Abstract:
A heat exchanger includes a core. The core includes a heat-exchange tube for a heat exchange medium to circulate therein. The core includes a fin joined to the heat-exchange tube. The heat exchanger includes a pair of header pipes connected with both ends of the core. Each of header pipes includes header pipe members. Each of header pipes has a joint member communicating with header pipe members. The joint member has communication holes arranged longitudinally of the header pipes at intervals.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2003-141845 filed on May 20, 2003; the entire contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   The present invention relates to a heat exchanger mounted on a vehicle such as an automobile. The heat exchanger includes, for example, a radiator for cooling an engine, an air-conditioning condenser, an oil cooler (ATF cooler) for cooling oil of automatic transmission, and an oil cooler for cooling an engine oil. 
   An automobile includes various heat exchangers. The heat exchangers include heat-exchange tubes through which medium flows, and header pipes connected to the heat-exchange tubes. Each of the header pipes includes communication holes in communication with the heat-exchange tubes. The communication holes become greater in diameter, as a header pipe extends upstream of the medium in the flowing direction. The communication holes become smaller in diameter, as the header pipe extends downstream of the medium. This arrangement uniformly distributes the medium, which flows from the header pipe to the heat-exchange tube (For example, Japanese Patent Application Laid-open No. H9-166368). 
   SUMMARY OF THE INVENTION 
   In the heat exchangers, however, when the refrigerant passes through the communication holes, flowing resistance becomes greater. The heat exchanger requires a thick header pipe to maintain withstanding pressure (destroy-resistance strength). This structure increases the weight and cost of the heat exchangers. 
   The present invention provides a heat exchanger that uniformly distributes medium, which flows from a header pipe having great strength to a heat exchanging tube. 
   The invention has a first aspect directed to the following heat exchanger. The heat exchanger includes a core. The core includes a heat-exchange tube for a heat exchange medium to circulate therein. The core includes a fin joined to the heat-exchange tube. The heat exchanger includes a pair of header pipes connected with both ends of the core. Each of header pipes includes header pipe members. Each of header pipes has a joint member communicating with header pipe members. The joint member has communication holes arranged longitudinally of the header pipes at intervals. 
   The communication holes have hole sizes greater at upstream side of flow of the heat-exchange medium in the header pipe members. The hole sizes are smaller, as the communication holes are closer to downstream side of the heat exchange medium. 
   The communication holes have hole pitches therebetween smaller at upstream side of the heat-exchange medium flowing in the header pipe member. The hole pitches are greater, as the communication holes are closer to downstream side of the heat exchange medium. 
   Joint members are located longitudinally of the header pipe. The joint members have a regulation member therebetween configured to regulate the heat exchange medium. 
   The invention has a second aspect directed to the following heat exchanger. The heat exchanger includes a tube having a fluid therein for exchanging heat between the fluid and airflow during running of a vehicle. The heat exchanger includes a header pipe in communication with the tube for the fluid. The header pipe includes a first pipe connected with the tube for the fluid to circulate between the first pipe and the tube. The header pipe includes a second pipe on the first pipe. The header pipe includes a joint interconnecting the first and second pipes for the fluid to circulate between the first and second pipes through the joint. 
   The second pipe has an inlet and a stopper therein. The joint has holes located between the inlet and the stopper in communication with the first and second pipes. The holes become smaller in size as the joint extends toward the stopper. 
   The second pipe has an inlet and a stopper therein. The joint has holes located between the inlet and the stopper at pitches in communication with the first and second pipes. The pitches become greater as the joint extends toward the stopper. 
   The second pipe has an inlet and a stopper therein. The joint has holes located between the inlet and the stopper in communication with the first and second pipes. The joint has a regulation member between the holes. 

