Heat exchanger

Abstract

 A heat exchanger includes a heat exchanger body (10) from which a connection duct (12) extends. The connection duct (12) includes and elastically deformable free end and two engaging walls (20) formed in respective rectangular apertures (18) proximate the free end of the duct (12). A coupling tube (14) for coupling the heat exchanger body (10) to a hose of an expansion tank includes a first portion (30) receivable in the connection duct (12) which includes two tangs (34) engageable with the engaging walls (20) to secure the coupling tube (14) within the connection duct (12), and a second portion (40) connectable to the expansion tank hose. A U-shaped recess (22) at the free end of the connection tube (12) engages a U-shaped locating portion (50) of the coupling tube (14) to align the coupling tube relative to the heat exchanger body (10).

Description

[0001] The present invention relates to a heat exchanger including a separate coupling tube for coupling the heat exchanger to a hose leading to an expansion tank.

[0002] It is known in heat exchangers used in vehicle radiators to have a removable coupling tube coupled between a port of the heat exchanger and a hose leading to an expansion tank. The coupling tube may be secured to the expansion tank by means, for example, of a bayonet fitting or of a snap-fit arrangement whereby lugs on the tube engage the opening of the heat exchanger.

[0003] The present invention seeks to provide an improved heat exchanger.

[0004] According to an aspect of the present invention, there is provided a heat exchanger as specified in claim 1.

[0005] The claimed arrangement can provide an improved connection between an expansion tank hose and a heat exchanger.

[0006] Preferably, a connection duct of the heat exchanger includes one or more elongate slots extending from the free end of the connection duct. Such slots can add elasticity to the free end of the connection duct to assist in fitting and removing the coupling tube to the connection duct.

[0007] In an embodiment, the connection duct includes one or more apertures, the or each aperture including the or a respective engaging wall. Preferably, two apertures are provided, disposed substantially opposite one another relative to the connection duct.

[0008] Advantageously, the connection duct includes a location recess extending from the free end of the connection duct, the coupling tube including a location portion receivable in the recess. The recess and location portion ensure that the coupling tube and hence the expansion chamber hose are given a predetermined orientation relative to the heat exchanger, which can be very important in the confined space in a vehicle.

[0009] Preferably, the location recess in the connection duct and the location portion of the coupling tube are substantially U-shaped. This shape facilitates insertion and orientation of the coupling tube in the connection duct.

[0010] An elastomeric seal may be disposed in an annular groove proximate an end of the first portion of a coupling tube of the heat exchanger, the elastomeric seal co-operating with the internal surface of the connection duct to provide a fluid-tight seal between the connection duct and the coupling tube.

[0011] Preferably, the internal surface of the connection duct includes a greater diameter portion at the free end of the connection duct and a smaller diameter portion at the end of the connection duct adjacent the heat exchanger body, the first portion of the coupling tube being substantially cylindrical. This arrangement can ensure that the elastomeric seal is not damaged during insertion of the coupling tube into the connection duct.

[0012] The first and second portions of the coupling tube may be substantially perpendicular to one another.

[0013] According to another aspect of the present invention, there is provided a coupling tube for coupling a heat exchanger body to an expansion tank hose.

[0014] An embodiment of the present invention is described below, by way of illustration only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of part of an embodiment of heat exchanger and coupling tube;

Figure 2 is a cross-sectional view of the heat exchanger and coupling tube taken along line 2-2 of Figure 1; and

Figure 3 is a cross-sectional view of the heat exchanger and coupling tube taken along line 3-3 of Figure 1.

[0015] Referring to Figures 1 to 3, there is shown part of a heat exchanger 10 of a vehicle radiator which includes a connection duct 12 extending from the body of the heat exchanger 10. A coupling tube 14 includes a first portion 30 fitting within the connection duct 12 and a second portion 40 substantially perpendicular to the first portion 30 and which in use is coupled to a hose (not shown) leading to an expansion tank. During use of the radiator, excess radiator fluid produced by expansion thereof is released from the heat exchanger 10 through the coupling tube 14 to the hose and eventually to the expansion tank. Fluid can also pass in the opposite direction to the radiator, as appropriate.

[0016] The connection duct 12 is substantially cylindrical and substantially circular in axial cross-section. At an end 16 of the connection duct 12 remote from the body of the heat exchanger 10, the duct 12 is provided with two opposing substantially rectangular apertures 18 therein, as best seen in Figures 1 and 3. Each aperture 18 includes an engaging wall 20 substantially parallel to and proximate the remote end 16 of the duct 12.

[0017] Located between the two apertures 18, there is provided a U-shaped location recess 22 extending from the remote end 16 towards the body of the heat exchanger 10 for aligning the second portion 40 of the coupling tube 14.

[0018] A pair of elongate narrow slots 24 are provided substantially opposite the location recess 22 and extend from the remote end 16 towards the body of the heat exchanger 10, terminating substantially at the same level as lower walls 26 of the rectangular apertures 18 and the end of the location recess 22. The slots 24, and also the location recess 22, provide a degree of elasticity at the remote end 16 of the connection duct 12 for assisting in connecting and disconnecting the coupling tube 14 to the connection duct 12, explained in further detail below.

