HEAT EXCHANGER ASSEMBLY

Abstract

 The present invention relates to a heat exchanger assembly (10) comprising a heat exchanger (12) comprising a core (20) with a plurality of heat exchanger tubes (26) for carrying a coolant fluid, the core (20) extending between two opposite manifolds (16, 18) and a reinforcement member (30, 32) extending along each lateral side of the core between the manifolds (16, 18). The assembly further comprises at least one plastic mounting bracket (14, 114) mounted to the reinforcement member, the mounting bracket (14, 114) comprising a base (60) fixed by means of a snap-fit joint to a metallic attachment member (50) brazed onto the reinforcement member (30, 32) and-a mounting feature (70) extending from the base (60). The attachment member (50) defines a slide rail (50) extending along the lateral side of the core (20), the base (60) being at least partially received within the slide rail (50) and snap-fittingly fixed therein.

Description

Technical Field

[0001] The invention generally relates to the field of heat exchangers, and specifically to a heat exchanger assembly comprising a mounting bracket.

Background Art

[0002] In vehicles such as passenger cars or trucks, heat exchangers are used as part of cooling circuits, which in turn are needed for cooling vehicle components like the engine, the transmission etc. Some of these cooling circuits employ a liquid heat exchange medium, which receives heat from the vehicle components and transfers heat to ambient air at the main heat exchanger, like a radiator, installed in the front of the vehicle. In other cases, the heat exchanger is a condenser, wherein the heat exchange medium (or fluid) enters the condenser in gaseous state, is condensed and cooled in the condenser and exits the condenser in liquid state.

[0003] Automotive heat exchangers generally include a central core made of regularly spaced tubes and featured with corrugated air fins. The tubes extend between a pair of tanks (or manifolds) at opposite ends of the core. A pair of reinforcement members extend along opposite edges of the core between the tanks. Two configurations are conventionally used for the heat exchangers: in the so-called crossflow configuration, the tanks are vertically oriented and the tubes forming the central core are horizontally oriented; alternatively, the heat exchanger tanks are horizontally oriented, and the tubes forming the central core are vertically oriented, which is referred to as downflow configuration.

[0004] A heat exchanger may be mounted directly into a vehicle but generally, two or more heat exchangers are used in combination. Such assemblies of multiple heat exchangers generally comprise a condenser, a radiator and a fan unit, thereby forming a cooling module, commonly referred to as CRFM, standing for Condenser Radiator and Fan Module. The condenser and radiator are rectangularly shaped of more or less comparable dimensions and placed in a closely-spaced, stacked relationship at a vehicle location where air flow therethrough is facilitated. In this regard, the fan unit is placed adjacent the condenser/radiator pair so as to assure air flow therethrough even in situations where the motor vehicle is stationary. The condenser is commonly mounted to the radiator by bracket(s) extending either from the header tanks or from the reinforcement members, wherein the bracket(s) accepts a fastener such as a bolt.

[0005] Conventionally, most of the brackets are metal pieces that are somehow held in place before the brazing operation and then are brazed into a fixed attachment. Such brackets are, e.g., disclosed in US 5,570,737. The bracket clamps on to the header tank prior to the furnace brazing of the heat exchanger assembly. The addition of the bracket during the furnace brazing introduces irregularities to the braze temperature profile. In addition, such brackets are limited to locations on the pre-brazed heat exchanger that are able to receive and retain the bracket until after the brazing joins the components. Moreover, such brackets are meant to be fastened to manifolds of a second heat exchanger and cannot be fastened to reinforcement members. Therefore, such brackets are not compatible with downflow cooling modules.

[0006] To avoid such drawbacks, a plastic bracket may be snapped onto the heat exchanger, such as disclosed in US 6,513,579. These plastic brackets are light molded pieces that are attached to the corners of the heat exchanger entirely post braze, in a press fit operation that requires no additional fasteners. However, they are shaped to be used only with rectangle or square-shaped tanks. Moreover, they include rigid snap on features that tend to damage the reinforcement members. Furthermore, such design is not compatible with packaging restrictions due to shape and position requirements of mounting brackets which are more and more frequently imposed by customers.