   
     BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
       FIG. 1  is a block diagram showing an air-conditioning system; 
       FIG. 2A  is a perspective view showing a heat exchanger according to a first embodiment; 
       FIG. 2B  is a perspective view showing the operation of the heat exchanger shown in  FIG. 2A , wherein F 1  indicates an airflow; 
       FIG. 3  is an enlarged longitudinal sectional view of a portion A 1  in  FIG. 2A ; 
       FIG. 4  is an enlarged cross sectional view taken along IV—IV in  FIG. 3 ; 
       FIG. 5  is a plan view of a joint member shown in FIG.  3 ; 
       FIG. 6  is a side view of the joint member shown in  FIG. 5 ; 
       FIG. 7  is a vertical sectional view of a primary portion of a heat exchanger according to a second embodiment, wherein F 2  indicates uniform separated flows; 
       FIG. 8  is a vertical sectional view of a primary portion of a heat exchanger according to a third embodiment; and 
       FIG. 9  is a longitudinal sectional view of a primary portion of a heat exchanger according to a fourth embodiment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Embodiments of the present invention will be described with reference to the accompanying drawings. Like members are designated with like reference numerals and the descriptions thereof are omitted. 
   First Embodiment 
   Referring to  FIG. 1 , a vehicle air-conditioning system  100  will be described. 
   The system  100  includes, as air conditioners, a compressor  101  and a condenser  17  in an engine room  110 , and an expansion valve  103  and an evaporator  105  in a passenger compartment  120 . Refrigerant absorbs heat from air in the passenger compartment  120 , and is cooled by the condenser  17  with airflow during running. 
   The system  100  includes an oil cooler  16  in the engine room  110 . The oil is heated to a high temperature in a transmission  107 , and is cooled by airflow in the oil cooler  16  during running of a vehicle. 
   The oil cooler  16  and the condenser  17  are configured as one unit or a complex heat exchanger  10 . 
   Referring to  FIG. 2A , the heat exchanger  10  includes the oil cooler  16  as a first heat exchanger on the left side (L 1  side in  FIG. 2A ) of a pseudo heat exchanging passage member  15 . The heat exchanger  10  includes the condenser  17  as a second heat exchanger on the right side (R 1  side in  FIG. 2A ) of the pseudo heat exchanging passage member  15 . In  FIG. 2A , a fin is omitted. 
   The condenser  17  cools refrigerant for an air conditioning cycle. The oil cooler  16  cools oil for an automatic transmission. 
   The heat exchanger  10  includes an upper header pipe  11  located at the upper and a lower header pipe  12  located at the lower. The heat exchanger  10  also includes a core  13  which interconnects the upper header pipe  11  and the lower header pipe  12  in the vertical direction. The heat exchanger  10  includes a liquid tank  14  connected to the side of the lower header pipe  12 . 
   The upper header pipe  11  includes, as header pipe members, an upper pipe  18  and a lower pipe  19  in vertical contact with each other. The upper and lower pipes  18  and  19  are in communication with each other using joint members  20  and  21  having communication holes  20   a,    20   b,    20   c,    20   d,    20   e  and  21   a,    21   b,    21   c,    21   d,    21   e.    
   The upper pipe  18  is closed off by two disk-shaped partitions  22  and  23  as stoppers. The partitions  22  and  23  are located at intermediate portion in the longitudinal direction. Partitions  22 ,  23 ,  24  and  25  are disposed at predetermined distances from one another. The partitions  24  and  26  have the joint members  20  and  21  therebetween. 
   The partitions  22  and  23  separate the upper pipe  18  into a pipe  18   a  for the condenser  17  and a pipe  18   b  for the oil cooler  16 . The lower pipe  19  is also provided with the partitions  24  and  25  in positional coincidence with the partitions  22  and  23 , and with a partition  26  in proximity to the liquid tank  14 . The partitions  24  and  25  separated the lower pipe  19  into a pipe  19   a  to  19   b  for the condenser  17  and a pipe  19   c  for the oil cooler  16 . The partition  26  separates the pipe  19   a  to  19   b  for the condenser into an inlet pipe  19   a  and an outlet pipe  19   b.    
   Like the upper header pipe  11 , the lower header pipe  12  includes an upper pipe  27  and a lower pipe  28  as adjacent header pipe members. The lower header pipe  12  includes joint members  29 ,  30  and  31  and partitions  32 ,  33 ,  34 ,  35  and  37 , which allow the upper pipe  27  and the lower pipe  28  to communicate with each other. The joint members  29  to  31  include communication holes  29   a,    30   a,  and  31   a,  respectively. The partitions  32  and  33  and the partition  36  and  37  are disposed at predetermined distances from one another. The partitions  32  and  33  separate the upper pipe  27  into a pipe  27   a  to  27   b  for the condenser  17  and a pipe  27   c  to  27   d  for the oil cooler  16 . The partition  35  separates the pipe  27   a  to  27   b  for the condenser into an outlet pipe  27   a  and an inlet pipe  27   b.  The partition  34  divides the pipe  27   c  to  27   d  for the oil cooler into an inlet pipe  27   c  and an outlet pipe  27   d.    
