Patent Publication Number: US-2016221414-A1

Title: Air conditioning unit

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is based on Japanese Patent Application No. 2013-195508 filed on Sep. 20, 2013 and Japanese Patent Application No. 2014-145210 filed on Jul. 15, 2014, the disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to an air conditioning unit. 
     BACKGROUND ART 
     Conventionally, an air conditioning unit for a rear seat is known to have an air conditioning case, a blower that draws air into a vehicle compartment and ventilates the air in the air conditioning case, a cooling heat exchanger that is disposed in the air conditioning case and cools the air by refrigerant, and a heating heat exchanger that is disposed in the air conditioning case and heats a cool air blown from the cooling heat exchanger by a warm water. The air conditioning unit for a rear seat blows air of which temperature is adjusted by the cooling heat exchanger and the heating heat exchanger to a rear seat side in the vehicle compartment (refer Patent Literatures 1 and 2). 
     PRIOR ART LITERATURES 
     Patent Literature 
     Patent Literature 1: JP H10-236137 A 
     Patent Literature 2: JP 2000-168346 A 
     SUMMARY OF INVENTION 
     Inventors of the present disclosure considered mounting an air conditioning unit  10 A for a rear seat between an outer plate  2  and a quarter trim  3  as shown in  FIG. 10 . The quarter trim  3  is an inner wall that is arranged on a rear side with respect to a front seat in a vehicle compartment in a traveling direction of a vehicle and is exposed to the vehicle compartment. 
     Recent vehicles tend to have a larger passenger space for a purpose of a comfort of a passenger. In conjunction of the trend, a mounting space in which the air conditioning unit  10 A for a rear seat is mounted between the outer plate  2  and the quarter trim  3  is getting smaller. Accordingly, a speed of air (refer an arrow Ya in  FIG. 10 ) that is drawn by a blower  30 A increases. Then, a pressure loss of the air increases, and a noise is caused. Therefore, even if an air introducing port of the blower  30 A is open toward the outer plate side, the noise that is caused when the blower  30 A draws air is reflected on the outer plate  2  and transmits into the vehicle compartment through the quarter trim  3 , and the passenger may feel uncomfortable. 
     The noise is not limited to cause in a case where the air conditioning unit  10 A for a rear seat is mounted between the outer plate  2  and the quarter trim  3 , and causes in a case where the air conditioning unit  10 A for a rear seat is mounted in a center console or a roof part. Moreover, a similar noise may be caused in an air conditioning unit blowing air to an area except for the rear seat side in the vehicle compartment. 
     The present disclosure addresses the above issues, and it is an objective of the present disclosure to provide an air conditioning unit with which a noise that transmits from a blower into a vehicle compartment can be reduced. 
     An air conditioning unit of the present disclosure has an air conditioning case, a blower, and a heat exchanger. The air conditioning case is arranged in a vehicle compartment on a rear side with respect to an instrument panel in a traveling direction of a vehicle and forms an air passage delivering air toward a specified area of the vehicle compartment. The blower has at least first and second impellers and a fan case housing the first and second impellers, and ventilates the air in the air conditioning case by drawing and blowing air, by using a rotation of the first and second impellers, through first and second suction ports formed in the fan case. The heat exchanger is arranged in the air conditioning case on an upstream side of the blower in an airflow direction and exchanges heat of the air. The blower draws air from the heat exchanger and blows the air to the specified area of the vehicle compartment. The fan case has a portion in which at least the first and second suction ports are formed, and the portion is arranged inside of the air conditioning case. 
     According to the air conditioning unit of the present disclosure, the fan case has the portion in which at least the first and second suction ports are formed, and the portion is arranged inside of the air conditioning case. Accordingly, when the blower draws air and causes a noise, an inner wall of the air conditioning case can suppress a transmission of the noise into the vehicle compartment. In addition, since the blower draws air from both of the first and second suction ports, a total area of the suction ports can be increased as compared to that of a blower drawing air from a single suction port. Accordingly, a pressure loss of air drawn by the blower decreases, and a flow speed of the air can decrease. Therefore, a noise caused when the blower draws air can be reduced. Thus, a noise transmitting from the blower into the vehicle compartment can be reduced. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective diagram illustrating an air conditioning unit for a rear seat according to a first embodiment of the present disclosure is mounted in a vehicle. 
         FIG. 2  is a perspective view illustrating the air conditioning unit for a rear seat except for an air conditioning case. 
         FIG. 3  is a view corresponding to a sectional view taken along a line III-III shown in  FIG. 2  and illustrating a condition where the air conditioning unit for a rear seat is mounted in the vehicle. 
         FIG. 4  is a sectional view illustrating an air conditioning unit for a rear seat according to a second embodiment of the present disclosure. 
         FIG. 5  is a perspective diagram illustrating a condition where an air conditioning unit for a rear seat according to a third embodiment of the present disclosure is mounted in a vehicle. 
         FIG. 6  is a perspective diagram illustrating a condition where an air conditioning unit for a rear seat according to a fourth embodiment of the present disclosure is mounted in a vehicle. 
         FIG. 7  is a perspective diagram illustrating a condition where an air conditioning unit for a rear seat according to a fifth embodiment of the present disclosure is mounted in a vehicle. 
         FIG. 8  is a diagram illustrating a configuration of an air conditioning unit for a rear seat according to a sixth embodiment of the present disclosure. 
         FIG. 9  is a diagram illustrating a configuration of an air conditioning unit for a rear seat according to a seventh embodiment of the present disclosure. 
         FIG. 10  is a sectional view illustrating an air conditioning unit for a rear seat according to a comparison example of the present disclosure. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments of the present disclosure will be described hereafter referring to drawings. In the embodiments, a part that corresponds to or equivalents to a matter described in a preceding embodiment may be assigned with the same reference number to simplify the description. In the flowing description, “front”, “rear”, “left”, “right”, “upper”, and “lower” will be referred on a traveling-direction basis on a condition of a vehicle traveling normally as shown, for example, in  FIG. 1 . 
     First Embodiment 
       FIGS. 1, 2, and 3  shows an air conditioner for a vehicle according to the present embodiment of the present disclosure. Arrows in  FIGS. 1 and 3  shows directions on a condition of being mounted in the vehicle. 
