FR2644569A1 - HEAT EXCHANGER, PARTICULARLY FOR MOTOR VEHICLES, AND METHOD FOR ASSEMBLING SAME - Google Patents

Abstract

The heat exchanger comprises a header plate 10 provided with a plurality of openings formed in projecting tubular end pieces 16 each connected to the header plate by an arcuate segment 20 as well as a retaining plate 34 having vias. of the same distribution as the end pieces 16 and through which the tubes of a heat exchange bundle are introduced, these tubes being at least partially deformable so as to each flare out on the segment 20 of their respective end piece.

Description

Heat exchanger, in particular for motor vehicles

  The invention relates to a heat exchanger which can be used in particular in motor vehicles, as well

  than a process for its assembly.

  It relates more precisely to a heat exchanger, of the type comprising a collecting plate, or plate with holes, provided with a plurality of openings arranged to receive respectively a plurality of tubes of a heat exchange bundle, of a sealingly determined by a plurality of grooves receiving the ends of

said plurality of tubes.

  A heat exchanger of this type is known from French patent application No. 86-12707, published under No. 2,587,100. In this known heat exchanger, the

  collector plate is made of plastic and the

  half of the tubes are force-fitted into grooves

  annulars formed in collars of the collecting plate

  trice. It is also planned, after the operation of sinking the tubes, to introduce a widening sleeve to radially widen both the plastic of the collars and the end of the tubes, which leads to an operation

  extra during assembly.

  Another heat exchanger of this type is known from French patent application No. 82-14513, published under

No. 2,512,191.

  In this known heat exchanger, the ends of the tubes are force-fitted into annular grooves, previously filled with glue, which are formed between

  two plates assembled one on the other.

  All of these known heat exchangers have the particular disadvantage of presenting risks of leakage at the level of the connection of the tubes with the collector plate. In addition, they do not allow easy assembly in one

single operation.

  The object of the invention is in particular to remedy the drawbacks

above.

  It proposes, for this purpose, a heat exchanger, of the type comprising a collecting plate provided with a plurality of openings arranged to receive respectively a plurality of tubes of a heat exchange bundle, in a determined sealed manner by a plurality of grooves receiving, with deformation, the ends of said

plurality of tubes.

  According to an essential characteristic of the invention, said openings are formed in projecting tubular ends each connected to the collector plate -by a segment in an arc of a circle, said tubes being at least partially deformable so as to each flare on the segment of their respective end piece and there is provided a retaining plate having crossings of the same distribution as said end pieces, through which pass said tubes, each crossing having a convex outline, the rear part of which is opposite the homologous segment delimits therewith a space when the

  holding plate is supported on the collecting plate

  trice. Therefore, the tubes of the bundle can be force-fitted, in a single operation, into the defined grooves

  between the tubular ends and the corresponding bushings

  the tubes flaring each on the segment of their

  respective nozzle during this driving-in operation.

  The sealed assembly of the tubes is thus carried out on the

  collector plate, in a single operation.

  In a preferred embodiment of the invention,

  said rear part of the outline of the crossing

  che on a rear face of the retaining plate which is capable of coming to bear on the collector plate, and said rear part is connected with an anterior part opening onto an anterior face of the plate

holding.

  According to an advantageous characteristic, said post-

  lower and said front part are connected at a narrow intermediate part, against which the tubular end piece comes into contact before introduction of the tube

in the crossing.

  Therefore, during the force fitting of the tube into the groove defined between the tubular end piece and the corresponding bushing, the end of the tube will be tightly sealed.

  between the tubular end piece and the bushing.

  Advantageously, said anterior part of the contour of

  the crossing widens towards the front side

  support plate, which facilitates

  the introduction of the tube into the crossing.

  According to another characteristic of the invention, each tubular end piece has an intermediate external wall, with parallel generators, one end of which is connected to one face of the manifold by said segment in an arc of a circle and the other end of which is free and goes in slimming

  to facilitate the introduction of the corresponding tube.

  In a preferred embodiment of the invention, said plurality of end pieces is formed in one piece with the collector plate in an elastically deformable material, for example plastic, allowing a radial deformation of the tubular extensions during

  the introduction of the tubes into the corresponding bushings

  dantes. According to another aspect, the invention relates to a method of assembling such a heat exchanger, according to which

  - the support plate is supported on the collection plate

  trice, so that said plurality of tips passes through said plurality of bushings, and is pressed

  then the tubes in the plurality of grooves thus obtained

  naked, which allows them to flare.