   The core  13  includes heat-exchange tubes  38  arranged side-by-side in the vertical direction. A refrigerant M 1  for heat-exchange flows through the heat-exchange tubes  38   a  and  38   b.  An oil M 2  flows through the heat-exchange tubes  38   c  and  38   d.  The core  13  includes corrugated fins (see  FIG. 3 ) disposed between the adjacent heat exchanging tubes  38 . 
   Referring to  FIG. 3 , the lower portion of the upper pipe  18  and the upper portion of the lower pipe  19  are in communication with each other using the joint members  20  and  21 . The joint members  20  and  21  are disposed between the partitions  24  and  26 . The joint members  20  and  21  have the communication holes  20   a  to  20   e  and  21   a  to  21   e  which extend vertically threrethrough. As shown in  FIGS. 5 and 6 , the total of respective five communication holes  20   a  to  20   e  and  21   a  to  21   e  are disposed at constant distances from one another in the longitudinal direction of the joint members  20  and  21 , i.e., along a flow direction of refrigerant M 1  in the header pipe  11  shown in  FIG. 3 , respectively. More specifically, the communication holes  20   a  to  20   e  and  21   a  to  21   e  of the joint member  20  and  21  all have the identical hole diameters D 20   a,  D 20   b,  D 20   c,  D 20   d,  D 21   e,  D 21   a,  D 21   b,  D 21   c  D 21   d  and D 21   e  for the identical flow path areas. The communication holes  20   a  to  20   e  and  21   a  to  21   e  all have the identical hole pitches P 20   ab,  P 20   bc,  P 20   cd,  P 20   de,  P 20   ef,  P 21   ab,  P 21   bc,  P 21   cd  and P 21   de  therebetween. The number of communication holes  20   a  to  20   e  or  21   a  to  21   e  is not limited to five, and the number can appropriately be changed in accordance with size and usage of the heat exchanger. 
   According to this embodiment, the heat exchanger  10  includes the upper pipe  18  and the lower pipe  19  as the header pipes  11  in communication with each other through the joint members  20  and  21 . This greatly enhances the heat exchanger  10  in strength as compared with a heat exchanger having one header pipe. The single header pipe, vertically elongated in an elliptic or rectangular shape, is required to enlarge the thickness to maintain the destroy-pressure resistance strength. That is, the upper pipe  18  and the lower pipe  19  in communication with each other represents a function that the header pipe is vertically extended in view of the cross sectional shape. However, the two closed cross section is superior to the one closed cross section in terms of strength. Therefore, this structure maintains the destroy-pressure resistance strength with minimum material cost. When HFC  134   a  is used as the refrigerant M 1 , the destroy pressure-resistance strength as a maximum pressure is, for example, 9.91 Mpa, against which the heat exchanger safely bears. This embodiment sufficiently maintains this destroy pressure-resistance strength. 
   The operations of the vehicle air-conditioning system  100  and the heat exchanger  10  will be described as the following. 
   Referring to  FIG. 1 , the air-conditioning system  100  is used as the air conditioner. The refrigerant M 1  is compressed by the compressor  101  to flow into the condenser  17 . The refrigerant M 1  is liquefied by the condenser  17 , radiating heat. The refrigerant M 1  is isenthalpic expanded by the expansion valve  103  to flow into the evaporator  104 . The refrigerant M 1  is evaporated in the evaporator  105 , cooling air in the passenger compartment  120 . 
   Next, the air-conditioning system  100  is used as an oil cooler. Oil M 2  is heated by the transmission  106  to flow into the oil cooler  16 . The oil M 2  is cooled in the oil cooler  16 . 
   Referring to  FIG. 2B , operations of the condenser  17  and the oil cooler  16  will be described. 
