MXPA96005319A

MXPA96005319A - Heat exchanger with sectionally pipe or oblonga and mont procedure

Info

Publication number: MXPA96005319A
Application number: MXPA/A/1996/005319A
Authority: MX
Inventors: Potier Michel
Original assignee: Valeo Thermique Moteur
Priority date: 1995-11-02
Filing date: 1996-11-01
Publication date: 1997-08-01

Abstract

The present invention relates to a heat exchanger, characterized in that it comprises a tube bundle and a manifold, the tube bundle has a multiplicity of tubes and at least one set of fins molded to the tubes, the manifold has a manifold plate formed with a plurality of holes, and a compressible seal each tube having a tube body and a sealing portion of the tube body and extending through the corresponding hole between the plurality of holes, a collar portion or sleeve of the tube. sealing gasket interposed between each tube sealing portion and corresponding to one of the holes between the plurality of holes, each tube sealing portion having a cross section defined by a first major axis and a first minor axis, and each body of tube having a cross section defined by a second major axis and a second minor axis, wherein the first and second of the major axes have length is equal, each tube sealing portion having a broadening portion, the length of the first minor axis being greater than that of the second axis.

Description

COLOR INTERCIMMITTER WITH OVFlLñDñ OR OBLONGA SECTION PIPES AND ASSEMBLY PROCEDURE The invention relates to a heat exchanger, in particular for motor vehicles, and to the method for its assembly. More particularly, it relates to a heat exchanger of the type comprising a multiplicity of tubes passing through fins and having ends inserted into the holes of a collector plate, with the interposition of a compressible seal, forming collars surrounding the ends of the latter. the tubes; and the ends of the tubes have an oval or oblong section, defined by a major axis and a minor axis. Heat intercarriers of this type are also referred to as "mechanical assembly heat intercarriers" because the ends of the tubes are then widened to ensure compression of the joint collars; what guarantees the tightness of the union of the tubes with the collector plate. Heat exchangers of that type are already known; and in them the ends of the tubes are deformed, before the assembly of the same in the collector plate, since these present a section different from that of the tubes. For this, it is known to round the section of each end of the tube, as taught in document FR-R-2 474 674, or to make it oval, as taught in European patent 0 387 678. However, the modification of each tube, at its end, has the disadvantage of hammering the metal constituting the tube and carrying out, possibly, weakening of the wall of the tube during the subsequent expansion operation to allow mechanical assembly. Furthermore, the change of section of the tube, between the part of the tube that carries the fins and the end of the tube, implies that a portion of the tube can not carry fins, or that said fins must be deformed, and this renders them ineffective. The purpose of the invention is mainly to overcome the aforementioned drawbacks. It proposes, consequently, a heat exchanger of the type defined in the introduction, in which the major axis of the end of the tube is equal to the major axis of the tube; while the minor axis of the end of the tube is greater than the minor axis of the tube, after a widening of the tube during the assembly of the heat exchanger. In this way, the end of the tube is not shaped before assembly; that is, before the assembly of the collector plate. This results in that, during the introduction of the ends of the tubes into the holes of the collector plate, the ends of the tubes have the same section as the latter. The fact that the tube is not formed before the assembly of the collector plate, the width of the tube, devoid of fins, can be made very weak, which increases the useful surface of the set of tubes. The mechanical assembly is obtained only by means of a widening of the tube in the direction of the minor axis; said widening operating on the walls of the greater radius of the end of the tube, which avoids the problems of beating, susceptible to be generated by the processes of the prior art. Due to this fact, the deformation of the end of the tube, which is the result of the widening, takes place in a limited area, which makes it possible to suppress the defects that are normally encountered and, in addition, to use metal alloys that have higher mechanical characteristics. According to another characteristic of the invention, the end section of the tube, before assembly, is equal to the section of the tube. In other words, the end section of the tube is not shaped before assembly. Advantageously, the compression of the seal collar in the direction of the major axis takes place before the introduction of the end of the tube, while the compression of the seal collar in the direction of the minor axis is the result of the widening of the tube. during the assembly of the heat intercooling device. According to another feature of the invention, the greater e of the tube is greater than the larger inner axis of the joint collar, before compression; while the minor axis of the tube is lower than the inner minor axis of the joint collar, before compression. In another aspect, the invention relates to a method for mounting a heat exchanger of the type defined above. The assembly method of this invention essentially comprises the following operations: a) providing a multiplicity of tubes passing through fins and each of which has an oval or elongated section, defined by a major axis and a minor axis, as well as a free end; b) providing a collector plate, provided with holes of oval or elongated section, and equipped with a compressible seal, which forms suitable collars for coupling, respectively, through the holes; c) compress each joint collar in the direction of its major axis; d) insert the respective ends of the tubes into the holes of the collector plate and the sealing rings, kept compressed in the direction of the major axis; and e) subjecting the ends of the tubes to widening in the direction of their minor axis, to ensure compression of the joint collar in that direction. According to another feature of the invention, in step a), the end section of each tube, before assembly, is identical to the section of the tube. Advantageously, the operation c) of compressing the collar of the joint in the direction of a major axis, is effected by means of a punch having a free end, suitable to be introduced at the corresponding end of the tube, without deforming said extreme. According to yet another characteristic of the invention, the operation d) of introducing the ends of the tubes is effected by displacement of the collector plate by means of a pressurizer. The invention also provides that the spreading operation e) is effected by means of a punch that enlarges the end of the tube in the direction of the minor axis. In the following description, which is given solely for illustrative purposes, reference is made to the appended drawings, in which: Figure 1 is a partial sectional view of a heat intercarriage according to the invention already assembled. Figure 2 is a view of the end of a tube of the heat exchanger of Figure 1. Figure 3 is a sectional view, taken along line III-III of Figure 1.

