GB2380965A

GB2380965A - Automotive heat exchanger having fluid connection piece

Info

Publication number: GB2380965A
Application number: GB0124774A
Authority: GB
Inventors: Paul Carman
Original assignee: Llanelli Radiators Ltd
Current assignee: Marelli Automotive Systems UK Ltd
Priority date: 2001-10-16
Filing date: 2001-10-16
Publication date: 2003-04-23
Also published as: EP1302740A3; GB0124774D0; EP1302740A2

Abstract

A fusion bonded automotive heat exchanger includes a header tank 1 having a connection piece 10 for fluid connection to an upstream or downstream conduit. The connection piece 10 cooperates with an aperture 4 in the header tank 1 and includes a flange (13, fig 3) abutting an outer surface of the header tank 1 about the aperture 4 and an end 15 projecting beyond the flange (13, fig 3) and through the aperture 4 in the header tank 1 such that one or more lateral projections 16 abut the internal surface of the header tank 1 about the aperture 4. The connection piece 10 is joined to the header tank 1 by lining up the projection(s) 16 with mouth portions 5,6 in the aperture 4, and after insertion of the connection piece 10, it is rotated so that it is locked in position before fusion bonding.

Description

Automotive Heat Exchanger Having Fluid Connection Fitment

The present invention relates to an automotive heat exchanger having a fluid connection fitment.

In the automotive industry heat exchangers such as radiators, condensers and the like are frequently 10 manufactured of aluminium material. Connection fitments for connection of the heat exchanger to connection hoses are typically brazed to respective header tanks of the heat exchanger. Brazing usually takes place by means of passing the assembled heat exchanger through a brazing furnace in 15 which the temperature of the assembly is elevated to a degree sufficient to ensure that brazing alloy cladding present on the surface of the aluminium components of the heat exchanger melts and flows to ensure bonding at brazed connection joints. One of the disadvantages with brazing 20 processes is that components frequently need to be clamped together. It is an object of the present invention to alleviate such problems.

According to a first aspect of the invention, there is 25 provided a fusion bonded automotive heat exchanger including a header tank having a fitment for fluid connection to an upstream or downstream conduit; the fitment comprising a connection piece cooperating with an aperture in the header tank, the connection piece including 30 a flange portion abutting an outer surface of the header tank about the aperture and a distal end projecting beyond the flange and through the aperture in the header tank, the connection piece carrying in the region of the distal end one or more lateral projection formations abutting the internal surface of the header tank about the aperture.

The receiving aperture in the header includes a laterally extending mouth portion corresponding to the lateral projection formation of the distal end of the connection 10 piece. The connection piece is rotated relative to the axis of the aperture to a configuration in which the projection and associated mouth portion are out of line.

Thus in assembly of the heat exchanger, the connection piece is advanced toward the aperture in the header tank 15 such that the flange portion abuts the outer surface of the header tank about the aperture and the distal end projects through the aperture in the header tank permitted by one or more of the lateral projection formations carried by the connection piece co-aligning with a respective lateral 20 mouth extension at the periphery of the aperture. The connection piece is then rotated relative to the aperture about the axis of the connection piece to a configuration in which the lateral projection formation of the connection piece and the respective aperture lateral mouth formation 25 are out of alignment.

The space between the lateral projection of the connection piece and the flange of the connection piece is shaped and dimensioned to be close on an interference fit with the 30 wall thickness of the header tank around the periphery of the aperture. Rotating the connection piece to its out of alignment position therefore ensures a secure enough connection between the connection piece and the header tank to permit the brazing operation without the requirement for 5 further clamping between the connection piece and the header tank.

