Patent Publication Number: US-11029073-B2

Title: Cold-storage heat exchanger

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation application of U.S. patent application Ser. No. 14/616,944 filed on Feb. 9, 2015, which is a divisional application of U.S. patent application Ser. No. 12/800,979 filed on May 27, 2010, now U.S. Pat. No. 8,978,411, which claims the benefit of priority from Japanese Patent Applications No. 2009-136630 filed on Jun. 5, 2009, and No. 2010-095227 filed on Apr. 16, 2010. The entire disclosures of all of the above applications are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a cold-storage heat exchanger used for a refrigerant cycle device. 
     BACKGROUND 
     Conventionally, a cold-storage type cooling device for a trucker nap, described in JP 8-175167A, is known. A container, in which a cold-storage material is sealed, is made of a resin film, in the cold-storage type cooling device of JP 8-175167A. A recess portion and a protrusion portion are provided on a surface of the container, and are configured such that an air passage for air cooled by the cold-storage material is formed by the recess portion. 
     In a cold storage time, refrigerant flows into refrigerant tubes in which the container is inserted, so as to configure an evaporator for a trucker nap. Thus, air passing through the air passage is supplied to the trucker, thereby performing a cooling operation by the evaporator. 
     In the above cold-storage type cooling device, an evaporator for a vehicle interior, for cooling the trucker during a vehicle running, is located separately from the evaporator for a trucker nap, such that refrigerant discharged from a compressor flows into both the evaporators in parallel. 
     In the above cold-storage type cooling device, a cold-storage heat exchanger used as the evaporator for a trucker nap only causes air to perform heat exchange with the cold-storage material and to flow, after being cold-stored. Thus, in order to perform the cooling of a vehicle compartment, another evaporator used as a cooling heat exchanger is required, thereby increasing the cost. 
     Furthermore, when the refrigerant tube and the cold storage container are bonded and brazed, a clearance may be caused between a surface of the cold storage container and a surface of the refrigerant tube, and thereby condensed water generated on the evaporator surface may enter into the clearance. Thus, in a case where the refrigerant temperature is equal to or lower than 0° C., the condensed water in the clearance is frozen. 
     When the condensed water is frozen in the clearance, the volume of the frozen part is expanded, thereby causing a frost break such as a break of the refrigerant tube and the cold storage container. If a cold storage, a cooling of a compartment due to the refrigerant tube, and a cooling of the compartment due to the cold release of the cold storage material are performed by using a single heat exchanger, air passes around the cold storage container even in the cold storage time, and water in the air easily adheres on the surface of the cold storage container. In this case, the above problem of the frost break is remarkable. 
     SUMMARY 
     An object of the disclosure is to provide a cold storage heat exchanger, which can perform by using a single heat exchanger, a cold storage, a cooling of a compartment due to a refrigerant tube, and a cooling of the compartment due to a cold release of a cold storage material, thereby preventing a problem regarding a freezing break. 
     According to an embodiment of the disclosure, a cold storage heat exchanger includes a plurality of refrigerant tubes having therein refrigerant passages and arranged to provide a clearance therebetween, and a cold storage container that is bonded to the refrigerant tube and defines a compartment receiving a cold storage material. A cooling air passage, in which air flows to cool a space to be cooled in a cold storage time of the cold storage material and in a cold release time of the cold storage material, is provided to contact a surface of the refrigerant tube on a side opposite to the cold storage container bonded to the refrigerant tube. An outer surface of the cold storage container, onto which the refrigerant tube is bonded, is provided with a plurality of protrusion portions or a plurality of recess portions. 
     According to another embodiment of the disclosure, a cold storage heat exchanger includes a plurality of flat tubes having therein refrigerant passages, and arranged to provide a clearance therebetween; and a cold storage container disposed in the clearance and bonded to at least one of the plurality of flat tubes, the cold storage container having therein a compartment receiving a cold storage material. The cold storage container has a plurality of protrusion portions protruding outward of the cold storage container and being in contact with a flat surface of the at least one flat tube. Each of the plurality of protrusion portions extends from an edge to another edge of the flat surface with continuously contacting the flat surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram showing a refrigerant cycle device for a vehicle air conditioner, according to a first embodiment of the disclosure; 
         FIG. 2  is a front view showing an evaporator according to the first embodiment; 
         FIG. 3  is a side view showing the evaporator when being viewed from the arrow III of  FIG. 2 ; 
         FIG. 4  is a schematic sectional view showing a part of the evaporator, in a section taken along the line IV-IV of  FIG. 2 ; 
         FIG. 5  is a schematic sectional view showing relationships between a refrigerant tube, a cold storage container and an air-side fin, in a section taken along the line V-V of  FIG. 3 ; 
         FIG. 6  is an inner side view of the cold storage container, when being viewed from the arrow VI of  FIG. 5 ; 
         FIG. 7  is a schematic diagram for explaining a draining state of condensed water flowing downwardly when the evaporator of the first embodiment is mounted in a position of a vertical direction; 
         FIG. 8  is a schematic diagram for explaining a state of discharging a treating solution in a surface processing step of the evaporator; 
         FIG. 9  is an enlarged side view showing a part of a cold storage container similar to  FIG. 6 , according to a second embodiment of the disclosure; 
         FIG. 10  is a schematic sectional view showing relationships between a refrigerant tube, a cold storage container and an air-side fin, in a section similar to  FIG. 5 , according to the second embodiment of the disclosure; 
         FIG. 11  is a characteristic diagram showing relationships between a capacity ratio of the evaporator, and a brazing surface ratio between the cold storage container and the refrigerant tube, in the above first embodiment and the above second embodiment of the disclosure; 
         FIG. 12  is a schematic diagram for explaining a flow of a brazing material in the structure of  FIG. 10 ; 
         FIG. 13  is a side view of a cold storage container having an uneven shape of a lattice arrangement, as an example of another embodiment of the disclosure; 
         FIG. 14  is a side view of a cold storage container having an uneven shape of an oblique arrangement, as an example of another embodiment of the disclosure; 
         FIG. 15  is a side view of a cold storage container having an uneven shape of a zigzag arrangement, as an example of another embodiment of the disclosure; 
         FIG. 16  is a side view of a cold storage container having an uneven shape of a round lattice arrangement, as an example of another embodiment of the disclosure; 
         FIG. 17  is a schematic sectional view showing relationships between a refrigerant tube, a cold storage container and an air-side fin, in a section taken along the line V-V of  FIG. 3 , according to a third embodiment of the disclosure; 
         FIGS. 18A and 18B  are sectional views for explaining a performance decrease due to a bonding ratio between an inner fin and a cold storage container of an evaporator according to the third embodiment, in which  FIG. 18A  indicates a case where an outer surface bonding ratio X is suitably small, and  FIG. 18B  indicates a case where the outer surface bonding ratio X is too large; 
         FIGS. 19A, 19B and 19C  are graphs for explaining performances due to the bonding ratio between the inner fin and the cold storage container of the evaporator according to the third embodiment; 
         FIG. 20  is a side view showing a part of rib shape on a surface of a cold storage container in an evaporator, according to a fourth embodiment of the disclosure; 
         FIG. 21  is a side view showing a part of rib shape on a surface of a cold storage container in an evaporator, according to a fifth embodiment of the disclosure; 
         FIG. 22  is a side view showing a part of rib shape on a surface of a cold storage container in an evaporator, according to a sixth embodiment of the disclosure; 
         FIG. 23  is a side view showing a part of rib shape on a surface of a cold storage container in an evaporator, according to a seventh embodiment of the disclosure; 
         FIG. 24  is a front view showing an evaporator with a cold storage material, formed by stacking plates, according to an eighth embodiment of the disclosure; 
         FIG. 25  is a left side view showing the evaporator with a cold storage material of  FIG. 24 ; 
         FIGS. 26A and 26B  are schematic sectional views showing in contrast, an evaporator in which a refrigerant tube is manufactured by a drawn-cup tube, and an evaporator in which a refrigerant tube is manufactured by extrusion, according to the eighth embodiment of the disclosure; 
         FIGS. 27A and 27B  are schematic sectional views showing in contrast, an evaporator in which a refrigerant tube is manufactured by a drawn-cup tube, and an evaporator in which a refrigerant tube is manufactured by extrusion, according to a ninth embodiment of the disclosure; 
         FIG. 28  is a schematic sectional view showing a part of an evaporator similar to  FIG. 4 , according to a tenth embodiment of the disclosure; 
         FIG. 29  is an enlarged schematic sectional view showing a part Z 33  of  FIG. 28 ; 
         FIG. 30  is an enlarged schematic sectional view showing a part Z 34  of  FIG. 28 ; 
         FIG. 31  is a graph showing a variation state of an evaporator temperature in accordance with an interruption operation of a compressor according to a tenth embodiment of the disclosure; and 
         FIG. 32  is a side view showing reverse V-shaped ribs formed on a surface of a cold storage container of the evaporator of  FIG. 28 . 