[0007] An alternative design for mounting brackets with a more compact design is disclosed in US 7,117,927. Such brackets have a U-shape and are merely clamped on the heat exchanger around the reinforcement members post-braze, i.e. away from the manifolds. However, such a design of mounting brackets presents enough robustness only because it uses the surface of the core like a clamp load, which gives rise to tube damage and center debonding. Moreover, such brackets may rotate or at least tilt around the reinforcement members, thereby complicating the assembly of heat exchangers or the mounting of CRFM.

Technical Problem

[0008] It is thus an object of the present invention to provide an alternative, improved design of a heat exchanger mounting bracket that does not comprise the above-mentioned drawbacks.

[0009] This problem is solved by a heat exchanger assembly as claimed in claim 1.

Summary of the Invention

[0010] According to the present invention, a heat exchanger assembly comprises 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, a reinforcement member extending along each lateral side of the core between the manifolds, and at least one plastic mounting bracket mounted to the reinforcement member.

[0011] The plastic mounting bracket comprises a base fixed by means of a snap-fit joint to a metallic attachment member brazed onto the reinforcement member. A mounting feature extends from the base of the bracket. The metallic attachment member defines a slide rail extending along the lateral side of the core, the base of the mounting bracket being at least partially received within the slide rail and snap-fittingly fixed therein

[0012] The present invention is based on a snap-fit joint (i.e. snap-fit connection) between the bracket and the metallic attachment member, i.e. the base of the bracket presents a shape which is complementary to the shape of the attachment member. The metallic attachment member and the base of the mounting bracket may present any shape known to a skilled person as long as they provide for a snap-fit connection / complementary shape connection, by clipping, snapping, sliding.... The bracket may thus easily and rapidly be assembled to (i.e. mounted on) the heat exchanger due to the snap-fit connection, without requiring either an additional part (e.g. a rivet, a screw, a pin, ...) or a tool.

[0013] Advantageously, the mounting bracket is easily and rapidly assembled to the heat exchanger by sliding the bracket through the attachment member (in a direction parallel to the main extension of the reinforcement member).

[0014] The present invention is of particular interest where the heat exchanger is a condenser with vertical manifolds, which is to be mounted on a downflow-type radiator with horizontal plastic manifolds.

[0015] Such a concept allows the mounting of the bracket at a distance from the manifolds thereby allowing to better manage the proximity between different heat exchangers in close spaces, such as the proximity between condenser and radiator in CRFM assemblies.

[0016] The inventive mounting bracket can be easily manufactured by injection molding and allows for rapid, firm and secure mounting onto the heat exchanger.

[0017] In embodiments, the reinforcement member comprises a recessed part and the metallic attachment member is brazed onto the recessed part. The recessed part may present any shape and dimensions compatible with the shape of the reinforcement member and the mounting bracket while ensuring a sufficient reinforcement/stability increase of the heat exchanger. It is however preferred that the recessed part be dimensioned so as to be entirely covered/filled by the metallic attachment member.

[0018] The reinforcement member may present any shape known to a skilled person, such as e.g. a U-shaped profile with two edge walls extending from a bottom wall away from the sides of the core. In such embodiments, the edge walls are shorter in the recessed/extruded part than in the remaining part of the reinforcement member.

[0019] Preferably, the base of the mounting bracket comprises an inner portion configured to be slideably engaged into the slide rail, the slide rail having an axial groove through which the inner portion connects (preferably by a web) an outer portion of the base from which the mounting feature extends. The axial groove has a narrower width than the inner portion of the base. Preferably, the axial groove has a width corresponding to the width of the web connecting the inner portion and the outer portion of the base of the mounting bracket.

[0020] In preferred embodiments, two cantilevered hooks extend axially from the inner portion of the base of the mounting bracket and engage respective edges of the attachment member. Additionally, a transverse wall may be arranged at one end of the base, i.e. perpendicularly to the main extension of the base. Advantageously, the transverse wall may engage an edge of the attachment member opposite the edge engaged by the hooks. The transverse wall advantageously prevents the base of the mounting bracket from being inserted too far in the metallic attachment member. After assembling of the mounting bracket and the attachment member, the transverse wall abuts the edge on one extremity, in the direction parallel to the main extension of the reinforcement member, of the metallic attachment structure, while the cantilever hooks abut on the edge at the other extremity. A sliding movement of the bracket is effectively prevented by the abutment on its two side.