     A vehicle  1  in which the air conditioner for a vehicle is mounted has a rear space  1   c  in a vehicle compartment on a rear side with respect to a front seat  1   a  and a rear seat  1   b  in a traveling direction of the vehicle. The rear space  1   c  is used to dispose a rearmost seat therein or used as a luggage room. 
     The air conditioner for a vehicle of the present embodiment further has an air conditioning unit  10  for a rear seat that performs an air-conditioning of a rear seat side in the vehicle compartment in addition to an air conditioning unit for a front seat (not shown) that performs an air-conditioning of a front seat side in the vehicle compartment. 
     The air conditioning unit for a front seat is well-known to be arranged in a substantially center part in a left-right direction (i.e., a width direction) of the vehicle inside of an instrument panel  1   d  (i.e., a dashboard) that is located in a foremost area of the vehicle compartment. Accordingly, a description about the air conditioning unit for a front seat will be omitted. 
     As shown in  FIG. 1 , the air conditioning unit  10  for a rear seat is arranged on a rear side with respect to the front seat  1   a  in the vehicle compartment. That is, the air conditioning unit  10  is arranged on a rear side with respect to the instrument panel  1   d . More specifically, the air conditioning unit  10  for a rear seat is arranged on a rear side of a rear side door. The air conditioning unit  10  for a rear seat of the present embodiment is arranged on a right side in the vehicle. 
     The air conditioning unit  10  for a rear seat is arranged between an outer plate  2  and a quarter trim  3 , as shown in  FIG. 3 . The outer plate  2  is located outside on the right side of the vehicle  1 . The quarter trim  3  is an inner wall arranged on a rear side with respect to the front seat  1   a  in the vehicle compartment. 
     The air conditioning unit  10  for a rear seat constitutes a so-called “fan suction layout” that is constituted by arranging a blower  30  on a most downstream side in an airflow direction in an air conditioning case  20 . 
     Specifically, the air conditioning unit  10  for a rear seat has the air conditioning case  20 , the blower  30 , an evaporator  40 , a heater core  50 , and an air mix door  60 , as shown in  FIGS. 2 and 3 . Illustration of the air conditioning case  20  is omitted in  FIG. 2 . 
     The air conditioning case  20  forms an outer shell of the air conditioning unit  10  for a rear seat and an air passage through which air ventilated toward the rear seat side flows. The air conditioning case  20  has a certain level of elasticity and is formed by resin (for example, polypropylene) that is excellent in intensity. 
     An introducing port  21  introducing air from inside of the vehicle compartment is formed in a front side in the air conditioning case  20  on a most upstream side in the air passage that is formed in the air conditioning case  20 . The introducing port  21  is open frontwards. 
     The blower  30  is arranged on a most downstream side in the air flow direction with respect to the air conditioning case  20 . The blower  30  constitutes a so-called “both-suction double fans” that draws air from two suction ports  34   a ,  34   b  by two impellers  32   a ,  32   b . Specifically, the blower  30  is a centrifugal-type multi-blade blower having an electric motor  31 , impellers  32   a ,  32   b , and a fan case  33 . In the present embodiment, a sirocco fan is used as the blower  30 . 
     The electric motor  31  rotates the impellers  32   a  and  32   b  by a rotation shaft  31   a . The rotation shaft  31   a  of the electric motor  31  is arranged to extend in the left-right direction. The impellers  32   a ,  32   b  are a centrifugal-type multi-blade fan and are arranged on a right side with respect to the electric motor  31 . The impellers  32   a  and  32   b  are fixed to the rotation shaft  31   a  of the electric motor  31 . The impeller  32   a  is arranged on a right side of the impeller  32   b . The impeller  32   a  draws air through the suction port  34   a  and blows the air outward in a radial direction by rotating. The impeller  32   b  draws air through the suction port  34   b  and blows the air outward in the radial direction by rotating. 
     The suction ports  34   a  and  34   b  are formed by the fan case  33 , respectively. The suction port  34   a  is open on a right side of the blower  30 . That is, the suction port  34   a  faces an inner wall that is provided with a right wall portion  20   a  of the air conditioning case  20 . In other words, the fan case  33  has a portion that is provided with the suction port  34   a , and the portion is arranged inside of the air conditioning case  20 . 
     The suction port  34   b  is open on a left side of the blower  30 . Accordingly, the suction port  34   b  faces an inner wall that is provided with a left wall portion  20   b  of the air conditioning case  20 . That is, the fan case  33  has a portion that is provided with the suction port  34   b , and the portion is arranged inside of the air conditioning case  20 . The fan case  33  is arranged on an outer side with respect to the impellers  32   a ,  32   b  in the radial direction centered at the rotation shaft  31   a . That is, the fan case  33  has the suction ports  34   a ,  34   b  and houses the impellers  32   a ,  32   b.    
     The fan case  33  collects air that is blown from the impellers  32   a ,  32   b  and blows the air from a blowing opening  22 . The blowing opening  22  connects to various blowing outlets through a duct that is not shown. The blowing outlets are open in a rear-seat side space  4  in the vehicle compartment. 
     The evaporator  40  is arranged in the air conditioning case  20  on an upstream side of the blower  30  in the airflow direction. The evaporator  40  is one of devices configuring a well-known vapor-compression type refrigerant cycle (not shown), and is a cooling heat exchanger cooling air that is to be blown into the vehicle compartment by exerting an absorption effect caused by evaporating a low-pressure refrigerant in the refrigerant cycle. 
     The evaporator  40  is configured by tubes, first and second tanks, and a heat exchanging fin to have a flat shape. The tubes are arranged in a direction perpendicular to the airflow direction. The first tank distributes refrigerant from an expansion valve to each of the tubes. The second tank collects refrigerant flowing out of the tubes and delivers the refrigerant to a compressor side. The heat exchanging fin is arranged on a surface of each of the tubes and promotes a heat exchange between refrigerant and air. Thus, air passes through the evaporator  40  in a thickness direction of the evaporator  40 , and the evaporator  40  cools the air by refrigerant and blows cool air. 
     According to the present embodiment, the evaporator  40  has an air outlet surface  40   a  as a cool-air blowing surface blowing cool air, and the evaporator  40  is arranged such that the air outlet surface  40   a  faces rightward. The air outlet surface  40   a  of the evaporator  40  is arranged to incline with respect to the traveling direction of the vehicle. The air outlet surface  40   a  is a heat radiating surface that is provided with the evaporator  40  in the thickness direction and located on a downstream side in the evaporator  40 . 
