Patent Publication Number: US-2022234417-A1

Title: Air conditioning unit

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application is a continuation application of International Patent Application No. PCT/JP2020/036354 filed on Sep. 25, 2020, which designated the U.S. and claims the benefit of priority from Japanese Patent Application No. 2019-197868 filed on Oct. 30, 2019. The entire disclosures of all of the above applications are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to an air conditioning unit. 
     BACKGROUND 
     An air conditioning unit having two heat exchangers housed in one frame can be attached to and detached from an air conditioning case. 
     SUMMARY 
     According to an aspect of the present disclosure, an air conditioning unit includes: an air conditioning case having a passage through which air flows from an air inlet into a cabin; a first heat exchanger disposed in the passage of the air conditioning case so as to adjust a temperature of the air flowing through the passage; a second heat exchanger disposed in the passage of the air conditioning case and located downstream of the first heat exchanger in a flow of air; and a closure portion provided on at least one of the first heat exchanger and the second heat exchanger so as to close a gap between the first heat exchanger and the second heat exchanger. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cross-sectional view of an air conditioning unit according to a first embodiment. 
         FIG. 2  is a perspective view of a second heat exchanger viewed from an upstream side in an air flow. 
         FIG. 3  is a perspective view of the second heat exchanger viewed from a downstream side in the air flow. 
         FIG. 4  is a front view of the second heat exchanger as viewed from a downstream side in the air flow. 
         FIG. 5  is a cross-sectional view taken along a line V-V of  FIG. 4 . 
         FIG. 6  is an external view illustrating a side surface of the air conditioning case in a state where a first heat exchanger and a second heat exchanger are not assembled to the air conditioning case. 
         FIG. 7  is an external view illustrating the side surface of the air conditioning case in a state where the first heat exchanger and the second heat exchanger are assembled to the air conditioning case. 
         FIG. 8  is an enlarged view of an area VIII of  FIG. 7 . 
         FIG. 9  is a cross-sectional view taken along a line IX-IX of  FIG. 8 . 
         FIG. 10  is an external view illustrating a side surface of an air conditioning case, in an air conditioning unit of a comparative example, in a state where a first heat exchanger and a second heat exchanger are not assembled to the air conditioning case. 
         FIG. 11  is a cross-sectional view of the air conditioning unit of the comparative example at a location corresponding to  FIG. 9 . 
         FIG. 12  is a front view of a second heat exchanger in an air conditioning unit according to a second embodiment. 
         FIG. 13  is a cross-sectional view taken along a line XIII-XIII of  FIG. 12 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     To begin with, examples of relevant techniques will be described. 
     An air conditioning unit conditions air in a cabin. The air conditioning unit has two heat exchangers for heating air flowing through a passage in an air conditioning case. The heat exchangers are housed in one frame and can be attached to and detached from the air conditioning case. 
     The air conditioning unit mounted on the vehicle is required to be downsized due to some restrictions relative to the vehicle. In contrast to such a demand, since the air conditioning unit needs a frame body for housing the two heat exchangers, the physique of the air conditioning unit becomes large. Further, the number of components increases. 
     In order to reduce the size of the body, it is conceivable to arrange the two heat exchangers close to each other. However, in that case, a partition wall provided between the two heat exchangers in the frame becomes thin. There is a concern that the partition wall may have insufficient rigidity or molding failure, and air leakage may occur. 
     In order to restrict the partition wall from becoming thin, it is conceivable to set a direction in which one of the two heat exchangers is inserted into the frame and a direction in which the other heat exchange is inserted into the frame opposite to each other. However, in that case, since the manufacturing process becomes complicated and the cycle time becomes long, the manufacturing cost increases. In such a case, it is difficult to reduce the size of the air conditioning unit. 
     The present disclosure provides an air conditioning unit which can be downsized in the body. 