According to a second aspect, the invention therefore provides a method of manufacturing a heat exchanger 10 comprising: i) assembling a heat exchanger including a header tank having a fitment for fluid connection to an upstream or downstream conduit; the fitment comprising a 15 connection piece cooperating with an aperture in the header tank, the connection piece including a flange portion abutting an outer surface of the header tank about the aperture and a distal end projecting beyond the flange and through the aperture in the header 20 tank permitted by one or more lateral projection formations carried by the connection piece coaligning with a respective lateral mouth extension at the periphery of the aperture; ii) rotating the connection piece relative to the aperture about the axis of the connection piece to a configuration in which the lateral projection formation of the connection piece and the respective aperture lateral mouth formation are out of 30 alignment; iii) fusion bonding the arrangement to produce a fused joint between the flange portion and the portion of the header tank about the aperture.

The flange portion preferably extends outwardly from the remainder of the connection piece to provide an annular flange surface extending substantially perpendicular to the axis of the connection piece.

The flange portion is preferably defined at a folded or upset bend comprising a double wall thickness of material of the connection piece.

Preferably the distal end projection of the connection 15 piece is less laterally extensive than the flange portion.

It is preferred that the connection piece carries a plurality of projection formations spaced angularly about the axis of the connection piece, the aperture including correspondingly angularly spaced mouth portions. 20 Beneficially the lateral projection formations of the connection piece are spaced at 180ù about the axis of the connection piece.

As mentioned above, it is preferred that the lateral 25 projection at the distal end of the connection piece is spaced from the facing portion of the flange by distance of substantially the thickness of the header tank in the region of the aperture.

Beneficially, the connection piece and header tank are formed of substantially the same material (preferably aluminium material beneficially clad in a suitable brazing alloy to permit brazing in a one shot brazing process).

This is beneficial because it ensures that for recycling 5 purposes the connection piece and header tank may be recycled in the same fashion rather than requiring disassembly for recycling.

The bayonet type connection between the connection piece 10 and header tank permits rapid assembly without the requirement for mechanical attachment by a secondary process (for example clamping) . The connection piece is simply inserted into the aperture, with the formations matched and rotated (typically by approximately 300) to an 15 out of alignment situation. This is sufficient to hold the connection piece relative to the header tank until the brazing process renders the joint permanent.

The invention will now be further described in a specific 20 embodiment by way of example only and with reference to the accompanying drawings in which: Figure 1 is a side view of a heat exchanger header tank; Figure 2 is a plan view of the header tank of Figure 1; Figure 3 is a part sectional view of a connection piece for co-operating with the aperture of the header tank of Figures 1 and 2 in accordance with the invention; Figure 4 is an end view of the connection piece of Figure 3; and Figure 5 is a plan view of the connection piece of Figures 4 and 3.

Referring to the drawings, Figures 1 and 2 show a header tank 1 for a heat exchanger such as a radiator or a condenser (or a combined, unified radiator/condenser). A 10 front face or tube plate 2 of the header tank includes a series of spaced plunging apertures 3 shaped and dimensioned to receive ends of heat exchanger tubes which extend between, typically, two spaced header tanks 1.

Third connection into or out of header tank 1 is provided 15 via aperture 4 which is generally of uniform diameter but has a pair of spaced laterally radially projecting mouth portions 5, 6 spaced angularly at 1800 from one another.

Connection piece 10 (shown in Figures 3 to 5) is generally tubular and includes a proximal end 11 provided with an inwardly tapering terminal portion 12 for ease of connection to a flexible hose.

The distal end of connection piece 10 includes an upset 25 wall portion 13 of double thickness wall abutting face against face to provide a flange face 14. The distal end portion of connection piece 10 includes an extension portion projecting distally from flange 14, distally projecting portion 15 being provided at 1800 angularly 30 spaced locations with respective laterally outward projecting formations 16. The distance between laterally outward projecting formations 16 and flange surface 14 is matched to the thickness of the material of the header tank about the periphery of aperture 4. The header tank material 4 therefore may be sandwiched between projection 16 and flange 14 in a sandwich or interference fit.

In use, the connection piece 10 is advanced toward aperture 4 in axial alignment and with projections 16 matched up 10 with mouth portions 5. Projections 16 pass through mouth portions 5 such that distal extension 15 passes through aperture 4 and flange surface 14 abuts against the external housing wall of header tank 1.

