and engaged in said aperture, wherein said aperture closely surrounds said locking lip and wherein said locking lip initially extends in a first direction away from said first face; bending said lip such that it extends along said locking surface, whereby said edge region of said aperture is locked between said first face and said bent protruding lip.

16. The method according to claim 15, wherein bending said lip includes plastically deforming, in particular by clinching, said lip to apply it on said locking surface.

17.The method according to claim 15 or 16, wherein said annular locking surface is defined by a chamfered edge of said aperture and forming said aperture comprises punching said container from outside by means of a cylindrical punching tool and shaping said edge region by means of a chamfer mandrel from inside, coaxial to said punching tool.

18.The method according to claim 15 or 16, wherein forming includes shaping said edge region into an outwardly protruding collar, an inner surface of which defines said annular locking surface.

19. The method according to claim any one of claims 15 to 18, wherein said protruding lip is dimensioned such that, after bending, it does not protrude beyond an inner surface of said lateral wall.

20. The method according to any one of claims 15 to 19, wherein said peripheral wall has a cylindrical shape, in particular with circular cross-section, and said first face has a curvature corresponding to that of said peripheral wall.

21. The method according to any one of claims 15 to 20, wherein said heat exchanger is a condenser and said container is a receiver dryer with desiccant material therein.