     According to one aspect of the present disclosure, an air conditioning unit configured to condition air in a cabin, the air conditioning unit includes: an air conditioning case having a passage through which air flows from an air inlet into the cabin, the air conditioning case having one opening; a first heat exchanger disposed in the passage of the air conditioning case through the one opening so as to adjust a temperature of the air flowing through the passage; a second heat exchanger disposed in the passage of the air conditioning case through the one opening and located downstream of the first heat exchanger in a flow of air; and a closure portion provided on at least one of the first heat exchanger and the second heat exchanger so as to close a gap between the first heat exchanger and the second heat exchanger. 
     Accordingly, it is possible to eliminate the frame and the partition wall between the first heat exchanger and the second heat exchanger. Therefore, the number of parts can be reduced, and the partition wall between the first heat exchanger and the second heat exchanger can have sufficient rigidity or be free from molding failure. The first heat exchanger and the second heat exchanger can be placed close to each other in the air conditioning unit, due to the closure portion provided on at least one of the first heat exchanger and the second heat exchanger to close the gap between the first heat exchanger and the second heat exchanger. Therefore, the air conditioning unit can be downsized. 
     A reference numeral attached to each component or the like indicates an example of correspondence between the component or the like and specific component or the like described in embodiments below. 
     Embodiments of the present disclosure will now be described with reference to the drawings. Parts that are identical or equivalent to each other in the following embodiments are assigned the same reference numerals and will not be described. 
     First Embodiment 
     A first embodiment will be described with reference to the drawings. The air conditioning unit  1  of the present embodiment is arranged inside an instrument panel of a vehicle (not shown). The air conditioning unit  1  sucks in one or both of inside air in the cabin and outside air outside the cabin, and blows out conditioned air having adjusted temperature and humidity into the cabin so as to condition air in the cabin. 
     The overall configuration of the air conditioning unit  1  of the present embodiment will be described. 
     As shown in  FIG. 1 , the air conditioning unit  1  includes an air conditioning case  10 , an evaporator  20 , a heater core  30  as a first heat exchanger, a positive temperature coefficient (PTC) heater  40  as a second heat exchanger, air mix doors  51  and  52 , and mode doors  61 ,  62 ,  63 . 
     The air conditioning case  10  is made of a resin such as polypropylene having a certain degree of elasticity and excellent strength. The air conditioning case  10  has a passage  11  inside the outer wall, and air flows through the passage  11 . 
     Air is introduced from the blower unit  70  into the passage  11  upstream of the evaporator  20 . The blower unit  70  is configured to take in inside air or outside air from the air inlet  71 ,  72  by driving a blower (not shown), and to flow the air to the upstream area of the evaporator  20  in the passage  11  in the air conditioning case  10 . The air conditioning case  10  has plural outlet openings  17 ,  18 ,  19  for blowing out air flowing through the passage  11  into the cabin. The outlet openings  17 ,  18 ,  19  are arranged on the downstream side of each heat exchanger. Therefore, the air introduced from the air inlet  71 ,  72  of the blower unit  70  flows through the passage  11  in the air conditioning case  10  and is supplied to the cabin from the outlet opening  17 ,  18 ,  19 . 
     The outlet openings  17 ,  18  and  19  are a defroster outlet opening  17 , a face outlet opening  18 , and a foot outlet opening  19 . The defroster outlet opening  17  blows out air toward the windshield of the vehicle. The face outlet opening  18  blows out air toward the upper body of the occupant seated on the front seat. The foot outlet opening  19  blows out air toward the feet of the occupant seated on the front seat. A duct (not shown) is attached to each of the outlet openings  17 ,  18 , and  19 . The duct is connected to each outlet provided in a predetermined place in the cabin. 