[0021] It may be noted that this is only an embodiment and that the transverse wall is not mandatory to lock the base axially, this can be achieved by the hooks alone. For example, the hooks may have square shaped protrusions that engage apertures in the attachment member.

[0022] Preferably, the cantilever hooks are configured to advantageously be forced toward each other - by elastic deformation - during assembly of the mounting bracket to the heat exchanger (i.e. sliding of the bracket in the attachment member) and present an elastic restoring force pushing them apart. Such a restoring force would act upon the attachment member, further locking the bracket in place by a frictional connection (friction locking).

[0023] According to the same or other embodiments, the base of the mounting bracket, preferably its inner portion, has substantially the same width as the core of the heat exchanger, in a direction perpendicular to both the extension direction of the manifolds and the extension direction of the reinforcement members. Advantageously, very thin mounting bracket may be used, thereby further reducing space requirement for the mounting bracket and allowing to better manage the proximity between different heat exchangers in close spaces, such as the proximity between condenser and radiator in CRFM assemblies.

[0024] Additionally or alternatively, the metallic attachment member is further clinched and/or welded to the reinforcement member. Preferably, such a clinching or welding occurs upon assembly of the heat exchanger, prior to the brazing operation, so as to ensure that the attachment member will stay in place (i.e. not slide along or tilt around the reinforcement member) during the brazing operation.

[0025] The metallic attachment member may be positioned onto the reinforcement member, and preferably clinched or welded thereto, before or after assembly of the tubes and reinforcement members to the manifolds (i.e. prior to or following a stacking operation). It is however preferred that the attachment member is positioned onto the reinforcement member prior to the stacking, as it would facilitate the positioning. Further advantageously, in embodiments wherein the attachment member is to be clinched and/or welded to the reinforcement member, it would be easier to perform such a clinching and/or welding operation prior to assembling the heat exchanger (better accessibility for a clinching or welding tool,... ).

[0026] Depending on the embodiments, the mounting feature of the mounting bracket may be formed as a flange, in particular a flat flange with an opening therein for a fastening member (such as e.g. a pin or a screw) or as a tab, in particular a reinforced tab.

[0027] One, preferably both, of the manifolds of the heat exchanger may be a round, one-piece manifold.

[0028] According to another aspect, the present invention relates to a cooling module as claimed in claim 11.

Brief Description of the Drawings

[0029] Embodiments of the invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:

Fig.1

is a perspective view of a heat exchanger assembly according to an embodiment of the invention;

Fig.2

is a an enlarged view around one mounting bracket of the heat exchanger assembly of Fig.1;

Fig.3

is a partial perspective view of a reinforcement member prior to assembly;

Fig.4

is a perspective view of an attachment member prior to assembling to the reinforcement member (a cut-out shows the interior of the attachment member);

Fig.5

is a perspective view of a mounting bracket of the heat exchanger assembly of Fig.1;

Fig.6

is an exploded view of the heat exchanger, attachment structure and mounting bracket;

Fig.7

are principle views illustrating the assembly of the mounting bracket to the heat exchanger; and

Fig.8

are principle cross-sectional views illustrating the assembly of the mounting bracket to the attachment member.

Description of Preferred Embodiments

[0030] Referring to the Figures, a heat exchanger assembly 10 generally comprises a heat exchanger 12 e.g. a condenser, radiator, or the like and at least one mounting bracket 14.

[0031] The heat exchanger 12 comprises a core 20 (or exchanger core) with flow tubes 26 and intervening air centers or air fins, which are not shown in detail. The exchanger core 20 extends along a first axis Z as well as along a second axis Y, which in the exemplary embodiments of Fig.1 are respectively a vertical axis and a lateral axis of the vehicle. The exchanger core thickness then extends along the third axis X. The heat exchanger core 20 therefore presents faces in the Y-Z plan and lateral sides in the X-Y plan. The heat exchanger 12 offers a crossflow configuration, whereby the tubes 26 extend along the Y axis.

