JP2007506931A - Curved heat exchanger and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a heat exchanger comprising a bundle of tubes (14) having a longitudinal axis (15) and at least one header (18) (20) into which the tubes open. According to the invention, the header (18) (20) has at least one curved area (CI) (CE). In a preferred embodiment of the invention, the longitudinal axes (15) of the tubes (14) are parallel to each other. The invention is particularly suitable for automotive heat exchangers.

Description

  The present invention relates to the field of automotive heat exchangers.

  In particular, the present invention relates to a heat exchanger comprising a core made of a tube having a longitudinal axis and at least one header into which the tube in the core opens.

  This type of heat exchanger is used in many scenes where heat is exchanged between different types of fluids (gas, liquid, and multiphase fluids). Such a heat exchanger is used to configure, for example, an automobile engine cooling radiator, a cabin heating radiator, an oil cooling radiator, an air conditioning condenser, an air conditioning evaporator, and the like.

  Most commonly, a secondary heat exchange surface is coupled to the core tube. In a brazed heat exchanger, such an exchange surface usually consists of a corrugated intermediate placed between two adjacent tubes in the core.

  The best known heat exchangers are generally flat in shape, manufactured by a flat assembly of various parts.

  However, in modern automobiles, space for various heat exchangers is increasingly limited. Furthermore, in modern automotive designs, conventional flat heat exchangers are not necessarily suitable for the automotive environment.

  It has already been proposed to produce a curved brazed heat exchanger so that this heat exchanger is adapted to the automotive environment.

  However, in all currently known solutions, such brazed heat exchangers are curved in the direction of the tube.

  Examples of curved heat exchangers are described in Patent Documents 1 to 4, for example.

  In these known solutions, the tube is bent in the direction of the tube, so that the tube itself is bent, but the header remains a normal straight line. These known solutions can be applied to various brazed heat exchangers where the heat exchange surfaces are flat fins or corrugated intermediates.

However, these known solutions are not suitable for certain configurations, and in particular we want to obtain a vertical flow heat exchanger, ie a heat exchanger in which the header is almost horizontal but the tubes are vertical. In case it is not suitable.
JP 2000-097579 A JP 08-327271 A European Publication No. 09627212 U.S. Pat. No. 4,443,921

  One object of the present invention is to overcome the aforementioned drawbacks.

  In particular, the present invention proposes a heat exchanger of the type described above that is curved in a manner different from the known methods, corresponding to the various shapes of automobiles.

  For this purpose, the invention provides that the header has at least one curved region, preferably each header is composed of a plurality of parts, each curved with approximately the same radius or radius of curvature. A heat exchanger of the type defined in the introductory part of the description is proposed.

  Therefore, compared to known solutions, the tube is not deformed because it is curved in the direction of the header.

  For this reason, it becomes a curved heat exchanger adaptable to various structures, especially the structure which a fluid flows into the vertical tube arrange | positioned between horizontal headers. Therefore, this header has a curved shape particularly suitable for an automobile having a curved front portion.

  In a preferred embodiment of the invention, the longitudinal axes of the tubes are parallel to each other.

  The present invention is preferably applied to brazed heat exchangers, but can also be applied to other types of heat exchangers, particularly mechanically assembled heat exchangers.

  Since the header is curved, each part of the header is subjected to different deformations.

  For this reason, it is advantageous for each header to have at least one side wall, which side wall has a deformation region that can be deformed by compression or expansion. Deformation due to compression appears as material shrinkage, and deformation due to elongation appears as side wall material elongation.

  The present invention can be applied to various types of headers.

  Therefore, in the first embodiment, each header has a U-shaped cross section having a bottom wall having a hole into which a tube can be fitted, and two side walls attached to the bottom wall, and preferably a deformation region. Is formed on at least one of the side walls.

  In this type of header, one of the side walls, called the “inner wall” or “concave wall”, is compressed during bending. In this case, it is advantageous to provide a deformation area by compression of the inner wall. Such a deformation region due to compression can be provided in a particularly concave shape.