     
    
    
     DETAILED DESCRIPTION 
     First Embodiment 
       FIG. 1  is a schematic diagram showing a refrigerant cycle device  1  for a vehicle air conditioner, according to a first embodiment of the disclosure. The refrigerant cycle device  1  for an air conditioner includes a compressor  10 , a radiator  20 , a decompression device  30  and an evaporator  40 . The components of the refrigerant cycle device  1  are connected in cycle by piping, thereby configuring a refrigerant circuit. 
     The compressor  10  is driven by an internal combustion engine (or electrical motor etc.) that is a driving source  2  for a vehicle traveling. Thus, the compressor  10  is also stopped when the driving source  2  stops. The compressor  10  draws refrigerant flowing out of the evaporator  40 , compresses the drawn refrigerant, and discharge the compressed refrigerant toward the radiator  20 . The radiator  20  is configured to cool high-temperature refrigerant from the compressor  10 . The radiator  20  is also called as a condenser. The decompression device  30  decompresses the refrigerant cooled by the radiator  20 . The evaporator  40  evaporates the refrigerant decompressed by the decompression device  30 , thereby cooling air to be blown into a vehicle compartment. 
       FIG. 2  is a front view showing the evaporator  40  according to the first embodiment.  FIG. 3  is a side view showing the evaporator  40  when being viewed from the arrow III of  FIG. 2 .  FIG. 4  is an enlarged sectional view showing a part of the evaporator  40 , in a section taken along the line IV-IV of  FIG. 2 .  FIG. 5  is a schematic sectional view showing relationships between a refrigerant tube, a cold storage container and an air-side fin, in a section taken along the line V-V of  FIG. 3 . 
     In  FIG. 2  and  FIG. 3 , the evaporator  40  includes a plurality of branched refrigerant passage members. The refrigerant passage members are made of metal such as aluminum. The refrigerant passage members are formed by headers  41 ,  42 ,  43 ,  44  positioned by pairs, and a plurality of refrigerant tubes  45  connected between the headers  41 ,  42 ,  43 ,  44 . 
     More specifically, as shown in  FIGS. 2 and 3 , a first header  41  and a second header  42  are configured as a pair of header tanks, and are arranged in parallel to be separated by a predetermined distance. Furthermore, a third header  43  and a fourth header  44  are configured as a pair of header tanks, and are arranged in parallel to be separated by a predetermined distance. The refrigerant tubes  45  are arranged at the same interval between the first header  41  and the second header  42 . 
     The refrigerant tubes  45  corresponding to the first header  41  and the second header  42  are made to communicate with the interiors of the first header  41  and the second header  42 . Thus, a first heat exchange portion  48  shown in  FIG. 3  is formed by the first header  41 , the second header  42  and the plural refrigerant tubes  45  arranged between the first and second headers  41  and  42 . The refrigerant tubes  45  are also arranged at the same interval between the third header  43  and the fourth header  44 . 
     The refrigerant tubes  45  corresponding to the third header  43  and the fourth header  44  are made to communicate with the interiors of the third header  43  and the fourth header  44 . Thus, a second heat exchange portion  49  is formed by the third header  43 , the fourth header  44  and the plural refrigerant tubes  45  arranged between the third and fourth headers  43  and  44 . 
     As a result, the evaporator  40  includes the first heat exchange portion  48  and the second heat exchange portion  49  which are arranged at two layers. With respect to the flow direction of air shown by arrow  400  in  FIG. 3 , the second heat exchange portion  49  is arranged at an upstream side, and the first heat exchange portion  48  is arranged at a downstream side. 
     A joint (not shown) is provided as a refrigerant inlet at an end portion of the first header  41  A partition plate (now shown) is located in the first header  41  approximately at a center in a longitudinal direction of the first header  41 , to partition an interior space of the first header  41  into a first partition area and a second partition area. Thus, the plurality of tubes  45  is separated into a first group and a second group based on the partition position of the first header  41 . 
     In the evaporator  40 , refrigerant is firstly supplied to the first partition area of the first header  41  from the refrigerant inlet. Then, the refrigerant is distributed into the plural refrigerant tubes  45  of the first group from the first partition area of the first header  41 . The refrigerant passing through the plural tubes  45  of the first group flows into the second header  42 , to be joined therein. 
     The refrigerant flows in the second header  42 , and is distributed into the plural refrigerant tubes  45  of the second group from the second header  42 . Then, the refrigerant passing through the plural tubes  45  of the second group flows into the second partition area of the first header  41 . Thus, in the first heat exchange portion  48 , a refrigerant path, in which refrigerant flows in a U shape, is formed. 
     A joint (not shown) is provided as a refrigerant outlet at an end portion of the third header  43 . A partition plate (now shown) is located in the third header  43  approximately at a center in a longitudinal direction of the third header  43 , to partition an interior space of the third header  43  into a first partition area and a second partition area. 
     Thus, the plurality of tubes  45  between the third header  43  and the fourth header  44  is separated into a first group and a second group based on the partition position of the third header  43 . The first partition area of the third header  43  is arranged adjacent to the second partition area of the first header  41 . Furthermore, the first partition area of the third header  43  is provided to communicate with the second partition area of the first header  41 . 
     Thus, the refrigerant flows from the second partition area of the first header  41  to the first partition area of the third header  43 . Then, the refrigerant is distributed into the plural refrigerant tubes  45  of the first group of the second heat exchange portion  49  from the first partition area of the third header  43 . The refrigerant passing through the plural tubes  45  of the first group flows into the fourth header  44 , to be joined therein. The refrigerant flows in the fourth header  44 , and is distributed into the plural refrigerant tubes  45  of the second group from the fourth header  44 , in the second heat exchange portion  49 . 