Figure 4 is a cross-sectional view of the collector plate and the seal of the heat exchanger of Figure 1, prior to assembly. Figure 5 is a sectional view, taken along the line VV of Figure 4; Figure 6 is a view similar to Figure 4, taken in the course of a process step, in which a punch is inserted through from each hole in the collector plate and is entangled in a tube of the set of tubes. Figure 7 is a view of the end of a tube, before assembly. Figure 8 is a sectional view, similar to Figure 6, taken in the course of a further stage of the process, in which the ends of the tubes have been introduced into the holes of the collector plate. Figure 9 is a sectional view, taken along line IX-IX of Figure 8. Figure 10 is a sectional view, taken along the line X-X of Figure 8; and Figure 11 is a sectional view, similar to Figure 10, showing the procedure of widening the end of the tube. The heat exchanger shown in Figures 1 and 3 comprises a bundle or assembly 10 formed by a multiplicity of tubes 12, of oval section, which are arranged parallel to each other and in a single row. The tubes 12 pass through a multiplicity of fins 14, constituted by metal plates substantially rectangular, perpendicular to each other. Each tube 12 comprises a free end 16, mechanically mounted in a collector plate 18, also called "collector". Before mounting the tubes and the collector plate, the ends 16 of the tubes have exactly the same section as the tubes, in the part that normally receives the fins 14. The collector plate 18 comprises a core 20, of generally rectangular shape, which it delimits a multiplicity of holes 22, of oval section, suitable to receive the ends 16 of the tubes. Each hole 22 is surrounded by a collar 24, directed to the side of the fins 14. The core 20 is extended by means of a peripheral channel 26 that delimits a neck and is terminated by a peripheral flange 28 forming folding legs. The collector plate 18 receives a compressible seal 30 comprising a core 32 which is applied to the core 20 of the collector plate. Said web 32 is connected to a multiplicity of sleeves 34 each of which is inserted in a hole 22 to guarantee tightness between the end 16 of a tube and the sleeve or collar 34 that is inserted in each hole 22, to guarantee the tightness between the end 16 of a tube and the corresponding collar 24. In addition, the core 32 forms on its periphery a flange 36 arranged in the channel 26, and suitable for guaranteeing tightness with a collecting box (not shown) in which the peripheral rim 28 is upset. As seen in FIG. 2, the end section 16 of the tube has a substantially oval shape, characterized by a major axis T'l (after assembly) and a minor axis t'2 (after assembly). The major axis T'l is equal to the major axis TI (figure 7) of section 16 of the end of the tube before assembly; this section being identical to that of the tubes in their normal part. Conversely, the minor axis T'2 is greater than the minor axis T2 before assembly (FIG. 7), because it is subjected to a first radial widening. In said first widening, a second localized radial widening is added, which results in the presence of two protrusions 38, as can be seen in figures 1, 2 and 3, and which allow to limit the displacement of the tube with respect to the collector. The assembly of the heat intercooling device of FIGS. 1 and 3 will now be described with reference to FIGS. 4 to 11. In FIG. 4, the collector plate 18 and its seal are seen before assembly. Before mounting, each collar or sleeve 34 of the joint 30 is in the uncompressed state. Present an internal major axis .11 (figure 5) that is lower than the major axis TI of the tube end 16 (figure 7). further, has a minor axis 32 (FIG. 5) that is greater than the minor axis T2 of the end of the tube (FIG. 7). As shown in Figure 6, the collecting plate 18, equipped with its gasket 30, is placed in the vicinity of the tube assembly 10, in such a way that the holes 22 are in relation to the ends 16 of the tubes. A multiplicity of punches 40 is then introduced in the direction of the arrow Fl, each of which has a body 42 of oval section, provided with an end 44, suitable to be inserted into the end 16 of a tube 12, without deform rlo. The punch 42 is designed to exert a compression on the inside of the collar or sleeve 34, only in the direction of its major axis, so that said major axis passes from the value DI (figure 5) to a value 3'1 (figure 6). ) corresponding to the TI value of the major axis of the tube, to facilitate the introduction of the tube in accordance with a pre-stressing procedure of the joint. However, said pre-effort of the joints is made only in the direction of its major axis. Indeed, it is not necessary to exert a previous effort in the direction of the minor axis, since the minor axis J2 of the compressible collar (Figure 5) is greater than or equal to the minor axis T2 of the end 16 of the tube. For this, a press 46 is used, as shown in FIG. 8, which moves in the direction of the arrow F2 and which rests on the core 32 of the compressible joint 30. The displacement of the press 46 causes displacement of the collection plate assembly 18-compressible joint 30, even though each end 16 is inserted in the collar 30, previously compressed in the direction of its major axis. As seen in Figures 8, 9 and 10, the end 16 of the tube then protrudes from the compressible joint 30. In this state, each of the sleeves or collars 34 is compressed in the direction of its major axis, but not in the direction of its minor axis. Then the widening of each of the ends 16 is carried out by means of a punch 48, displaced in the direction of the arrow F3 (figure 11), which comprises a body 50, terminated at one end 52, which is inserted in the end 16 of the tube to deform it essentially in the direction of the minor axis, and to form the two protuberances 38 (Fig. 1 to 3). Said widening allows to exert a compression on the collar 34 in the direction of its minor axis. It suffices then to move the punch 48 in a direction opposite that of the arrow F3, to obtain a heat exchanger such as that shown in FIGS. 1 and 3. It will be understood that, according to the invention, the end of each tube it is formed only after assembly, and that said shaping is obtained only by a widening in the direction of the minor axis. From this it results that the broadening is carried on the faces of the greater radius of the section of the tube, which eliminates the problems of beating or hammering. The invention is particularly applicable to the production of heat exchangers for motor vehicles, in particular for cooling or heating radiators.