  Similarly, in U-shaped headers of the type described above, one of the side walls, called “outer wall” or “convex wall”, extends when bent. In this case, it is advantageous if the deformation region is a deformation region due to expansion. The deformation region due to such extension can be, for example, a bellows shape.

  In order to further facilitate the deformation of the U-shaped header, it is advantageous to provide a deformation area between the holes in the bottom wall that fit the tube. As a result, the region surrounding the tube fitting hole is not affected during bending.

  The invention can also be applied to other types of headers, in particular headers formed by a series of end plates that receive tubes.

  French Patent Application No. 0117033 (Publication No. 2834336) discloses a heat exchanger in which each end of a tube is inserted into an end plate provided with two opposing perforated bosses. Each header is formed by an assembly of end plates that are aligned and joined together, usually by brazing.

  In this case, the deformation region is formed in a boss that forms the side wall.

  The present invention is particularly applicable to a heat exchanger in which corrugated intermediate elements having substantially straight portions alternately with bent portions are arranged between tubes.

  According to the present invention, the bent portion absorbs deformation caused by the curvature of the core. The bent portion is usually formed in an arc shape having a predetermined initial radius, and the radius of the bent portion is changed when the heat exchanger is bent. This change appears as a decrease in the radius of the inner or concave surface or an increase in the radius of the outer or convex surface.

  In another aspect, the present invention relates to a method of manufacturing a heat exchanger as described above comprising a tube core and at least one header and having a generally flat configuration, the method comprising an act of bending the header. .

The method of the present invention comprises:
a) assembling the tube core and header to form a heat exchanger having a generally flat configuration;
b) brazing the heat exchanger thus assembled flatly to form a brazed heat exchanger;
c) gradually curling the brazed heat exchanger to curve the header so that the core tubes remain substantially parallel to each other.

  Therefore, the bending is first performed with a brazed flat heat exchanger. It is necessary to bend gradually and bend the header. The core tubes remain substantially parallel to each other.

  In a first embodiment of the method, the bending action is performed by a roller having an axis parallel to the longitudinal axis of the tube.

  To that end, the curving operation is gradually curved away from the opposing pair of rollers and the opposing pair of rollers with the brazing heat exchanger according to operation b) disposed therebetween. This is done by three rollers, the third moving roller.

  In a second embodiment of the method, the bending operation c) is performed by a moving press that interacts with moving elements with variable spacing.

  This bending operation is arranged so as to abut on a press having a molding surface arranged so as to abut on the first surface of the convex heat exchanger and on a second surface of the convex heat exchanger. It is preferable to carry out with two reversed rollers. The two reversing rollers have axes parallel to each other and parallel to the longitudinal axis of the core tube, and gradually move away from each other as the press moves toward the first surface of the heat exchanger To do.

  In the following description, given by way of example, reference is made to the accompanying drawings.

  In FIG. 1, the code | symbol 10 shows the whole brazing type heat exchanger by this invention. The heat exchanger 10 includes a core 12 formed by a plurality of parallel flat tubes 14 with a corrugated intermediate body 16 forming a secondary heat exchange surface disposed therebetween. The flat tube 14 of the core 12 has longitudinal axes 15 parallel to each other. In FIG. 1, only the longitudinal axis 15 of the two flat tubes 14 is shown.

  In this example, the heat exchanger 10 is configured to be incorporated into an automobile, and the flat tube 14 is substantially vertical. One end of the flat tube 14 opens into the header 18 (upper part in this case), and the other end opens into the header 20 (lower part in this case). This type of heat exchanger forms in particular a radiator for cooling the engine of a motor vehicle.

  The headers 18 and 20 are curved, and the core 12 is similarly curved. The flat tubes 14 are parallel to each other, and the corrugated intermediate 16 undergoes a certain deformation during bending.

  Accordingly, the heat exchanger has an inner CI (or concave side) and an outer CE (or convex side).

  In the illustrated example, the header is uniformly bent over the entire length of the header, but it is also possible to curve only a part of each header and make the other part a straight line.