     Then, the refrigerant passing through the plural tubes  45  of the second group flows into the second partition area of the third header  43 . Thus, in the second heat exchange portion  49 , a refrigerant path, in which refrigerant flows in a U shape, is also formed. The refrigerant in the second partition area of the third header  43  flows from the refrigerant outlet toward the compressor  10 . 
     In the evaporator  40 , the plurality of tubes  45  are arranged approximately at certain intervals, and clearances are formed between the plural refrigerant tubes  45 . A plurality air-side fins  46  and a plurality of cold-storage containers  47  are arranged in the clearances between the plural refrigerant tubes  45 , to have a predetermined regularity. A part of the clearances between the refrigerant tubes  45  is used as cooling air passages  460 . The remaining part in the clearances is used as receiving portions  461  in each of which the cold storage container  47  is disposed. 
     The receiving portions  461  are set to be in a range equal to more than 10% and equal to or lower than 50% of the total clearances formed between the plural refrigerant tubes  45 . The cold storage containers  47  are arranged and distributed approximately uniformly in an entire heat exchange area of the evaporator  40 . In the example of  FIG. 2 , two refrigerant tubes  45  positioned at two sides of the cold storage container  47  define the cooling air passages  460  for exchanging heat with air on each side opposite to the cold storage container  47 . 
     On the other point, as shown in  FIG. 4 , two refrigerant tubes  45  ( 45   a ) and  45  ( 45   b ) are arranged between the two air-side fins  46   a  and  46   b , and one cold storage container  47  is arranged between the two refrigerant tubes  45  ( 45   a ) and  45  ( 45   b ). 
     As shown in  FIGS. 4 and 5 , the refrigerant tubes  45  are multi-hole tubes each of which has a plurality of refrigerant passages extending in a tube longitudinal direction. The refrigerant tubes  45  ( 45   a ,  45   b ) are flat tubes. This multi-hole tube can be formed by an extrusion process. A plurality of refrigerant passages  45   c  shown in  FIG. 4  extend in the refrigerant tube  45  in a direction perpendicular to the paper surface of  FIG. 4 . 
     The plural refrigerant tubes  45  are arranged in plural lines (e.g., two lines). In each arrangement line, the plural refrigerant tubes  45  are arranged such that the side surfaces of the tubes  45  are opposite to each other. The plural refrigerant tubes  45  are arranged to define the cooling air passages  460  for performing heat exchange with air, and the receiving portions  461  for receiving the cold storage containers  47 , between adjacent two refrigerant tubes  45   a  and  45   b.    
     In the evaporator  40 , the air-side fins  46  is provided in the cooling air passages  460  so as to increase contact areas with air to be supplied to the vehicle compartment. In the present embodiment, the air-side fins  46  ( 46   a  and  46   b ) are formed by a plurality of corrugated fins. 
     The air-side fins  46  are thermally connected with the two adjacent refrigerant tubes  45 . The air-side fins  46  are bonded to the two adjacent refrigerant tubes  45  by using a bonding material superior in the thermal transmission. For example, a brazing material can be used as the bonding material. The air-side fin  46  is a louver plate formed by bending a metal plate such as a thin aluminum plate in a wave shape. 
     The evaporator  40  further includes the plural cold storage containers  47 . The cold storage containers  47  are made of a metal such as aluminum, for example. The cold storage container  47  is a cylindrical shape having concavities and convexities on its left and right surfaces of  FIG. 4 . 
     The cold storage container  47  is closed at its longitudinal two ends (e.g., top and bottom ends of  FIGS. 2 and 5 ), so that a chamber for receiving therein the cold storage material  50  is partitioned and sealed as shown in  FIG. 5 . The cold storage container  47  has main surfaces at its two side wall portions. The two side wall portions for defining the main surfaces of the cold storage container  47  are arranged respectively in parallel with the refrigerant tubes  45 . 
     The cold storage container  47  is disposed between adjacent two refrigerant tubes  45 . The cold storage container  47  is connected thermally to the two refrigerant tubes  45  arranged adjacently at two sides of the cold storage container  47 , at protrusion portions  47   a   1  of its outer shell  47   a.    
     The cold storage container  47  is bonded to the two adjacent refrigerant tubes  45  by using a bonding material superior in the thermal transmission. As the bonding material, a resin material such as a brazing material or adhesive can be used. In the first embodiment, the cold storage container  47  is brazed to the refrigerant tubes  45 . 
     A brazing material is provided between the cold storage container  47  and the refrigerant tubes  45 , so as to be connected by a larger sectional area therebetween. As the brazing material, a brazing foil may be arranged between the cold storage container  47  and the refrigerant tube  45 . In this case, the cold storage container  47  can be bonded to the refrigerant tube  45  to have a superior heat transmission therebetween. 
     The cold storage container  47  is provided with an outer shell  47   a  defining an outer surface of the cold storage container  47 . The outer shell  47   a  of the cold storage container  47  is formed to have an uneven surface shape. In the present embodiment, by using the uneven surface shape, the brazing performance of the cold storage container  47  with the refrigerant tube  45  can be improved. Because of the uneven surface shape of the outer shell  47   a  of the cold storage container  47 , the brazing area can be made smaller, thereby preventing a void or a clearance from being caused. 
     In  FIG. 5, 47   a   1  indicates protrusion portion (convexities), and  47   a   2  indicates recess portion (concavities) of the outer shell  47   a  of the cold storage container  47 . The protrusion portion  47   a   1  of the outer shell  47   a  of the cold storage container  47  is brazed to the refrigerant tube  45 . The brazing material contains silicon (Si). By adjusting a silicon amount contained in the brazing material, a degree of flux of the brazing material flowing into a brazing portion between the cold storage container  47  and the refrigerant tube  45  can be adjusted. The brazing material can easily flow into the brazing portion as the amount of Si becomes larger in the brazing material. The recess portion  47   a   2  of the outer shell  47   a  of the cold storage container  47  defines a cold-storage side air passage  461   a.    
     Furthermore, the uneven shape is formed in repeat by plural times in both of a longitudinal direction (top-bottom direction of  FIG. 5 ) of the cold storage container  47  and a lateral direction (top-bottom direction of  FIG. 4 ) of the cold storage container  47 . By the uneven surface shape of the outer shell  47   a  of the cold storage container  47 , draining performance of water such as condensed water can be improved. 
     As shown in  FIG. 5 , an inner fin  47   f  is arranged inside of the cold storage container  47  to be thermally and mechanically connected to an inner wall of the cold storage container  47 . The inner fin  47   f  is bonded to the inner wall of the cold storage container  47  by using a bonding material that is superior in the heat transmission. Thus, the bonding of the inner fin  47   f  to the inner wall of the cold storage container  47  can be performed by brazing. Because the inner fin  47   f  is connected to the inner side of the cold storage container  47 , it can prevent a deformation of the cold storage container  47 , and pressure resistance performance can be improved in the cold storage container  47 . 