[0032] The core 20 is surrounded by a four sided, generally rectangular frame. Two sides of the frame are comprised of a pair of manifolds 16, 18, also referred to as header tanks, typically metal (e.g. brazeable aluminum alloy) or plastic, and the other two sides are a pair of reinforcement members (or core reinforcements) 30, 32. The reinforcement members 30, 32 extend along the edges of the core (Y direction) and are fixed at both ends to the manifolds 16, 18, thereby forming four right angle corners.

[0033] The first manifold 18 is connected by the exchanger core 20 (or simply core) to the second manifold 16. The first manifold 18 and the second manifold 16 each have a roughly circular shape and are elongate along the first axis Z, which is a vertical axis of the vehicle when the heat exchanger 12 is in the embodiment of Fig.1. Both manifolds 16, 18 are identically shaped. It should be noted that the shape of the manifolds is roughly circular in the embodiment presented in the figures, but they may be generally cylindrical with various kinds of cross-section, including prismatic shapes.

[0034] The fluid to be cooled may enter the heat exchanger via the first manifold 18 and flows through the tubes of the exchanger core 20, where it is cooled by ambient air, to the second manifold 16. The first and second manifolds can be respectively inlet and outlet manifolds. However, according to other non-limiting exemplary embodiments, the first manifold 18 can present an inlet fluid portion and an outlet fluid portion. The inlet portion receives a fluid through an inlet port during operation of the heat exchanger. The fluid is then distributed to a lower part of the exchanger core and guided to the second manifold. From there, it is distributed to an upper part of the exchanger core and guided to the outlet portion of the first manifold, which communicates with an outlet port to evacuate the fluid.

[0035] Referring to Fig.1, the heat exchanger 12 is shown with four brackets 14, 114 so that the heat exchanger assembly 10 comprises four mounting brackets, namely two upper mounting brackets 14 and two lower mounting brackets 114. Each bracket 14, 114 is preferably an injection molded, plastic part, attached to the heat exchanger 12 post braze. As will be explained in detail below, the mounting bracket 14, 114 is fixed by means of a snap-fit joint to a metallic attachment member 50 that is brazed onto a respective reinforcement member 30, 32.

[0036] Conventionally, the reinforcement members 30, 32 are metal bars that extend along the heat exchanger resting over and protecting the outermost pair of air centers, thereby allowing the core to be banded together prior to brazing. Reinforcement members are typically extruded elements and may have U or L-shaped cross-section. In the present embodiment, as shown in Fig.3 the reinforcement member 30 presents a U-shape cross-section with two legs or edge walls 34, 36 extending from the faces of the core 20 and a central portion or bottom wall 38 extending over a side of the core.

[0037] In other words, the reinforcement member 30 presents a U-shaped profile with two edge walls 34, 36 extending from a bottom wall 38 away from the sides of the core 20. The two edge walls 34, 36 may have similar or different heights. Two recessed parts 40, one near each extremity, are provided on each reinforcement member 30, 32. The edges walls 34, 36 are shorter in the recessed part 40 than in the remaining part of the reinforcement member 30, 32. For example, edge walls 34, 36 in the recessed part 40 may have a height of about 25 to 60%of the height of the respective edge wall 34, 36 in the remaining part of the reinforcement member 30, 32.

[0038] The recessed parts 40 advantageously facilitate positioning of the respective attachment members 50, by defining the actual location where the attachment members 50 have to be placed.

[0039] The metallic attachment member 50 itself is better seen in Fig.4. The attachment member is formed as a slide rail extending along the lateral side of the core (direction Y). It may e.g. be a C-shaped metal profile, e.g. of aluminium or aluminium alloy. Here, the attachment member 50 has a base wall 51, and two sidewalls 52.1, 52.2 extending from opposite sides of the outer base wall 51. The two sidewalls 52.1, 52.2 are inwardly bent at their free ends and define an axial groove 55. The edges at the axial ends of the attachment member are indicated 54.1, 54.2. The rail base wall 51 has a front surface facing toward the mounting bracket and an opposite back surface facing toward the reinforcement member 30.

[0040] Length and width, in the direction of the Y and X axis respectively, of the attachment member 50 substantially correspond to the dimensions of the recessed part 40 of the reinforcement member 30. Advantageously, the center part of the base wall 51 is offset to conform to the shape of the recessed parts 40. This favors a good binding during brazing of the metallic attachment member to the reinforcement member.