  In the present invention, the bending operation of the heat exchanger is performed after assembling various parts and after brazing.

  FIG. 2 shows a portion of the heat exchanger 10 prior to assembly. In this case, the upper header 18 is straight and has a U-shaped cross section. The header 18 includes a bottom wall 22 having a fitting hole 24 into which a flat tube is fitted (FIGS. 2 and 3). These fitting holes 24 are elongated holes that are parallel to each other and into which one end of the flat tube 14 can be fitted.

  The bottom wall 22 is integral with two side walls 26 that are substantially parallel to each other. The header 18 is closed by a cover 28 having a top wall 30 and two end walls 32 (FIG. 2).

  The lower header 20 (not shown in FIG. 2) is also closed with a similar cover. After assembly, the heat exchanger is brazed and deformed into a curved shape. This curvature causes the headers 18 and 20 and the core 12 to bend the flat tube 14 that is parallel to each other, while the corrugated intermediate 16 is slightly deformed.

  FIG. 4 shows a modification of the header 18. The inner side wall 26 undergoes deformation due to compression (material shrinkage), and the outer side wall 26 undergoes deformation due to material stretching.

  FIG. 5 shows in more detail the deformation region 34 due to compression (material contraction) and the deformation region 36 due to elongation (material expansion).

  These deformation regions 34 and 36 naturally occur when the header 18 is bent.

  As shown in FIG. 6, a deformation region 38 is also generated on the bottom wall 22. These deformation | transformation area | regions 38 generate | occur | produce in the area | region between the fitting holes 24 and 24 for fitting a flat tube.

  The deformation area described above occurs naturally when the header is bent.

  It is advantageous to control the position at which such deformation occurs by applying preliminary deformation to at least one side wall 26 and, if necessary, the bottom wall.

  7 to 11 show the first embodiment.

  In this embodiment, the deformation region by compression including the recess 40 is provided on the side wall 26 located on the lower side. The indentations 40 are formed in a fold shape extending in a direction substantially parallel to each other and parallel to the curved generatrices.

  As shown in FIGS. 8 and 9, it is advantageous to provide a recess 40 in the side wall 26 between the fitting holes 24, 24 in the bottom wall 22. However, no preliminary deformation is performed on the outer side wall 26.

  As shown in FIG. 10, the side wall 26 is subjected to deformation due to stretching of the material. A deformation region 38 similar to the deformation region 38 shown in FIG.

  Next, the embodiment shown in FIGS. 12 to 16 will be described. Similar to the previous embodiment, the inner side wall 26 is formed with a parallel fold-shaped recess 40. In addition, the outer side wall 26 is provided with a parallel bellows-shaped concave portion 42, so that the outer side wall is easily deformed during bending.

  In this case, as shown in FIGS. 13 and 14, it is advantageous to provide a bellows-like recess 42 on the side wall 26 on the outer side of the fitting hole 24 into which the flat tube is fitted in the bottom wall 22.

  With reference to FIGS. 17 to 20, another embodiment of the present invention in which the header 18 is formed by a plurality of end plates 44 that receive the end of the flat tube 14 will be described.

  Each end plate 44 forms a casing, and two bosses 46 having circular holes 48 are connected to both ends thereof. These end plates are arranged in alignment with each other and communicate with each other through corresponding circular holes 48 to form a header that communicates with the core flat tube.

  This type of end plate is described in the above-mentioned French patent application No. 0117033 (Publication No. 2834336).

  The end plates are assembled by brazing the bosses 46 together. First, the end plate 44 is aligned as shown in FIG. Next, the entire heat exchanger is curved. Thereby, as shown in FIG. 19, the header formed by the end plate 44 is curved.

  FIG. 20 shows a state in which deformation occurs in the boss area. The boss is advantageously substantially frustoconical, which facilitates deformation.

  In this manner, a header that is deformed in the same manner as the bellows is manufactured by deformation of the boss.