     As shown in  FIG. 5 , the inner fin  47   f  is formed into a wave shape by bending a metal plate such as a thin aluminum plate. Because the surface of the cold storage container  47  is an uneven-shaped surface, the inner fin  47   f  is bonded to the recess portion  47  of the outer shell  47   a  of the cold storage container  47 , that is, the inside protrusion portion protruding to the inside of the cold storage container  47 . Therefore, mechanical strength and pressure resistance performance of the cold storage container  47  can be increased by using the inner fin  47   f . Thus, the protrusion portion  47   a   1  of the outer shell  47   a  protruding outside is not bonded to the inner fin  47   f . In  FIG. 5, 460  indicates the cooling air passage, and  461   a  indicates the cold-storage side air passage. 
       FIG. 4  shows the inner fin  47   f  as a plate material when the inner fin  47   f  is viewed from the top side of  FIG. 5 . In  FIG. 5 , the inner fin  47   f  bent in a wave shape is schematically indicated. Actually, a plurality of louvers are formed in the wave-shaped fin by cutting and standing the plate material. 
       FIG. 6  is an inner side view of the cold storage container  47  showing an inner wall of the cold storage container  47 , when being viewed from the arrow VI of  FIG. 5 . The cold storage container  47  molded by aluminum in  FIG. 6  is a rectangular container having a height dimension of about 225 mm, a width dimension of about 50 mm, and a thickness dimension of about 5 mm, for example. The height dimension is the dimension of the cold storage container  47  in the top and bottom direction of  FIG. 6 . As shown in  FIG. 6 , the plural protrusion portions  47   a   1  on the container surface are formed in a zigzag arrangement. When the plural protrusion portions  47   a   1  are formed in the zigzag shape on the surface of the cold storage container  47 , the container  47  can be easily removed from a die in a press molding. Furthermore, the lateral width dimension of the brazing portion of each protrusion portion  47   a   1  is set to be equal to or lower than a width of 2-5 mm, in order to prevent void. 
     Inside of the cold storage container  47  having the thickness about 5 mm, the inner fin  47  is disposed, as shown in  FIG. 5 . In  FIG. 6, 47   g  indicates a punching-out portion configured to stop and fix the inner fin  47 . The inner fin  47   f  and the cold storage material  50  are contained inside of the cold storage container  47  approximately to a height position where the punching-out portion  47   g  is provided. Furthermore, air is sealed in the interior of the cold storage container  47  at an upper side of the punching-out portion  47   g . Thus, by the compression action of the air, a stress applied to the cold storage container  47  in the expansion of the cold storage material  50  can be reduced (refer to  FIG. 5 ). 
     The operation effects of the first embodiment will be described. In the present embodiment, the plural recess portions  47   a   2  and the plural protrusion portions  47   a   1  are provided on the surface of the cold storage container  47 . Therefore, only the outer surfaces of the protrusion portions  47   a   1  are used as the contact portion between the cold storage container  47  and the refrigerant tube  45 . Furthermore, condensed water or a treating solution used in the evaporator surface process can be discharged easily by using the clearance between the protrusion portions  47   a   1  (or/and using the surfaces of the recess portions  47   a   2 ). 
       FIG. 7  is a schematic diagram for explaining a state of condensed water flowing downwardly when the evaporator is mounted to a vehicle air conditioner in a position of a vertical direction. In  FIG. 7 , the arrows  47   h   1  show the streams of the condensed water flowing in parallel from the top direction to the down direction, on the surfaces of the recess portions  47   a   2  of the outer shell  47   a  of the cold storage container  47 , between the protrusion portions  47   a   1  arranged in a zigzag shape. 
     Because of the protrusion portions  47   a   1 , it can prevent a flat contact in a wide area, thereby preventing a void generation in the brazing portion after the brazing. Therefore, the brazing performance between the cold storage container  47  and the refrigerant tube  45  can be improved. 
     In the present embodiment, the plural recess portions  47   a   2  and the plural protrusion portions  47   a   1  are provided on the surface of the cold storage container  47 . Therefore, only the inside protrusions of the recess portions  47   a   2  can be made to contact the inner fin  47   f  of the cold storage container  47 . 
     As a result, an inner path  50   a  can be secured between the inner fin  47   f  and the cold storage container  47 . Thus, in a sealing step for sealing the cold storage material  50 , a time for sealing the cold storage material  50  can be effectively shortened. 
       FIG. 8  is a schematic diagram for explaining a state of removing a treating solution in a surface processing step of the evaporator. After the dipping of the cold storage container  47  is performed in a treating solution, air is blown by a blower to the cold storage container  47 . In  FIG. 8 , the arrows  47   h   2  show the streams of the treating solution flowing on the surfaces of the recess portions  47   a   2  of the cold storage container  47  between the protrusion portions  47   a   1  arranged in a zigzag shape. Furthermore,  471  and  472  indicate the direction of air blown by the blower in the surface processing step. 
     Because the uneven shape of the cold-storage container  47  is repeated in the longitudinal direction and the lateral direction of the cold storage container  47 , the draining performance can be secured regardless of the mounting angle of the evaporator. In particular, it is preferable to provide thin and long oval protrusion portions  47   a   1  along the longitudinal direction of the cold storage container  47 , as shown in  FIG. 7 . In this case, the draining performance of the condensed water, press-molding performance of the cold storage container  47 , and sealing performance of the cold storage material  50  can be more improved. 
     Second Embodiment 
     Next, a second embodiment of the disclosure will be described.  FIG. 9  is a side view showing a cold storage container  47  according to the second embodiment, corresponding to that of  FIG. 6 . In the present embodiment and the following embodiments, a part that corresponds to a matter described in the above first embodiment may be assigned with the same reference numeral, and the explanation for the part may be omitted. Only different structures and features different from the above-described first embodiment will be mainly described in the present embodiment and the following embodiments. 
     As shown in  FIG. 9 , in the second embodiment, the cold storage container  47  is provided with plural protrusion portions  47   a   1  each having an open-hole shape at its center portion (i.e., protrusion tip surface). As shown in  FIG. 10 , via open-hole portions  47   a   3  opened at the protrusion portions  47   a   1 , the cold storage material  50  in the cold storage container  47  can directly contact the surface of the refrigerant tube  45 . 
     Further, it is preferable to set the brazing width of the protrusion portion  47   a   1  in the left-right direction of  FIG. 9  to be in a range of 2 mm to 5 mm. 
       FIG. 10  is an enlarged sectional view showing relationships between the refrigerant tube  45 , the cold storage container  47  and the air-side fin  46 , similarly to  FIG. 5 . The cold storage material  50 , sealed in the cold storage container  47  together with the inner fin  47   f , exposes from the inside of the cold storage container  47  into the open-hole portions  47   a   3 , thereby directly contacting the surface of the refrigerant tube  45 . In  FIG. 10, 460  indicates the cooling air passage, and  461   a  indicates the cold-storage side air passage. 
     After the protrusion portions  47   a   1  of the cold storage container  47  are brazed to the refrigerant tube  45 , the cold storage material  50  is sealed in the cold storage container  47  by the surface of the refrigerant tube  45 . Thus, it can prevent the cold storage material  50  from leaking from the open-hole portions  47   a   3  of the cold storage container  47 . 