     The evaporator  20  is a refrigerant heat exchanger for cooling the air flowing through the passage  11  in the air conditioning case  10 . The evaporator  20  constitutes a well-known refrigeration cycle together with a compressor, a condenser, an expansion valve, and the like (not shown). The evaporator  20  is arranged downstream of the expansion valve and upstream of the compressor in the refrigeration cycle. A refrigerant that has been decompressed by the expansion valve into gas-liquid two-layer state flows inside a tube (not shown) of the evaporator  20 . The evaporator  20  cools the air by heat exchange between the refrigerant flowing inside the tube and the air passing outside the tube. The first heat exchanger adjusts the temperature of the air flowing through the passage  11  in the air conditioning case  10 . Specifically, the heater core  30  as the first heat exchanger is a hot water heat exchanger for heating the air flowing through the passage  11  in the air conditioning case  10 . The heater core  30  is provided downstream of the evaporator  20  in the air flow in the passage  11  in the air conditioning case  10 . A heat medium such as engine cooling water flows inside a tube (not shown) of the heater core  30 . The heater core  30  heats the air by exchanging heat between the heat medium flowing inside the tube and the air passing outside the tube. 
     The second heat exchanger is provided downstream of the first heat exchanger in the air flow. Specifically, the PTC heater  40  as the second heat exchanger and the heater core  30  as the first heat exchanger are arranged substantially in parallel and close to each other. The PTC heater  40  is an electric heat exchanger for heating the air flowing through the passage  11  in the air conditioning case  10 . The PTC heater  40  energizes an electric resistor to generate heat. The PTC heater  40  heats the air by heat exchange between the heat radiating fin including the electric resistor and the air passing between the heat radiating fins. The specific configuration of the PTC heater  40  will be described later. 
     The air mix doors  51 ,  52  and the mode doors  61 ,  62 ,  63  are arranged in the passage  11  of the air conditioning case  10 . 
     The air mix doors  51 ,  52  are two sliding doors provided between the evaporator  20  and the heater core  30 . In  FIG. 1 , the air mix doors  51 ,  52  are arranged so that all of the air that has passed through the evaporator  20  flows through the heater core  30 . It is possible to allow a part or all of the air that has passed through the evaporator  20  to bypass the heater core  30  by changing the positions of the air mix doors  51 ,  52 . The positions of the air mix doors  51 ,  52  are switched according to the selected air conditioning mode. 
     The mode doors  61 ,  62 ,  63  are a defroster door  61 , a face door  62 , and a foot door  63 . The defroster door  61  adjusts the amount of air blown from the defroster outlet opening  17 . The face door  62  adjusts the amount of air blown from the face outlet opening  18 . The foot door  63  adjusts the amount of air blown from the foot outlet opening  19 . The positions of the mode doors  61 ,  62 ,  63  are also switched according to the selected air conditioning mode. 
     Next, the configuration of the PTC heater  40  will be described with reference to  FIGS. 2 to 5 . The arrows AF in  FIGS. 2, 3 and 5  indicate the air flow direction when the PTC heater  40  is installed in the air conditioning case  10 . As shown in  FIGS. 2 to 5 , the PTC heater  40  has a heat radiating fin  41 , a frame  42 , a flange  43 , and a closure portion  44 . The heat radiating fin  41  includes an electric resistor that generates heat when energized. The heat radiating fins  41  are arranged in parallel at predetermined intervals. When the air passes between the heat radiating fins  41 , the air is heated. The frame  42  constitutes the outer frame of the heat radiating fin  41 . The frame  42  is made of a resin (such as PA66/GF) having excellent heat resistance, rigidity, dimensional stability, and the like. The flange  43  is provided at one end of the frame  42 . The flange  43  is made of a resin having the same characteristics as the frame  42 . As shown in  FIG. 4 , the flange  43  has a connector  45  for energizing the electric resistor. 
     As shown in  FIGS. 2 and 5 , the closure portion  44  is provided at a side of the PTC heater  40  opposing the heater core  30 . The closure portion  44  is provided so as to extend from the PTC heater  40  toward the heater core  30 . As shown in  FIG. 5 , the outer edge  441  of the closure portion  44  adjacent to the heater core  30  has a shape along the outer edge of the heater core  30 . In  FIG. 5 , for convenience of explanation, the closure portion  44  is hatched, although it is not a cross section, in order to show the closure portion  44  in an easy-to-understand manner. Further, in  FIG. 5 , the position of the outer edge of the heater core  30  is shown by a broken line. As shown in  FIG. 5 , the closure portion  44  is configured to close the gap between the PTC heater  40  and the heater core  30 . 