  FIG. 21 shows a specific embodiment of the end plate 44 that supports the flat tube 14. FIG. 22 shows a heat exchanger in which the entire assembly formed of the end plate 44 and the flat tube 14 shown in FIG. 21 is curved.

  In the embodiment of FIGS. 17-20, 21 and 22, a corrugated intermediate element of the type schematically shown in FIG. 1 can be inserted between the tubes.

  FIG. 23 exaggerates the deformation performed by the corrugated intermediate 16 disposed between the two flat tubes 14, 14. The enlarged side 50 of the flat tube 14 is parallel to each other and parallel to the enlarged side of the other tubes.

  Initially, the flat tube 14 and the corrugated intermediate 16 have a shape indicated by a solid line in FIG. After bending, the angle between the flat tubes is α (exaggerated in FIG. 23), and the corrugated intermediate 16 is also deformed (also exaggerated in FIG. 23). The curved shape is indicated by a broken line in FIG.

  As shown in FIG. 24, the corrugated intermediate body 16 includes a substantially straight portion 52 (a louver is provided if necessary) first connected by a bent portion 54 having a radius R. As an example, the radius R is 0.4 mm.

  Outside the curved portion, the corrugated intermediate 16 undergoes deformation due to expansion. Therefore, the radius of curvature R decreases and changes from 0.5 mm to 0.4 mm, for example. On the other hand, on the inner side (FIG. 25), the corrugated intermediate body 16 is deformed by compression, and the radius of the curvature R becomes large. As an example, this inner radius varies from 0.5 mm to 0.6 mm.

  On the other hand, the pitch P (FIGS. 24 and 25) remains the same both inside and outside.

  Therefore, deformation by the corrugated intermediate 16 at the time of bending occurs at the bent portion 54. Therefore, if the radius of curvature of the bent portion of the corrugated intermediate 16 is appropriately selected and the radius of curvature of the curved region of the heat exchanger is appropriately selected, the deformation is concentrated on the corrugated intermediate 16 and the flat tube is not deformed. . Further, since this deformation occurs in the bent portion, it does not affect the brazed joint between the bent portion and the tube of the heat exchanger.

  The manufacturing method according to the present invention basically includes the operation of bending the header of the heat exchanger.

  In one embodiment for manufacturing a heat exchanger according to the present invention, first, in a first operation, a tube core and a header are assembled and a conventional general heat exchanger having a substantially flat configuration is assembled. Form.

  In the second operation, the heat exchanger thus assembled is brazed to form a brazed heat exchanger. Thereafter, in a third operation, the brazed heat exchanger is gradually bent to curve the header. The core tubes remain substantially parallel to each other. As described above, since the corrugated intermediate is between the core tubes, its deformation is limited.

  FIG. 26 shows a first embodiment of a method for performing the bending with a roller. Specifically, the bending is performed by three rollers including a pair of opposed rollers 56 and 58 and a third moving roller 60. These rollers 56, 58, 60 have axes 62, 64, 66 parallel to each other and parallel to the longitudinal axis 15 of the heat exchanger tube.

  The initially flat brazed heat exchanger 10 passes between two rollers 62, 64 that define a thickness-matched space therebetween. The outer CE of the heat exchanger 10 passes under rollers 60 that gradually move away from the rollers 56, 58 in the direction of arrow 68.

  27 and 28 show another embodiment of the method according to the invention using a press 70 and two reversing rollers 72, 74 whose axes 76, 78 are parallel to each other and parallel to the longitudinal axis 15 of the core tube. An embodiment is shown.

  The press 70 has a molding surface 80 disposed so as to abut on the first surface of the heat exchanger 10 having a concave shape. This first surface corresponds to the inner CI. The reversing rollers 72 and 74 are in contact with the opposite surface, ie, the outside CE, which is convex. The initially flat heat exchanger 10 is placed on rollers 72, 74 such that the longitudinal axis 15 of the exchanger tube is substantially parallel to the roller axes 76, 78.

