US3805569A

US3805569A - Apparatus for the connection by setting of collectors on water-boxes of heat exchangers

Info

Publication number: US3805569A
Application number: US00242388A
Authority: US
Inventors: A Chartet
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-12-01
Filing date: 1972-04-10
Publication date: 1974-04-23
Anticipated expiration: 1991-04-23

Abstract

Apparatus for the connection by crimping or clamping of collectors on water-boxes of heat exchangers is characterized in that parts of the collector and the water-box are surrounded by an electrically conductive or magnetically responsive metallic belt or strip which is then submitted to at least one high electromagnetic pulse. The device comprises a support on which is placed the water-box, a collar the inner walls of which are shaped correspondingly to the water-box, at least one induction coil connected to a pulse generator and surrounding said collar.

Description

[451 Apr. 23, 1974 Harvey......... Ferguson ABSTRACT 8 Claims, 15 Drawing Figures 9/1971 Turner.........

Primary Examiner-Richard J. l-lerbst Attorney, Agent, oFFi rm-Dvvig ht H. Smiley; lmire and Smiley Apparatus for the connection by crimping or clamping of collectors on water-boxes of heat exchangers is characterized in that parts of the collector and the water-box are surrounded by an electrically conductive 821d 26/14 or magnetically responsive metallic belt or strip which is then submitted to at least one high electromagnetic pulse. The device comprises a support on which is placed the water-box, a collar the inner walls of which are shaped correspondingly to the water-box, at least one 72/56 induction coil connected to a pulse generator and surrounding said collar.

1 wh t/ k l a United States Patent Chartet APPARATUS FOR THE CONNECTION BY SETTING OF COLLECTORS ON WATER-BOXES OF HEAT EXCHANGERS [76] Inventor: Andre Chartet, 2bis Avenue du Chateau, Meudon (Haute-de-Seine), France [22] Filed: Apr. 10, 1972 [21] Appl. No.: 242,388

Related US. Application Data [62] Division of Ser. No. 94,237, Dec. 1, 1970.

[52]. US. [51] Int. [58] Field of Search.........

[56] References Cited UNITED STATES PATENTS 3,431,625 3/1969 Schenk et a1. 3,439,403 4/1969 Lippmann e't 3,555,651 1/1971 Latussek et 3,571,921 3/1971 Pieper........ 3,363,686 '1/196'8 Bifice'r.............

PATENTED APR 2 3 1974 SHEET 2 OF 4 PATENTEDAPRZB mm 3.805 569 sum 3 [1F 4 APPARATUS FOR THE CONNECTION BY SETTING OF COLLECTORS ON WATER-BOXES OF HEAT EXCHANGERS This is a division, of application Ser. No. 94,237, filed Dec. 1, 1970.

BACKGROUND OF THE INVENTION An attempt has been made to connect heat exchanger water-boxes and collectors by crimping or clamping in order to avoid long and expensive welding or brazing operations. Up to now, the results thus obtained have not been satisfactory because crimping or clamping of the water-box on the collector and viceversa of the collector on the water-box causes undue stresses during the crimping or clamping operations on the fragile parts such as said water-boxes and especially said collectors. Besides these stresses frequently are applied in an irregular manner, often causing warping detrimental to the life of the manufactured device.

Another disadvantage is caused by the fact that the known crimping or clamping apparatus do not allow to correctly perform such a work on angles existing on collectors and water-boxes whereby often resulting in a poor tightness.

SUMMARY OF THE INVENTION According to the invention, sections of the collector and the water-box to be connected together are surrounded by a belt of electric conductive metal, and then said belt is submitted for a very short period about a few milliseconds to the action of at least one pulse generated by a high electromagnetic field, operating substantially perpendicularly to the different sections of said belt, whereby obtaining the crimping or clamping of this belt on said collector and water-box.

BRIEF DESCRIPTION OF DRAWINGS cation of the invention on a two fluid tubular exchanger;

FIGS. 7 and 8 are partial sectional views illustration additional characteristics;

FIG. 9 is a partial perspective of a variant of embodiment;

FIG. 10 is a partial enlarged sectional view of a detail of FIG. 9;

FIG. 11 is a partial plan view along line XI-XI of FIG. 10;

FIG. 12 is a diagrammatic perspective of the shapin device according to a variant of embodiment;

FIG. 13 is a diagrammatic cross-sectional view showing the shaping device of FIG. 12 in the working conditions of FIG. I, and

FIG. 14 is a partial cross-sectional view illustrating another variant of embodiment.

