Abstract:
A heat exchanger according to the present invention has tube capable of flowing a fluid through interiors of the tube, a partition member provided in the tube to extend in the flowing direction of the fluid flows, a flow-through space determined by using the partition member in the tube, the fluid flowing through the interior of the flow-through space, and a non-flow-through space determined by using the partition member in the tube, the fluid being unable to flow through the interior of the non-flow-through space. Heat is exchanged between the fluid and the exterior of the tube. A portion of the tube corresponding to the non-flow-through space is mainly applied with an external action.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a heat exchanger and particularly relates to a heat exchanger which can be appropriately applied to a condenser, a radiator, an oil cooler or the like to be installed in a vehicle. 
     An example of a heat exchanger applied for a vehicle may be one applied to a condenser of an air conditioner as shown in FIG.  8 . It is noted that reference symbol R denotes the right side of the vehicle, L denotes the left side thereof and UPR denotes the upper side thereof in FIG.  8 . 
     The condenser as shown in FIG. 8 is installed, for example, crosswise in the front portion of the vehicle. The condenser is provided with right and left header pipes  101 , a plurality of tubes  102  coupled to both the right and left header pipes  101  and fins  103  arranged between the tubes  102 , respectively. 
     When a refrigerant fed from a compressor (not shown) of the air conditioner flows through the tubes  102 , heat is exchanged between the refrigerant and the air passing through the fins  103 , thereby cooling the refrigerant and cooling a car cabin or the like. 
     SUMMARY OF THE INVENTION 
     According to more detailed studies done by the inventor of the present invention, each tube of the condenser shown in FIG. 8 may have a sectional construction as shown in FIG. 9 or  10 . It is noted that reference symbol FR denotes a front side of the vehicle and UPR denotes an upper side thereof in FIGS. 9 and 10. 
     In FIG. 9, a tube  202  is formed by use of an aluminum material and extrusion process. In the tube  202 , a plurality of refrigerant channels  202   a  parallelly aligned in the longitudinal direction of the vehicle are formed. The refrigerant channels  202   a  of this type are designed to flow a refrigerant therethrough. The reason for providing a plurality of channels  202   a  is to increase the contact area between the refrigerant and the wall surfaces of the channels, i.e., to increase a radiating area to thereby increase heat exchange efficiency. 
     Meanwhile, in FIG. 10, an inner fin type tube  202 ′ is shown. A tube main body  221  is formed by folding a metal plate and an inner fin  222  is inserted into the main body  221 . The interior of the tube main body  221  is provided with a plurality of refrigerant channels  202   a ′ defined by the inner fin  222  and these refrigerant channels  202   a ′ are designed to flow a refrigerant therethrough. 
     In case of the above-stated inner fin type tube, the tube main body and the inner fin can be made thin compared with the extruded tube. Thus, the inner fine type tube is advantageously light weight while maintaining the same radiating area, and air and pressure tightness as those of the extruded tube. 
     With the inner fin type tube having these advantages, however, it is true that its toughness should be taken into consideration because of the thinner tube main body or the like. 
     For example, the condenser may be arranged at the lower front portion of the vehicle in view of the layout efficiency of the vehicle components, condenser characteristics or the like. In that case, however, a foreign matter such as a pebble bounced on the road and flew up therefrom is collided against the tube main body  221  as shown by an arrow in FIG.  10 . 
     If the foreign matter is collided against the tube main body  221  as stated above, i.e., the tube main body  221  is applied with an external action such as an external force, the tube main body  221 , the inner fin  222  and the channels  202   a ′ may possibly be deformed or the like, which are by no means preferable for heat exchange function. 
     To avoid such disadvantages, the coupled portion  221   a  of the tube main body  221 , which is a relatively tough portion, may be arranged in the front side of the vehicle against which the foreign matter tends to be collided, however, the strength of the main body  221  to be able to attain in practicable has its limit. In the meantime, the plate thickness of the tube main body  221  or the like can be simply and uniformly increased. If so, however, even a part of the plate thickness of the tube main body  221  positioned at the rear and the upper front portion of the vehicle or the like, which do not inherently need to increase its strength, is increased. As a result, not only the weight of the condenser increase but also the heat exchange characteristics thereof deteriorates. Thus, this is not an advisable countermeasure. 
     The present invention has been made as a result of the above-stated studies. It is, therefore, an object of the present invention to provide a heat exchanger capable of removing the influence of an external action such as the application of an external force and capable of exhibiting sufficient heat exchange characteristics while satisfying the demand for providing a condenser lighter in weight. 