  Initially, the rollers 72 and 74 are close to each other, and then when the press moves in the vertical direction indicated by the arrow 82, the rollers 72 and 74 move away from each other as indicated by the arrow 84. As a result, deformation occurs gradually and complete bending occurs as shown in FIG. 28, and the rollers 72 and 74 move as far as possible from each other.

  The movement of the press 70 (arrow 82) and the movement of the rollers 72, 74 in the direction away from each other (arrow 84) are advantageously performed gradually and simultaneously. However, this movement can be accelerated in sequence.

  In this way, a heat exchanger having one or more curved regions can be manufactured. Each portion of the region can have a constant or variable radius of curvature.

  It is also possible to combine one or more curved regions and one or more non-curved regions. The curved regions can have opposing concave surfaces to form, for example, an S-shaped heat exchanger.

  The present invention has been described above with reference to a heat exchanger having two headers. However, the present invention is, for example, a heat exchanger having a U-shaped end or one header having a hairpin tube open therein. It can also be applied to.

  The present invention can be preferably applied to heat exchangers of automobiles, that is, private cars, freight cars, motorcycles and the like.

1 is a perspective view of a brazed heat exchanger in which a header according to the present invention is U-shaped and has a curved structure; FIG. It is a fragmentary perspective view of the heat exchanger of FIG. 1 which shows a mode that a cover is mounted | worn with the header before brazing and a curve. It is the figure which looked at the U-shaped header before curve from the top. It is a figure similar to FIG. 3 of the header after the curve which removed the cover. FIG. 5 is a perspective view of the header after bending, with the cover shown in FIGS. 3 and 4 removed. It is a figure which shows the deformation | transformation of the bottom wall of the U-shaped header of FIGS. It is a fragmentary perspective view of another U-shaped header before curve. It is the figure which looked at the header of FIG. 7 before the curve from the top. It is a figure similar to FIG. 8 of the header after a curve. FIG. 10 is a perspective view of the header of FIGS. 7 to 9 after bending. It is a figure which shows the deformation | transformation of the bottom wall of the header of FIGS. FIG. 6 is a partial perspective view of another U-shaped cross-section header according to the present invention before bending. It is the figure which looked at the header of FIG. 12 before curvature from the top. It is a figure similar to FIG. 13 after the curve of the header of FIG. It is a perspective view after the curve of the header of Drawings 12-14. It is a figure which shows the deformation | transformation of the bottom wall of the header of FIGS. It is a fragmentary perspective view of the heat exchanger with which each header is formed by the overlapping end plate which supports each flat tube of a core individually. It is the figure which looked at the header of the heat exchanger of FIG. 17 before curve from the top. It is the same figure as FIG. 18 of the header after a curve. It is a figure which shows a deformation | transformation of the end plate after a curve. It is a perspective view of the end plate which receives the edge part of a flat tube. It is a fragmentary perspective view of the heat exchanger which has a some flat tube and the end plate similar to FIG. FIG. 6 is a schematic view showing a deformation of a corrugated intermediate element disposed between two adjacent flat tubes of a core. It is a figure which shows the change of the radius of the bending part of the waveform intermediate | middle element in the outer side and inner side of a curved part. It is a figure which shows the change of the radius of the bending part of the waveform intermediate | middle element in the outer side and inner side of a curved part. It is a figure which shows the bending operation | work of the heat exchanger performed using a roller. It is a figure which shows the bending | flexion operation | work of the heat exchanger by the press linked | linked with a receiving roller. It is a figure which shows the bending | flexion operation | work of the heat exchanger by the press linked | linked with a receiving roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Heat exchanger 12 Core 14 Flat tube 15 Longitudinal axis 16 Corrugated intermediate body 18, 20 Header CI, CE Curved region 22 Bottom wall 24 Fitting hole 26 Side wall 28 Cover 30 Top wall 32 End wall 34, 36, 38 Deformation region 40 Indentation 42 bellows-shaped concave portion 44 end plate 46 boss 48 circular hole 50 enlarged side 52 linear portion 54 bent portion 56, 58 roller 60 moving roller 62, 64, 66 shaft 68 arrow 70 press 72, 74 reverse roller 76, 78 shaft 80 molding Surface 82, 84 Arrow