DETAIIJED DESCRIPTION OF THE INVENTON FIG. I shows, in accordance with one embodiment of the invention, how the process of the invention is put into practice to ensure the fixing of water-boxes on the collectors of a radiator core. On this figure the core comprises tubes 1 connected to heat dissipators 2, for example fins slipped on the tubes, or corrugated intercalary strips placed between the tubes. The ends of this core are provided with collectors 3 and 4 in communication with the tubes l. Water Boxes 5 and 6 are tightly secured to collectors 3 and 4 respectively.

According to the invention, the material of the tubes 1, dissipators 2, collectors 3, 4'and water-boxes 5, 6 is not taken into consideration. For example the tubes 1 can be made of brass, aluminum or stainless steel; the dissipators 2 can be made of steel, copper or aluminum, the collectors 3 and 4 can also be made of brass, steel, treated or not treated, even made of synthetic material; and it is the same for water-boxes 5, 6. The way the tubes are connected to the collectors and the tubes to the dissipators is not taken into consideration in the embodiment of the invention actually, any usual assembling method put into practice in technics can be applied, such as soft soldering, brazing, adhesively sticking, etc.

In the process of the invention, the core so-to-speak, i.e. the tubes 1, the dissipators 2 and the collectors 3, 4 are assembled; and to connect the collectors to the water-boxes the method is as follows.

A field shaping collar 7 is prepared preferably made of copper with beryllium and the inner wall 7a of said collar is shaped to have a form corresponding in section to the parts of collectors and water-boxes to be joined together. If the the collectors and water boxes are rectangular with slightly rounded angles then the inner wall 7a is made in a corresponding way. If the collector and- /or the water-box shows some recesses or projections then in the same way the wall 7a is shaped to at least approximately follow said recesses or projections.

The field shaping collar 7 is surrounded by at least one winding 8 and as shown on FIG. 2 the ends of the winding or of each winding are connected to a pulse generator for example to the two plates of a capacitor battery 9 respectively. Further, a switching component 10 is provided, for example a fast circuit-breaker which can be composed of an electronic device, said circuitbreaker being mounted in series between the capactor battery 9 and winding 8. To charge the capacitors 9, a power transformer 11 is provided, the primary winding thereof being fed by mains 12.

The unit comprising the fields shaping collar 7 and winding 8 is mounted on a support 13 which delimits a supporting bed 14 on the top of which is put a waterbox, in the present case the box 6, with reference to FIG. 1. This bed is designed to keep the water-box in a correct position in relation with the shaping collar 7.

In the example shown, the shaping collar is provided on wall 7a thereof, with a thin rim 15, for example made of synthetic material such as polytetrafluoroethylene or polyamide, said rim delimiting at the lower section thereof, a flange 15a used as a stop for a belt 16 centered by said rim 15. The belt 16 is made of magnetically responsive, electric conductive material, for example aluminum, copper, brass or steel. This belt has also a similar shape as the collector and water-box to be slipped onto the latter.

From above it is noticed that in the described embodiment, the belt 16 is installed into rim 15, the waterbox 6 is installed and is centered by said belt 16 and kept at a suitable level by bed 14, then the radiator core is installed in such a way that the collector 4 thereof rests on the waterbox 6 while being centered by belt 16.

These operations being performed and in supposing that the capacitor battery 9 has already been charged, only the circuit-breaker 10 has to be turned-off, which causes the discharge of the capacitors into the winding 8 thus generating in collar 7 and belt 16 the induction of eddy currents and a radial field which causes the sudden warping of the belt 16 in the areas not resting on the collector 4 and the water-box 6, thus said belt is set on the collector and the water-box, as shown in 16a, at the upper section of FIG. 1.

In order that the above described crimping or clamping operation will ensure the tightness between the collector and the water-box, many possibilities can be contemplated. For example, as shown in FIG. 3, the waterbox 6a can be made ofa relatively flexible material, for example of elastomere, and provided with a marginal flange 18 on which the belt 16 is set at the same time as on a moulding 19 of collector 4 which can in that case be metallic. If the collector is made of electric conductive metal, this is for example made of brass, aluminum or steel, then it is the collector 4a (FIG. 3a) which can form a belt 16a on the peripheric edge thereof, said belt 16a being then set onto the marginal flange 18 of water-box 6a. The warping of belt 16 by an electromagnetic effect as described above occurring in a very short period of time of about 50 milliseconds, it has been noticed that the metal of the belt, during the warping thereof, was acting like a fluid and that it could be extended in some sections and contracted in some other. Consequently, the marginal flange 18 of the water-box, as shown in FIG. 4 for a collector 6b, can be provided with projects which are wrapped by the belt 16 as shown in 16,.

Also the FIG. 4 shows that it is possible to place, between collector 4 and water-box 6b, a gasket 20 which can be made of soft material or of glue.

