Patent Publication Number: US-2016238329-A1

Title: Heat exchanger

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The application is based on a Japanese Patent Application No. 2013-195507 filed on Sep. 20, 2013, the contents of which are incorporated herein by reference in its entirety. 
     FIELD OF THE INVENTION 
     The present disclosure relates to a heat exchanger with tubes for heat exchange. 
     BACKGROUND ART 
     Conventionally, there are known heat exchangers with tubes for heat exchange. For example, a heat exchanger disclosed in Patent Document 1 includes a plurality of tubes and fins that promote heat exchange. In the heat exchanger, liquid adhesive is charged into gaps between the tube and the fin. That is, the fins are fixed to the tubes with the adhesive. 
     PRIOR ART LIST 
     Patent Document 
     
         
         [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2009-36428 
       
    
     SUMMARY OF INVENTION 
     The inventors of the present application have found through their studies that in a heat exchanger with tubes for heat exchanger, like the heat exchanger described in Patent Document 1, fine solids are caught in and mixed into air flowing around the tubes of the heat exchanger to fly toward the tubes, and then hit the tubes in some cases. For example, when the heat exchanger is mounted within an engine room of a vehicle, solids, such as small stones, thrown up by traveling of the vehicle collide with the tubes of the heat exchanger, disadvantageously causing damage to the tube. 
     To solve the disadvantage described above, the inventors have proposed that a protective member designed to protect the tube is provided on the upstream side of air flow, exclusively to which solids fly to come, with respect to the tube. However, the protective member needs to protect the tube while not interfering with the air flow flowing into the surroundings of the tube as much as possible. Thus, it is necessary to position the protective member without misaligning it with respect to the tube. 
     In view of the above matter, it is an object of the present disclosure to provide a heat exchanger that can protect tubes at the front side of a vehicle by a protective member while preventing the protective member from becoming misaligned with respect to the tube. 
     Further, it is another object of the present disclosure to provide a heat exchanger that can protect tubes from solids flying toward the tubes by a protective member while preventing the protective member from becoming misaligned with respect to the tube. 
     A heat exchanger according to a first aspect of the present disclosure includes: a tube that allows a heat medium flowing therein to exchange heat with air flowing around the tube, and has an upstream side end on an upstream side of an air flow; and a protective member covering the upstream side end and being fixed to the upstream side end of the tube. The protective member is configured to protect the tube from a solid flying to the tube. 
     The protective member for protecting each tube from solids that are flying toward the tube is fixed to the upstream side end of the tube while covering the upstream side end, so that the protective member can be prevented from becoming misaligned with respect to the tube. Further, the protective member can protect the tube from solids that are flying toward the tube in a vehicle or the like, on the side of the tube exclusively to which solids fly to come, that is, on the upstream side of air flow on which the side end of the tube on the upstream side is positioned. 
     A heat exchanger for a vehicle according to a second aspect of the present disclosure includes: a core portion including a plurality of tubes, each of the tubes allowing a heat medium to flow through therein, and fins disposed on both sides of each of the tubes, the core portion being configured to exchange heat between the heat medium and air; a tank portion connected to an end in a longitudinal direction of the tube; and a protective member fixed to an upstream end of at least a part of the plurality of tubes on an upstream side of an air flow. The protective member is disposed at a front side of the vehicle with respect to the tube. 
     For example, the protective member may be formed by solidifying a fluid material having fluidity. Further, the tubes may be arranged, for example, to have their longitudinal directions in parallel to the vehicle width direction. The protective member may be fixed to the end of the tube on the upstream side of the air flow, in a lower part of the core portion. 
     For example, the protective member may be fixed to a part of the tube in the longitudinal direction. The fin may protrude toward the upstream side of the air flow with respect to the tube. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an entire structural diagram of a heat exchanger according to a first embodiment. 
         FIG. 2  is a cross-sectional view taken along the line II-II in  FIG. 1 . 
         FIG. 3  is a diagram for explaining a step of fixing a cover member to a side end of each tube on the upstream side in a manufacturing procedure for the heat exchanger shown in  FIG. 1 . 
         FIG. 4  is an enlarged perspective view of an IV part shown in  FIG. 3 . 
         FIG. 5  is a diagram illustrating the features of a heat exchanger according to a second embodiment, which corresponds to the section taken along the line II-II of  FIG. 1 . 
         FIG. 6  is a diagram showing a first modified example of the section of a tube, which corresponds to  FIG. 2 . 
