GB1590032A

GB1590032A - Heat exchangers

Info

Publication number: GB1590032A
Application number: GB4716077A
Authority: GB
Original assignee: Chausson Usines SA
Current assignee: Chausson Usines SA
Priority date: 1976-11-19
Filing date: 1977-11-11
Publication date: 1981-05-28
Also published as: BE860672A; FR2371662B1; FR2371662A1; DE2750237A1; IT1087245B; ES231980U; ES231980Y

Description

(54) IMPROVEMENTS IN OR RELATING ' HEAT EXCHANGERS (71) We, SOCIETE ANONYME DES USINES CHAUSSON, a company duly organized under the laws of France, of 35, rue Malakoff, 92 ASNIERES, France, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement: The present invention relates to heat exchangers and in particular to the provision of sealtight gaskets between the ends of circulation tubes of the heat exchangers and end plates in which said tubes are engaged.

Long ago it has been proposed to place on one side of the end plate a distortable and flexible element comprising sockets engaged in tube passages provided in this end plate, then to engage the tubes into said sockets and to inflate or crimp the tubes to distort the sockets held by the end plate.

It has also been proposed by the Applicants, particularly in French patent 69 02 350, to provide the sockets engaged in the tube passages or apertures of the end plate with a flange made by moulding to bear on one side of the end plate, while the sockets are connected together on the other side of the end plate by a continuous plate made of flexible material which simultaneously forms a gasket between the end plate and a header box covering the same.

The arrangements mentioned above are generally satisfactory but they nevertheless exhibit some disadvantages. Especially, when the sockets are formed from a continuous plate made of moulded flexible material covering the whole end plate and besides have a flange provided to bear on the other side of the end plate, it is relatively difficult to position said sockets because said flanges form an obstacle thereto.

It is intended with the present invention to create a new gasket having all the advantages of the previously described gasket, but in which the above mentioned disadvantage is eliminated, as well as being able to place the tubes without having to expand or otherwise distort them, which greatly simplifies the manufacture of the heat exchangers.

According to the invention, there is provided a heat exchanger comprising a flexible gasket for tubes and end plates of the heat exchanger, the gasket comprising a sheet in which are formed sockets engaged in tube passages of the end plate, said sockets each having a height greater than the thickness of the end plate or than the height of the respective flanges of the end plate and being provided, in a portion there of which protrudes from the end plate with an inner rim delimiting a passage of a cross section smaller than that of a respective tube, whereby the rim is widened out and folded back to bear on the end plate or on a flange of the end plate by means of the tube when engaged in the socket.

Various other features of the invention are moreover shown in the following detailed description.

Embodiments of the object of the invention are shown by way of non restrictive examples in the accompanying drawing, in which: Figure 1 is a diagrammatic cross sectional elevation view of a heat exchanger of the radiator type; Figures 2 and 3 are enlarged cross sectional elevation views showing use of a gasket of the heat exchanger with thick end plates; Figure 4 is a cross sectional elevation view, similar to Figure 2, showing use of a gasket of the heat exchanger with thin end plates providec with flanges; and Figures 5 and 6 are views similar to Figure 2 but illustrating two further embodiments.

Referring now to the drawing, Figure 1 shows in a diagrammatic way a heat exchanger of the radiator type, which comprises tubes 1 engaged in fins 2 and in end plates 3 covered with header boxes 4.

In the present case and in a well known way, the tightness between the tubes 1 and the end plates 3 is provided by sockets 5 formed from a sheet 6 which covers one of the sides of the end plate. The sheet 6 can be used, also, to ensure a tightness between each end plate and each header box, the periphery of this sheet being clamped by means of fasteners, clips or other elements 7 connecting an end plate to a header box.

Also in a well known way, the sockets 5 form, at their end opposite to the sheet 6, a rim 8 bearing on the end plate 3 which is thus embedded.

As better shown in Figures 2 and 3, the end plate, now shown at 3a, is a thick end plate, for example made of plastics material, and the tube passages formed therein are advantageously provided with walls 9 widening out towards the side facing the fins 2. For end plates of this type, the sheet 6 is placed on the side of the end plate facing the fins, and the sockets 5 have an inner bore 10 with oblique walls, for example in the shape of a truncated hyperbola. The sockets 5 extend up to the top of the upper high wall 31 of the end plate and they have an inner rim 81 forming a shoulder 11 underneath the rim.