As already mentioned, the water-boxes can be made of metal without any prejudice. This is shown on FIG. 5 on which the water-box is designated by 60 while the belt 16a is directly shaped by collector 4a as shown on FIG. 3a.

The invention can be embodied in the same way for other types of exchangers and FIG. 6 illustrates an example in which the exchanger is composed ofa core of tubes Ia contained in an envelope 21, said tubes running into collector-plates 22 which are covered by end flanges 23 forming feeding boxes. A belt 16b, made of conductive metal is then simultaneously used as a connection between the envelope 21, the collector-plate 22 and the end flange 23. From this figure it is noticed that the field causing the warping of belt 16b has for its effect to delimit in the latter, a groove 24 when care is taken to provide the collector plate 22 with a diameter smaller than the one of the envelope 21 and flange 23; this is used as a mark if it becomes necessary to saw said belt 16b to disassemble the unit.

Particularly when the water-box, as the one designated by reference 6d in FIG. 7, is made of material which can be warped even temporarily during the setting operation or when the material of the water-box shows some brittleness, it is then advantageous that the lower surface 25 of the marginal flange 18 thereof delimits a housing 26 the collector 4b is at least partially embedded with also eventually a seal 27. Thus when the belt is warped whereby causing the setting of the unit, the collector 4b cooperates with the water-box to form a very strong hollow girder, whereby preventing any temporary warping of said water-box.

It has been noticed that the belt 16c is thus better applied on all the sections of the water-box and collector that it has to fit on, and the result is that the seal 27 is strongly compressed. This ensures an assembling of a very good holding and a perfect tightness.

FIG. 8 shows a development of FIG. 7 according to which the collector 4b is also embedded in an housing of the water-box 18 and besides, said figure shows that it is sometimes advantageous to also provide a peripheric groove or spaced-out recesses 28 in the lateral edge of marginal flange 18 of the water-box 6e.

As mentioned above, a seal 29 can be placed between the collector and the water-box and, for example, said seal can be shaped as represented in FIG. 8.

At the moment of the warping of belt 16d the latter penetrates into the groove or into housings 28 while getting folded beneath the water-box and collector. This embodiment ensures an extremely intimate joint of the two parts to be connected together, while making rigid the periphery of the belt due to the fact of the warping 16d, that said belt has to sustain in order to fit at least partially on the groove or housings 28.

FIGS. 9 to 11 illustrate a development of the invention providing a very good rigidity of the belt (then designated by 162) when put into place and further causing said belt to exert a permanent resilient pressure on the water-box 6f and on collector 4c. For that purpose the water-box 6f is provided at least at the four angles thereof with projecting ribs 30 the section of which is increasing from top to bottom of the water-box, these ribs presenting for example a rounded outline as shown on FIG. 10. At the moment of the warping sustained by belt l6e through action of the electromagnetic field developed from the discharge current, the two

lateral sides

16, and 16 of the belt l6e are folded above the top of marginal flange 18 of the water-box and under the collector 4c which is, preferably, embedded as in FIGS. 7 and 8.

Because of the presence of ribs 30, the side 16, comes to a stop against said ribs; this increases the elongation to which the side 16, is subjected during the warping thereof.

In that case it is noticed that said side 16, is only submitted to an elongation but no one of the sections thereof is submitted to a contraction. The result is that the metal delimiting the side 16, stays under strain when folded, that makes the water-box be always applied on the top of the collector. Relating to side 16 it has been noticed that the same result could be obtained if the ribs 30 were extended beneath the collector and that anyway a similar result could still be obtained even without extending said ribs. In fact, in that case, and by suitably setting the power of the shaping pulses, said side 16 get folded as shown in FIGS. 10 and 11 forming at the angles of the belt a warped fold 31 which constitutes a kind of rib causing the metal of side 16 to be also kept strained and also rendered more rigid because of the presence of said folds 31.

According to FIGS. 11 to 13, to assemble each col lector 3 to each water-box 5, a belt 16f is utilized and the water-box S is supported by a bed 14 while the belt 16f centered by the water-box and the collector eventually rests on a projected flange 14a of bed 14.

The field shaping collar 7, is made up in the form of a single winding for example made of copper with beryllium having a shape corresponding to the one of belt 16f.

To allow the application of an electrical pulse designed to generate, from the winding formed by the shaping collar 7 electromagnetic forces ensuring the shaping of belt 16f, said single winding 7 is, for example, formed from a strip the ends thereof 32, 33 are fastened up on an insulating core 34 and also on feeding conductors 35 connected to the pulse generator which comprises the capacitors 9, transformer 11 and the electric current line 12.