     A contact area is set at 100% as a reference, if all the outer surface of a cold storage container  47  without an uneven shape (i.e., without the recess portions  47   a   2  and the protrusion portions  47   a   1 ) or without the open-hole portion  47   a   3  is used as the contact surface contacting the surface of the refrigerant tube  45 . In this case, when the uneven shapes or/and the hole-open portions  47   a   3  are provided in the outer surface of the cold storage container  47  so that the contact area of the cold storage container  47  partially contacting the refrigerant tube  45  becomes equal to or larger than 10% (more preferably, equal to or larger than 20%) as in the first and second embodiments, the heat exchanging capacity can be sufficiently obtained in the evaporator for an air conditioner, as described later. Here, the contact area corresponds to a brazing area. 
       FIG. 11  is a characteristic diagram showing relationships between a capacity ratio of the evaporator, and a brazing surface ratio between the cold storage container  47  and the refrigerant tube  45 . In  FIG. 11 , the capacity ratio of the evaporator is set at 100%, when the brazing area ratio is set at 100% in a case where all the outer surface of the cold storage container  47  without an uneven shape or without the open-hole portion  47   a   3  is used as the contact surface contacting the surface of the refrigerant tube  45 . As shown in  FIG. 11 , even when the cold storage container  47  is provided with the uneven shape or the open-hole portions at the protrusion portions  47   a   1 , when the ratio of the brazing area partially contacting the refrigerant tube  45  is set equal to or larger than 10%, the capacity ratio of the evaporator can be maintained equal to or larger than 90%. 
     In a case where the open-hole portions  47   a   3  are provided, it is preferable to use a brazing material formed on the inner surface of the cold storage container  47  to be different from a brazing material formed on the outer surface of the cold storage container  47 , as the brazing materials used at the brazing portion between the cold storage container  47  and the refrigerant tube  45 . The fluidity of the brazing material becomes larger, as an amount of silicon Si contained in the brazing material becomes larger. 
       FIG. 12  is a schematic diagram for explaining a flow of a brazing material in the structure of  FIG. 10 . In  FIG. 12 , arrow  47 IN indicates a flow of an inner-surface brazing material formed on an inner surface of the cold storage container  47 , and arrow  47 OUT indicates a flow of an outer-surface brazing material formed on an outer surface of the cold storage container  47 . 
     The fluidity of the brazing material becomes larger, as an amount of silicon Si contained in the brazing material becomes larger. When the fluidity of the inner-surface brazing material of the cold storage container  47  is made higher than the fluidity of the outer-surface brazing material of the cold storage container  47 , the brazing of the cold storage container  47  to the refrigerant tube  45  can be preferably performed. The reason will be explained below. 
     The outer-surface brazing material of the cold storage container  47  includes a sacrificial anticorrosion material. By limiting the fluidity of the outer-surface brazing material flowing into between the cold storage container  47  and the refrigerant tube  45 , the brazing at a necessary portion due to the outer-surface brazing material can be secured, and it is preferable to improve the anticorrosion performance of the brazing portion between the cold storage container  47  and the refrigerant tube  45 . Thus, in the present embodiment, the silicon Si amount is made larger in the inner-surface brazing material of the cold storage container  47  than that in the outer-surface brazing material of the cold storage container  47 , thereby increasing the fluidity of the inner-surface brazing material shown by the arrow  47 IN in  FIG. 12 . 
     In the present embodiment, because the brazing of the brazing portion between the cold storage container  47  and the refrigerant tube  45  is performed by using both the flow of the inner-surface brazing material flowing from the inner surface of the cold storage container  47  and the flow of the outer-surface brazing material flowing from the outer surface of the cold storage container  47 , the bonding performance of the cold storage container  47  to the refrigerant tube  45  can be effectively obtained and maintained. 
     Modification of the Above-Described First and Second Embodiments 
     The disclosure is not limited to the above-described embodiments, but the following changes and modifications will become apparent to those skilled in the art. For example, in the above-described first embodiment, the zigzag uneven shape is formed on the surface of the cold storage container  47 . However, as shown in  FIG. 13 , a grill-arrangement oval-uneven shape may be formed on the surface of the cold storage container  47 . Moreover, an uneven shape of the cold storage container  47  may be an oval-shaped slanting arrangement shown in  FIG. 14 , may be a round zigzag arrangement shown in  FIG. 15 , or may be a round grill arrangement shown in  FIG. 16 . 
     Third Embodiment 
       FIG. 17  is an enlarged sectional view showing relationships between a refrigerant tube, a cold storage container and an air-side fin, according to a third embodiment, in a section taken along the line V-V of  FIG. 3  similarly to  FIG. 5 . In the third embodiment, a bonding ratio of the outer surface of the cold storage container  47  or a bonding ratio of the inner surface of the cold storage container  47  is set in a predetermined range. 
     In  FIG. 17, 460  indicates a cooling air passage, and  461   a  indicates a cold-storage side air passage. In a case where the surface of the cold storage container  47  is configured to have ribs of an uneven shape, when an area ratio of the outer surface of the cold storage container  47  defining the protrusion portions  47   a   1  is set at X %, and when an area ratio of the inner surface of the cold storage container  47  defining the recess portion  47   a   2  is set at Y %, X+Y=100%. Here, the outer surface of the cold storage container  47  defining the protrusion portion  47   a   1  is the portion of the virtual lines indicated by the chain lines in  FIG. 17 . In contrast, the inner surface of the cold storage container  47  defining the recess portion  47   a   2  is the portion of the cold storage container  47  contacting the inner fin  47   f.    
     As shown in  FIG. 17 , the inner fin  47   f  having a uniform width is provided in the cold storage container  47 . By forming the uneven shape of the surface of the cold storage container  47 , the inner fin  47   f  is made to partially contact the inner surface of the cold storage container  47  and to partially not contact the inner surface of the cold storage container  47 . When the area ratio X of the virtual line portion of the cold storage container  47  is large, that is, when the area ratio Y of the recess portion  47   a   2  is small, a ratio of the non-contact area between the cold storage container  47  and the inner fin  47   f  becomes large, thereby reducing the performance of the heat exchanger (e.g., evaporator). 
     On the other hand, when the area ratio X of the virtual line portion is small, that is, when the area ratio Y is large, it is difficult to have a sufficient contact area between the cold storage container  47  and the refrigerant tubes  45  ( 45   a ,  45   b ). In this case, the amount of the cold storage material and the amount of the brazing material can be made small, but heat exchanging performance of a cold storage heat exchanger (e.g., evaporator) is reduced. 
     The inner fin  47   f  is bent in a wave shape to have ending portions, so that the tip portions of the bending portions partially contact the inner surface of the cold storage container  47 . The wave height of the bending portions (i.e., the width of the inner fin  17  in the left-right direction of  FIG. 17 ) is made uniform. When the wave height of the bending portions of the inner fin  47   f  is made uniform, the inner fin  47   f  can be easily manufactured and assembled. 
       FIGS. 18A and 18B  are schematic diagrams for explaining a decrease in heat exchange performances due to the bonding ratio between the inner fin  47   f  and the cold storage container  47 .  FIG. 18A  shows a case where the area ratio (bonding ratio) X of the outer surface of the cold storage container  47  is in a suitable range, and  FIG. 18B  shows a case where the bonding ratio X of the outer surface of the cold storage container  47  is too large. 
