JP2016183787A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger that can prevent an unjointed part from occurring by reliably brazing between a tube and a corrugated fin.SOLUTION: The heat exchanger includes a corrugated fin 400 in which a projection 415 projecting toward the tube is formed in part of a flat surface 410 that is part to be brazed to an external surface of the tube at least before the corrugated fin 400 is brazed.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a heat exchanger having a configuration in which corrugated fins are brazed to the outer surface of a tube.

  For example, a heat exchanger such as a condenser includes a tube through which a fluid passes and a corrugated fin formed by bending a metal plate into a wave shape, and the corrugated fin is brazed to the outer surface of the tube. (For example, refer to the following Patent Document 1).

  At least one of the tube and the corrugated fin is formed as a clad material in which a brazing material (for example, an Al—Si alloy) is roll-bonded to the surface thereof. The brazing is performed by heating the whole in an oven in a state where each top portion (surface to be joined) of the corrugated corrugated fin is in contact with the outer surface of the tube. The brazing material that has been melted by heating to become a liquid spreads so as to fill the entire gap between the contact point between the tube and the corrugated fin.

JP-A-5-106985

  When heated in an oven for brazing, it is rare for the temperature of the heat exchanger to rise while remaining uniform throughout. Usually, the temperature of a part of the tube or the corrugated fin is locally increased (or decreased), and the part is deformed due to a difference in thermal expansion.

  As a result, among the tops of the corrugated corrugated fins, some tops may be separated from the tubes. If the above-mentioned separation occurs when the temperature of the brazing material is rising and the temperature is lower than its melting point, the starting point for the brazing material to spread is formed even if the brazing material is subsequently melted. Not. For this reason, some of the tops of the corrugated fins may remain unbonded to the outer surface of the tube.

  When the unjoined part as described above is generated, heat transfer between the tube and the corrugated fin is remarkably reduced at the part. For this reason, the performance of the whole heat exchanger will fall.

  This invention is made | formed in view of such a subject, The objective can perform brazing between a tube and a corrugated fin reliably, and can prevent that an unjoined location arises. It is to provide a heat exchanger.

  In order to solve the above problems, the heat exchanger according to the present invention includes a tube through which a fluid passes and a corrugated fin formed by bending a metal plate into a wave shape, and is provided on the outer surface of the tube. A heat exchanger having a structure in which the corrugated fins are brazed, and at least before the corrugated fins are brazed, a surface to be joined which is a portion of the corrugated fins that is brazed to the outer surface of the tube A protruding portion that protrudes toward the tube is formed in a part of the tube.

  In the heat exchanger having such a configuration, when the surface to be joined of the corrugated fin is brought into contact with the outer surface of the tube (before brazing), the protruding portion contacts the outer surface of the tube before other portions. Touch. After that, when substantially the entire surface to be joined is brought into contact with the outer surface of the tube, a part of the corrugated fin is elastically deformed, so that the protruding portion is urged (pressed) toward the outer surface of the tube. ) State.

  For this reason, even if a part is deformed due to a difference in thermal expansion in the process of temperature rise thereafter, at least the protruding portion of the joined surface continues to contact the outer surface of the tube. That is, a state in which a part of the surface to be joined and the outer surface of the tube are in contact with each other is maintained, and a starting point (contact portion) when the brazing material spreads continues to exist. As a result, among the top portions of the corrugated fins, it is reliably prevented that a part of the top portions and the tube remain unbonded.

  ADVANTAGE OF THE INVENTION According to this invention, the heat exchanger which can perform brazing between a tube and a corrugated fin reliably and can prevent that an unjoined location arises is provided.

It is a figure showing typically the whole heat exchanger composition concerning a 1st embodiment of the present invention. It is a figure which expands and shows the junction location of a tube and a corrugated fin among the heat exchangers of FIG. It is a figure which shows the shape of the corrugated fin before brazing is performed. It is a figure for demonstrating a deformation | transformation of the corrugated fin of FIG. 3 when brazing is performed. It is a figure which shows the shape of the corrugated fin before brazing is performed of the heat exchanger which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating a deformation | transformation of the corrugated fin of FIG. 5 when brazing is performed. It is a figure which shows the shape of the corrugated fin before brazing is performed of the heat exchanger which is a modification of 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  The heat exchanger 10 according to the first embodiment of the present invention is used as a condenser (condenser) for an automobile. The heat exchanger 10 is disposed in a part of a route through which the air-conditioning refrigerant circulates in the automobile. As shown in FIG. 1, the heat exchanger 10 includes a pair of header tanks 100 and 200, a tube 300, a corrugated fin 400, and a pair of side plates 510 and 520.