The collar 7 is advantageously electrically insulated for example it is put into a thin insulating envelope and except for the core 34 to which it is connected, it is freely mounted on the top of flange 14a of bed 14 to be able to become out of shape or distorted at least in some of the sections thereof when it is run through by the discharge current of the capacitors 9.

Accordingly during the warping that it sustains under the influence of the mutual electromagnetic repulsion generated between itself and the belt 16f at the moment of the discharge of capacitors 9, said shaping device tends to become rounded in the linear sections thereof, or presents a large radius of curve, whereby resulting in bringing together the sections thereof having a small radius of curve to the angles of belt 16fand consequently in increasing the setting pressure in those areas where it has been deemed necessary to dispose of a more important force.

The warping of collar 7, can also be controlled and as shown in FIG. 13, support edges 36 or resilient blocks can be designed in some areas of the periphery thereof, which allows to accurately check the forces applied on the belt l6f whereby causing the setting thereof. Thus it is possible as also shown in FIGS. 13 and 14 to fold at l80 the edge 16f, of said belt in order to pinch the turned-down edges of mutual centering 5,, 3, formed by the water-box 5 and the collector 3 respectively while the other edge l6f is folded at right angle on a peripheral support section of the water-box 5, ensuring a great strength to the finished assembling.

FIG. 14 illustrates an embodiment in which the shaping collar comprises several superposed single windings 7 7,,,,..7,, which are respectively connected to separate generators or to separate generators or to separate outputs of a same generator whereby the electrical pulse applied to each single winding can be adjusted. Through that way it is moreover possible to vary the forces applied to the different zones of the belt 16f, for example a more important force can be applied from single winding 7 to cause the folding of edge 16f only from belt 7 to avoid any warping of the turned-down edges of the collector and water-box, while a strength of intermediary importance can be generated from single winding 7, to ensure the folding of edge l6f The invention is not rectricted to the embodiments shown and described in detail for various modifications thereof can moreover be applied to it without departing the scope of the invention. Particularly, the rim 15 can be removed when the belt is directly formed by the collector. Also the capacitor working in relaxation can be replaced by various pulse generators as by electronic generators rendering eventually possible to successively apply several pulses to complete shaping of belt 16.

I claim:

1. Apparatus for securing together two abutting parts by an electro-magnetically responsive and deformable clamping strip surrounding and spanning the abutting portions of such parts, comprising:

eleetro-magnetic force producing collar means to be positioned in surrounding relation to said strip and abutting part portions; said collar means being resiliently distortable from a rest configuration conforming with said strip to a distorted energized configuration;

a pulse power generator, and

means electrically connecting said generator to said collar means to energize said collar means to cause the latter to move from its rest configuration to its energized configuration such that unequal forces are applied about the periphery of said strip to magneto-form said strip into clamping relation with said abutting part portions.

2. Apparatus according to claim 1 wherein said collar means has spaced end portions, and said connecting means is electrically connected to both said ends.

3. Apparatus according to claim 2 wherein said collar means comprises a plurality of independent collars in juxtaposed relation and each independently connected by said connecting means to said generator.

4. Apparatus according to claim 3 wherein said generator has a plurality of pairs of power outputs, said connecting means connecting each pair of outputs to one only of said collars, whereby each collar may be energized with a selectively different power.

5. Apparatus according to claim 4 comprising means for adjusting the resiliency of at least a portion of at least one collar.

6. Apparatus according to claim 5 wherein said collar is rectangular in configuration said rest and said adjusting means comprises resilient pressure members engaging the elongate portions of said collar.

7. Apparatus according to claim 1 comprising means for adjusting the resiliency of said collar means.

8. Apparatus according to claim 7 wherein said collar means is rectangular in configuration said rest and said adjusting means comprises resilient pressure members engaging the elongate portions of said collar means.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. I 3,805, DATED 3 April 23, 1974 INVENTOR(S) Andre Ghartet It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Address: Asnieres France Signed and fieaicd this thirtieth Day of September 1975 [SEAL] ANGUS RUTH C. MASON C. MARSHALL DANN Arresting Officer (mnmissiuncr nj'ialenls and Trademark-x

Claims

1. Apparatus for securing together two abutting parts by an electro-magnetically responsive and deformable clamping strip surrounding and spanning the abutting portions of such parts, comprising: electro-magnetic force producing collar means to be positioned in surrounding relation to said strip and abutting part portions; said collar means being resiliently distortable from a rest configuration conforming with said strip to a distorted energized configuration; a pulse power generator, and means electrically connecting said generator to said collar means to energize said collar means to cause the latter to move from its rest configuration to its energized configuration such that unequal forces are applied about the periphery of said strip to magneto-form said strip into clamping relation with said abutting part portions.