  In the following description, given as an example,

  reference is made to the appended drawing, in which: FIG. 1 is a partial sectional view of a header plate of a heat exchanger according to the invention; - Figure 2 is a partial sectional view of a holding plate of a heat exchanger according to the invention; - Figure 3 is a partial sectional view of a heat exchanger comprising a header plate according to Figure 1 and a holding plate according to Figure 2, held in abutment against one another; - Figure 4 is a view similar to that of Figure 3 also showing a heat exchange tube at the start of the introduction operation; and - Figure 5 is a view similar to that of Figure 4 also showing the end of the tube at the end of introduction. We first refer to Figure 1 which shows a

  collector plate 10, for example formed from plastics material

  tick, comprising a posterior face 12 and an anterior face 14 generally parallel to one another. The collector plate 10 is formed from a single piece molding with a plurality of protruding tubular ends 16, only one of which is shown in FIG. 1. Each tubular end piece has, in the example, a symmetry

  of revolution around an axis XX extending perpendicularly

  rement on the faces 12 and 14 of the plate 10. The tubular end piece

  the space 16 has an intermediate external wall 18 with generatrix parallel to the axis XX, this wall 18 connecting to the front face 14 by a segment 20 in

  arc. This segment 20 is connected to the front face

  lower 14 of the collector plate by a shoulder 22 formed back from the face 14. The shoulder 22 has, in the example, a circular contour and has a height h which is calculated as a function of

the thickness of the bundle tubes.

  The other end of the wall 18 is connected to a frustoconical wall 23 which tapers and is connected to an annular edge 24 situated at the free end of

end piece 16.

  Each endpiece 16 internally defines an opening 26 limited by a first cylindrical wall 28 which, at one of its ends, opens onto the rear face 12 of the plate 10 and which, at its other end, opens onto an annular shoulder 30, located substantially at

  level of connection of wall 18 and wall 23.

  The opening 26 is limited, beyond the shoulder 30, by a second cylindrical wall 32, of smaller diameter than the wall 28, and opening onto the annular edge 24. The opening 26 is thus narrower in the region of the free end of the nozzle, which allows in particular

to strengthen this tip.

  Referring now to Figure 2 which shows a holding plate 34, also made of plastic, having a rear face 36 and an opposite face 38. This plate is formed in one piece with a

  plurality of collars 40 each having a cylindrical wall

  drique 42, in the example with a circular section, which is connected on the one hand to the front wall 38 and, on the other hand, to a front wall 44. The collars 40 each define a bushing 46, the plurality of bushings 46 having the same distribution as the tubular ends

  16 of the collecting plate 10 of FIG. 1.

  Each bushing 46 has a shape of revolution centered on an axis YY and has a convex contour comprising a rear part 48 suitable for being situated opposite the segment 20 when, as will be seen below, the retaining plate 34 is brought into abutment against the plate

collector 10.

  The rear part 48 of the contour of the bushing 46 opens onto the rear face 36 of the retaining plate and it is connected with a front part 50 opening out.

  on the front face 44 of the collar of the hand plate-

  yours. The posterior part 48 and the anterior part 50 have

  both form an arc of a circle and they are connected

  tooth at a narrow intermediate portion 52, of annular shape, in the region where the bushing 46 has the smallest diameter. This diameter is substantially equal to the external diameter of the wall 18 of the endpiece 16 (Figure 1) so that this endpiece can come into contact. with the intermediate part 52 when the

  plates 10 and 34 are supported one on the other.

  The front part 50 widens in the direction of the front face 44 of the collar of the retaining plate to facilitate, as will be seen below, the introduction

of a tube in the crossing.

  We will now describe the assembly of a heat exchanger

  according to the invention with reference to Figures 3 to 5.

  As shown in FIG. 3, the retaining plate 34 is held in abutment by its rear face 36 against the front face 14 of the collector plate 10, in such a way that the end pieces 16 are introduced into the corresponding bushings 46. In this position , each end piece 16 comes into contact, through its external face 18, with the narrow intermediate part 52 of the corresponding bushing 46.

  Thus, each tubular endpiece 16 and its corresponding crossing

  dante 46 together define a first annular space 54 which widens in the direction of the front face 44 of the collar to facilitate, as will be seen below, the introduction of the end of a tube. The end piece 16 and the crossing 46 also define a second space 56 which is delimited by the rear part 48 of the outline

  of the bushing 46 and by the segment 20 of the tubular end piece

area 16.

  As shown in Figure 4, the header plate 10 and the holding plate 34 are intended to receive a plurality of tubes 58 (only one of which is shown in Figure 4) forming part of a heat exchange bundle. These tubes have the same distribution as the end pieces 16 and the bushings 46. Each tube 58, which is made of deformable metal, for example aluminum, comprises a cylindrical body 60 which is connected by a part

  frustoconical 62 at an enlarged cylindrical end 64.