Subsequently connection piece 10 is rotated about its axis of approximately 30ù such that lateral projection 16 out of alignment with lateral mouth portion projections 5, 6. At this point the flange surface 14 abuts the outer surface of the header tank approximate the aperture 4, and the projections 16 abut the inner surface of the header tank about the periphery of aperture 4. The interference fit is sufficient to prevent projections 16 realigning with mouth portions 5, 6 and therefore the connection is secure enough for the purposes of entering the brazing furnace.

Typically the outer surface of header tank 1 and the outer surface of the connection piece 10 are clad in aluminium brazing alloy. This is a commonly used technique in the art of brazing aluminium components used in the automotive 30 heat exchanger field. The flange 14 provides a good surface for forming a secure brazed bond with the external surface of the header tank. The heat exchanger assembly including the secured connection piece and header tank are pressed through a brazing furnace in order to braze the assembly.

Claims

Claims:

1. A fusion bonded automotive heat exchanger including 5 a header tank having a fitment for fluid connection to an upstream or downstream conduit; the fitment comprising a connection piece cooperating with an aperture in the header tank, the connection piece including a flange portion abutting an outer surface 10 of the header tank about the aperture and a distal end projecting beyond the flange and through the aperture in the header tank, the connection piece carrying in the region of the distal end one or more lateral projection formations abutting the internal 15 surface of the header tank about the aperture.

2. A heat exchanger according to claim 1, wherein the receiving aperture in the header includes a laterally extending mouth portion corresponding to the lateral 20 projection formation of the distal end of the connection piece, the connection piece being rotated relative to the axis of the aperture to a configuration in which the projection and associated mouth portion are out of line. 25

3. A heat exchanger according to claim 1 or claim 2, wherein the flange portion extends outwardly from the remainder of the connection piece to provide an annular flange surface extending substantially 30 perpendicular to the axis of the connection piece.

4. A heat exchanger according to any preceding claim, wherein the flange portion is defined at a folded or upset bend comprising a double wall thickness of the material of the connection piece.

5. A heat exchanger according to any preceding claim, wherein the distal end projection of the connection piece is less laterally extensive than the flange portion.

6. A heat exchanger according to any preceding claim, wherein the connection piece carries a plurality of projection formations spaced angularly about the axis of the connection piece, the aperture including 15 correspondingly angularly spaced mouth portions.

7. A heat exchanger according to claim 6, wherein the lateral projection formations of the connection piece are spaced at 180 degrees about the axis of the 20 connection piece.

8. A heat exchanger according to any preceding claim, wherein the lateral projection of the distal end of the connection piece is spaced from the facing 25 portion of the flange by a distance of substantially the thickness of the header tank in the region of the aperture.

9. A heat exchanger according to any preceding claim, 30 wherein the connection piece and the header tank are formed of substantially the same material.

10. A heat exchanger according to any preceding claim, wherein the connection piece and the header tank are formed of aluminium material.

11. A heat exchanger according to any preceding claim, wherein the assembly comprising the connection piece and the header tank are of brazed aluminium 10 construction, the connection piece and header tank being of aluminium material; aluminium brazing alloy being present in a brazed joint between the flange portion and the portion of the header tank about the aperture.

12. A method of manufacturing a heat exchanger comprising: i) assembling a heat exchanger including a header 20 tank having a fitment for fluid connection to an upstream or downstream conduit; the fitment comprising a connection piece cooperating with an aperture in the header tank, the connection piece including a flange portion abutting an 25 outer surface of the header tank about the aperture and a distal end projecting beyond the flange and through the aperture in the header tank permitted by one or more lateral projection formations carried by the connection piece co30 aligning with a respective lateral mouth extension at the periphery of the aperture; ii) rotating the connection piece relative to the aperture about the axis of the connection piece 5 to a configuration in which the lateral projection formation of the connection piece and the respective aperture lateral mouth formation are out of alignment; iii) fusion bonding the arrangement to produce a fused joint between the flange portion and the portion of the header tank about the aperture.