     A heat exchanger according to the present invention is provided with a tube capable of flowing a fluid through interior of the tube; a partition member provided in the tube to extend in the flowing direction along which the fluid flows; a flow-through space determined by use of the partition member in the tube, the fluid flowing through the interior of the flow-through space; and a non-flow-through space determined by use of the partition member in the tube, the fluid being unable to flow through the interior of the non-flow-through space. Heat is exchanged between the fluid and the exterior of the tube. A portion of the tube corresponding to the non-flow-through space is mainly applied with an external action. 
     In other words, a heat exchanger according to the present invention is provided with a fluid channel capable of flowing a fluid flow through the interior of the channel; partition means for partitioning the fluid channel; a flow-through section determined by use of the partition means in the fluid channel, the fluid being allowed to flow through the interior of the flow-through section; and a non-flow-through section determined by use of the partition means in the fluid channel, the fluid being unable to flow through the interior of the non-flow-through section. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a view showing a condenser serving as a heat exchanger in accordance with a first embodiment of the present invention, seen from the front side of a vehicle; 
     FIG. 2 is a cross-sectional view of a tube taken along line B—B of FIG. 1; 
     FIG. 3 is a perspective view showing assembly steps of the tube of the condenser in accordance with the embodiment; 
     FIG. 4 is a view showing the tube of the condenser in accordance with the embodiment, seen from the upper side of the vehicle; 
     FIG. 5 is a partially cross-sectional view showing the connection structure between the tube and the header pipe of the condenser in accordance with the embodiment, seen from the upper side of the vehicle; 
     FIG. 6 is a cross-sectional view of a tube, corresponding to FIG. 2, in accordance with a second embodiment in the present invention; 
     FIG. 7 is a partially cross-sectional view showing the connection structure, corresponding to FIG. 5, in accordance with a third embodiment in the present invention; 
     FIG. 8 is a view showing a condenser serving as a general heat exchanger, seen from the front side of a vehicle; 
     FIG. 9 is a cross-sectional view of a tube taken along line A—A of FIG. 8 according to the studies of the inventor of the present invention; and 
     FIG. 10 is a cross-sectional view of another tube taken along line A—A of FIG. 8 according to the studies of the inventor of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Now, the embodiments of the present invention will be described in detail, while appropriately referring to the accompanying drawings. 
     First, a heat exchanger in the first embodiment according to the present invention will be described with reference to FIGS. 1 to  5 , taking a condenser C of an air conditioner for a vehicle V as an example. 
     In FIGS. 1 to  5 , reference symbol FR denotes the front side of the vehicle V, L denotes the left side thereof, R denotes the right side thereof and UPR denotes the upper side thereof. 
     As shown in FIG. 1, the condenser C in this embodiment is installed crosswise in the front portion of the vehicle V. The condenser C is provided with right and left header pipes  1 , a plurality of tubes  2  coupled to the right and left header pipes  1  and fins  3  arranged between the tubes  2 , respectively. 
     When a refrigerant fed from a compressor, which is not shown therein, flows through the tubes  2 , heat is exchanged between the refrigerant and the air passing through the tubes  2  to thereby cool a car cabin. 
     A tube main body  31  is constituted by folding an aluminum plate as shown in FIG.  2 . The depth (length in the longitudinal direction of the vehicle) is set larger than a conventional length L by Δ. As shown in FIG. 3, an inner fin  32  is inserted into a tube main body  31  in the width direction of the tube and a round bar-shaped partition bar  33  (corresponding to a partition member) made of aluminum is inserted thereinto in the same direction. The partition bar  33  partitions a space within the tube main body  31  into a vehicle front side space  41  (corresponding to a non-flow-through space) and a vehicle rear side space  42  (corresponding to a flow-through space). The diameter of the partition bar  33  is set sufficiently larger than the plate thickness of the tube main body  31 . The inner fin  32  is inserted into the rear side space  42 , whereby the rear side space  42  is further divided into a plurality of coolant channels  42   a.    
     The length of the partition bar  33  is set larger than the width of the tube main body  31 . As shown in FIG. 4, the partition bar  33  is inserted into the tube main body  31  so that the both ends of the bar  33  protrude from the both ends of the tube main body  31  by tube positioning portions  33   a , respectively. The surface of the partition bar  33  is coated with a clad material containing a brazing filler material as in the case of the inner fin  32 . When the tube  30  is inserted into a furnace to carry out brazing, the upper and lower convex portions of the inner fin  32  and, at the same time, the upper and lower portions of the partition bar  33  are brazed to the inner wall of the tube main body  31 . Thus, even if the partition bar is added, it is ensured that the inner fin is bonded to the tube main body  31  without increasing the number of brazing steps. 