[0041] As can be seen on Fig. 8a, the attachment member 50 is preferably clinched to the reinforcement member 30 prior to the brazing operation, resulting in a stamp 56 being visible on the base wall 51 of the metallic attachment member 50.

[0042] Turning now to Fig.5, an embodiment of the upper mounting brackets 14 will be described in detail.

[0043] Each mounting bracket 14 advantageously has a base 60 shaped so as to provide a form-fit connection with the attachment member 50. In the embodiment of the figures, the base comprises an inner portion 64 connected to an outer portion 62 by a web 63. In the assembled state of the heat exchanger assembly 10, the inner portion 64 connects the outer portion 62 through the axial groove 55 of the attachment member shaped as a slide rail, i.e. the web 63 is received inside the groove of the slide rail 50. The outer portion 62 extends substantially parallelly to the inner portion 64. The inner and outer portions 62, 64 are further connected by a transverse wall 66, arranged at one end of the base 60, i.e. perpendicularly to the main extension of the base. Transverse wall 66 is provided to act as a stop or abutment member. As visible e.g. from Fig. 8c, the transverse wall 66 is in abutment against the outer edge 54.1 of the slide rail 50, in particular against the inwardly bent edge portions of the sidewalls 52.1, 52.2.

[0044] The inner portion 64 of the base 60 of the mounting bracket 14 is thus configured to be slideably coupled to/engaged into and movable into the slide rail (i.e. metallic attachment member 50). The dimensions of the inner portion 64 are such that it cannot be removed from engagement with the attachment member 50 through the groove 55.

[0045] The base 60 further presents two cantilever hooks 68.1, 68.2 extending axially from the inner portion 64, and formed so as to engage the edge 54.2 at the other end of the attachment member 50. As illustrated e.g. on Fig. 8c, the hooks comprise axially extending legs 69.1, 69.2 provided with protrusions that abut against the edge 54.2 of the attachment member 50 in the assembled position of the mounting bracket 14. In this configuration the mounting bracket is fixedly joined to the attachment member 50: the base portion is maintained in the X and Z direction in the attachment member 50 by form-fit, whereas it is locked in the Y direction thanks to the combination of the hooks and transverse wall. It may be noted that this is only an embodiment and that the transverse wall is not mandatory to lock the base axially, this can be achieved by the hooks alone. For example, the hooks may have square shaped protrusions that engage apertures in the sidewalls.

[0046] The mounting bracket 14 further comprises an integral mounting feature 70 extending from the upper portion 62 in the direction opposite to the base portion 64. The mounting feature 70 is here a flat flange provided with a through hole 72 to allow the mounting bracket 14 to be secured to a structure in the vehicle, or to another heat exchanger or heat exchanger assembly. The dimensions of the through hole 72 will be adapted in practice depending in the type/size of the matching fixing member, such as e.g. a screw, pin, rivet, etc.

[0047] Mounting brackets 114, arranged on the lower side of heat exchanger 12, are similar to mounting brackets 14, and include identical bases, however the mounting feature is different. Indeed, the mounting feature of mounting bracket 114 is designed as a fixing tab (see Fig. 1) that is mounted by engagement into a mating feature on the vehicle or on another heat exchanger, or for mating with other components or insulators. The fixing tab may advantageously be reinforced by ribbing for increased stiffness (not shown).

[0048] Fig. 7 and 8 schematically illustrates the assembly steps of an upper mounting bracket 14 to a heat exchanger assembly 12 according to the present invention. Lower mounting brackets are assembled in the same way.

[0049] Fig.8a shows a B-B cross-section as defined on Fig. 7a. Fig. 8b shows a C-C cross-section as defined on Fig. 7b. Fig. 8c shows a A-A cross-section as defined on Fig. 7c. It may be noted that the cutting line extends into two different planes; in particular the change of level occurs on the right-hand side of the attachment member, extending through a portion of the bent upper ends of sidewalls 52.1, 52.2.

[0050] First, the attachment members are positioned in respective recessed portions of the reinforcement members, and then clinched thereto (not shown).

[0051] The reinforcement members with the attachment members are assembled with the exchanger tubes fins, manifolds and then brazed.