         FIG. 7  is a diagram showing a second modified example of the section of a tube, which corresponds to  FIG. 2 . 
         FIG. 8  is a diagram showing a first modified example of the positions of formation of the cover members in the heat exchanger, which corresponds to  FIG. 1 . 
         FIG. 9  is a diagram showing a second modified example of the position of formation of the cover member in the heat exchanger, which corresponds to  FIG. 1 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In the following, preferred embodiments of the present disclosure will be described with reference to the accompanying drawings. The mutually same or equivalent parts in the respective embodiments below are indicated by the same reference characters throughout the figures. 
     First Embodiment 
       FIG. 1  shows an entire structural diagram of a heat exchanger  10  in a first embodiment of the present disclosure.  FIG. 2  is a cross-sectional view taken along the line II-II of  FIG. 1 . The heat exchanger  10  shown in  FIG. 1  is mounted outside a vehicle compartment in a vehicle, specifically, in an engine room. The heat exchanger  10  exchanges heat between the outside air and an engine coolant that cools the engine, thereby dissipating heat of the engine coolant into the outside air. That is, the heat exchanger  10  is a heat exchanger for a vehicle, and the engine coolant is used as a heat medium. The coolant is allowed to circulate through the heat exchanger  10 , for example, by an electric water pump (not shown). 
     In  FIG. 1 , an arrow DR 1  represents the vertical direction of the vehicle with the heat exchanger  10 , that is, a vehicle up-and-down direction DR 1 , with the upper side of  FIG. 1  corresponding to the upper side of the vehicle. In this embodiment, the vehicle up-and-down direction DR 1  corresponds to the arrangement direction of tubes. An arrow DR 2  represents the lateral direction of the vehicle, that is, a vehicle width direction DR 2 . In this embodiment, the vehicle width direction DR 2  corresponds to the tube longitudinal direction in which each tube  12  extends. Further, an arrow DR 3  shown in  FIG. 2  represents the longitudinal direction of the vehicle, that is, a vehicle front-and-rear direction DR 3  with the left side of  FIG. 2  corresponding to the front side of the vehicle. The vehicle up-and-down direction DR 1 , the vehicle width direction DR 2 , and the vehicle front-and-rear direction DR 3  are perpendicular to one another. 
     As shown in  FIGS. 1 and 2 , the heat exchanger  10  includes a core portion  16  including a plurality of tubes  12  and fins  14 , and a pair of first and second header tanks  18  and  20  that are assembled to both ends of the core portion  16 . 
     Each of the plurality of tubes  12  has an outer peripheral surface  121  forming the outer peripheral surface of the tube  12 , and allows air, or the outside air to flow around the outer peripheral surface  121 . In the tube  12 , the engine coolant as a fluid for heat exchange that exchanges heat with the outside air flows through the tube  12 . The tube  12  is a pipe that is made of an aluminum alloy and extends linearly in the vehicle width direction DR 2 . The engine coolant flows through the tubes  12  in the vehicle width direction DR 2 , while the outside air flows from the front side to the rear side of the vehicle along the vehicle front-and-rear direction DR 3 . 
     As shown in  FIG. 2 , the section of the tube  12  perpendicular to the flow direction of the engine coolant, or the vehicle width direction DR 2  has a flat shape that extends in the vehicle front-and-rear direction DR 3  as the air flowing direction. As shown in  FIG. 1 , the plurality of tubes  12  are stacked in the vehicle up-and-down direction DR 1  perpendicular to the air flow direction, and arranged in parallel with each other. 
     Each fin  14  includes a thin film made of an aluminum alloy, and molded in the form of wave as viewed from the vehicle front-and-rear direction DR 3 . The fin  14  is bonded to the flat surfaces of the tube  12  on both sides, for example, by brazing and the like. Such fins  14  serve to promote heat exchange between the engine coolant circulating through the tubes  12  and the air as the external fluid by increasing a heat transfer area with the air. Referring to  FIG. 2 , the width of the fin  14  in the vehicle front-and-rear direction DR 3  is set equal to or slightly larger than that of the tube  12 . 
     The first header tank  18  shown in  FIG. 1  is connected to one end of each of all tubes  12 , and has a shape that extends in the lamination direction of the tubes  12 , that is, in the vehicle up-and-down direction DR 1 . The first header tank  18  has an internal space formed therein, which communicates with all tubes  12 . The first header tank  18  includes an inlet  181  into which the engine coolant flows. 