     In the case of  FIG. 18A , the heat transmission distance from the refrigerant tubes  45   a ,  45   b  to the inner fin  47   f  and to the cold storage material  50  is made shorter, thereby increasing heat transmission amount. In contrast, in the case of  FIG. 18B , the heat transmission distance from the refrigerant tubes  45   a ,  45   b  to the inner fin  47   f  and to the cold storage material  50  is made longer, thereby decreasing heat transmission amount. 
     Because of the uneven portion is provided in the cold storage container  47 , a part of the inner fin  47   f  does not contact the cold storage container  47 , and is not brazed to the inner wall of the cold storage container  47 . Thus, the performance of the cold storage heat exchanger is changed by the uneven shape and dimension. 
       FIGS. 19A, 19B and 19C  are graphs for explaining the heat exchange performances due to the bonding ratio between the inner fin  47   f  and the cold storage container  47 .  FIG. 19A  is a graph showing the relationship between a bonding ratio X and a cold release time after the cold storage material  50  is sufficiently cold-stored.  FIG. 19B  is a graph showing the relationship between the bonding ratio X and a cold storage time (Seconds).  FIG. 19C  is a graph showing the relationship between a bonding ratio X and a cold release time (Seconds) when the cold storage is performed for a limited time and is not completely finished. 
     In  FIGS. 18A-18B  and  FIGS. 19A-19C , when the bonding ratio X becomes larger, the volume of the cold storage material  50  at a portion adjacent to the bonding portion is increased. Therefore, in a case where cold storage is sufficiently performed for the cold storage material  50 , the cold release time becomes larger as the bonding ratio X increases, as in the graph of  FIG. 19A . 
     Here, the time for solidifying all the cold storage material  50  is defined as the cold storage time. In this case, when the bonding ratio X becomes larger as in  FIG. 18B , the heat transmission path for transmitting heat to the inside of the cold storage material  50  becomes longer as in  FIG. 18B , and thereby the heat exchange efficiency of the air-side fins  46  ( 46   a ,  46   b ) is decreased. 
     Therefore, as in the graph of  FIG. 19B , when the bonding ratio X is large, the cold storage time becomes pretty large. Furthermore, the time, for which the cold storage can be performed, is a limited time having a relation with the driving time of a vehicle. Therefore, it is necessary to effectively use the cold storage material  50  mounted in the vehicle, and to completely perform the cold storage of the cold storage material  50 . In the graph of  FIG. 19B , TL indicates the above-described limited time. 
       FIG. 19C  is a graph showing the cold release time when the cold storage is performed in the limited time TL. As in the graph of  FIG. 19C , the cold release time becomes maximum at the bonding ratio of about 50%. As in the graphs of  FIGS. 19A-19C , in order to effectively perform the cold storage in the limited time and in order to secure the cold release time by a small amount of the cold storage material  50 , it is preferable to set the bonding ratio X at 50% or lower. 
     With respect to the outside surface (X+Y portion) of the cold storage container  47 , it is preferable to set the ratio X of the contact area to be in a range of 20% to 50%, when the cold storage container  47  is partially bonded to the outer surface of the refrigerant tube  45 . In this case, it is possible to limit a decrease in the heat exchange performance of the cold-storage heat exchanger to be in a range equal to smaller than 1%, while the ratio X of the contact area can be made small. 
     Furthermore, the contact ratio between the cold storage container  47  and the refrigerant tube  45  is set so that a sufficient heat transmission amount can be secured therebetween. Thus, it is possible to store the thermal amount in the cold storage material  50  in a limited time, and the cold release can be performed for a sufficient long time by using the stored thermal quantity. Accordingly, when the vehicle engine is stopped at the red light of a traffic intersection, a supplemental air-conditioning effect for a vehicle compartment can be increased. 
     Fourth Embodiment 
     Next, a fourth embodiment of the disclosure will be described. In the above-described embodiments, the plural protrusion portions  47   a   1  or the plural recess portions  47   a   2  are formed in the cold storage container  47 , so as to have uneven shapes shown in any one of  FIGS. 6, 7, 8, 9, 13, 14, 15 and 16 . However, in the fourth embodiment, ribs composed of plural protrusion portions  47   a   1  are formed into reverse-V shapes (slanting shapes). 
       FIG. 20  shows the shape of ribs formed on the surface of the cold storage container  47  according to the fourth embodiment of the disclosure. The cold storage container  47  is assembled to a vehicle, such that the lower side of the cold storage container  47  in  FIG. 20  is positioned on the bottom side in the top-bottom direction of the vehicle. The plural protrusion portions  47   a   1  or the plural recess portions  47   a   2  are formed on the surface of the cold storage container  47 , respectively in a mountain shape having a top portion and two slanting portions at two sides of the top portion, so that condensed water flows downwardly from the top portion to be separated at the left and right two sides of the top portion. 
     Because the protrusion portions  47   a   1  or the recess portions  47   a   2  are formed in slanting shapes, the condensed water generated on the surface of the cold storage container  47  can be separated into the left and right sides from the mountain-shaped top portion, and can be promptly discharged outside along the slanting portions. Thus, it can prevent the refrigerant tube  45  and the cold storage container  47  from being broken due to the volume expansion of the frozen condensed water, thereby preventing a freezing crack. 
     Thus, even when the condensed water remains on the surface of the cold storage container  47  and is frozen thereon, the frozen ice can be easily removed, thereby preventing the freezing crack. Because condensed water can flow along the slanting portions separated into the left and right sides, the length of the slanting portions can be made shorter, thereby improving the discharge performance of the condensed water. 
     Specifically, the protrusion portions  47   a   1  or the recess portions  47   a   2  are formed on the surface of the cold storage container  47  such that a protrusion height of the rib of the slanting shape is equal to or more than 0.2 mm. Furthermore, a rib pitch, which is a clearance between adjacent protrusion portions  47   a   1  or a clearance between adjacent recess portions  47   a   2 , is set equal to or more than 3 mm. In addition, the plural ribs are overlapped by plural layers equal to or more than three, from the top direction of the cold storage container  47  toward the bottom direction of the cold storage container  47 . 
     When the air-conditioning of the vehicle compartment is performed by using the cold-storage container  47 , condensed water may stay in the cooling fin  46  within the cooling air passage  47  (see  FIG. 17  or the like), and in the cold-storage side air passage  461   a  between the refrigerant tube  45  integrated with the cooling fin  46  and the cold storage container  47 . In this case, when the frost of the condensed water is caused in a low load, the cold storage container  47  and the refrigerant tube  45  may be broken. 
     In the fourth embodiment, the ribs composed of the reverse V-shaped protrusion portions  47   a   1  are arranged between the refrigerant tube  45  and the cold storage container  47 , so as to reduce the amount of condensed water staying in the space between the refrigerant tube  45  and the cold storage container  47 . 
     Thus, it can prevent condensed water on an upper side of the cold storage container  47  from flowing into the reverse V-shaped rib on a lower side of the cold storage container  47 . As a result, the amount of the condensed water staying between the refrigerant tube  45  and the cold storage container  47  can be reduced. Furthermore, even when the freezing of the condensed water is caused, it can remove the generated ice to an outer side (i.e., paper face-back direction of  FIG. 17 ) from the space between the refrigerant tube  45  and the cold storage container  47 . 