  The header tank 100 is a container for storing the refrigerant supplied to the heat exchanger 10 and supplying the refrigerant to a tube 300 described later. The header tank 100 is formed as an elongated rod-shaped container. The header tank 100 is disposed on the side of the heat exchanger 10 (left side in FIG. 1) so that the longitudinal direction thereof extends in the vertical direction.

  The header tank 100 has a supply port 101. The supply port 101 is a portion serving as an inlet for the refrigerant supplied from the outside of the heat exchanger 10, and is formed on one end side (upper side in FIG. 1) of the header tank 100 in the longitudinal direction.

  The header tank 200 is a container having substantially the same shape as the header tank 100. The header tank 200 is for receiving the refrigerant that has passed through the tube 300 described later from the header tank 100 and discharging the refrigerant to the outside. The header tank 200 is disposed on the side of the heat exchanger 10 (on the right side in FIG. 1) so that the longitudinal direction of the header tank 200 extends in the vertical direction in the same manner as the header tank 100.

  The header tank 200 has a discharge port 201. The discharge port 201 is a portion serving as an outlet of the refrigerant discharged from the heat exchanger 10 to the outside, and is formed on one end side (lower side in FIG. 1) of the header tank 200 in the longitudinal direction.

  In FIG. 1, the x-axis is set with the horizontal direction and the direction from the header tank 100 toward the header tank 200 as the x direction. Further, the y-axis is set with the y direction being the horizontal direction and the direction perpendicular to the x direction (the direction from the back side to the front side of the drawing). Furthermore, the z-axis is set with the direction perpendicular to both the x-direction and the y-direction and directed vertically upward being the z-direction. In the subsequent drawings, the x axis, the y axis, and the z axis are similarly set.

  The tube 300 is an elongated pipe having a flat cross section, and a plurality of tubes 300 are provided in the heat exchanger 10. A flow path along the longitudinal direction is formed inside the tube 300. Each tube 300 has its longitudinal direction along the x-axis, and is laminated so as to be aligned along the z direction in a state of being parallel to each other.

  Each tube 300 has one end connected to the header tank 100 and the other end connected to the header tank 200. With such a configuration, the internal space of the header tank 100 and the internal space of the header tank 200 are communicated with each other through the flow paths in the tubes 300.

  The corrugated fin 400 is formed by bending a metal plate into a wave shape, and is disposed between the tubes 300. The tops of the corrugated fins 400 that are wavy are arranged along the longitudinal direction (x direction) of the tube 300 on both the upper and lower sides of the corrugated fins 400. Further, all the top portions of the corrugated fins 400 are in contact with the outer surface of the tube 300 and are brazed.

  The corrugated fin 400 is formed with linear cuts 431 (see FIG. 3) that are parallel to each other, and portions between the cuts 431 are louvers 432. The louver 432 is slightly inclined with respect to the other portions of the corrugated fin 400, thereby further improving the heat transfer performance of the corrugated fin 400.

  FIG. 2 is an enlarged view showing a joint portion between the tube 300 and the corrugated fin 400. As shown in FIG. 2, each top portion of the corrugated fin 400 having a wave shape is a flat surface 410 or 420 whose normal is along the z axis, and substantially the entire flat surface 410 or 420 is the tube 300. It is in contact with the outer surface of the. The flat surface 410 is the top on the z direction side, and the flat surface 420 is the top on the −z direction side. Hereinafter, both of the flat surfaces 410 and 420 may be indicated and expressed as “flat surface 410 etc.”.

  A brazing material 600 is interposed between the outer surface of the tube 300 and the flat surface 410 and between the outer surface of the tube 300 and the flat surface 420. That is, the flat surface 410 and the like are portions (bonded surfaces) that are brazed to the outer surface of the tube 300. A specific method of brazing will be described later.

  Returning to FIG. 1, the description will be continued. Each of the side plates 510 and 520 is a reinforcing member formed by bending a metal plate, and is provided to increase the rigidity of the heat exchanger 10. The side plate 510 is disposed in the upper part of the heat exchanger 10, and the side plate 520 is disposed in the lower part of the heat exchanger 10. One end of each of the side plates 510 and 520 is fixed to the header tank 100, and the other end is fixed to the header tank 200. Corrugated fins 400 are also disposed between the tube 300 disposed on the most z-direction side and the side plate 510. Similarly, the corrugated fin 400 is also disposed between the tube 300 disposed most on the −z direction side and the side plate 520.