     The closure portion  44  is made of a resin having the same characteristics as the frame  42  and the flange  43 . The closure portion  44 , the frame  42 , and the flange  43  are integrally formed of resin. A side of the closure portion  44  opposite to the heater core  30  is connected to the frame  42  and the flange  43 . Therefore, the closure portion  44  has a highly rigid structure. 
     As shown in  FIGS. 3 and 5 , the flange  43  of the PTC heater  40  has a fitting groove  46 . Specifically, the fitting groove  46  is continuously provided in a portion of the flange  43  opposite to the heater core  30 , an upper portion and a lower portion in  FIG. 5  (that is, a portion excluding the closure portion  44 ). The fitting groove  46  fits into a rib provided around the opening of the air conditioning case  10  described later. 
     A method of assembling the heater core  30  and the PTC heater  40  to the air conditioning case  10  will be described. 
       FIG. 6  is an external view of the side surface of the air conditioning case  10  in a state where the heater core  30  and the PTC heater  40  are not assembled to the air conditioning case  10 . The side surface of the air conditioning case  10  has one opening  15  for attaching/detaching the heater core  30  and the PTC heater  40 . The air conditioning case  10  has the rib  16  that fits into the fitting groove  46  provided in the flange  43  of the PTC heater  40 , and the rib  16  is provided adjacent to the opening  15 . 
       FIGS. 7 and 8  are external views of the side surface of the air conditioning case  10  in which the heater core  30  and the PTC heater  40  are assembled to the air conditioning case  10 .  FIG. 9  is a cross-sectional view taken along a line IX-IX of  FIG. 8 . The heater core  30  and the PTC heater  40  are installed inside the air conditioning case  10  through the one opening  15  provided on the side surface of the air conditioning case  10 . Therefore, the heater core  30  and the PTC heater  40  can be attached to and detached from the same direction with respect to the air conditioning case  10 . In  FIG. 9 , the arrow R represents the direction in which the heater core  30  and the PTC heater  40  are attached to and detached from the air conditioning case  10 . Both the heater core  30  and the PTC heater  40  are directly fitted into the opening  15  of the air conditioning case  10 . The gap between the heater core  30  and the PTC heater  40  is closed by the closure portion  44  provided in the PTC heater  40 . 
     The flange  43  of the PTC heater  40  is provided so as to cover the outer side of the opening  15  of the air conditioning case  10 . The fitting groove  46  provided on the surface of the flange  43  adjacent to the air conditioning case  10  is fitted to the rib  16  provided around the opening  15  of the air conditioning case  10 . 
     A seal packing  31  is provided at a portion of the heater core  30  that fits into the inner wall surface of the opening  15  of the air conditioning case  10 . The seal packing  31  can be formed of a material having a low elastic modulus such as porous urethane or rubber. The seal packing  31  is provided so as to surround the end portion of the heater core  30 . In  FIG. 8 , for convenience of explanation, the seal packing  31  is hatched, although it is not a cross section, in order to show the seal packing  31  in an easy-to-understand manner. The seal packing  31  is provided in a compressed state between the heater core  30  and the inner wall surface of the opening  15  of the air conditioning case  10 , and between the heater core  30  and the closure portion  44 . As a result, the seal packing  31  provided on the heater core  30  comes into close contact with the inner wall surface of the opening  15  of the air conditioning case  10  and the closure portion  44 , so as to restrict air leakage from the passage  11  in the air conditioning case  10  to the outside. 
     It is possible to abolish the seal packing  31  so that the inner wall surface of the opening  15  of the air conditioning case  10  and the outer edge of the heater core  30  come into contact with each other. Even in such a configuration, it is possible to reduce air leakage by improving the dimensional accuracy of each configuration. That is, the heater core  30  and the PTC heater  40  of the present embodiment are configured to be directly fitted to the opening  15  of the air conditioning case  10 , without using a rigid body such as frame body in a comparison example. The configuration of direct fitting in the present specification means fitting without using a rigid body such as frame body in the comparison example. The configuration of direct fitting in the present specification includes both of a fitting via a seal packing  31  and a configuration in which the seal packing  31  is not interposed. 