[0052] A mounting bracket 14 with a base 60 configured for being fixed by means of a snap-fit connection to the attachment member (i.e. formed to correspond to (i.e. be complementary of) a form of the metallic attachment member 50) is approached to the metallic attachment member 50 and positioned with its inner portion 64 being parallel to the reinforcement member 30 (Fig. 7a and 8a).

[0053] The two cantilever hooks 68.1, 68.2 are elastically deformed toward each other (e.g. pressed toward each other) and the inner portion 64 is slideably engaged into the metallic attachment member 50 (Fig. 7b and 8.b), while the web 63 of the base 60 is slideably engaged into the axial groove of the attachment member.

[0054] The mounting bracket 14 is pushed/slid until the transverse wall 66 abuts against an edges 54.1 of the metallic attachment member 50. The restoring force of the cantilever hooks 68.1, 68.2 push them apart, restoring the initial configuration of the inner portion 64 of the base 60. The hooks exit the slide rail (i.e. metallic attachment member) 50 and abut against the other edges 54.2, thereby locking the mounting bracket in place (Fig. 7c and 8c).

[0055] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

Claims

1. A heat exchanger assembly (10) comprising:

a heat exchanger (12) comprising a core (20) with a plurality of heat exchanger tubes (26) for carrying a coolant fluid, the core (20) extending between two opposite manifolds (16, 18), a reinforcement member (30, 32) extending along each lateral side of the core between the manifolds (16, 18);

at least one plastic mounting bracket (14, 114) mounted to the reinforcement member, the mounting bracket (14, 114) comprising:

- a base (60) fixed by means of a snap-fit joint to a metallic attachment member (50) brazed onto the reinforcement member (30, 32); and

- a mounting feature (70) extending from the base (60),

wherein the attachment member (50) defines a slide rail (50) extending along the lateral side of the core (20), the base (60) being at least partially received within the slide rail (50) and snap-fittingly fixed therein.

2. The heat exchanger assembly (10) according to claim 1, wherein

the base (60) of the mounting bracket (14, 114) comprises an inner portion (64) configured to be slideably engaged into the slide rail,

the slide rail (50) having an axial groove (55) through which the inner portion (64) connects an outer portion (62) of the base (60), from which the mounting feature (70) extends;

the axial groove (55) having a narrower width than said inner portion (64).

3. The heat exchanger assembly (10) according to claim 1 or 2, wherein
two cantilevered hooks (68.1, 68.2) extend axially from the inner portion (64), and engage respective edges (54.2) of the attachment member (50).

4. The heat exchanger assembly (10) according to any one of the preceding claims, wherein the base (60) of the mounting bracket (14, 114), preferably its inner portion (64), has substantially the same width as the core (20) of the heat exchanger (12), in a direction perpendicular to both the extension direction of the manifolds (16, 18) and the extension direction of the reinforcement members (30, 32).

5. The heat exchanger assembly (10) according to any one of the preceding claims, wherein the mounting feature (70) is formed as a flange, in particular a flat flange (70) with an opening (72) therein for a fastening member or as tab, in particular a reinforced tab.

6. The heat exchanger assembly (10) according to any one of the preceding claims, wherein the metallic attachment member (50) is further clinched and/or welded to the reinforcement member (30, 32).

7. The heat exchanger assembly (10) according to any one of the preceding claims, wherein the reinforcement member (30, 32) has a recessed part (40) and wherein the metallic attachment member (50) is brazed into the recessed part (40).

8. The heat exchanger assembly (10) according to any one of the preceding claims, wherein the mounting bracket (14, 114) is formed by injection molding.

9. The heat exchanger assembly (10) according to any one of the preceding claims, wherein at least one, preferably both, of the manifolds (16, 18) of the heat exchanger is a round, one-piece manifold.

10. Use of a heat exchanger assembly (10) according to any one of the preceding claims as a condenser.

11. A cooling module comprising:

- a heat exchanger assembly (10) as claimed in any one of the preceding claims; and

- at least a second heat exchanger;

wherein the first heat exchanger (12) is mounted to the second heat exchanger by way of the mounting features (70) of the mounting brackets (14, 114) installed onto the reinforcement members (30,32) of the first heat exchanger (12).

12. Use of a cooling module according to the preceding claim, wherein the first heat exchanger (12) is configured as a condenser and the second heat exchanger is configured as a radiator.

Drawing