[0019] A plurality of buttresses 28 are provided at the base of the connection duct 12, being coupled to the heat exchanger body 10 and the connection duct 12. Typically, the heat exchanger body 10, connection duct 12 and buttresses 28 may be formed as an integral piece, for example from a single moulding.

[0020] As can be seen in Figures 2 and 3, the internal surface of the connection duct 12 includes a portion of greater diameter at the remote end 16 and a portion of smaller diameter at the end adjacent the body of the coupling tube 14. The greater diameter portion extends, in this embodiment, for approximately half the length of the connection duct 12. Although not shown in Figures 2 and 3, the interface between the greater and smaller diameter portions of the connection duct 12 may be of tapered form to provide a substantially smooth internal surface to the duct 12.

[0021] The first portion 30 of the coupling tube 14 has a generally cylindrical outer surface which is substantially circular in axial cross-section. Proximate the free end of the first portion 30, there is provided an annular groove of square cross-section which houses an annular elastomeric seal 32 of known type.

[0022] In order to facilitate insertion of the first portion 30 of the coupling tube into the connection duct 12, the free end of the first portion 30 is tapered.

[0023] First and second tangs 34 are provided on the outer surface of the first portion 30 and taper towards its free end, such that each tang 34 includes a wall substantially perpendicular to the axis of the first portion 30 which co-operates in use with the engaging wall 20 of its respective rectangular aperture 18 in the connection duct 12.

[0024] The second portion 40 of the coupling tube 14 is substantially cylindrical and substantially circular in axial cross-section. At the free end of the second portion 40, there may be provided, as shown in Figure 2, a wedge-shaped annular retaining member 42 for use in retaining an expansion tank hose on the second portion 40.

[0025] At the junction between the first and second portions 30,40, the coupling tube 14 is provided with a portion 50 which in plan view has a part-annular shape and in front elevational view being substantially U-shaped. When the coupling tube 14 is fitted to the connection duct 12, the portion 50 occupies the space provided by the U-shaped recess 22 in the connection duct 12.

[0026] It is envisaged that on assembly of the heat exchanger, the hose will first be fitted to the second portion 40 of the coupling tube 14. Then, following the fitting of the heat exchanger 10 to a vehicle, the first portion 30 of the coupling tube 14 is aligned with the open end of the connection duct 12 and slid therein. The greater interior diameter portion of the connection duct 12 ensures that the elastomeric seal 32 is not damaged by the various surfaces of the rectangular apertures 18, the slots 24 and the U-shaped recess 22.

[0027] As the tangs 34 of the coupling tube 14 reach the remote end 16 of the connection duct 12, they cause the connection duct 12 to deform elastically, this being facilitated by the slots 24 and the U-shaped recess 22. The U-shaped portion 50 aligns the coupling tube 14 relative to the connection duct 12 such that the second portion 40 and the hose connected thereto take a predetermined orientation relative to the heat exchanger body 10. The tangs 34 eventually register with their respective rectangular apertures 18, at which point the end of the duct 12 snaps over the tangs 34 to secure the coupling tube 14 in the connection duct 12.

[0028] The coupling tube 14 can be removed from the connection duct 12, when necessary, by bending the end of the connection duct 12 radially outwardly at the location of the apertures 18 so as to release the tangs 34 from the apertures 18. This can be achieved with any suitable tool.

[0029] The disclosures in British patent application no. 9324184.2, from which this application claims priority, and in the abstract accompanying this application are incorporated herein by reference.

Claims

1. A heat exchanger including a heat exchanger body (10) from which a connection duct (12) extends, the connection duct including an elastically deformable free end and one or more engaging walls (20) proximate the free end; and a coupling tube (14) for coupling the heat exchanger body to a hose of an expansion tank, the coupling tube comprising a first portion (30) receivable in the connection duct and including one or more tangs (34) on an outer surface thereof engageable with the engaging wall or walls to secure the coupling tube within the connection duct, and a second portion (40) connectable to an expansion tank hose.

2. A heat exchanger according to claim 1, wherein the connection duct includes one or more elongate slots (24) extending from the free end of the connection duct.

3. A heat exchanger according to claim 1 or 2, wherein the connection duct includes one or more apertures (18), the or each aperture including the or a respective engaging wall.

4. A heat exchanger according to claim 3, including two apertures (18) disposed substantially opposite one another relative to the connection duct.

5. A heat exchanger according to any preceding claim 1, wherein the connection duct includes a location recess (22) extending from the free end of the connection duct, the coupling tube including a location portion (50) receivable in the recess.

6. A heat exchanger according to claim 5, wherein the location recess (22) in the connection duct and the location portion (50) of the coupling tube are substantially U-shaped.

7. A heat exchanger according to any preceding claim, comprising an elastomeric seal (32) disposed in an annular groove proximate an end of the first portion (30) of the coupling tube, the elastomeric seal co-operating with the internal surface of the connection duct to provide a fluid-tight seal between the connection duct and the coupling tube.

8. A heat exchanger according to any preceding claim, wherein the internal surface of the connection duct includes a greater diameter portion at the free end of the connection duct and a smaller diameter portion at the end of the connection duct adjacent the heat exchanger body, the first portion of the coupling tube being substantially cylindrical.

9. A heat exchanger according to any preceding claim, wherein the first and second portions of the coupling tube are substantially perpendicular to one another.

Drawing