     The second header tank  20  is symmetrically structured with respect to the first header tank  18  with the core portion  16  sandwiched between the header tanks. Specifically, the second header tank  20  is connected to the other end of each of all tubes  12 , and has a shape that extends in the vehicle up-and-down direction DR 1 . The second header tank  20  has an internal space formed therein, which communicates with all tubes  12 . The second header tank  20  includes an outlet  201  from which the engine coolant flows. 
     The heat exchanger  10  is configured in the way described above, whereby the engine coolant flowing from the inlet  181  into the first header tank  18  is distributed by the first header tank  18  to the respective tubes  12 . The distributed engine coolants flow through the respective tubes  12  from the side of the first header tank  18  to the side of the second header tank  20  and are collected together at the second header tank  20 . The collected coolant flows out of the outlet  201  toward the outside of the heat exchanger  10 . 
     As shown in  FIGS. 1 and 2 , the heat exchanger  10  includes a plurality of cover members  22 . The cover member  22  is a protective member that serves to protect the tube  12  from solids, such as small stones, thrown up by traveling of the vehicle. In detail, the cover member  22  is the protective member that has such a thickness that can protect the tubes  12  from the solids. Since the solids tend to fly from the upstream side of the air flow, or the front side of the vehicle to reach the heat exchanger  10 , each cover member  22  is formed to cover a part  121   a  on the upstream side of the air flow, that is, the upstream side end  121   a  of the outer peripheral surface  121  of the corresponding tube  12 . In short, the cover members  22  are positioned at the front side of the vehicle with respect to the tubes  12 . Each cover member  22  is fixed to the upstream side end  121   a  of the corresponding tube  12 , for example, by bonding and the like. 
     In the lamination direction of the tubes  12 , that is, in the vehicle up-and-down direction DR 1 , the width of the cover member  22  is set equal to or slightly smaller than the minor axis as the width of the flat-shaped tube  12  such that the cover member does not interfere with introduction of the outside air into between the adjacent tubes  12  as much as possible. As illustrated in  FIG. 2 , a tip end  22   a  of the cover member  22  on the upstream side of the air flow is rounded. 
     The cover member  22  includes resin, or polymer material, such as acrylic resin, silicon resin, a resin containing a volatile solvent, a thermosetting resin, and an UV curing resin. For example, the cover members  22  are formed as illustrated in  FIGS. 3 and 4 .  FIG. 3  is a diagram for explaining a step of fixing the cover members  22  to the upstream side ends  121   a  of the tubes  12  (see  FIG. 2 ) when viewing the heat exchanger  10  from the same direction as that in  FIG. 1 .  FIG. 4  is an enlarged perspective view of an IV part shown in  FIG. 3 . 
     First, to form the cover members  22 , in a first step, a resin material  221  for the cover member  22  is prepared. The resin material includes, for example, a liquid resin having a high viscosity, is prepared. The resin material  221  is a material serving as, for example, an adhesive. In the following second step, as shown in  FIGS. 3 and 4 , the resin material  221  for the cover member  22 , that is, the fluid material  221  having fluidity is applied onto the upstream side end  121   a  of each tube  12  of the core portion  16  across the entire length of the tube  12  (see  FIG. 2 ). At this time, for example, a dispenser nozzle  26  is used. The dispenser nozzle  26  is fed in the longitudinal direction of the tube  12  as indicated by the arrow ARs of  FIG. 4 , while pouring the resin material  221  from the dispenser nozzle  26 . The amount of outflow of the resin material  221  from the dispenser nozzle  26  and the feeding rate of the dispenser nozzle  26  are adjusted such that the cover member  22  formed over the upstream side end  121   a  has an appropriate thickness that is previously determined experimentally to protect the tube  12  from chipping. In this embodiment, the cover members  22  are formed for all the tubes  12 . 
     In a next third step, the resin materials  221  applied over the upstream side ends  121   a  of the tubes  12  are solidified. Thus, the cover members  22  are completed. In the third step, to promote the solidification of the resin material  221 , the resin materials  221  are heated as needed. 
     As mentioned above, in this embodiment, each of the cover members  22  is fixed to the upstream side end  121   a , which is a part of the outer peripheral surface  121  of the tube  12  on the upstream side of the air flow, while covering the upstream side ends  121   a . Thus, the cover members  22  are less likely to be misaligned with the tubes  12 , and can protect the tubes  12  from solids on the upstream side of the air flow, exclusively to which solids fly to come, that is, at the vehicle front side. In short, the tubes  12  can be protected from chipping. 