     The heater core  50  is arranged on the upstream side of the blower  30  in the airflow direction in the air conditioning case  20 . The heater core  50  is a heating heat exchanger that heats air to be blown into the vehicle compartment by engine cooling water (i.e., warm water) and blows warm air. 
     Specifically, the heater core  50  is configured by tubes, first and second tanks, and a heat exchanging fin to have a flat shape. The tubes are arranged in a direction perpendicular to the airflow direction. The first tank distributes engine cooling water from a side of an engine for traveling to each of the tubes. The second tank collects engine cooling water flowing from the tubes and delivers to the side of the engine for traveling. The heat exchanging fin is arranged on a surface of each of the tubes and promotes a heat exchange between engine cooling water and air. Accordingly, air passes through the heater core  50  in a thickness direction of the heater core  50 , and the heater core  50  heats air by engine cooling water and blows warm air. 
     The heater core  50  has an air outlet surface  50   a  as a warm-air blowing surface blowing warm air, and the evaporator  40  is arranged such that the air outlet surface  50   a  faces leftward. The air outlet surface  50   a  of the heater core  50  is arranged to incline with respect to the traveling direction of the vehicle. The air outlet surface  50   a  is a heat radiating surface that is provided with the heater core  50  in the thickness direction and located on a downstream side in the heater core  50 . 
     According to the present embodiment, the evaporator  40  and the heater core  50  are arranged in parallel in a direction intersecting with the airflow direction. A condition where the evaporator  40  and the heater core  50  are arranged in parallel in the direction intersecting with the airflow direction includes a condition where the evaporator  40  and the heater core  50  are arranged to be adjacent to each other in a direction intersecting with the airflow direction. Accordingly, similar to the present embodiment, the evaporator  40  and the heater core  50  may not be arranged to be parallel with each other and may incline to each other. The evaporator  40  and the heater core  50  are arranged in V-shape such that a dimension between the air inlet surface  40   b  and the air inlet surface  50   b  increases toward an upstream side in the airflow direction (i.e., toward a front side of the vehicle). 
     The air inlet surface  50   b  is a portion of the heater core  50  to which air introduced from the introducing port  21  flows. The air inlet surface  40   b  is a portion of the evaporator  40  to which air introduced from the introducing port  21  flows. 
     An outflow passage  27  is formed between the air outlet surface  40   a  of the evaporator  40  and the right wall portion  20   a  of the air conditioning case  20 . The outflow passage  27  is a passage that delivers cool air, which is blown from the evaporator  40 , toward the blower  30 . 
     An outflow passage  28  is formed between the air outlet surface  50   a  of the heater core  50  and the left wall portion  20   b . The outflow passage  28  is a passage that delivers warm air, which is blown from the heater core  50 , toward the blower  30 . The air mix door  60  is arranged on a downstream side in the airflow direction with respect to the outflow passages  27 ,  28 . The air mix door  60  is operated by the electric motor  61  and supported swingably. The air mix door  60  moves rotatably in a range between a position X 1  shown by a solid line and a position X 2  shown by a chain line, and changes a ratio between an air volume passing through the outflow passage  27  and an air volume passing through the outflow passage  28  by changing a ratio between an opening area of the outflow passage  27  and an opening area of the outflow passage  28 . 
     Specifically, the air mix door  60  has a shield portion  60   a  and an guiding path  60   b . The shield portion  60   a  closes an opening portion of one of the outflow passages  27 ,  28 . The guiding path  60   b  guides warm air from the outflow passage  28  to flow to the suction port  34   a  as shown by an arrow c, and guides cool air flowing from the outflow passage  27  to flow to the suction port  34   b  as shown by an arrow b. Thus, depending on a rotational position of the air mix door  60 , the ratio between an air volume of warm air flowing from the heater core  50  to the suction ports  34   a ,  34   b  and an air volume of cool air flowing from the evaporator  40  to the suction ports  34   a ,  34   b.    
     According to the present embodiment, a sound absorption member  70  is fixed to the inner wall of the right wall portion  20   a  of the air conditioning case  20 . The sound absorption member  70  is formed to cover the suction port  34   a  around the suction port  34   a . The sound absorption member  70  is a sound absorber configured by a sound absorption material such as foamed polyurethane to have a plate shape. 
     An operation of the air conditioning unit  10  for a rear seat according to the present embodiment will be described hereafter. 
     When the electric motor  31  rotates the impellers  32   a ,  32   b  in the blower  30 , air flows in the air conditioning case  20  from the introducing port  21  to the blower  30 . 
     A part of air flowing into the air conditioning case  20  passes the evaporator  40  in the thickness direction. On this occasion, the air is cooled by refrigerant in the tubes and is blown from the air outlet surface  40   a  as cool air. The cool air blown from the air outlet surface  40   a  flows from the outflow passage  27  toward a side of the blower  30 . 
     On the other hand, a remaining air other than a part of air flowing to a side of the evaporator  40  among the air blowing from the introducing port  21  passes the heater core  50  in the thickness direction. On this occasion, the remaining air is heated by the engine cooling water (i.e., warm water) while being passing through the heater core  50 . Accordingly, warm air flows from the air outlet surface  50   a  of the heater core  50  to a side of the blower  30  through the outflow passage  28 . Thus, cool air flowing from the outflow passage  27  and warm air flowing from the outflow passage  28  flows to the side of the blower  30 . 
     The blower  30  draws air flowing from the outflow passages  27 ,  28  through the suction ports  34   a ,  34   b  as shown by the arrows a, b, c, d, mixes the air, and blows the air as a conditioned air from the blowing opening  22  through the fan case  33 . The blown conditioned air blows from the blowing outlets to the rear-seat side space  4  of the vehicle compartment through the duct. 
     Here, although a noise occurs when the air flowing from the outflow passages  27 ,  28  is drawn by the suction ports  34   a ,  34   b , the noise can be prevented from transmitting into the vehicle compartment by a wall surface of air conditioning case  20 . In addition, the noise caused when the air flowing from the outflow passages  27 ,  28  is drawn by the suction ports  34   a  and  34   b  is absorbed by the sound absorption member  70 . 