Claims

NOVELTY OF THE INVENTION CLAIMS l.- Heat interchanger of the type comprising a multiplicity of tubes (12) passing through fins (14) and having ends (16) inserted in the holes (22) of a collecting plate (18), with the interposition of a joint compressible seal (30) forming sleeves (34) that surround the ends (16) of the tubes, and wherein the end of each tube has an oval or oblong section, defined by a major axis (TI) and a minor axis ( T2) characterized in that the major axis (T'l) of the end (16) of the tube (12) is equal to the major axis (TI) of the tube; while the minor axis (T'2) of the end (16) of the tube (12) is greater than the minor axis (T2) of the tube as a consequence of a widening of the tube during the assembly of the heat exchanger.
2. Heat exchanger according to claim 1, further characterized in that the end section (16) of the tube (12), before assembly, is equal to the section of the tube (12).
3. Heat interconnector according to any of claims 1 and 2, further characterized in that the compression of the sleeve or collar (34) of the seal in the direction of the major axis (DI) is carried out before the introduction of the end (16) of tube (12), while compression of the collar (34) of the seal (30) in the direction of the minor axis (D2) results in the widening of the tube (12) during assembly of the exchanger
4. Heat intercalator according to any of claims 1 to 3, further characterized in that the major axis (TI) of the tube is greater than the major axis of the interior (DI) of the sleeve (34) of the joint (30) before compression; and the minor axis (T2) of the tube (12) is lower than the minor axis of the interior (D2) of the sleeve (34) of the joint, before compression.
5. Method of mounting a heat exchanger according to any of claims 1 to 4, characterized in that it comprises the following operations: a) provide a multiplicity of tubes (12) passing through fins (14); each of which has an oval or elongated section, defined by a major axis (TI) and a minor axis (T2), as well as by a free end (16); b) providing a collector plate (18), provided with holes (22), of oval or elongated section, and equipped with a compressible seal (30), which forms sleeves (34) suitable for coupling, respectively, through the holes (22); c) compressing each collar (34) of the joint (30) in the direction of its major axis (DI); d) inserting the respective ends (16) of the tubes (12) into the holes (22) of the collector plate (18) and the collars (34) of the sealing joint (30), which are kept compressed in the direction of its major axis; and e) subjecting the ends (16) of the ports (12) to a widening in the direction of their minor axis, to guarantee the compression of the collar (34) of the joint in that direction.
6. Method according to claim 5, characterized in that in operation (a) the end section (16) of each tube (12), an + ee of the assembly, is identical to that of the tube (12).
7. Method according to claims 5 and 6, further characterized in that the compression operation (c) of the collar (34) of the seal (30) in the direction of its major axis is effected by means of a punch (40). ) having a free end (44) suitable for entering the end (16) of the corresponding tube (12), without deforming it.
8. Method according to any of claims 5 to 7, further characterized in that the operation (d) of introducing the ends (16) of the tubes (12) is effected by displacement of the collector plate (18) by means of a pressure (46).
9. Method according to any of claims 5 to 8, further characterized in that the spreading operation (e) is performed by means of a punch (48) that enlarges the end (16) of the tube (12) in the direction of the minor ee.