     In this embodiment, as shown in  FIG. 2 , the tip end  22   a  of the cover member  22  is formed to be rounded at the section of the cover member  22  as viewed from the flow direction of the engine coolant, which can easily introduce the outside air into a gap between the tubes  12 , that is, a gap where the fin  14  is installed. 
     Further, in this embodiment, the width of the cover member  22  in the lamination direction of the tubes  12  is set equal to or less than the width of the tube  12 , making it difficult to interfere with the introduction of the outside air into the gap between the tubes  12  without narrowing the gap between the tubes  12  as viewed from the front side of the vehicle. 
     In this embodiment, the cover members  22  are formed by applying and solidifying the fluid resin material  221  onto the upstream side ends  121   a  of the tubes  12 , so that the cover members  22  can be configured as separate members from the tubes  12 . Thus, if the cover member  22  is damaged, for example, has any crack or the like, the damage is less likely to be transferred to the tubes  12 , which is a merit of this embodiment. The structures of the tube  12  and fin  14  do not need to be modified, compared to a structure without having the cover member  22 . 
     Second Embodiment 
     Next, a second embodiment of the present disclosure will be described. In this embodiment, a different point from the above-mentioned first embodiment will be mainly described, and the description of the same or equivalent parts as those of the first embodiments will be omitted or simplified below. 
       FIG. 5  illustrates a diagram of the features of a heat exchanger  10  of this embodiment, which corresponds to the section taken along the line II-II of  FIG. 1  described above. That is,  FIG. 5  is a diagram of this embodiment corresponding to  FIG. 2  of the first embodiment. The heat exchanger  10  of this embodiment has the same outer appearance as that of the first embodiment as viewed from the vehicle front side, and thus can be illustrated as shown in FIG.  1 . 
     As can be seen from the comparison between  FIGS. 5 and 2 , in this embodiment, the shape of the fin  14 , specifically, the dimension of the fin  14  with respect to the tube  12  in the vehicle front-and-rear direction DR 3  differs from that of the fin  14  in the first embodiment. 
     As shown in  FIG. 5 , in the vehicle front-and-rear direction DR 3 , that is, in the air flow direction, the width dimension of the fin  14  is set larger than the width dimension of the flat-shaped tube  12 , that is, the dimension of the major axis of the tube  12 . The position of the end of the fin  14  on the downstream side of the air flow in the air flow direction is the same or substantially the same as that of the end of the tube  12 . 
     On the other hand, the end of the fin  14  on the upstream side of the air flow is positioned to protrude toward the upstream side of the air flow, compared to the position of the end of the tube  12  on the upstream side of the air flow. The protruding amount Dwf of the fin  14  from the tube  12  toward the upstream side of the air flow is larger than a thickness Tcv of the cover member  22  in the air flow direction. In short, the fin  14  protrudes more toward the upstream side of the air flow than the cover member  22  fixed to the upstream side end  121   a  of the tube  12  adjacent to the fin  14 . 
     As mentioned above, in this embodiment, the fin  14  protrudes more toward the upstream side of the air flow, compared to the cover member  22  fixed to the upstream side end  121   a  of the tube  12  adjacent to the fin  14 . Thus, in a step of applying the liquid resin material  221  (see  FIG. 4 ) for the cover member  22  onto the upstream side end  121   a  of the tube  12 , the fin  14  can easily hold the applied resin material  221  on the upstream side end  121   a  of the tube  12 , which is another merit of this embodiment. 
     Other Embodiments 
     (1) In each of the above-mentioned embodiments, the cover member  22  is made of resin. However, material for the cover member  22  is not limited, but may be, for example, other polymer materials, such as rubber. For example, when the cover member  22  is made of soft material, such as rubber or soft resin, that is, when the cover member  22  has a lower hardness than that of the tube  12 , the impact caused when solids collide with the cover member  22  is less likely to be transferred to the tubes  12 , compared to when the cover member is not made so, which is another merit of the embodiment. 
     The cover member  22  may include metal having a lower melting point, such as a solder. If the cover member  22  includes such metal, the cover member  22  is formed by solidifying the melted metal as the material for the cover member  22  at the upstream side end  121   a  of the corresponding tube  12 . 