     According to the present embodiment, the ratio between an air volume of cool air passing through the outflow passage  27  and an air volume of warm air passing through the outflow passage  28  is set by the air mix door  60 . Therefore, a temperature of air blowing from the blowing opening  22  to a side of the rear-seat side space  4  through the duct and blowing outlets is set by a rotational position of the air mix door  60 . 
     The position X 1  shown in  FIG. 3  shows an example where the air mix door  60  fully opens the outflow passage  27  and fully closes the outflow passage  28 . The position X 2  shown in  FIG. 3  shows an example where the air mix door  60  fully closes the outflow passage  27  and fully opens the outflow passage  28 . 
     According to the above-described present embodiment, the air conditioning unit  10  for a rear seat includes the air conditioning case  20  (i) that is disposed between the inner wall, which is arranged in the vehicle compartment on the rear side with respect to the front seat, and the outer plate  2 , which is arranged on the outer side in the vehicle in the left-right direction, and (ii) that delivers air to the rear seat side in the vehicle compartment. The air conditioning unit  10  has the blower  30 , the evaporator  40 , and the heater core  50 . The blower  30  ventilates air in the air conditioning case  20  by drawing and blowing air by using a rotation of the impellers  32   a ,  32   b  centered at the rotation shaft  31   a . The evaporator  40  and the heater core  50  are arranged on the upstream side of the blower  30  in the air conditioning case  20  and exchange heat with air. By ventilating air by using a rotation of the impellers  32   a ,  32   b  of the blower  30 , air from the evaporator  40  and the heater core  50  is drawn through the suction ports  34   a ,  34   b  and blown to the rear seat side in the vehicle compartment. The portion of the fan case  33  that is provided with at least the suction ports  34   a ,  34   b  is arranged inside of the air conditioning case  20 . Thus, the suction ports  34   a ,  34   b  are surrounded by an inner wall of the air conditioning case  20 . 
     Accordingly, when the blower  30  draws air flowing from the evaporator  40  and the heater core  50  and causes a noise, the inner wall of the air conditioning case  20  can suppress a transmission of the noise into the vehicle compartment. That is, the noise caused when the blower  30  draws air can be shut up in the air conditioning case  20 . In addition, since the blower  30  draws air from both of the suction ports  34   a ,  34   b , a total area of the suction ports ( 34   a ,  34   b ) can be increased as compared to that of a blower drawing air from a single suction port. Accordingly, a pressure loss of air drawn by the blower  30  decreases, and a flow speed of the air can decrease. Therefore, a noise caused when the blower  30  draws air can be reduced. Thus, a noise transmitting from the blower  30  into the vehicle compartment can be reduced. 
     According to the present embodiment, the sound absorption member  70  absorbing sound caused when the blower  30  draws air is disposed in the air conditioning case  20 . Therefore, a noise transmitting from the blower  30  into the vehicle compartment can be certainly suppressed. 
     According to the present embodiment, the evaporator  40  is arranged such that the air outlet surface  40   a  faces rightward. The hater core  50  is arranged such that the air outlet surface  50   a  faces leftward. Therefore, a dimension of the air conditioning case  20  in the left-right direction can be smaller as compared to a case where the evaporator  40  is arranged such that the air outlet surface  40   a  faces in an upper-lower direction and the heater core  50  is arranged such that the air outlet surface  50   a  faces in the upper-lower direction. 
     Second Embodiment 
     In the above-described first embodiment, an example in which the evaporator  40  and the heater core  50  are arranged in parallel in a direction intersecting with the airflow direction is described. In an second embodiment, an example in which the evaporator  40  and the heater core  50  are arranged in series in the airflow direction. 
       FIG. 4  is a sectional view illustrating an air conditioning unit  10  for a rear seat according to the second embodiment of the present disclosure. 
     The air conditioning unit  10  for a rear seat has the air conditioning case  20 , the blower  30 , and the air mix door  60 . In  FIG. 4 , the same reference numbers as  FIG. 2  show the same members, and the explanation is simplified. 
     According to the present embodiment, the evaporator  40  is arranged such that the air outlet surface  40   a  faces leftward. The air outlet surface  40   a  of the evaporator  40  is arranged to incline with respect to the traveling direction. The heater core  50  is arranged on a downstream side with respect to the evaporator  40  in the airflow direction. That is, the heater core  50  and the evaporator  40  are arranged in series in the airflow direction. The heater core  50  is arranged such that the air outlet surface  50   a  faces leftward. The air outlet surface  50   a  of the heater core  50  is arranged to incline with respect to the traveling direction. 
     According to the present embodiment, the evaporator  40  and the heater core  50  are arranged such that the air outlet surface  40   a  and the air outlet surface  50   a  are located to be parallel with each other. A bypass passage  26  is formed between the air outlet surface  50   a  of the heater core  50  and the right wall portion  20   a  of the air conditioning case  20 . The bypass passage  26  is a passage that delivers cool air blowing from the evaporator  40  to a side of the blower  30  while bypassing the heater core  50 . 
     The air mix door  60  is arranged on a downstream side with respect to the heater core  50  in the airflow direction. The air mix door  60  of the present embodiment is provided with a slide type door that is arranged to be moved slidably by the electric motor  61 . The air mix door  60  changes a ratio between an air volume passing through the bypass passage  26  and an air volume passing through the outflow passage  27  by changing a ratio between an opening area of the bypass passage  26  and an opening area of the outflow passage  27   
     Similar to the above-described first embodiment, the blower  30  of the present embodiment draws air from the suction ports  34   a ,  34   b  by a rotation of the impellers  32   a ,  32   b  and blows the air from the blowing opening  22  of the fan case  33 . The portion of the fan case  33  that is provided with at least the suction ports  34   a ,  34   b  is arranged inside of the air conditioning case  20 . Thus, the suction ports  34   a ,  34   b  are surrounded by the inner wall of the air conditioning case  20 . In  FIG. 4 , illustration of the rotation shaft  31   a  of the electric motor  31  is omitted. 
     An operation of the air conditioning unit  10  for a rear seat according to the present embodiment will be described hereafter. 
     When the electric motor  31  rotates the impellers  32   a ,  32   b  in the blower  30 , air is introduced into the air conditioning case  20  from the introducing port  21 . Accordingly, air flows toward the blower  30  from the introducing port  21  in the air conditioning case  20 . 
