CONNECTION OF REDUCED OVERALL DIMENSIONS BETWEEN AN ALUMINUM TUBE AND A HEAT EXCHANGER

Abstract

A connection arrangement between an aluminum tube and a heat exchanger, wherein the tube has an outer diameter D and comprises an end flange abutted against a connection flange of the heat exchanger and fastened thereto by means of a fastener. The tube further comprises an elbow arranged close to the end flange, and a rectilinear segment extending from the end flange to an end cross-section of the elbow. The elbow has a bend radius R, referred to the central axis of the tube, such that 0.5DRD and the end cross-section of the elbow is arranged at a distance d from the connection flange of the heat exchanger such that d0.5D. The fastener consists of a tube clamp of plastic material encircling the connection flange of the heat exchanger and the end flange of the tube. The tube clamp comprises a pair of clamp halves snap-fitted to each other.

Claims

1. A connection arrangement between an aluminum tube and a heat exchanger, comprising a heat exchanger provided with a connection flange within which a fluid flow duct is formed, and an aluminum tube having an outer diameter D and comprising an end flange abutted against the connection flange of the heat exchanger and fastened thereto by means of a fastener, the tube further comprising an elbow arranged close to the end flange, and a rectilinear segment extending from the end flange to an end cross-section of the elbow, wherein: the elbow has a bend radius R, referred to the central axis of the tube such that 0.5DRD and the end cross-section of the elbow is arranged at a distance d from the connection flange of the heat exchanger such that d0.5D, and the fastener consists of a tube clamp of plastic material encircling the connection flange of the heat exchanger and the end flange of the tube, the tube clamp comprising a pair of clamp halves snap-fitted to each other.

2. A method for connecting an aluminum tube to a heat exchanger, comprising the steps of: providing a heat exchanger provided with a connection flange within which a fluid flow duct is formed, providing an aluminum tube having an outer diameter D and comprising an end flange, the tube further comprising an elbow arranged close to the end flange and a rectilinear segment extending from the end flange to an end cross-section of the elbow, abutting the end flange of the tube against the connection flange of the heat exchanger, and fastening the end flange of the tube to the connection flange of the heat exchanger by means of a fastener, wherein: the elbow has a bend radius R, referred to the central axis of the tube, such that 0.5DRD and the end cross-section of the elbow is arranged at a distance d from the connection flange of the heat exchanger such that d0.5D, and the fastener consists of a tube clamp of plastic material comprising a pair of separate clamp halves snap-fittable to each other, the fastening step comprising moving the clamp halves closer to each other and to the connection flange of the heat exchanger and the end flange of the tube, in a direction perpendicular to the rectilinear segment of the tube, until the clamp halves encircle the connection flange of the heat exchanger and the end flange of the tube and snap-fit to each other.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 shows a sectional view of a connection arrangement between a heat exchanger and an aluminum tube, taken in the bending plane of a tube elbow;

[0027] FIG. 2 shows a perspective view of the mounting of a tube clamp to the connection arrangement in FIG. 1; and

[0028] FIG. 3 shows a perspective view of the tube clamp fastened to the arrangement in FIG. 2.

DETAILED DESCRIPTION OF THE DRAWINGS

[0029] The figures show a portion of a heat exchanger, indicated as a whole with reference numeral 3, and a connection flange 5 is also shown, which in the example shown is formed on a sleeve 6 welded to a manifold of the heat exchanger 3. Within the connection flange 5 a fluid flow duct is formed to allow the transfer of fluid from the tube to the heat exchanger if it is an inlet tube, and from the heat exchanger to the tube if it is an outlet tube.

[0030] The arrangement shown also comprises an aluminum tube 10 having an outer diameter D and comprising an end flange 12 abutted against the connection flange 5 of the heat exchanger 3. Letter z indicates a central axis of tube 10. By way of geometrical comparison, FIG. 1 also shows an aluminum tube 10 of a conventional arrangement, having the same diameter D. Letter z indicates a central axle of tube 10.