Claims (18)

  A core comprising a tube (14) having a longitudinal axis and at least one header (18) (20) into which the tube of the core opens, wherein the header (18) (20) is at least one curved A heat exchanger having a region (CI) (CE).   2. A heat exchanger according to claim 1, characterized in that the longitudinal axes (15) of the tubes (14) are parallel to each other.   The heat exchanger according to claim 1, wherein the heat exchanger is a brazing type.   Each of said headers (20) has at least one side wall (26) (46), said side wall having a deformation region which can be deformed by compression or expansion, The heat exchanger as described in any one.   Each of the headers (18), (20) has a U-shaped cross section having a bottom wall (22) with a fitting hole (24) for receiving the tube and two side walls (26) attached to the bottom wall. 5. A heat exchanger according to claim 4, characterized in that the deformation region (34) (36) is formed on at least one of the side walls (26).   6. A heat exchanger according to claim 5, characterized in that one of the side walls (26) which is an "inner wall" is compressed during bending and the deformation area is a deformation area (34) (40) due to compression. .   The heat exchanger according to claim 6, characterized in that the deformation region due to compression comprises a recess (40).   6. A heat exchanger according to claim 5, characterized in that one of the side walls (26) which is the "outer wall" extends when bent and the deformation area is a deformation area (36) (42) by extension.   The heat exchanger according to claim 8, characterized in that the deformation region due to stretching comprises a bellows-shaped recess (42).   10. The deformation region (38) according to any one of claims 5 to 9, characterized in that the deformation area (38) is provided between the fitting hole (24) for receiving the tube of the bottom wall (22). Heat exchanger.   Each end of each tube (14) is fitted into an end plate (44) provided with two opposed perforated bosses (46), and the headers (18) and (20) are arranged in position. The heat exchange according to claim 4, wherein the heat exchanger is formed as an assembly of the end plates that are joined two by two, and the deformation region is formed in the boss that forms the side wall. vessel.   Alternately with the bend (54), a corrugated intermediate (16) having a substantially straight portion (52) is disposed between the tubes (14), the bend (54) being deformed by the curvature of the core. The heat exchanger according to any one of claims 1 to 11, wherein the heat exchanger is adapted to absorb water.   13. A heat exchanger (12) having a generally flat configuration comprising a core of a tube (14) and at least one header (18) (20). A method of manufacturing a heat exchanger according to claim, comprising the act of bending the header (18) (20). a) assembling the core of the tube (14) and the header (18) (20) to form a heat exchanger having a generally flat configuration;
b) the heat exchanger (10) assembled in this way is brazed flat to form a brazed heat exchanger;
The method according to claim 13, comprising the step of: c) gradually bending the brazed heat exchanger (10) to curve the header (18) (20).   The bending operation c) is performed by rollers (56) (58) (60) having axes (62) (64) (66) parallel to the longitudinal axis (15) of the tube (14). The method according to claim 14.   The curving motion c) is made up of a pair of opposed rollers (56), (58) and the pair of rollers (56) (58) between which the brazed heat exchanger (10) according to motion b) is disposed. 16. The method according to claim 15, characterized in that it is carried out by three rollers, including a third moving roller (60) that gradually curves away from the heat exchanger.   15. Method according to claim 14, characterized in that the bending action c) is performed by a press (70) interacting with reversing rollers (72) (74) with variable spacing.   A press (70) having a molding surface (80) arranged to abut the first surface of the heat exchanger having a curved shape for the bending operation c), and a convex shape of the heat exchanger. Two reversing rollers (72) (74) arranged so as to abut on the second surface, the two reversing rollers (72) (74) being parallel to each other and the tube of the core (14) having an axis (76) (78) parallel to the longitudinal axis (15), and gradually moving away from each other when the press moves toward the first surface of the heat exchanger. The method according to claim 17, wherein the method moves to.

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