     Air flowing in the air conditioning case  20  passes the evaporator  40 . In this case, air is cooled by refrigerant in the tubes and blown from the air outlet surface  40   a  as a cool air. A part of the blowing cool air passes the bypass passage  26  and flows to a side of the blower  30 . 
     On the other hand, a remaining cool air other than the cool air passing through the bypass passage  26  among the cool air blowing from the air outlet surface  40   a  passes the heater core  50 . On this occasion, the remaining cool air is heated by warm water in the tubes when passing through the heater core  50 . Accordingly, a warm air from the air outlet surface  50   a  of the heater core  50  flows to the side of the blower  30 . Thus, the cool air flowing from the bypass passage  26  and the warm air flowing from the heater core  50  flow to a side of the suction ports  34   a ,  34   b  of the blower  30  as shown by arrows a, b. 
     The blower  30 , with rotation of the impellers  32   a  and  32   b , draws air, which flows from the outflow passages  27 ,  28 , through the suction ports  34   a ,  34   b  and blows the air from the blowing opening  22  through the fan case  33 . The blown air is blown into the rear-seat side space  4  in the vehicle compartment from the blowing outlets through the duct. 
     Here, a ratio between an air volume of cool air flowing from the bypass passage  26  and an air volume of warm air flowing from the heater core  50  is set by the air mix door  60 . Accordingly, a temperature of air blowing from the blowing opening  22  into the rear-seat side space  4  through the duct and the blowing outlets is set depending on a rotational position of the air mix door  60 . 
     According to the above-described present embodiment, similar to the above-described first embodiment, the portion of the fan case  33  provided with at least the suction ports  34   a ,  34   b  is arranged inside of the air conditioning case  20 . Thus, the suction ports  34   a ,  34   b  are surrounded by the inner wall of the air conditioning case  20 . Even if a noise is caused when the blower  30  draws air flowing from the evaporator  40  and the heater core  50 , the inner wall of the air conditioning case  20  can suppress a transmission of the noise into the vehicle compartment. In addition, since the impellers  32   a ,  32   b  of the blower  30  draws air from both of the suction ports  34   a ,  34   b , a total area of the suction ports ( 34   a ,  34   b ) can be increased as compared to that of a blower drawing air from a single suction port. Accordingly, a flow speed of air drawn by the blower  30  can decrease. Therefore, a noise caused when the blower  30  draws air can be reduced. Thus, a noise transmitting from the blower  30  into the vehicle compartment can be reduced. 
     Third Embodiment 
     In the above-described first and second embodiments, the air conditioning unit  10  for a rear seat is arranged between the outer plate  2  and the quarter trim  3 . In a third embodiment, an air conditioning unit  10  for a rear seat is arranged between a driver seat (Dr) and a passenger seat (Pa). 
       FIG. 5  is a diagram illustrating a condition where an air conditioning unit  10  for a rear seat according to a third embodiment of the present disclosure is mounted in a vehicle.  FIG. 5  is an overhead view of the vehicle compartment. 
     The air conditioning unit  10  for a rear seat of the present embodiment is arranged on a rear side of the instrument panel  1   d . More specifically, the air conditioning unit  10  for a rear seat is arranged between a driver seat  80   a  and a passenger seat  80   b  on a front side with respect to the rear seat  80   c . The driver seat  80   a  and the passenger seat  80   b  are arranged in the left-right direction. The air conditioning unit  10  for a rear seat is arranged inside of a center console box  81 . The blowing opening  22  of the air conditioning unit  10  for a rear seat is arranged to face a rear side. A conditioned air blown from the blowing opening  22  of the air conditioning unit  10  for a rear seat is blown to a rear side in the vehicle compartment through a blowing outlet  81   a  of the center console box  81 .  FIG. 5  shows an example in which a front right-side seat is defined to as the driver seat  80   a , and a front left-side seat is defined to as the passenger seat  80   b . A configuration of the air conditioning unit  10  for a rear seat according to the present embodiment is the same as that of the air conditioning unit  10  for a rear seat of the above-described first embodiment, thereby a description thereof is omitted. 
     According to the above-described present embodiment, the portion of the fan case  33  of the blower  30  that is provided with at least the suction ports  34   a ,  34   b  is arranged inside of the air conditioning case  20 , similar to the above-described first embodiment. Thus, the suction ports  34   a ,  34   b  are surrounded by the inner wall of the air conditioning case  20 . Accordingly, when the blower  30  draws air and causes a noise, the inner wall of the air conditioning case  20  can suppress a transmission of the noise into the vehicle compartment. In addition, since the impellers  32   a ,  32   b  of the blower  30  draws air from both of the suction ports  34   a ,  34   b , a total area of the suction ports ( 34   a ,  34   b ) can be increased as compared to that of a blower drawing air from a single suction port. Accordingly, a flow speed of air drawn by the blower  30  can decrease. Therefore, a noise caused when the blower  30  draws air can be reduced. Thus, a noise transmitting from the blower  30  into the vehicle compartment can be reduced. 
     Fourth Embodiment 
     In the above-described third embodiment, the air conditioning unit  10  for a rear seat is arranged between the driver seat (Dr) and the passenger seat (Pa). In a fourth embodiment, an air conditioning unit  10  for a rear seat is disposed in a roof part. 
       FIG. 6  is a diagram illustrating a condition where the air conditioning unit  10  for a rear seat according to the fourth embodiment of the present disclosure is mounted in a vehicle.  FIG. 6  is a diagram of the vehicle compartment when viewed from the width direction (i.e., the left-right direction). 
     The air conditioning unit  10  for a rear seat of the present embodiment is arranged in a roof part  82  in the vehicle compartment on a rear side with respect to the instrument panel  1   d . Specifically, the air conditioning unit  10  for a rear seat is arranged on a lower side of the roof part  82 . The air conditioning unit  10  for a rear seat is covered by a face wall  83  from a lower side in the upper-lower direction. The face wall  83  has a suction port  83   a  opening toward a front side and a blowing outlet  83   b  opening toward a rear side. The air conditioning unit  10  for a rear seat adjusts a temperature of air, which is drawn from the vehicle compartment through the suction port  83   a , by the evaporator  40  and the heater core  50  and blows the air from the blowing outlet  83   b  to a side of the rear seat  80   c  through the blowing opening  22 . 