     In order to compare with the air conditioning unit  1  of the first embodiment, an air conditioning unit of the comparative example will be described with reference to  FIGS. 10 and 11 . Even in the air conditioning unit of the comparative example, it is assumed that the heater core  30  and the PTC heater  40  are arranged close to each other. 
       FIG. 10  is an external view of the side surface of the air conditioning case  10  of the comparative example in a state where the heater core  30  and the PTC heater  40  are not assembled to the air conditioning case  10 . The side surface of the air conditioning case  10  of the comparative example has a first opening  151  for attaching/detaching the heater core  30  and a second opening  152  for attaching/detaching the PTC heater  40 . A partition wall  153  that separates the first opening  151  and the second opening  152  is provided between the first opening  151  and the second opening  152 . The partition wall  153  constitutes a part of the air conditioning case  10 . 
       FIG. 11  is a cross-sectional view of a state in which the heater core  30  and the PTC heater  40  are assembled to the air conditioning case  10  of the comparative example, and corresponds to  FIG. 9  referred to in the description of the first embodiment. The heater core  30  is fitted to the inner wall surface of the first opening  151 . The PTC heater  40  is fitted to the inner wall surface of the second opening  152 . The space between the heater core  30  and the PTC heater  40  is closed by the partition wall  153  of the air conditioning case  10 . 
     In the comparative example, the flange  43  of the PTC heater  40  is provided so as to cover the outer side of the second opening  152  of the air conditioning case  10 . In the comparative example, the fitting groove  46  is provided over both the side of the flange  43  adjacent to the heater core  30  and the side of the flange  43  away from the heater core  30 . The fitting groove  46  fits to the rib  161  provided around the second opening  152  of the air conditioning case  10 . 
     In the air conditioning unit of the comparative example, the partition wall  153  provided between the first opening  151  and the second opening  152  is thin. Therefore, it is conceivable that the partition wall  153  has insufficient rigidity or molding failure. In that case, when the PTC heater  40  is assembled to the air conditioning case  10 , the rib  161  provided on the partition wall  153  and the fitting groove  46  of the flange  43  of the PTC heater  40  may be misaligned from each other. At this time, as shown by the broken line  153   a  in  FIG. 11 , the partition wall  153  shifts from the normal position. In that case, air leaks from the passage  11  in the air conditioning case  10  to the outside. Therefore, in the configuration of the air conditioning unit of the comparative example, it is difficult to arrange the heater core  30  and the PTC heater  40  close to each other because there is a concern that the partition wall  153  has insufficient rigidity or molding defects. 
     The air conditioning unit  1  of the first embodiment has the following effects compared with the air conditioning unit of the comparative example. 
     (1) In the first embodiment, the heater core  30  and the PTC heater  40  are installed inside the air conditioning case  10  through the one opening  15  provided in the air conditioning case  10 . The gap between the heater core  30  and the PTC heater  40  is closed by the closure portion  44  provided so as to extend from the PTC heater  40  toward the heater core  30 . 
     This makes it possible to eliminate the partition wall  153  between the first opening  151  and the second opening  152  in the air conditioning unit of the comparative example. According to the first embodiment, since the connection area where the PTC heater  40  and the closure portion  44  are connected is large, it is possible to restrict the closure portion  44  from becoming insufficiently rigid or molding poorly. Therefore, in the air conditioning unit  1 , the rigidity of the closure portion  44  provided in the PTC heater  40  is increased and the moldability is improved. Further, the heater core  30  and the PTC heater  40  are arranged close to each other to downsize the air conditioning unit  1 . 
     (2) In the first embodiment, the outer edge  441  of the closure portion  44  adjacent to the heater core  30  has a shape along the outer edge of the heater core  30 . 