     Next, procedures for incorporating the tubes  30  into the condenser will be described. 
     As shown in FIG. 5, a plurality of notches  1   a  for coupling the tubes are formed on the right and left header pipes  1  of the condenser C in advance. One end of each tube  30  is engaged with its corresponding notch  1   a  and the tube positioning portion  33   a  is abutted against the inner wall of the header pipe  1  for positioning purposes. The same operation is performed for the right and the left header pipes  1 . Next, when brazing is conducted in the furnace, portions denoted by reference numbers  51  and  52  shown in FIG. 5, the upper and lower surfaces of the notches  1   a  and the outer surface of the tube main body  31  are continuously brazed together, thereby fixing the tube  30  to the header pipe  1 . At this moment, the rear side space  42  of the tube main body  31  is communicated with a space  1 b within the header pipe  1 , whereas the front side space  41  is not communicated with the space  1   b  within the header pipe  1 . Although a gap may possibly be formed between the end portion of the tube  30  and the wall surfaces of the notches  1   a  due to the dimensional tolerance of the partition bar  33  or the like, the leakage of the refrigerant within the space  1   b  from the gap S to the outside can be effectively prevented by brazing the portion denoted by reference number  51 . 
     In the condenser C in this embodiment constituted as stated above, the refrigerant forcedly fed by a compressor, which is not shown, flows from the space  1   b  of the header pipe  1  into the rear side space  42  of the tube  30  and heat is exchanged between the refrigerant flowing through the rear side space  42  and the air passing through the fin  3  to thereby cool the refrigerant. As already stated above, since the front side space  41  is not communicated with the tube main body  31 , the refrigerant does not flow into the front side space  41 . In this way, although the tube main body  31  has a space through which a refrigerant does not flow, the rear side space  42  has the same width L as that in the conventional case and heat exchange efficiency is not inferior to that in the conventional case. 
     While the vehicle is travelling, an object such as a pebble may be let fly toward the vehicle and collided against the front side of the tube main body  31 . Since the refrigerant flows through the front side space  41  of the tube  31 , even if a crack CR or a hole is made on the front side portion of the tube main body  31 , it is possible to effectively prevent the refrigerant from leaking outside due to the collision of the pebble. In some cases, the pebble or the like may penetrate the tube main body  31  and collide against the partition bar  33 . If so, however, the impetus of the pebble goes down because of its collision against the tube main body  31 . Besides, since the partition bar  33  has a diameter sufficiently larger than that of the tube main body  31 , cracking is effectively prevented even if the pebble is collided against the partition bar  33  and leakage of the refrigerant is thereby effectively avoided. 
     As stated above, in this embodiment, since the space  41  through which the refrigerant does not flow is provided in the front side portion of the tube  30 , it is possible to surely prevent leakage of the refrigerant without increasing the plate thickness of the tube main body  31 , i.e., without increasing the weight and hampering the radiation performance of the heat exchanger or condenser. Particularly, due to the partition bar  33  formed out of a round bar, it is possible to constantly secure an enough brazing area even if the position of the partition bar  33  is rotated relative to the tube main body  31 . Thus, the air tightness of the heat exchanger does not deteriorate. Meanwhile, it is noted that a square partition bar may be used instead of the round bar. In that case, if the partition bar is arranged so that the square portion of the bar is abutted against the inner wall of the tube main body  31 , the brazing area in which the bar is brazed to the inner wall may be decreased and enough air tightness may not be maintained. Considering this, it is possible to add a clad material if required. In addition, as shown in FIG. 5, the protruding portions on the both ends of the partition bar  33  are used for positioning the bar  33  relative to the header pipes  1 . Due to this, it is possible to dispense with a side plate for coupling the upper and lower ends of the right and left header pipes as conventionally used and to thereby reduce the number of components. 
     Next, description will be given to a heat exchanger in a second embodiment according to the present invention. 
     The heat exchanger in the second embodiment has basically the same construction as that of the heat exchanger in the first embodiment and can be applied to a condenser of an air conditioner for a vehicle V as in the case of the first embodiment. The heat exchanger in this embodiment differs from that in the first embodiment in the construction of a fin arranged within a tube. It is noted that the same constituent elements of the heat exchanger in this embodiment as those in the first embodiment are denoted by the same reference symbols and that description will not be, therefore, given to the specific construction thereof. 
     Specifically, as shown in FIG. 6, an inner fin  32 ′ inserted into a tube main body  31  in the width direction of the tube (direction in which a refrigerant flows through) has a fin shape continuing between one end portion  32 ′ a  and the other end portion  32 ′ b  as in the case of the first embodiment. Differently from the first embodiment, the fin shape is matched to the shape of a partition member  33 . 