     According to the above-described present embodiment, similar to the first through fourth embodiments, the portion of the fan case  33  of the blower  30  that is provided with at least the suction ports  34   a ,  34   b  is arranged inside of the air conditioning case  20 . Thus, the suction ports  34   a ,  34   b  are surrounded by the inner wall of the air conditioning case  20 . Accordingly, the present disclosure provides the same effect as the first through fourth embodiments. 
     When the air conditioning unit  10  for a rear seat is arranged on a side of the roof part  82 , the blowing opening  22  and the blowing outlet  83   b  of the air conditioning unit  10  for a rear seat are arranged in a position near ears of a passenger seating the rear seat. Accordingly, since the suction ports  34   a ,  34   b  are surrounded by the inner wall of the air conditioning case  20 , an effect that reduces a noise of the blower  30  can be improved. 
     Fifth Embodiment 
     In the above-described third embodiment, the air conditioning unit  10  for a rear seat is arranged between the driver seat (Dr) and the passenger seat (Pa). In a fifth embodiment, an air conditioning unit  10  for a rear seat is disposed in the vehicle compartment on a rear side of a rearmost seat  80   d.    
       FIG. 7  is a diagram illustrating a condition where the air conditioning unit  10  for a rear seat according to the fifth embodiment of the present disclosure is mounted in a vehicle.  FIG. 7  is a diagram of the vehicle compartment when viewed from the width direction (i.e., the left-right direction). 
     The air conditioning unit  10  for a rear seat according to the present embodiment is arranged in the vehicle compartment on the rear side of the rearmost seat  80   d  and on a front side with respect to a trunk room  85 . The rearmost seat  80   d  is a seat that is arranged in a rearmost area of the vehicle compartment of the vehicle. 
     The blowing opening  22  of the air conditioning unit  10  for a rear seat connects to a blowing outlet  86   a  through a duct  86 . The blowing outlet  86   a  is located above the rearmost seat  80   d  in the roof part  82 . Accordingly, the air conditioning unit  10  for a rear seat of the present embodiment adjusts a temperature of air, which is drawn from the vehicle compartment through the suction port  83   a , by the evaporator  40  and the heater core  50  and blows the air from the blowing outlet  86   a  to a side of the rear seat  80   c  through the blowing opening  22  and the duct  86  as shown by an arrow B. 
     According to the above-described present embodiment, similar to the first through fourth embodiments, the portion of the fan case  33  that is provided with at least the suction ports  34   a ,  34   b  is arranged inside of the air conditioning case  20 . Thus, the suction ports  34   a ,  34   b  are surrounded by the inner wall of the air conditioning case  20 . Accordingly, the present disclosure provides the same effect as the first through fourth embodiments. 
     Especially, in a vehicle in which an engine for traveling is disposed on a front area in the vehicle, an engine sound transmitted from the engine for traveling is quiet for a passenger seating the rear seat, and it is required to keep quiet. Accordingly, since the suction ports  34   a ,  34   b  are surrounded by the inner wall of the air conditioning case  20 , an effect that reduces a noise of the blower  30  can be improved. 
     Sixth Embodiment 
     In the above-described first embodiment, an example in which the evaporator  40  and the heater core  50  are arranged such that the air inlet surfaces  40   b ,  50   b  face each other. In a sixth embodiment, the evaporator  40  and the heater core  50  are arranged such that the air outlet surfaces  40   a ,  50   a  face each other. 
       FIG. 8  is a diagram illustrating a condition where the air conditioning unit  10  for a rear seat according to the sixth embodiment of the present disclosure is mounted in a vehicle. In  FIG. 8 , the same reference numbers as  FIG. 3  show the same members, and the explanation of which is omitted. 
     In the air conditioning unit  10  for a rear seat of the present embodiment, the air conditioning case  20  is provided with introducing ports  21   a ,  21   b  instead of the introducing port  21  that is shown in  FIG. 3 . The introducing port  21   a  is formed in the air conditioning case  20  on a side of the right wall portion  20   a . The introducing port  21   b  is formed in the air conditioning case  20  on a side of the left wall portion  20   b.    
     The evaporator  40  and the heater core  50  are arranged such that the air outlet surfaces  40   a ,  50   a  face each other across an air passage  93 . Specifically, the evaporator  40  and the heater core  50  are arranged in parallel with respect to the airflow direction and are arranged in a V-shape such that a distance L between the air outlet surfaces  40   a ,  50   a  increases toward a downstream side in the airflow direction. That is, the evaporator  40  and the heater core  50  are arranged such that cool air from the air outlet surface  40   a  intersects with warm air from the air outlet surface  50   a.    
     An air mix door  60 A that is alternative to the air mix door  60  shown in  FIG. 3  is arranged between the air outlet surface (i.e., the cool-air blowing surface)  40   a  of the evaporator  40  and the air outlet surface (i.e., the warm-air blowing surface)  50   a  of the heater core  50 . The air mix door  60 A has a door body  63  having a plate shape and a rotation shaft  64  arranged on an end portion of the door body  63  in a planar direction. The air mix door  60 A is supported rotatably centered at the rotation shaft  64 . 
     The air mix door  60 A adjusts a temperature of conditioned air that is blown into the vehicle compartment from the blowing opening  22  by changing a ratio between an air volume of cool air blowing from the air outlet surface  40   a  of the evaporator  40  and an air volume of warm air blowing from the air outlet surface  50   a  of the heater core  50  depending on a position of the air mix door  60 A. 
     When the air mix door  60 A is positioned at a position X 1  shown in  FIG. 8 , a max-cool mode in which the air volume of cool air blowing from the evaporator  40  becomes maximum, and the air volume of warm air blowing from the heater core  50  becomes minimum is performed. When the air mix door  60 A is positioned at a position X 2  shown in  FIG. 8 , a max-hot mode in which the air volume of cool air blowing from the evaporator  40  becomes minimum, and the air volume of warm air blowing from the heater core  50  becomes maximum is performed. 
     In the air conditioning case  20 , a mixing space  90  is formed between the evaporator  40 , the heater core  50  and the suction ports  34   a ,  34   b  of the blower  30 . In the mixing space  90 , cool air blown from the air outlet surface  40   a  of the evaporator  40  and warm air blowing from the air outlet surface  50   a  of the heater core  50  are mixed. 