     Fifth Embodiment 
     Next, a fifth embodiment of the disclosure will be described.  FIG. 21  shows the shape of ribs on the surface of the cold storage container  47  according to the fifth embodiment of the disclosure. The cold storage container  47  is assembled to a vehicle, such that the lower side of the cold storage container  47  in  FIG. 21  is positioned on the bottom side in the top-bottom direction of the vehicle. In the above-described fourth embodiment, the ribs are arranged substantially by the same pitch to be overlapped from the top direction to the bottom direction of the cold storage container  47 . However, in the fifth embodiment, as shown in  FIG. 21 , the ribs are arranged by different pitches to be overlapped from the top direction to the bottom direction of the cold storage container  47 . 
     Sixth Embodiment 
     Next, a sixth embodiment of the disclosure will be described.  FIG. 22  is a side view showing a part of rib shapes formed on a surface of a cold storage container  47  in an evaporator, according to a sixth embodiment of the disclosure. In the above-described fourth and fifth embodiments, the ribs are arranged to be overlapped from the top direction to the bottom direction of the cold storage container  47 , such that the left and right slanting shapes are continuously formed in each rib. However, in the sixth embodiment, as shown in  FIG. 22 , the ribs of the slanting shapes are arranged on the surface of the cold storage container  47  such that left and right slanting shapes are separated by a center groove in each rib. 
     Seventh Embodiment 
     Next, a seventh embodiment of the disclosure will be described.  FIG. 23  is a side view showing a part of rib shapes on a surface of a cold storage container  47  in an evaporator, according to a seventh embodiment of the disclosure. In the above-described sixth embodiment, the ribs with the left and right separated slanting shapes are arranged substantially by the same pitch to be overlapped from the top direction to the bottom direction of the cold storage container  47 . However, in the seventh embodiment, as shown in  FIG. 23 , the ribs having the left and right separated slanting shapes separated at its width center are arranged by different pitches to be overlapped from the top direction to the bottom direction of the cold storage container  47 . 
     In the above examples shown in  FIGS. 20 to 23 , the reverse V-shaped ribs or the slanting-shaped ribs are arranged on the surface of the cold-storage container  47  such that the plural protrusion portions  47   a   1  or the plural recess portions  47   a   2  are overlapped in the top-bottom direction of the cold-storage container  47 . Furthermore, in the ribs, the left and right slanting portions, through which condensed water flows from a mountain tip portion separately to the left and right sides, are formed to extend to left and right two ends  47   t  of the cold storage container  47 . 
     Accordingly, a large part of the generated condensed water is discharged to outside from the two ends  47   t  on the outside surface of the cold storage container  47 . Therefore, it is difficult for the condensed water to be stored in a lower portion of the cold storage container  47 , thereby preventing a freezing break in which the refrigerant tube  45  and the cold storage container  47  are broken in the lower portion. 
     Furthermore, in the plural protrusion portions  47   a   1  or the plural recess portions  47   a   2 , the left and right slanting portions, through which condensed water flows from a mountain tip portion separately to the left and right sides, are formed to extend to left and right two ends  47   t  on the outside surface of the cold storage container  47 . In addition, as shown in  FIG. 20 , the plural protrusion portions  47   a   1  or the plural recess portions  47   a   2  are provided, such that a cross angle θ between a straight line and an extending line of the slanting portions are set in a range of 30-60 degrees. Here, the straight line is a connection line connecting a pair of the left and right two ends  47   t  by the shortest distance, as shown in  FIG. 20 . Thus, even when the vehicle is tilted on a slop, a draining performance of the condensed water can be sufficiently obtained. 
     Furthermore, the protrusion portions  47   a   1  of the cold storage container  47  and the refrigerant tube  45  are brazed to be in closely contact, by an area equal to or larger than 80% with respect to the opposite surface between the plural protrusion portions  47   a   1  of the cold storage container  47  and the refrigerant tube  45 . Thereby, condensed water can be certainly discharged to the outside of the cold storage container  47  along the slanting portions of the protrusion portions  47   a   1 . 
     Eighth Embodiment 
     Next, an eighth embodiment of the disclosure will be described. In the above-described embodiments, the refrigerant passage portion of the evaporator  40  is configured by the headers  41 ,  42 ,  43 ,  44  and the refrigerant tubes  45  located between the headers  41 ,  42 ,  43 ,  44 , as shown in  FIGS. 2 and 3 . 
     The respective refrigerant tubes  45  are made to communicate with corresponding headers  41 ,  42 ,  43 ,  44  at the ends of the refrigerant tubes  45 . Moreover, each refrigerant tube  45  is a flat tube having multi-holes, which is formed by the extrusion process to have therein plural refrigerant passages extending in the tube longitudinal direction. The ribs on an uneven surface can be formed via the extrusion process by using a pressurization roller, similarly to the method described in JP 2004-3787A. 
     In the eighth embodiment, plural pairs of plates, each pair having integrated tank portion and refrigerant tube portion, are stacked in a stacking direction, thereby forming a heat exchanger. A stack-type heat exchanger described in JP 2001-221535 can be used and incorporated by reference in the present embodiment. 
     The ribs with the uneven shape, composed of the protrusion portions  47   a   1  and the recess portions  47   a   2 , can be formed on a surface of a cup-shaped tube (drawn-cup tube) formed by overlapping a pair of plates, by using a method described in JP 2004-3787A that is incorporated by reference in the present embodiment. The contents described in JP 2004-3787A and JP 2001-221535A can be incorporated herein by reference, as the technical contents of the present specification. 
       FIG. 24  is a front view of an evaporator with a cold storage material in the eighth embodiment formed, by the above-mentioned stacking plates.  FIG. 25  is a left side view showing the evaporator with the cold storage material of  FIG. 24 . As shown in  FIG. 24  and  FIG. 25 , the tank portion and refrigerant tube portion of the evaporator are formed integrally by overlapping a pair of plates. Plural pairs of the overlapped plates are stacked, and the cold storage containers  47  are inserted partially between the stacked parts. In  FIGS. 24 and 25 , uneven shapes on the surface of the cold-storage container  47  or the refrigerant tube  45  are not shown. Moreover, in  FIG. 24  and  FIG. 25 , parts corresponding those of  FIG. 2  are indicated by the same reference numbers. 
       FIGS. 26A and 26B  are schematic sectional views by comparison, showing an evaporator in which a refrigerant tube is manufactured by a drawn-cup tube according to the eighth embodiment, and an evaporator in which a refrigerant tube is manufactured by extrusion. That is, a refrigerant tube  45  of the eighth embodiment shown in  FIG. 26A  is a drawn-cup tube. 
     In  FIG. 26A , an air-side fin  46  is provided in a cooling air passage  460  on the left side, a refrigerant tube  45  of a drawn-cup type having therein an inner fin  45   f  is provided at one side of the air-side fin  46 , and a cold storage container  47  having an uneven surface is bonded to a surface of the refrigerant tube  45  opposite to the surface on the air side. 
     The air-side fin  46 , the refrigerant tube  45  and the cold storage container  47  are configured as one unit. For example, Plural units can be overlapped to configure an evaporator. Another air-side fin  46  may be bonded to the right surface of the cold storage container  47  shown in  FIG. 26A  to form a unit. Alternatively, another refrigerant tube  45  having therein an inner fin  45   f  may be bonded to the right surface of the cold storage container  47  to form a unit. 