  The refrigerant supplied from the supply port 101 flows into the internal space of the header tank 100 and is stored. Thereafter, it flows in the flow path in the tube 300 in the x direction, reaches the internal space of the header tank 200, and is discharged from the discharge port 201 to the outside.

  It is to be noted that the internal space of the header tank 100 and the internal space of the header tank 200 are divided into upper and lower portions by a partition plate, and the refrigerant flows while reciprocating between the header tank 100 and the header tank 200. It is good also as an aspect. In carrying out the present invention, the path through which the refrigerant passes is not particularly limited.

  A blower fan (not shown) is provided in the vicinity of the heat exchanger 10, and air (outside air) introduced from the outside of the vehicle by the blower fan is sent toward the heat exchanger 10. The air passes between the tubes 300 while flowing in the y direction. At this time, the heat of the refrigerant passing through the flow path in the tube 300 is transferred to the air (heat exchange between the air and the refrigerant is performed), and the temperature of the refrigerant decreases.

  Further, the heat of the refrigerant is also transmitted to the air through the corrugated fins 400. That is, the contact area with the passing air is increased by the corrugated fin 400, and heat exchange between the refrigerant and the air is performed efficiently.

  A method for brazing the tube 300 and the corrugated fin 400 will be described. The tube 300 in the present embodiment has a configuration in which layers of a brazing material 600 made of an Al—Si alloy are rolled and bonded to both surfaces of plate-like aluminum, and is formed as a so-called clad material.

  When brazing is performed, all the top portions (flat surfaces 410, 420) of the corrugated fin 400 are brought into contact with the outer surface of the tube 300 in advance, and the heat exchanger 10 is maintained so as to maintain the state. Fix the whole with a jig. In addition, in each state, the entire flat surface 410 or the like may be in contact with the entire tube 300, but only the minute portion of the flat surface 410 or the like is in contact with the entire tube 300. There are many.

  Thereafter, the entire heat exchanger 10 together with the jig is heated to about 600 degrees in an oven. Due to the heating, the brazing material 600 starts to melt on the surface of the corrugated fin 400. At this time, at the place where the flat surface 410 and the corrugated fin 400 are in contact, both the flat surface 410 and the corrugated fin 400 are in contact (wet) with the molten brazing material 600.

  After that, the range where the liquid brazing material 600 is touched (wet) gradually spreads starting from the location. Ultimately, the brazing material 600 is interposed in the entire gap between the flat surface 410 and the tube 300. That is, substantially the entire flat surface 410 and the like are wetted by the brazing material 600, and the entire portion of the outer surface of the tube 300 that faces the flat surface 410 and the like is also wetted by the brazing material 600. .

  When the heating by the oven is finished and the temperature of the heat exchanger 10 is lowered, the brazing material 600 returns to the solid state again. As a result, each flat surface 410 and the like are joined to the outer surface of the tube 300 by the brazing material 600.

  By the way, when the heat exchanger 10 is heated in the oven, it is rare that the temperature of the heat exchanger 10 rises in a uniform state as a whole. Usually, the temperature of a part of the tube 300, the corrugated fin 400, and the jig is locally increased (or decreased), and the parts are deformed due to a difference in thermal expansion.

  For this reason, even if all the flat surfaces 410 etc. are in contact with the outer surface of the tube 300 before the heating, some of the flat surfaces 410 etc. There may be a gap between the surface. That is, a flat surface 410 or the like in which there is no portion that touches the outer surface of the tube 300 may occur.

  If such a state occurs before the brazing material 600 is melted, the starting point for the brazing material 600 to spread wet is not formed on the flat surface 410 or the like. That is, the brazing material 600 melts on the surface of the flat surface 410 or the like, but the portion of the outer surface of the tube 300 that faces the flat surface 410 or the like does not touch the brazing material 600 at all ( It wo n’t get wet).

  As a result, even when heating by the oven is completed, some flat surfaces 410 and the like remain unbonded to the outer surface of the tube 300. When such an unjoined part arises, the heat transfer between the tube 300 and the corrugated fin 400 will fall remarkably in the said part. For this reason, the heat exchange performance of the heat exchanger 10 will fall.

  Therefore, in the heat exchanger 10 according to this embodiment, the shape of the corrugated fin 400 is devised to prevent the occurrence of unjoined locations as described above. FIG. 3 is a diagram showing the shape of the corrugated fin 400 before the soldering is performed and before the flat surface 410 and the like are brought into contact with the outer surface of the tube 300.