     According to the present embodiment having the above-described configuration, air flows from the introducing ports  21   a ,  21   b  to the blower  30  in the air conditioning case  20  when the electric motor  31  rotates the impellers  32   a ,  32   b  of the blower  30 . 
     On this occasion, air flows from the introducing port  21   a  to the air inlet surface  40   b  of the evaporator as shown by an arrow e. The air is cooled by refrigerant and blown from the air outlet surface  40   a  of the evaporator  40  as shown by an arrow g. 
     On the other hand, air flows from the introducing port  21   b  to the air inlet surface  50   b  of the heater core  50  as shown by an arrow f. The air is heated by the engine cooling water (i.e., warm water) and blown from the air outlet surface  50   a  of the heater core  50  as shown by an arrow h. 
     Cold air blowing from the evaporator  40  and warm air blowing from the heater core  50  intersect with each other and mixed together. The mixed air is drawn as a conditioned air to the suction ports  34   a ,  34   b  as shown by arrows k, j. The drawn air is blown from the blowing opening  22  to the rear side in the vehicle compartment through the fan case  33 . 
     According to the above-described present embodiment, similar to the first through fifth embodiments, the portion of the fan case  33  of the blower  30  that is provided with at least the suction ports  34   a ,  34   b  is arranged inside of the air conditioning case  20 . Thus, in the air conditioning unit  10  for a rear seat, the suction ports  34   a ,  34   b  that are provided with the fan case  33  of the blower  30  are surrounded by the inner wall of the air conditioning case  20 . Accordingly, when the blower  30  draws air flowing from the evaporator  40  and the heater core  50  and causes a noise, the inner wall of the air conditioning case  20  can suppress a transmission of the noise into the vehicle compartment. Therefore, similar to the first embodiment, the noise caused when the blower  30  draws air can be shut up in the air conditioning case  20 . 
     In addition, similar to the first embodiment, since the blower  30  draws air from both of the suction ports  34   a ,  34   b , a pressure loss of air drawn by the blower  30  can decrease, and a flow speed of the air can decrease as compared to that of a blower drawing air from a single suction port. Therefore, a noise caused when the blower  30  draws air can be reduced. Thus, a noise transmitting from the blower  30  into the vehicle compartment can be reduced. 
     According to the present embodiment, the evaporator  40  and the heater core  50  are arranged in a V-shape such that the distance L between the air outlet surfaces  40   a ,  50   a  increases toward a downstream side in the airflow direction. Accordingly, the mixing space  90  is provided on a downstream side with respect to the suction ports  34   a ,  34   b  of the blower  30  in the airflow direction. Therefore, cold air from the evaporator  40  and warm air from the heater core  50  are mixed in the mixing space  90 , and the mixed air is drawn into the suction ports  34   a ,  34   b  of the blower  30 . 
     According to the first embodiment, cold air from the evaporator  40  is drawn to the suction port  34   a  of the blower  30  as a laminar flow, and warm air from the heater core  50  is drawn to the suction port  34   b  of the blower as a laminar flow. Therefore, the impeller  32   a  blows cold air, and the impeller  32   b  blows warm air. Thus, air blown from the impellers  32   a ,  32   b  through the blowing opening  22  has a temperature variation. 
     In contrast, according to the present embodiment, as described above, cold air from the evaporator  40  and warm air from the heater core  50  are mixed in the mixing space  90 , and the mixed air is drawn to the suction ports  34   a ,  34   b  of the blower  30 . Accordingly, the conditioned air that is a mixture of warm air and cold air is drawn by the impeller  32   a ,  32   b  and blown from the blowing opening  22  to the rear seat side in the vehicle compartment. Therefore, a performance (i.e., an air mix performance) mixing cool air from the evaporator  40  and warm air from the heater core  50  on an upstream side with respect to the impellers  32   a  and  32   b  in the airflow direction can be improved. As a result, a cause of the temperature variation in the air blowing from the blower  30  can be suppressed. 
     Seventh Embodiment 
     In the sixth embodiment, an example in which the impellers  32   a ,  32   b  are housed in the common fan case  33 . In a seventh embodiment, the impellers  32   a ,  32   b  are respectively housed in two fan cases that are independent from each other. 
       FIG. 9  is a diagram illustrating a condition where the air conditioning unit  10  for a rear seat according to the seventh embodiment of the present disclosure is mounted in a vehicle. In  FIG. 9 , the same reference numbers as  FIG. 8  show the same members, and the explanation of which is omitted. 
     An air conditioning unit  10  for a rear seat according to the present embodiment has fan cases  33   a ,  33   b  instead of the fan case  33 . The fan case  33   a  configures a first housing member that houses the impeller  32   a . The fan case  33   a  is provided with a suction port  34   a  and a blowing opening  22   a . Accordingly, the fan case  33   a  and the impeller  32   a  configure a first centrifugal-type blower. 
     The fan case  33   b  configures a second housing member that houses the impeller  32   b . The fan case  33   b  is provided with a suction port  34   b  and a blowing opening  22   b . Accordingly, the fan case  33   ba  and the impeller  32   b  configure a second centrifugal-type blower. 
     The fan cases  33   a ,  33   b  are arranged on a downstream side with respect to the mixing space  90  in the airflow direction. The fan cases  33   a  and  33   b  are arranged such that the suction ports  34   a ,  34   b  face each other across the air passage  92  formed in the air conditioning case  20 . 
     According to the present embodiment configured as described above, cold air from the evaporator  40  and warm air from the heater core  50  are mixed in the mixing space  90 . The mixed air is drawn as the conditioned air to the suction port  34   a  of the blower  30  through the air passage  92  as shown by an arrow k. The impeller  32   a  blows the conditioned air drawn from the suction port  34   a  to an outer side in the radial direction. The fan case  33   a  collects the conditioned air blown from the impeller  32   a  and blows the conditioned air from the blowing opening  22   a.    
     On the other hand, the air mixed in the mixing space  90  is drawn as the conditioned air to the suction port  34   b  of the blower  30  through the air passage  92  as shown by an arrow j. The impeller  32   b  blows the conditioned air drawn from the suction port  34   b  to an outer side in the radial direction. The fan case  33   b  collects the conditioned air blown from the impeller  32   b  and blows the conditioned air from the blowing opening  22   b.    