     (2) In each of the above-mentioned embodiments, the upstream side end  121   a  of the tube  12  has a shape that expands toward the upstream side of the air flow at the section of the tube  12  perpendicular to the flow direction of the engine coolant, but may have other shapes. For example, the tube  12  may have the sectional shape shown in  FIG. 6 or 7 . 
       FIG. 6  is a diagram corresponding to  FIG. 2 , that is, the sectional view taken along the line II-II of  FIG. 1 , while showing a first modified example of the section of the tube  12 . In the first modified example, as shown in  FIG. 6 , the upstream side end  121   a  of the tube  12  has a planar shape perpendicular to the air flow direction. In other words, the upstream side end  121   a  of the tube  12  has the planar shape facing the upstream side of the air flow. 
       FIG. 7  is a diagram corresponding to  FIG. 2 , that is, the sectional view taken along the line II-II of  FIG. 1 , while showing a second modified example of the section of the tube  12 . In the second modified example, as shown in  FIG. 7 , the upstream side end  121   a  of the tube  12  has the shape recessed toward the inside of the tube  12  in the air flow direction. In other words, the upstream side end  121   a  of the tube  12  has the concave shape recessed toward the inside of the tube  12  on the section of the tube  12  as viewed from the flow direction of the engine coolant. 
     The tube  12  has the sectional shape shown in  FIG. 6 or 7 , thereby easily holding the resin material  221  on the upstream side end  121   a  in the step of applying the liquid resin material  221  (see  FIG. 4 ) of the cover member  22  onto the upstream side end  121   a  of the tube  12 , which is another merit of the embodiment. 
     (3) In each of the above-mentioned embodiments, as shown in  FIG. 1 , the cover member  22  is provided across the entire length of each of all the tubes  12  of the core portion  16 . However, for example, as shown in  FIGS. 8 and 9 , the cover members  22  may be provided for some parts of tubes  12  in the core portion  16 . 
       FIG. 8  is a diagram showing a first modified example of the positions of formation of the cover members  22  in the heat exchanger  10 , which corresponds to  FIG. 1 . Referring to  FIG. 8 , the cover members  22  are provided across the entire lengths of the tubes  12 . However, unlike  FIG. 1 , the cover members  22  are not provided for all the tubes  12  in  FIG. 8 , but only for some of the tubes  12  located under the vehicle. 
       FIG. 9  is a diagram showing a second modified example of the positions of formation of the cover members  22  in the heat exchanger  10 , which corresponds to  FIG. 1 . Referring to  FIG. 9 , unlike  FIG. 1 , the cover members  22  are provided across parts of the entire lengths of some of the plurality of tubes  12  included in the core portion  16 . As illustrated in  FIGS. 8 and 9 , the cover members  22  may be provided in necessary positions of the heat exchanger  10 . 
     (4) In each of the above-mentioned embodiments, the flow of the engine coolant in the heat exchanger  10  is a cross flow where the engine coolant flows in the vehicle width direction DR 2 . However, the engine coolant flow is not limited thereto, but may be, for example, a down flow where the engine coolant flows from the upward side to the downward side in the vehicle up-and-down direction DR 1 . 
     (5) In the above-mentioned second embodiment, the fins  14  protrude more toward the upstream side of the air flow than the cover members  22  fixed to the upstream side ends  121   a  of the respective tubes  12 . However, the fins  14  may protrude more toward the upstream side of the air flow than only the respective tubes  12 , but may not protrude more than the cover members  22 . Even with such an arrangement, in the step of applying the liquid resin material  221  (see  FIG. 4 ) onto the upstream side end  121   a  of each of the tubes  12 , the applied resin material  221  can be easily held on the upstream side ends  121   a  of the tubes  12  by the fins  14 , which is a merit that this embodiment can obtain to some degree. 
     The present disclosure is not limited to the embodiments described above, and various modifications and changes can be made to the present disclosure. It is obvious that elements included in each of the above-mentioned embodiments are not necessarily essential unless otherwise specified, and except when clearly considered to be essential in principle. When referring to a specific number about a component of the above-mentioned embodiments, such as the number of components, a numerical value, an amount, or a range, the above-mentioned respective embodiments are not limited to the specific number, unless otherwise specified, except when limited to the specific number in principle, and the like. Further, when referring to the material, shape, positional relationship, or the like of the components, etc., the above-mentioned respective embodiments are not limited to such a material, shape, positional relationship, or the like, unless otherwise specified, and except when clearly limited to the specific material, shape, positional relationship, or the like in principle.