  As shown in FIG. 3, the flat surface 410 of the corrugated fin 400 is formed with a plurality of protrusions 415 protruding outward (z-direction side) by cutting and raising a part thereof. The protrusions 415 are formed at substantially the center of the flat surface 410 along the x direction, and three at equal intervals along the y direction (only two of them are shown in FIG. 3). It is formed to line up.

  In FIG. 3, only the flat surface 410 on the z direction side is shown, but a similar protrusion (hereinafter referred to as “protrusion 425”) is also formed on the flat surface 420 on the −z direction side. . The protrusion 425 is formed so as to cut and raise the flat surface 420 and protrude toward the −z direction.

  As schematically shown on the left side of FIG. 4, when the tube 300 and the corrugated fin 400 are brought into contact with each other before brazing, first, the projections 415 (and the projections 425) are formed on the outer surface of the tube 300. ). Thereafter, each tube 300 is moved closer to the corrugated fin 400, and finally the flat surface 410 (and the flat surface 420) is brought into contact with the outer surface of the tube 300 (right side in FIG. 4). ).

  At this time, the protrusion 415 is elastically deformed and pushed into the −z direction. The tip of each protrusion 415 is in a state of being biased (pressed) toward the outer surface of the tube 300 by the restoring force of the elastic deformation.

  In such a state, when the heat exchanger 10 is heated by the oven, even if the outer surface of the tube 300 and the flat surface 410 are slightly separated due to a difference in thermal expansion, the respective protrusions 415 are formed in the tube 300. The state of being in contact with the outer surface of is maintained. That is, a state where a part of the corrugated fin 400 (flat surface 410) and the outer surface of the tube 300 are in contact with each other is always maintained, and a starting point (contact portion) when the brazing material 600 spreads continues to exist. . As a result, a flat surface 410 that remains unbonded to the outer surface of the tube 300 after brazing is reliably prevented.

  As shown in FIG. 3, the tip of the protrusion 415 in the present embodiment has an arc shape. However, the shape of the protrusion 415 is not limited to this. For example, the tip of the protrusion 415 may be a rectangle or a triangle.

  Further, the corrugated fin 400 is locally plastically deformed so that a part of the flat surface 410 rises upward (z-direction side) instead of forming the protrusion 415 by cutting and raising a part of the flat surface 410. It is good as well.

  Further, the number of the protrusions 415 is not limited to three, and one or more protrusions 415 may be formed on each flat surface 410. In either case, the same effects as in the present embodiment can be obtained.

  In the above, the shape and number of the protrusions 415 and the effect of bringing the protrusions 415 into contact with the outer surface of the tube 300 first have been described, but the protrusion 425 is the same as above.

  A heat exchanger according to a second embodiment of the present invention will be described. In this embodiment, it differs from the heat exchanger 10 only in the shape of the corrugated fin 400A. Below, description of the part which is common in the heat exchanger 10 is abbreviate | omitted.

  FIG. 5 is a diagram illustrating the shape of the corrugated fin 400 </ b> A before brazing and before contact with the outer surface of the tube 300. As shown in FIG. 5, in the corrugated fin 400 </ b> A, the portion corresponding to the flat surface 410 (and the portion corresponding to the flat surface 420) in the first embodiment is not flat but curved (curved). . For this reason, below, the part corresponding to the flat surface 410 among the corrugated fins 400A will be referred to as a “curved surface 410A”. Similarly, a portion corresponding to the flat surface 420 in the corrugated fin 400A is referred to as a “curved surface 420A”.

  As shown on the left side of FIG. 6, when the corrugated fin 400A is viewed along the x direction, the curved surface 410A, which is the upper surface thereof, is curved so as to be convex toward the z direction. ing. Also, the curved surface 420A, which is the lower surface, is curved so as to be convex toward the z direction side (so as to be concave when viewed from the −z direction side).

  The corrugated fin 400A having such a shape can be formed by setting the tips (and valleys) of the teeth of a pair of formed gears formed with a metal plate sandwiched therebetween in a curved shape.

  As schematically shown on the left side of FIG. 6, when the tube 300 and the corrugated fin 400 </ b> A are brought into contact with each other before brazing, first, the curved surface 410 </ b> A with respect to the outer surface of the tube 300 on the z direction side. The central portion 415A (the central portion along the y direction which is the air passage direction) is applied. Further, the ends 425A and 426A (both ends along the y direction) of the curved surface 420A are applied to the outer surface of the tube 300 on the −z direction side, respectively. Thereafter, each tube 300 is moved closer to the corrugated fin 400A, and finally the curved surface 410A (and the curved surface 420A) is brought into contact with the outer surface of the tube 300 (right side in FIG. 6). ).