[0031] The end flange 12 of tube 10 is fastened to the connection flange 5 of the heat exchanger 3 by means of a fastener 20 described hereinafter.

[0032] Tube 10 of the arrangement according to the invention comprises an elbow 14 arranged close to the end flange 12, and a rectilinear segment 16 extending from the end flange 12 to an end cross-section 14a of elbow 14.

[0033] Tube 10 of the conventional arrangement comprises an elbow 14 arranged close to the end flange 12, and a rectilinear segment 16 extending from the end flange 12 to an end cross-section 14a of elbow 14.

[0034] Elbow 14 of tube 10 of the arrangement according to the invention has a bend radius R, referred to the central axis z of tube 10, such that 0.5DRD and the end cross-section 14a of elbow 14 is arranged at a distance d from the connection flange 5 of the heat exchanger 3 such that d0.5D.

[0035] Elbow 14 of tube 10 of the conventional arrangement has a bend radius R, referred to the central axis z of tube 10, equal to 1.5D.

[0036] The overall dimensions determined by the arrangement according to the invention is indicated by length y, while thesignificantly largeroverall dimensions determined by the conventional arrangement is indicated by length x.

[0037] The end flange 12 of tube 10 is fastened to the connection flange 5 of the heat exchanger 3 by means of a fastener 20, consisting of a tube clamp of plastic material encircling the connection flange 5 of the heat exchanger 3 and the end flange 12 of tube 10.

[0038] As is shown in FIGS. 2 and 3, the tube clamp 20 comprises a pair of clamp halves 21 identical to each other, each having a C-shape and provided with end portions 21a, 21b that mate when the clamp halves 21 are in the closed position shown in FIG. 3. Each clamp half 21 on its radially inner surface has a groove (visible in particular in FIG. 1) adapted to enclose flanges 5 and 12 in the axial direction.

[0039] At or in the vicinity of the end portions 21a of the clamp halves 21, snap-fitting elements are arranged. In particular, in the example shown the snap-fitting elements comprise, on one of the end portions, indicated with reference numeral 21a, of each clamp half 21, an elastic hook portion 23 protruding radially outwards and tangentially forward with respect to the respective end portion 21a of the clamp half 21 and, on the other one of the end portions, indicated with reference numeral 21b, of each clamp half 21, an engagement tooth commitment 25 protruding radially outwards with respect to the respective end portion 21b of the clamp half 21. The engagement tooth 25 of an end portion 21b of a clamp half 21 is adapted to be engaged by the hook portion 23 of the end portion 21a in front of the other clamp half 21 when the clamp halves 21 are in the closed position shown in FIG. 3.

[0040] In the example shown, the snap-fitting elements further comprise, on one of the end portions, indicated with reference numeral 21b, of each clamp half 21, a pin 27 protruding tangentially forward from the respective end portion 21b of the clamp half 21 and, on the other one of the end portions, indicated with reference numeral 21a, of each clamp half 21, a hole 29 formed in the respective end portion 21a of the clamp half 21. Pin 27 of an end portion 21b of a clamp half 21 is adapted to be fitted into hole 29 of the end portion 21a in front of the other clamp half 21 when the clamp halves 21 are in the closed position shown in FIG. 3. Pins 27 and holes 29 cooperate with the hook portions 23 and the engagement teeth 25 to make the clamp halves 21 integral with each other after reaching the closed position shown in FIG. 3.

[0041] Once the end flange 12 of tube 10 is abutted against the connection flange 5 of the heat exchanger 3, such flanges 5 and 12 are fastened to each other by the tube clamp 20 described above.

[0042] In order to make such fastening, the clamp halves 21 are moved close to each other and to the connection flange 5 of the heat exchanger 3 and to the end flange 12 of tube 10, perpendicular to the straight section 16 of tube 10, in the direction indicated by arrows M in FIG. 2. With this movement, the clamp halves 21 are made to encircle the connection flange 5 of the heat exchanger 3 and the end flange 12 of tube 10, snap-fitting the clamp halves to each other.