When the tubes 1 are forced into the sockets 5 in direction of the arrowfi, their ends come into abutment against the shoulder 11, which has for its effect to turn back the inner rim 81 while swivelling around the edge 3' of the end plate. The outer wall of the rim 8I thus forms a bearing surface against the end plate, and the inner wall of the rim 8 exerts a pressure which is particularly strong on the periphery of the tube 1 while consequently ensuring a perfect tightness.

It is advantageous, as shown in the drawings, that the sockets 5 will form at the lower portion, an abutment 12 which prevents the first fin 2 from bearing on the sheet 6 itself and which determines the distance of the engagement of the tubes 1 in the sockets.

To facilitate the introduction of the tubes 1 into the sockets, it is advantageous that their end 11 be slightly narrowed as illustrated in an exagerated way in the drawing.

Figure 4 shows an embodiment according to which the end plate 3b is thin and made for example of metal, and is formed with flanges 13 to delimit the tube passages in which are engaged the sockets 5 of the sheet 6. As previously, the rim 8, is formed inside the socket, but above the top of flanges 13. When the tubes 1 are engaged up to where the first fin 2 comes to bear on the abutment 12, then the rim 81 of each socket is partly folded back on the top of the corresponding flange 13.

Figure 5 shows a variant according to which the end plate, now shown at 3c, is manufactured for example in a corrodable material and must be covered on its whole surface by the sheet 6 which is then placed on the side of the end plate facing the inside of the header box 4, so that the flanges 13 are then turned towards the fins 2.

In this case, the sockets 5 are so made to take at least approximately the shape of the flanges 13, and a rim 82 is formed inside the socket by the portion of the same which protrudes from the flange 13, but the outer wall 8' facing the tubes 1 is rounded to delimit a ramp tending to drive the tube towards the inside of the socket 5. In this manner, at the moment of introducing the tube 5 according to the arrowfi,the rim 82 is widened out according to the arrows f2 which has for its effect to bend it and to apply the same on the top of the flange 13.

To facilitate this movement, it is advantageous that the outer wall of the socket 5 will have a groove 14 substantially at the level of the top of each flange 13. Besides, the groove 14 prevents any shearing by the inner edge of the flange 13 at the moment of bending the rim 82.

Figure 6 illustrates a similar embodiment but in which the inside of each socket 5 has a bore with a double conicity 5a, 5b. The conicity 5a can however be a cylinder. As previously, it is advantageous that a groove 14 be formed level with the top of flange 13. It is the conicity 5b which is driven by the end of the tube 1 and acts as a ramp to cause the separation of the end of the socket and its application on the top of the flange 13.

As in the case described with reference to Figure 2, it is advantageous that the end 11 of the tubes 1 be slightly narrowed or chamfered, but this is not necessary.

WHAT WE CLAIM IS: 1. A heat exchanger comprising a flexible gasket for tubes and end plates of the heat exchanger, the gasket comprising a sheet in which are formed sockets engaged in tube passages of the end plate, said sockets each having a height greater than the thickness of the end plate or than the height of respective flanges of the end plate and being provided in a portion thereof which protrudes from the end plate with an inner rim delimiting a passage of a cross section smaller than that of a respective tube, whereby the rim is widened out and folded back to bear on the end plate or on a flange of said end plate by means of the tube when engaged in the socket.

2. A heat exchanger as claimed in Claim 1, wherein a groove is formed in each socket in the outer wall thereof at the level of the wall of the end plate or of the flange towards which the rim is folded back.

3. A heat exchanger as claimed in Claim 1 or 2, wherein the sheet in which the sockets are formed is placed on the side of the end plate which is turned towards cooling fins of the heat exchanger.

4. A heat exchanger as claimed in any one of Claims 1 to 3, wherein the sheet in which the sockets are formed is turned towards a header box which covers the end plate.

5. A heat exchanger as claimed in any one of Claims 1 to 4, wherein the sheet delimits protruding portions forming an abutment to limit the distance of introduction of the tubes into the sockets.