     As a result, the seal packing  31  provided on the heater core  30  can be brought into close contact with the closure portion  44 . Therefore, the air conditioning unit  1  can surely restrict air leakage from the gap between the heater core  30  and the closure portion  44 . 
     (3) In the first embodiment, the frame  42  and the closure portion  44  are integrally formed. 
     As a result, the rigidity of the closure portion  44  can be increased, and the manufacturing cost can be reduced. 
     (4) In the first embodiment, the air conditioning unit  1  includes the seal packing  31  provided on the heater core  30 . The seal packing  31  is in close contact with the inner wall surface of the opening  15  of the air conditioning case  10  and the closure portion  44 . 
     As a result, the air conditioning unit  1  can restrict air leakage by filling the gap between the heater core  30  and the closure portion  44  with the seal packing  31 . 
     (5) In the first embodiment, the flange  43  of the PTC heater  40  has the fitting groove  46 . The fitting groove  46  is configured to fit with the rib  16  provided adjacent to the opening  15  of the air conditioning case  10 . 
     As a result, the air conditioning unit  1  can restrict air leakage from a portion of the flange  43  opposite to the closure portion  44 . 
     (6) In the first embodiment, the heater core  30  and the PTC heater  40  are removable in the same direction with respect to the air conditioning case  10 . The heater core  30  and the PTC heater  40  are directly fitted to the opening  15  of the air conditioning case  10 . 
     Accordingly, it is possible to improve the assembling property of the heater core  30  and the PTC heater  40  with respect to the air conditioning case  10 . Therefore, the cycle time at the time of manufacturing can be shortened, and the manufacturing cost can be reduced. Further, since the air conditioning unit  1  of the first embodiment does not have the frame body of the comparison example, the increase in the number of parts is restricted and the air conditioning unit  1  can be downsized. 
     Second Embodiment 
     A second embodiment will be described below. The second embodiment is a modification of the first embodiment in which the second heat exchanger is modified, and the other parts are the same as those of the first embodiment. Therefore, only the parts different from the first embodiment will be described. 
     As the second heat exchanger, the air conditioning unit  1  of the second embodiment has a dummy heat exchanger  47  as shown in  FIGS. 12 and 13 , in place of the PTC heater  40  in the first embodiment. The dummy heat exchanger  47  does not have a heat exchange function and is composed of a member having a predetermined air resistance. 
     Specifically, the dummy heat exchanger  47  has a plate member  48 , a flange  43 , and a closure portion  44 . The plate member  48  has plural holes  49  through which air can pass. The ventilation resistance of the plate member  48  is set to be substantially the same as that of the PTC heater  40  in the first embodiment. The flange  43  is provided at one end of the plate member  48 . The closure portion  44  provided in the dummy heat exchanger  47  is also configured to close the gap between the dummy heat exchanger  47  and the heater core  30  as in the first embodiment. 
     Similar to the first embodiment, in the air conditioning unit  1  of the second embodiment, the rigidity and the moldability of the closure portion  44  provided in the dummy heat exchanger  47  as the second heat exchanger are improved, and the heater core  30  and the dummy heat exchanger  47  can be arranged close to each other. Therefore, the air conditioning unit  1  can be downsized. In addition, the second embodiment can also exert the same action and effect as the first embodiment. 
     Other Embodiments 
     The present disclosure is not limited to the embodiments described above, and can be modified as appropriate. The above embodiments are not independent of each other, and can be appropriately combined except when the combination is obviously impossible. Further, in each of the above-mentioned embodiments, it goes without saying that components of the embodiment are not necessarily essential except for a case in which the components are particularly clearly specified as essential components, a case in which the components are clearly considered in principle as essential components, and the like. Further, in each of the embodiments described above, when numerical values such as the number, numerical value, quantity, range, and the like of the constituent elements of the embodiment are referred to, except in the case where the numerical values are expressly indispensable in particular, the case where the numerical values are obviously limited to a specific number in principle, and the like, the present disclosure is not limited to the specific number. In each of the above embodiments, when the shapes, positional relationships, and the like of the components and the like are referred to, the shapes, positional relationships, and the like are not limited thereto unless otherwise specified or limited to specific shapes, positional relationships, and the like in principle. 