   The refrigerant M 1  flows into the upper pipe  18   a  of the upper header pipe  11 . The refrigerant M 1  flows from the upper pipe  18  into the inlet pipe  19   a  through the communication holes  20   a  to  20   e  and  21   a  to  21   e.  The refrigerant M 1  flows from the inlet pipe  19   a  into a first tube group  38   a.  The refrigerant M 1  is liquefied in the first tube group  38   a  to flow into the outlet pipe  27   a.  At that time, the refrigerant M 1  exchanges heat with airflow F 1  through the first tube group  38   a  and is cooled. 
   The refrigerant M 1  flows from the outlet pipe  27   a  into the lower pipe  28   a  through the communication holes  29   a  and  30   a  of the joint members  29  and  30 . The refrigerant M 1  flows from the lower pipe  28   a  into the inlet pipe  27   b  via the liquid tank  14 . Excessive refrigerant is temporarily reserved in the liquid tank  14 . 
   The refrigerant M 1  flows from the inlet pipe  27   b  into a second tube group  38   b,  where the refrigerant M 1  exchanges heat with the airflow F 1  and is cooled. The refrigerant M 1  flows from the second tube group  38   b  into the outlet pipe  19   b  and flows out toward the evaporator  105 . 
   On the other hand, oil M 2  flows from the inlet pipe  27   c  of the lower header pipe  12  into a third tube group  38   c,  where the oil M 2  exchanges heat with the airflow F 1  through the third tube group  38   c  and is cooled. The oil M 2  flows from the third tube group  38   c  into a fourth tube group  38   d  via the lower pipe  19   c,  where the oil M 2  is further cooled by the airflow F 1 . The oil M 2  flows from the fourth tube group  38   d  into an outlet pipe  27   d.  The oil M 2  flows from the outlet pipe  27   d  into the lower pipe  28   b  through the communication hole  31   a  of the joint member  31 , and flows out toward the transmission  107 . 
   Second Embodiment 
   Referring to  FIG. 7 , a heat exchanger  45  according to a second embodiment will be described. 
   Joint members  50  and  51  include communication holes  50   a  to  50   e  and  51   a  to  51   e  of hole diameters D 50   a,  D 50   b,  D 50   c,  D  50   d,  D 50   e  and D 51   a,  D 51   b,  D 51   c,  D 51   d,  D 51   e  disposed along the header pipes  18  and  19  in the longitudinal direction. As the joint members  50  and  51  extend toward the downstream of the refrigerant M 1  or toward the partition  22  in the longitudinal direction, the hole diameters D 50   a  to D 50   e  and D 51   a  to D 51   e  become gradually smaller. All the communication holes  50   a  to  50   e  and  51   a  to  51   e  have the identical hole pitches P 50   ab,  P 50   bc,  P 50   cd,  P 50   de,  P 51   ab,  P 51   bc,  P 51   cd  and P 51   de  set therebetween. 
   The joint member  50  is disposed upstream of the joint member  51  in the flowing direction of the refrigerant M 1 . Each of the joint members  50  and  51  includes five communication holes  50   a  to  50   e  or  51   a  to  51   e.  As the joint member  50  extends from the upstream (left side in  FIG. 7 ) toward the downstream (right side in  FIG. 7 ) in the flow of refrigerant M 1 , the hole diameter D 50   a  to D  50   e  of the joint member  50  become gradually smaller. The hole pitches P 50   ab  to P 50   de  are constant over the entire communication holes  50   a  to  50   e.  As the joint member  51  extends from the upstream (left side in  FIG. 7 ) toward the downstream (right side in  FIG. 7 ) in the flow of the refrigerant M 1 , the hole diameter D 51   a  to D 51   e  of the joint member  51  become gradually smaller. The hole pitch P 51   ab  to P 51   de  are constant over the entire communication holes  51   a  to  51   e.  The hole diameter D 51   a  of the most upstream communication hole  51   a  in the joint member  51  is smaller than the hole diameter D 50   e  of the most downstream communication hole  50   e  in the joint member  50 . That is, the hole diameters D 50   a  to D 50   e  and D 51   a  to D 51   e  become smaller, as communication holes  50   a  to  50   e  and  51   a  to  51   e  approach to the partition  22 . 