     The refrigerant tube  45  of  FIG. 26B  is formed by extrusion similarly to the first embodiment.  FIG. 26B  is a modification of the first embodiment. In  FIG. 26B , an inner fin  47   f  is not provided in the cold storage container  47 , which is different from the first embodiment shown in  FIG. 4 . In  FIGS. 26A and 26B , the evaporator formed by using a drawn-cup method with laminated plates, is compared with the evaporator formed by extrusion. 
     Ninth Embodiment 
     Next, a ninth embodiment of the disclosure will be described.  FIGS. 27A and 27B  are schematic sectional views by comparison, showing an evaporator in which a refrigerant tube is manufactured by a drawn-cup tube, and an evaporator in which a refrigerant tube is manufactured by extrusion, according to the ninth embodiment; 
     That is, a refrigerant tube  45  of the ninth embodiment shown in  FIG. 27A  is a drawn-cup tube. In  FIG. 27A , an air-side fin  46  is provided in a cooling air passage  460  on the left side, and a refrigerant tube  45  of a drawn-cup type having therein a refrigerant tube fin  45   f  (inner fin) is provided at one side of the air-side fin  46 . 
     One surface of the refrigerant tube  45  is formed in uneven to have protrusion portions  45   a   1  as ribs, and recess portions  45   a   2 . A flat cold storage container  47  without an uneven portion on the surface is bonded to a surface of the refrigerant tube  45  opposite to the surface of the air-side fin  46 . Thus, a cold-storage side air passage  461   a  is formed between the recess portions  45   a   2  of the refrigerant tube  45  and the flat surface of the cold storage container  47 . 
     The air-side fin  46 , the refrigerant tube  45  and the cold storage container  47  are configured as one unit. For example, Plural units can be overlapped to configure an evaporator. Another air-side fin  46  may be bonded to the right surface of the cold storage container  47  shown in  FIG. 27A  to form a unit. Alternatively, another refrigerant tube  45  having therein an inner fin  45   f  may be bonded to the right surface of the cold storage container  47  to form a unit. 
     The refrigerant tube  45  of  FIG. 27B  is formed by extrusion similarly to the first embodiment of  FIG. 4 .  FIG. 27B  is a modification of the first embodiment. In  FIG. 27B , the surface of the cold storage container  47  is formed to be flat without an uneven portion, the protrusion portions  45   a   1  and the recess portions  45   a   2  are formed on the one surface of the refrigerant tube  45  to form ribs, and an inner fin  47   f  is not provided in the cold storage container  47 , which are different from the above-described first embodiment. In  FIGS. 27A and 27B , the evaporator formed by using a drawn-cup method with laminated plates, is compared with the evaporator formed by extrusion. 
     Tenth Embodiment 
     Next, a tenth embodiment of the disclosure will be described.  FIG. 28  is a schematic sectional view showing a part of an evaporator similar to  FIG. 4  of the first embodiment, according to the tenth embodiment of the disclosure.  FIG. 29  is an enlarged schematic sectional view showing a part Z 33  of  FIG. 28 ; 
       FIG. 30  is an enlarged schematic sectional view showing a part Z 34  of  FIG. 28 ;  FIG. 31  is a graph showing a variation state of an evaporator temperature in accordance with an interruption operation of a clutch connected to a compressor according to the tenth embodiment.  FIG. 32  is a side view showing reversed V-shaped ribs formed on a surface of a cold storage container  47  of the evaporator of  FIG. 28 . 
     As shown in  FIG. 28 , the refrigerant tubes  45  are multi-hole tubes, each of which has therein a plurality of refrigerant passages extending in a tube longitudinal direction. Left and right refrigerant tubes  45   a  and  45   b  ( 45 ) are arranged at two sides of a cold storage container  47  having therein an inner fin  47   f , and two cooling air passages  460  for performing heat exchange with air are provided respectively at left and right sides of the left and right refrigerant tubes  45   a  and  45   b.    
     The refrigerant tube  45  and the cold storage container  47  contact at positions, and are bonded at the contact positions by a brazing material  33   r , as shown in  FIG. 29 . When a void  33   v  exists in the brazing material  33   v   1 , the condensed water  33   v   1  may stay in the void  33   v  of the brazing material  33   v   1 . 
     In the cold-storage side air passage  461   a  formed by the recess portions  47   a   2  on the surface of the cold storage container  47  of  FIG. 28 , a space  34   v  is provided as shown in  FIG. 30 . When air to be conditioned is blown by a cooling fan (not shown), air flows in the space  34   v , and water contained in air is condensed as a condensed water  34   v   1 . In this case, the condensed water  34   v   1  easily stays in the space  34   v . The space  34   v  is adapted as the cold-storage side air passage  461   a , when the cold storage material releases cold in the cold storage container  47 . 
     As shown in  FIG. 31 , the temperature of the evaporator (cold storage heat exchanger) changes to be repeated in accordance with interruption of a clutch connected to the compressor  10  of  FIG. 1 , thereby repeating freezing and solution of condensed water as shown in  FIG. 31 . In order to prevent a freezing break, a width W of a bonding flat portion of  FIG. 29  is set equal to or smaller than 0.8 mm. 
     Furthermore, the ribs formed by the protrusion portions  47   a   1  adjacent to the recess portions  47   a   2  are formed in reverse V-shape, as shown in  FIG. 32  when being viewed from the arrow Z 36  of  FIG. 30 . Therefore, the condensed water  34   v   1 , staying in the space  34   v  of  FIG. 30  formed by the recess portion  47   a   2  on the surface of the cold storage container  47 , can be discharged outside of the cold storage container  47 , as in arrows Y 36  of  FIG. 32 . 
     The width dimension of the recess portion  47   a   2  between the protrusion portions  47   a   1  is set, such that condensed water can be drawn in the direction shown by the arrow Y 361  from bottom by using the clearances between the protrusion portions  47   a   1 . Thus, even when condensed water becomes ice, the ice can easily fall on the surface of the cold storage container  47 , and can be easily removed to the outside. Therefore, it can prevent a stress for causing a freezing break from being generated. 
     In the cold storage heat exchanger in which the cold storage container  47  is integrated with the cooling fins  46   a ,  46   b  of the cooling air passage  460  for air-conditioning of the vehicle compartment, if condensed water stays in the cold-storage side air passage  461   a  between the refrigerant tube  45  and the cold storage container  47  so that a freezing (frost) of the condensed water is generated in a low load, the cold storage container  47  and the refrigerant tube  45  may be broken. According to the tenth embodiment, the reverse V-shaped ribs are arranged in the spaces between the refrigerant tube  45  and the cold storage container  47  as shown in  FIG. 32 , so as to reduce an amount of condensed water staying in the spaces between the refrigerant tube  45  and the cold storage container  47 . 
     Thus, in the tenth embodiment, it can restrict condensed water on the cold storage container  47  from flowing, from an upper side rib to a lower side rib on the surface of the cold storage container  47 . As a result, the amount of the condensed water staying between the refrigerant tube  45  and the cold storage container  47  can be reduced in the cold storage heat exchanger. Furthermore, even when the freezing of the condensed water is caused, it can easily remove the generated ice to an outer side from the space between the refrigerant tube  45  and the cold storage container  47 .