     With this construction, when the inner fin  32 ′ is inserted into the tube main body  31 , one end portion  32   a′  of the inner fin  32 ′ is engaged with the inner wall of the tube main body  31  positioned right in FIG.  6  and the respective vertex portions of the fin shape are also engaged with the inner wall thereof. The inner fin  32 ′ is thereby inserted into the tube main body  31  while being surely guided and finally placed at a position set relative to the tube main body  31 . 
     Next, when the partition member  33  is inserted into the tube main body  31 , it contacts with the curved portion of the fin shape positioned at the other end portion  32 ′ b  and guided surely. Finally, the partition member  33  is placed at a position set relative to the tube main body  31 . 
     Thereafter, the right and left header pipes  1  having the tube main body  31  into which the inner fin  32  and the partition member  33  are inserted to be arranged at set positions, respectively, are put in a furnace and brazing is conducted as in the case of the first embodiment and the tube  31  is eventually completed. 
     As stated above, in this embodiment, the partition member  33  is inserted into the tube main body  31  while being positioned using the curved portion of the fin shape of the inner fin  32 ′. This makes it possible to efficiently and accurately install the partition member  33  into the tube main body  31  without the need to provide a dedicated positioning member. 
     Next, description will be given to a heat exchanger in a third embodiment according to the present invention. 
     The heat exchanger in the third embodiment, like that in the second embodiment, has basically the same constitution as that in the first embodiment and can be applied to a condenser of an air conditioner for a vehicle V, as well. The heat exchanger in this embodiment differs from that in the first embodiment in the construction of a partition bar arranged in a tube. It is noted that the same constituent elements of the heat exchanger in this embodiment as those in the first embodiment are denoted by the same reference symbols and that description will not be, therefore, given to the specific constitution thereof. 
     Specifically, as shown in FIG. 7, a partition bar  33 ′ is inserted into a tube main body  31  as in the case of the first embodiment. The length of the bar  33 ′ is the same as the width of the tube main body  31  and no protruding portions protruding from the tube main body  31  are provided. 
     With this construction, when each tube  30  is incorporated into right and left header pipes  1 , one end of each tube  30  and, at the same time, its corresponding end of the partition bar  33 ′ fixed to the tube  30  are engaged with their corresponding notch  1   a  of one of the header pipes  1 , and then the other end of the tube  30  and, at the same time, its corresponding end of the partition bar  33 ′ are engaged with their corresponding notch  1   a  of the other of the header pipes  1 , thereby positioning the tubes  30  and the right and left header pipes  1 . 
     Next, the right and left header pipes  1  relative to which the tubes  30  are positioned, are put in a furnace and brazing is conducted. Then, notices  1   a  such as portions denoted by  51 ′ and  52 ′ are bonded to each tube  30  and the tubes  30  are fixed to the header pipes  1 . 
     As stated above, in this embodiment, the header pipes  1  are positioned without providing the partition bar  33 ′ with additional protruding portions. This makes it possible to efficiently and sufficiently position the header pipes  1  with a simple construction. 
     The above-stated embodiments concern a constitution in which the interior of the tube is partitioned in the longitudinal direction of the vehicle so that a non-flow-through space is provided. It is also possible to partition the interior of the tube in the vertical direction or other directions of the vehicle since the non-flow-through space may be provided at a position toward which pebbles or the like tend to be let fly from the road. 
     In addition, the above-stated embodiments concern a constitution in which the interiors of all tubes are partitioned and non-flow-through spaces are provided, respectively. It goes without saying that it is also possible to partition only a specified tube or specified tubes and a non-flow-through space or spaces may be provided, as required. 
     Further, the heat exchangers in the above embodiments have been described while exemplifying a condenser of an air conditioner installed in a vehicle to which the present invention is applied. Needless to say, the present invention is also applicable to a radiator, an oil cooler or the like and further applicable to components other than vehicle installed components as long as it is necessary to provide a non-flow-through space therein. 
     Moreover, it is possible to configure a heat exchanger by combining the constitution for positioning the partition member within each tube in the second embodiment and that for positioning the tubes and the header pipes in the third embodiment, as required. 
     The entire contents of a Patent Application No. TOKUGANHEI 11-36054, with a filing date of Feb. 15, 1999 in Japan, are hereby incorporated by reference. 
     Although the invention has been described above by reference to certain embodiments of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art, in light of the teachings. The scope of the invention is defined with reference to the following claims.