   The cross section areas of the communication holes  50   a  to  50   e  and  51   a  to  51   e,  or the total of the flow path areas is the identical to that of the communication holes  20   a  to  20   e  and  21   a  to  21   e  in the first embodiment. From this relation, the flow rate of refrigerant M 1  through the joint members  50  and  51  is the identical to that of the first embodiment. 
   According to the operation and benefit, the heat exchanger  45  enhances the in destroy pressure-resistance strength. The heat exchanger  45  allows refrigerant M 1  to be uniformly distributed to the heat exchanging tubes  38 , which realizes uniform separated flows F 2 . 
   As shown in  FIG. 7 , the upper pipe  18  is closed off by the partition  22  disposed upstream. The refrigerant M 1  flows through the upper pipe  18  and flows into the lower pipe  19  through the communication holes  50   a  to  50   e  and  51   a  to  51   e  of the joint members  50  and  51 . Here, the refrigerant M 1  hits against the partition  22  and is stopped from flowing. Thus, the downstream refrigerant M 1  becomes greater in dynamic pressure than upstream refrigerant M 1 , allowing the downstream refrigerant M 1  to flow toward the lower pipe  19  faster than the upstream refrigerant M 1 . According to this embodiment, as the joint members  50  and  51  extend toward the downstream, the hole diameters D 50   a  to D 50   e  and D 51   a  to D 51   e  of the communication holes  50   a  to  50   e  and  51   a  to  51   e  become smaller. While, as the hole diameters D 50   a  to D 50   e  and D 51   a  to D 51   e  become smaller, the flow-path resistances become greater. Thus, the downstream communication holes  50   c  to  50   e  and  51   c  to  51   e  have flow-path resistance greater than the upstream communication holes  50   a,    50   b,    51   a  and  51   b.  From the above, the flow rates of the refrigerant M 1 , flowing from the upper pipe  18  to the lower pipe  19 , become uniform over the header pipe  11  in the longitudinal direction. The result permits the refrigerant M 1  to be uniformly distributed to the tubes  38   a  of the condenser  17 . 
   Third Embodiment 
   Referring to  FIG. 8 , a heat exchanger according to a third embodiment will be described. 
   The joint members  52  and  53  include communication holes  52   a  to  52   f  and  53   a  to  53   d  arranged at hole pitches P 52   ab,  P 52   bc,  P 52   cd,  P 52   de,  P 52   ef,  P 53   ab,  P 53   bc,  and P 53   cd.  The hole pitches P 52   ab  to P 52   ef  and P 53   ab  to P 53   cd  become gradually greater as the joint members  52  and  53  extend toward the downstream of the refrigerant M 1  or the partition  22 . The hole pitch P 53   ab  to P 53   cd  is set greater than the hole pitch P 52   ab  to P 52   ef.  All the communication holes  52   a  to  52   f  and  53   a  to  53   d  have the identical hole diameters D 52   a,  D 52   b,  D 52   c,  D 52   d,  D 52   e,  D 52   f,  D 53   a,  D 53   b,  D 53   c  and D 53   d.    
   The joint member  52  is disposed upstream of the joint member  53  in the flow of the refrigerant M 1 . The joint members  52  and  53  have the six and four communication holes  52   a  and  53   a,  respectively. As the joint member  52  extends from the upstream side (left side in  FIG. 8 ) toward the downstream side (right side in  FIG. 8 ) in the flow of the refrigerant M 1 , the pitch P 52   ab  to P 52   ef  between the communication holes  52   a  to  52   f  gradually becomes greater. All the communication holes  52   a  to  52   f  have the identical hole diameters D 52   a  to D 52   f  or the identical flow path areas. As the joint member  53  extends from the upstream side (left side in  FIG. 8 ) toward the downstream side (right side in  FIG. 8 ) in the flow of the refrigerant M 1 , the pitch P 53   ab  to P 53   cd  between the communication holes  53   a  to  53   d  gradually becomes greater. All the communication holes  53   a  to  53   d  have the identical hole diameters D 53   ab  to D 53   cd  or the identical flow path areas. The minimum hole pitch P 53   ab  between the most upstream communication holes  53   a  and  53   b  of the joint member  53  is greater than the maximum hole pitch P 52   ef  between the most downstream communication holes  52   e  and  52   f.  That is, the pitches P 53   aab  to P 53   cd  become greater, the communication holes  52   a  to  53   d  approach to the partition  22 . The cross section areas of the communication holes  52   a  to  52   f  and  53   a  to  53   d  or the total of the flow path areas is the identical to that of the communication holes  20   a  to  20   e  and  21   a  to  21   e  in the first embodiment. From this relation, the flow rate of refrigerant M 1 , passing through the joint members  52  and  53 , is the identical to that of the first embodiment. 