     Thus, the impellers  32   a ,  32   b  can blow air, which is drawn into the fan cases  33   a ,  33   b  through the suction ports  34   a ,  34   b , from the blowing openings  22   a ,  22   b  to the rear seat side in the vehicle compartment. 
     According to the above-described present embodiment, similar to the first through fifth embodiments, the portion of the fan case  33  of the blower  30  that is provided with at least the suction ports  34   a ,  34   b  is arranged inside of the air conditioning case  20 . Thus, in the air conditioning unit  10  for a rear seat, the suction ports  34   a ,  34   b  provided with the fan cases  33   a ,  33   b  of the blower  30  are surrounded by the inner wall of the air conditioning case  20 . Thus, similar to the first embodiment, a noise transmitting from the blower  30  into the vehicle compartment can be reduced. 
     According to the present embodiment, the suction port  34   a  of the fan case  33   a  and the suction port  34   b  of the fan case  33   b  are arranged to face each other across the air passage  92 . The suction ports  34   a ,  34   b  are arranged on the downstream side of the mixing space  90  in the airflow direction. Accordingly, cool air from the evaporator  40  and warm air from the heater core  50  are mixed in the mixing space  90 , and the mixed air flows to the suction ports  34   a ,  34   b . As a result, the performance (i.e., the air mix performance) mixing cool air and warm air can be further improved. Thus, a cause of the temperature variation in the air blowing from the blower  30  into the vehicle compartment can be suppressed more effectively. 
     (Other Modifications) 
     In the first and second embodiments, the air conditioning unit  10  for a rear seat that is disposed between the outer plate  2  located on the right side in the vehicle and the quarter trim  3  is the air conditioning unit of the present disclosure. However, an air conditioning unit  10  for a rear seat that is disposed between the outer plate  2  located on a left side in the vehicle and the quarter trim  3  may be the air conditioning unit of the present disclosure instead. 
     In the first through seventh embodiments, an example in which the evaporator  40  and the heater core  50  are used as the heat exchanger is described. However, one of the evaporator  40  and the heater core  50  may be the heat exchanger. For example, a so-called “cooling-specified” air conditioning unit  10  for a rear seat in which the evaporator  40  of the evaporator  40  and the heater core  50  is arranged in the air conditioning case  20  may be the air conditioning unit of the present disclosure. 
     In the first through seventh embodiments, an example in which the air conditioning unit  10  for a rear seat blowing air to the rear seat side in the vehicle compartment is the air conditioning unit of the present disclosure is described. However, an air conditioning unit blowing air to a specified area except for the rear seat side in the vehicle compartment may be the air conditioning unit of the present disclosure. In this case, an arrangement location of the air conditioning unit of the present disclosure may be any location as long as being on a rear side with respect to the instrument panel  1   d  in the vehicle compartment. For example, an air conditioning unit blowing air to a front seat side may be the air conditioning unit of the present disclosure. 
     In the first through seventh embodiment, an example in which the evaporator  40  is used as the cooling heat exchanger cooling air by refrigerant is described. However, a peltier element may be used as the cooling heat exchanger and cools air. 
     In the first through seventh embodiments, an example in which the heater core  50  is used as the heating heat exchanger heating air by engine cooling water (i.e., warm water) is described. However, an electric heater may be used as the heating heat exchanger and heats air. 
     In the first and second embodiments, an example in which the sound absorption member  70  is arranged in the air conditioning case  20  is described. However, the heat absorption member  70  may be omitted from the air conditioning case  20 . 
     In the first and second embodiments, an example in which the sound absorption member  70  is arranged on the side of the suction port  34   a  of the air conditioning case  20  is described. However, the sound absorption member  70  may be arranged on a side of the suction port  34   b  in the air conditioning case  20 . Alternatively, the sound absorption member  70  may be arranged on both sides of the suction ports  34   a ,  34   b  in the air conditioning case  20 . Further, in the third through seventh embodiments, the sound absorption member  70  may be arranged similar to the first and second embodiments. 
     In the first through seventh embodiments, an example in which the evaporator  40  is arranged such that the air outlet surface  40   a  faces in the left-right direction is described. However, the evaporator  40  may be arranged such that the air outlet surface  40   a  faces in a direction other than the left-right direction. 
     In the first through seventh embodiments, an example in which the heater core  50  is arranged such that the air outlet surface  50   a  faces in the left-right direction is described. However, the heater core  50  may be arranged such that the air outlet surface  50   a  faces in a direction other than the left-right direction instead. 
     In the first through seventh embodiments, an example in which a centrifugal-type blower is used as the blower  30  is described. However, a blower other than the centrifugal-type blower may be used as long as being a blower that has the suction ports  34   a ,  34   b.    
     In the first through seventh embodiments, an example in which the suction ports  34   a ,  34   b  of the blower  30  face in the left-right direction. However, the suction ports  34   a ,  34   b  of the blower  30  may face in a direction (e.g., the upper-lower direction) other than the left-right direction. 
     A vehicle in which the air conditioning unit  10  for a rear seat of the present disclosure is mounted may be any vehicle as long as having a space for mounting the air conditioning unit  10  for a rear seat between the outer plate  2  and the quarter trim  3 . 
     In the first through seventh embodiments, an example in which the electric motor operates the air mix door  60  ( 60 A) is described. However, the air mix door  60  ( 60 A) may be operated by an operational force that is generated when a user operates an operation part. 
     Moreover, the air conditioning unit  10  for a rear seat of the sixth and seventh embodiments may be arranged in the center console box  81  similar to the third embodiment. The air conditioning unit  10  for a rear seat may be arranged in the roof part  82  similar to the fourth embodiment, or the air conditioning unit  10  for a rear seat may be arranged on the rear side of the rearmost seat  80   d  in the vehicle compartment similar to the fifth embodiment. Furthermore, an area in which the air conditioning unit  10  for a rear seat of the present disclosure is arranged may be any area as long as being an area on a rear side with respect to the instrument panel in the vehicle compartment. 
     It should be understood that the present disclosure is not limited to the above-described embodiments and intended to cover various modification within a scope of the present disclosure as described hereafter. Above-described embodiments are not unrelated to each other and can be combined as required except for a case of being clearly improper.