     (1) In each of the embodiments, a general air conditioning unit for a cabin is described, but is not limited to this. The air conditioning unit  1  may be configured to have an inside/outside air two-layer mode in which the inside air introduced from the inside air inlet and the outside air introduced from the outside air inlet are separately supplied to the cabin. 
     (2) In each of the embodiments, the heater core  30  is exemplified as the first heat exchanger, but is not limited to this. The first heat exchanger is, for example, a heat medium type heat exchanger in which a heat medium other than engine cooling water flows, or a refrigerant type heat exchanger such as condenser or evaporator for a refrigerating cycle. 
     (3) The PTC heater  40  and the dummy heat exchanger  47  are exemplified as the second heat exchanger, but not limited to this. The second heat exchanger may be an electric heat exchanger other than the PTC heater  40 , a heat medium heat exchanger through which engine cooling water or other heat medium flows, or a refrigerant heat exchanger such as condenser for a refrigeration cycle. 
     (4) In each of the embodiments, the closure portion  44  that closes the gap between the first heat exchanger and the second heat exchanger is provided in the second heat exchanger, but not limited to this. The closure portion  44  may be provided in the first heat exchanger, or may be provided in both the first heat exchanger and the second heat exchanger. 
     According to the first aspect shown in part or all of the embodiments, an air conditioning unit for a cabin includes an air conditioning case, a first heat exchanger, a second heat exchanger, and a closure portion. The air conditioning case has a passage for air introduced from an air inlet to flow into the cabin. The first heat exchanger is installed in the passage of the air conditioning case through one opening provided in the air conditioning case, and regulates the temperature of the air flowing through the passage. The second heat exchanger is installed inside the air conditioning case from the same opening as the first heat exchanger, and is provided on the downstream side of the first heat exchanger in a flow of air. The closure portion is provided on at least one of the first heat exchanger and the second heat exchanger, and is configured to close the gap between the first heat exchanger and the second heat exchanger. 
     According to the second aspect, the outer edge of the closure portion is shaped along the outer edge of the other of the first heat exchanger and the second heat exchanger. 
     Accordingly, the air conditioning unit can restrict air leakage from the location between the other of the first heat exchanger and the second heat exchanger and the closure portion. 
     According to the third aspect, the second heat exchanger is any one of an electric heat exchanger, a refrigerant heat exchanger, a heat medium heat exchanger, or a dummy heat exchanger. The closure portion is integrally formed with the frame or plate member of the second heat exchanger. 
     Accordingly, it is possible to increase the rigidity of the closure portion and reduce the manufacturing cost by integrally forming the frame or plate member of the second heat exchanger and the closure portion. 
     According to the fourth aspect, the air conditioning unit further includes a seal packing provided between the other of the first heat exchanger and the second heat exchanger and the closure portion. 
     Accordingly, the air conditioning unit can restrict air leakage by filling the gap between the other of the first heat exchanger and the second heat exchanger and the closure portion with the seal packing. 
     According to the fifth aspect, the second heat exchanger has a flange that closes the opening of the air conditioning case. The flange has a fitting groove that fits with a rib provided around the opening of the air conditioning case. 
     Accordingly, the air conditioning unit can restrict air leakage from a portion of the flange opposite to the closure portion. 
     According to the sixth aspect, the first heat exchanger and the second heat exchanger are attachable to and removable from the air conditioning case in the same direction, and are directly fitted to the opening of the air conditioning case. 
     Accordingly, it is possible to improve the assembling property of the first heat exchanger and the second heat exchanger with respect to the air conditioning case. Therefore, the cycle time at the time of manufacturing can be shortened, and the manufacturing cost can be reduced. Further, according to the configuration of the sixth aspect, since the air conditioning unit does not have a frame body, the increase in the number of parts is prevented and the air conditioning unit can be downsized.