   According to the operation and benefit, the heat exchanger  46  enhances the destroy pressure-resistance strength, and allows the refrigerant M 1  to be uniformly distributed to the heat exchanging tubes  38 . 
   As shown in  FIG. 8 , the hole pitches P 52   ab  to P 52   ef  and P 53   ab  to P 53   cd  between the communication holes  52   a  to  52   f  and  53   a  to  53   d  become greater as the joint members  52  and  53  extend toward the downstream or partition  22 . The hole pitches P 53   ab  to P 53   cd  are greater than the hole pitches P 52   ab  to P 52   ef.  As the refrigerant M 1  flows downstream toward the partition  22  in the upper pipe  18 , the dynamic pressures become larger. While, the downstream communication holes  52   d  to  52   f  and  53   c  and  53   d  have flow path resistance identical to the upstream communication holes  52   a,    52   b,    53   a  and  53   b.  From the above, the flow rates of the refrigerant M 1 , flowing from the upper pipe  18  to the lower pipe  19 , become uniform over the header pipe  11  in the longitudinal direction. The result allows the refrigerant M 1  to be uniformly distributed to the tubes  38  of the condenser  17 . 
   Fourth Embodiment 
   Referring to  FIG. 9 , a heat exchanger according to a fourth embodiment will be described. 
   This embodiment has joint members  55  and  56  having identical configurations. The joint members  55  and  56  are arranged in series along a flow direction of the refrigerant M 1  in the header pipe  11  or longitudinal direction of the header pipe  11 . The joint members  55  and  56  have a regulating plate  57  located therebetween. The regulating plate  57  is fixed to the upper portion of the inner peripheral surface of the upper pipe  18 . The regulating plate  57  is of substantially semi-circular shape as viewed from front. The regulating plate  57  extends downward in a direction (radial direction of the upper pipe  18 ) perpendicular to the flowing direction of the refrigerant M 1 . 
   The joint member  55  includes communication holes  55   a  to  55   f.  As the joint member  55  extends toward the downstream of the refrigerant M 1  or the partition  22 , the hole pitches P 55   ab,  P 55   bc,  P 55   cd,  P 55   de  and P 55   ef  between the communication holes  55   a  to  55   f  gradually becomes greater. All the communication holes  55   a  to  55   f  has the identical hole diameters D 55   a,  D 55   b,  D 55   c,  D 55   d,  D 55   e  and D 55   f.  The joint member  56  includes communication holes  56   a  to  56   f  at hole pitches P 56   ab,  P 56   bc,  P 56   cd,  P 56   de  and P 56   ef.  The hole pitches P 56   ab  to P 56   ef  between the communication holes  56   a  to  56   f  gradually become greater, as the joint member  56  extends toward the downstream of the refrigerant M 1  or the partition  22 . All the communication holes  56   a  to  56   f  have the identical hole diameters D 56   a,  D 56   b,  D 56   c,  D 56   d,  D 56   e  and D 56   f.  The joint members  55  and  56  have respective identical hole diameters D 55   a  to D 56   f  and D 56   a  to D 56   f  and respective identical hole pitches P 55   ab  to P 56   ef  and P 56   ab  to P 56   ef  for the identical configuration. The cross section areas of the communication holes  55   a  to  55   f  and  56   a  to  56   f  or the total of the flow path areas is identical to that of the communication holes  20   a  to  20   e  and  21   a  to  21   e  in the first embodiment. The flow rate of the refrigerant M 1 , flowing through the joint members  55  and  56 , is identical to that of the first embodiment. The regulating plate  57  appropriately controls the flowing direction and the flow rate of the refrigerant M 1 . The regulating plate  57  is disposed between the joint members  55  and  56  to stop a portion of the flow of the refrigerant M 1  in front of the joint member  56 , reducing the flow velocity thereof. 