  As shown in FIG. 4, this end 64 is presented in the common axis of the end piece and of the bushing, so that the front edge 66 of the end 64 is introduced into the annular space 54. We exercise then an axial force F so that the edge 66 of the end 64 penetrates

  in the groove delimited between the nozzle and the transfer.

  During this introduction, the wall 18 of the end piece 16 deforms radially inwards (FIG. 5) and the wall of the tube is thus tightly clamped between the rear part 48 of the contour of the bushing 46 and the segment 20 of the tubular end piece i6. The front edge 66 of the end 64 thus gradually penetrates into the space 56 while approaching the shoulder 22, which progressively causes the flaring of the end 64. At the end of introduction (FIG. 5), we notes that the end 64 has a flared shape with an arcuate outline, this flared shape being imposed by the outline of the crossing 46 which forms a template and by

  the tubular wall of the end piece 16 which is applied elastically

  only in the direction of the template, taking into account the material used. The collecting plate 10 can be attached to the opening of a housing to form a water box or be an integral part of a so-called "tubular" water box in which the collecting plate is molded at the same time as the walls of said box forming a single piece. In the position shown in Figure 5, we see that

  the end of the tube is tightly connected to the whole

  ble constituted by the collector plate and the retaining plate and a fluid can thus flow successively through the opening 26 and in the tube 58 or in the

reverse.

  The invention applies to heat exchangers, in particular

  for motor vehicles, for example radiators

  heating or cooling, or even evaporators

  ters for air conditioning installation.

  Although the invention has been described with particular reference to

  linked to tubes of circular cylindrical section, it can also be applied to other cylindrical tubes,

in particular with oval section.

Claims (10)

Claims   1. - Heat exchanger, of the type comprising a collecting plate (10) provided with a plurality of openings (26) arranged to receive respectively a plurality of tubes (58) of a heat exchange bundle, a sealing manner determined by a plurality of grooves receiving, with deformation, the ends of said plurality of tubes, characterized in that said openings (26) are formed in projecting tubular end pieces (16) each connected to the collector plate (10) by a segment   in an arc (20), said jubes being at least partial-   Lely deformable to flare each on the segment of their respective end piece and in that there is provided a holding plate (34) having bushings (46) of the same distribution as said end pieces (16), through which pass said tubes (58), each bushing (46) having a convex contour, the posterior part (48) of which is located opposite the segment (20) delimits therewith a space (56) when the retaining plate (34) is   resting on the collecting plate (10).   2. - Heat exchanger according to claim 1, character-   laughed in that said rear part (48) of the contour of the bushing (46) opens onto a rear face (36) of the retaining plate (34) which is capable of coming to bear on the collector plate (10) and what said   rear part (48) is connected with an anterior part   upper (50) opening onto an anterior face (44) of the retaining plate.   3. - Heat exchanger according to claim 2, character-   laughed in that said rear part (48) and said front part (50) are connected at a narrow intermediate part (52) against which the tubular end piece (16) comes into contact before introduction of the tube (58 ) in the crossing.   4. - Heat exchanger according to claim 3, character-   laughed in that said front part (50) widens in the direction of the front face (44) of the retaining plate to facilitate the introduction of the tube into the crossing (46).   5. - Heat exchanger according to any one of the res-   dications 2 to 4, characterized in that the retaining plate (34) has a plurality of collars (40) surrounding   respectively said plurality of bushings (46).   6. - Heat exchanger according to any one of the res-   dications 1 to 5, characterized in that each tubular end piece   the space (16) has an intermediate external wall (18), with parallel generators, one end of which is connected to one face (14) of the manifold by said segment in an arc (20) and the other end of which is connected to a thinned wall (23), on the side of the free end of   the nozzle to facilitate the introduction of the tube (58).   7. - Heat exchanger according to claim 6, character-   risé in that the segment in an arc (20) is connected to said face (14) of the collector plate (10) by a shoulder (22) formed recessed with respect to said face.   8. - Heat exchanger according to one of claims   6 and 7, characterized in that the opening (26) formed in each tubular endpiece (16) is narrower   (32) in the region of the free end of said tip.   9. - Heat exchanger according to one of claims   6 to 8, characterized in that said plurality of end pieces (16) is formed in one piece with the collecting plate (10) in an elastically deformable material, for example plastic, allowing a radial deformation of the tubular extensions ( 16) during the introduction of the tubes (58) into the corresponding bushings and then allowing the tight clamping of the tubes between   bushings and tubular fittings.   10. - Method of assembling a heat exchanger according to   one of claims 1 to 9, characterized in that   the support plate (34) is supported on the collector plate (10) so that said plurality of end pieces (16) are introduced respectively through said plurality of bushings (46) and in that one then forcefully introduces the tubes (58) into the grooves (54,56) thus defined.