6. A heat exchanger as claimed in any one

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. other elements 7 connecting an end plate to a header box. Also in a well known way, the sockets 5 form, at their end opposite to the sheet 6, a rim 8 bearing on the end plate 3 which is thus embedded. As better shown in Figures 2 and 3, the end plate, now shown at 3a, is a thick end plate, for example made of plastics material, and the tube passages formed therein are advantageously provided with walls 9 widening out towards the side facing the fins 2. For end plates of this type, the sheet 6 is placed on the side of the end plate facing the fins, and the sockets 5 have an inner bore 10 with oblique walls, for example in the shape of a truncated hyperbola. The sockets 5 extend up to the top of the upper high wall 31 of the end plate and they have an inner rim 81 forming a shoulder 11 underneath the rim. When the tubes 1 are forced into the sockets 5 in direction of the arrowfi, their ends come into abutment against the shoulder 11, which has for its effect to turn back the inner rim 81 while swivelling around the edge 3' of the end plate. The outer wall of the rim 8I thus forms a bearing surface against the end plate, and the inner wall of the rim 8 exerts a pressure which is particularly strong on the periphery of the tube 1 while consequently ensuring a perfect tightness. It is advantageous, as shown in the drawings, that the sockets 5 will form at the lower portion, an abutment 12 which prevents the first fin 2 from bearing on the sheet 6 itself and which determines the distance of the engagement of the tubes 1 in the sockets. To facilitate the introduction of the tubes 1 into the sockets, it is advantageous that their end 11 be slightly narrowed as illustrated in an exagerated way in the drawing. Figure 4 shows an embodiment according to which the end plate 3b is thin and made for example of metal, and is formed with flanges 13 to delimit the tube passages in which are engaged the sockets 5 of the sheet 6. As previously, the rim 8, is formed inside the socket, but above the top of flanges 13. When the tubes 1 are engaged up to where the first fin 2 comes to bear on the abutment 12, then the rim 81 of each socket is partly folded back on the top of the corresponding flange 13. Figure 5 shows a variant according to which the end plate, now shown at 3c, is manufactured for example in a corrodable material and must be covered on its whole surface by the sheet 6 which is then placed on the side of the end plate facing the inside of the header box 4, so that the flanges 13 are then turned towards the fins 2. In this case, the sockets 5 are so made to take at least approximately the shape of the flanges 13, and a rim 82 is formed inside the socket by the portion of the same which protrudes from the flange 13, but the outer wall 8' facing the tubes 1 is rounded to delimit a ramp tending to drive the tube towards the inside of the socket 5. In this manner, at the moment of introducing the tube 5 according to the arrowfi,the rim 82 is widened out according to the arrows f2 which has for its effect to bend it and to apply the same on the top of the flange 13. To facilitate this movement, it is advantageous that the outer wall of the socket 5 will have a groove 14 substantially at the level of the top of each flange 13. Besides, the groove 14 prevents any shearing by the inner edge of the flange 13 at the moment of bending the rim 82. Figure 6 illustrates a similar embodiment but in which the inside of each socket 5 has a bore with a double conicity 5a, 5b. The conicity 5a can however be a cylinder. As previously, it is advantageous that a groove 14 be formed level with the top of flange 13. It is the conicity 5b which is driven by the end of the tube 1 and acts as a ramp to cause the separation of the end of the socket and its application on the top of the flange 13. As in the case described with reference to Figure 2, it is advantageous that the end 11 of the tubes 1 be slightly narrowed or chamfered, but this is not necessary. WHAT WE CLAIM IS:

1. A heat exchanger comprising a flexible gasket for tubes and end plates of the heat exchanger, the gasket comprising a sheet in which are formed sockets engaged in tube passages of the end plate, said sockets each having a height greater than the thickness of the end plate or than the height of respective flanges of the end plate and being provided in a portion thereof which protrudes from the end plate with an inner rim delimiting a passage of a cross section smaller than that of a respective tube, whereby the rim is widened out and folded back to bear on the end plate or on a flange of said end plate by means of the tube when engaged in the socket.

6. A heat exchanger as claimed in any one

of Claims 1 to 5, wherein each said inner rim delimits, on the side thereof turned towards the tubes, a peripheral ramp converging towards the bore of the socket and against which a respective tube bears when it is engaged in the respective socket.

7. A heat exchanger as claimed in any one of Claims 1 to 6, wherein the inner bore of each socket has a double conicity.

8. A heat exchanger, substantially as hereinbefore described with reference to any one of the embodiments illustrated in the accompanying drawing.