   According to the embodiment, the heat exchanger  54  includes the regulating plate  57  disposed between the joint members  55  and  56 . The regulating plate  57  stops a portion of the flow of the refrigerant M 1  in front of the joint member  56 , and reduces the flow velocity thereof. This structure allows the dynamic pressure of the refrigerant M 1  to be applied longitudinally to the joint members  55  and  56  in equal profile. That is, as the joint member  55  or  56  extends toward partition  22 , the dynamic pressure becomes greater. While, the joint members  55  and  56  have the communication holes  55   a  to  55   f  and  56   a  to  56   f  having respective identical hole diameters D 55   a  to D 55   f  and D 56   a  to D 56   f  and respective identical hole pitches P 55   ab  to P 55   ef  and P 56   ab  to P 56   ef.  This structure allows the refrigerant M 1  to be uniformly distributed to the heat exchanging tubes  38 . The joint members  55  and  56  with identical configurations reduce the productive cost. 
   The heat exchanger of this invention is not limited to the above-described embodiments, and can variously be changed and modified. 
   For example, in the above embodiments, the joint members  20 ,  21 ,  50 ,  51 ,  52 ,  53 ,  55 ,  56  have the communication holes  20   a  to  20   e,    21   a  to  21   e,    50   a  to  50   e,    51   a  to  51   e,    52   a  to  52   f,    53   a  to  53   d,    55   a  to  55   f  and  56   a  to  56   f  having hole diameters and hole pitches, which may are appropriately changed, allowing the refrigerant M 1  to be equally distributed to the heat exchanging tubes  38 . The reducing of the amount of the downstream separated flows may reduce the influence of heat on the condenser  17  from the oil cooler  16 . 
   The core  13  includes the high temperature side oil cooler  16  and the low temperature side condenser  17 . With this configuration, heat from the oil cooler  16  is prone to influence a portion of the heat exchanging tubes  38  as the condenser  17  in proximity to the oil cooler  16 . If the heat is transferred from the oil cooler  16  to the condenser  17 , the heat-exchange performance of the entire heat exchanger is possibly deteriorated. On the other hand, if the amount of separated flows of the refrigerant M 1  in the condenser  17  in proximity to the oil cooler  16  is restricted, the condenser  17  does not have heat influence of the oil cooler  16 , maintaining high heat-exchange performance. 
   The fourth embodiment has the regulating plate  57  that stops a portion of the refrigerant M 1  from flowing in front of the joint member  56 . Alternatively, a regulating plate may have such a shape that allows a flowing direction of the refrigerant M 1  to be changed. 
   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 above teachings. The scope of the invention is defined with reference to the following claims. 
   According to the invention, header pipe members communicate with each other through a joint member having communication holes, thus enhancing a header pipe in strength. Here, a heat exchanger with one header pipe is required to enlarge thickness for maintaining pressure-resistance (destroy-pressure resistance). While, the invention has the header pipe of the header pipe members, and the header pipe members communicate with each other through the joint member. This structure reduces pressure receiving size of respective header pipes, ensuring pressure-resistance with small thickness, maintaining pressure-resistance with minimum material cost. 
   The communication holes have hole sizes greater at upstream side of the medium. The hole sizes become smaller as the communication holes approach to downstream side of the medium. This allows downstream communication holes to have greater flow-path resistance than upstream communication holes. This structure allows flow rate of medium from one header pipe member to the other header pipe member to be uniform over the joint member in the longitudinal direction. The result permits medium to be uniformly distributed from the other header pipe member to a heat-exchange tube. 
   The communication holes has hole pitches therebetween, which become greater as the communication holes approach to downstream side. The downstream hole pitches have greater flow-path resistance than the upstream hole pitches. This structure allows flow rate of medium from one header pipe member to the other header pipe member to be uniform over the joint member in the longitudinal direction. The result permits medium to be uniformly distributed from the other header pipe member to a heat-exchange tube. 
   A header pipe has joint members therein, which have a regulating member therebetween configured to regulate flow of medium. This structure appropriately regulates flow of the medium relative to the header pipe member at downstream side. This allows the joint members to have identical structures.