  At this time, the entire corrugated fin 400A is elastically deformed, and the curved surface 410A and the curved surface 420A are both flat surfaces. The central portion 415A of the curved surface 410A and the end portions 425A and 426A of the curved surface 420A are both biased (pressed) toward the outer surface of the tube 300 by the restoring force of the elastic deformation. It has become.

  In this state, when the heat exchanger 10 is heated by the oven, even if the outer surface of the tube 300 and the curved surface 410A are slightly separated due to a difference in thermal expansion, the central portion 415A is outside the tube 300. The state of being in contact with the surface is maintained. Similarly, even if the outer surface of the tube 300 and the flat surface 420 are slightly separated from each other, the state where each of the end portions 425A and 426A is in contact with the outer surface of the tube 300 is maintained.

  That is, a state where a part of the corrugated fin 400A (curved surfaces 410A, 420A) and the outer surface of the tube 300 are in contact with each other is always maintained, and there is a starting point (contact portion) when the brazing material 600 spreads. Keep doing. As a result, it is possible to reliably prevent the curved surfaces 410A and 420A from remaining unbonded to the outer surface of the tube 300 after brazing.

  Note that the shape of the corrugated fin 400A bent as in the present embodiment may be different from that shown on the left side of FIGS. For example, the modification shown in FIG. 7 may be used.

  In the corrugated fin 400B shown in FIG. 7, the portion that is brazed to the tube 300 on the z-direction side is not the curved surface 410A but two flat surfaces 411B and 412B. The flat surface 411B on the y direction side is inclined so that the normal line is slightly directed to the y direction side. The flat surface 412B on the −y direction side is inclined so that the normal line is slightly directed to the −y direction side. As a result, a central portion 415B that is a boundary portion between the flat surface 411B and the flat surface 412B is a portion protruding toward the z-direction side.

  In addition, the portion of the corrugated fin 400B that is brazed to the tube 300 on the −z direction side is not the curved surface 420A but two flat surfaces 421B and 422B. The flat surface 421B on the y direction side is inclined so that the normal line is slightly directed to the −y direction side. The flat surface 422B on the −y direction side is inclined so that the normal line is slightly directed to the y direction side. As a result, the end portion 425B on the most y direction side of the flat surface 421B and the end portion 426B on the most −y direction side of the flat surface 422B are both protruding portions toward the −z direction side. Yes.

  Even if the bent corrugated fin 400B has such a shape, the center portion 415B, the end portion 425B, and the end portion 426B continue to contact the outer surface of the tube 300 during brazing. For this reason, there exists an effect similar to what was demonstrated referring FIG.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In other words, those specific examples that have been appropriately modified by those skilled in the art are also included in the scope of the present invention as long as they have the characteristics of the present invention. For example, the elements included in each of the specific examples described above and their arrangement, materials, conditions, shapes, sizes, and the like are not limited to those illustrated, but can be changed as appropriate. Moreover, each element with which each embodiment mentioned above is provided can be combined as long as technically possible, and the combination of these is also included in the scope of the present invention as long as it includes the features of the present invention.

10: heat exchanger 300: tubes 400, 400A, 400B: corrugated fins 410, 420: flat surfaces 415, 425: projections 410A, 420A: curved surfaces 415A: central portions 425A, 426A: end portions 600: brazing materials 411B, 412B , 421B, 422B: flat surface 415B: central portion 425B, 426B: end portion

Claims (4)

A tube (300) through which a fluid passes, and corrugated fins (400, 400A, 400B) formed by bending a metal plate into a wave shape, and the corrugated fins are soldered to the outer surface of the tube A heat exchanger of a configured configuration,
At least before the corrugated fin is brazed,
Of the corrugated fin, a part to be joined to the outer surface of the tube (410, 420, 410A, 420A, 411B, 412B, 421B, 422B) protrudes toward the tube. The heat exchanger is characterized in that protruding portions (415, 425, 415A, 425A, 426A, 415B, 425B, 426B) are formed. The protrusion is
2. The heat exchanger according to claim 1, wherein the heat exchanger is formed by locally plastically deforming a part of the surfaces to be joined. The protrusion is
2. The heat according to claim 1, wherein the heat is formed by bending the whole surface to be bonded so that a part of the surface to be bonded (415 </ b> A, 415 </ b> B) protrudes toward the tube. Exchanger.   4. The brazing of the corrugated fin to the outer surface of the tube is performed in a state where the protruding portion is pressed against the outer surface of the tube. The heat exchanger according to item.

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