Patent Publication Number: US-2022227201-A1

Title: Air conditioner for vehicle

Description:
TECHNICAL FIELD 
     The present invention relates to an air conditioner for a vehicle. 
     Priority is claimed on Japanese Patent Application No. 2019-115307 filed on Jun. 21, 2019, the content of which is incorporated herein by reference. 
     BACKGROUND ART 
     For example, as described in PTL 1 below, an air conditioner for a vehicle used in an automobile or the like includes a heater core that is a heat exchanger for heating, an evaporator that is a heat exchanger for cooling, a unit case that defines an air mixing space in which warm air or cold air passing through the heater core and the evaporator is mixed, and an air mixing damper that changes the mixing ratio between the warm air and the cold air in the air mixing space. In the case of such a device, it is possible to achieve air having a desired temperature with a change in mixing ratio between the cold air and the warm air by adjusting the amount of rotation of the air mixing damper. 
     The air mixing damper is rotatably supported with respect to the unit case via a member called a damper lever. The damper lever is integrally provided with a pin that protrudes in a direction orthogonal to a direction in which the damper lever rotates. The pin is fitted into a guiding groove of a main lever provided separately from the damper lever. The main lever rotates around the axis thereof by being driven by a driving source (actuator). When the main lever rotates, the pin of the damper lever is guided along the guiding groove, and thus the posture (angle of rotation) of the damper lever is changed. 
     The main lever has a sliding portion that slides with respect to the unit case and the damper lever. In the above-described example, the main lever rotates in a state of being inserted into a hole portion formed in the unit case. In addition, the guiding groove formed on the main lever is in a state of being in slide-contact with the pin of the damper lever. Therefore, it is necessary to reduce friction generated between the main lever, the damper lever, and the unit case. Here, in the related art, each of the main lever and the damper lever is generally formed of polyacetal (POM) or polybutylene terephthalate (PBT). 
     CITATION LIST 
     Patent Literature 
     [PTL 1] Japanese Unexamined Patent Application Publication No. 2017-13733 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, since the main lever and the damper lever slide on each other as described above, in a case where the main lever and the damper lever are formed of the same member, a frictional force generated between the main lever and the damper lever becomes large. As a result, sliding portions between the main lever and the damper lever may be worn or deteriorated at an early stage. As a result, the durability of the air conditioner for a vehicle is limited. 
     The present invention has been made to solve the above-described problems, and an object thereof is to provide an air conditioner for a vehicle that is inexpensive and that has a high durability. 
     Solution to Problem 
     According to an aspect of the present invention, there is provided an air conditioner for a vehicle which is installed in the vehicle, the air conditioner including an evaporator that cools air, a heater core that heats the air, a unit case that accommodates the evaporator and the heater core and in which an air mixing space where the air supplied from the evaporator and the air supplied from the heater core are mixed with each other is defined and a plurality of flow paths through which the air mixed in the air mixing space flows are formed, a plurality of dampers that cause the plurality of flow paths to switch between an open state and a closed state, a plurality of damper levers that rotatably support the plurality of dampers with respect to the unit case and that include pins extending to be parallel to rotation axes of the dampers, and a main lever in which a guiding groove into which the pins are fitted is formed and that rotates around an axis to guide the pins and to rotate the damper levers. The main lever includes a main lever main body in which the guiding groove is formed and a shaft portion that is provided at a position of the axis, supports the main lever main body with respect to the unit case such that the main lever main body is rotatable around the axis, and is provided with a claw portion that is engaged with the unit case so as not to fall off from the unit case, and the shaft portion has a toughness higher than the main lever main body and is formed of a material different from the unit case. 
     According to the above-described configuration, the main lever includes the main lever main body and the shaft portion. Of these, the shaft portion has a toughness higher than the main lever main body and is formed of a material different from the unit case. Therefore, in comparison with a configuration in which the shaft portion and the unit case are formed of the same material, a frictional force generated between the shaft portion and the unit case can be reduced. Furthermore, since the main lever main body and the shaft portion are formed of different materials from each other, the damper levers sliding on the main lever main body can be formed of the same material as the shaft portion. In this case as well, a frictional force generated between the damper levers and the main lever main body can be reduced. Furthermore, since it is easy to select an inexpensive material, cost reduction can be realized. 
     In the air conditioner for a vehicle, the shaft portion and the damper levers may be formed of one material selected from the group consisting of polyacetal and polybutylene terephthalate, and the main lever main body may be formed of polypropylene. 
     According to the above-described configuration, the toughness of the shaft portion and the damper levers can be made higher than the toughness of the main lever main body. 
     In the air conditioner for a vehicle, an extension portion that extends in a radial direction with respect to the axis may be formed at an end portion of the shaft portion that is on a side opposite to the claw portion. 
     According to the above-described configuration, the shaft portion is engaged with the unit case from one side via the claw portion and is fixed to the unit case from the other side by means of the extension portion provided on the end portion that is on the side opposite to the claw portion. That is, since the extension portion is provided, it is possible to eliminate a possibility that the shaft portion falls off toward the other side from the one side. 
     In the air conditioner for a vehicle, at least one of the plurality of dampers may be an air mixing damper that is provided in the air mixing space and that adjusts a mixing state of the air supplied from the evaporator and the air supplied from the heater core. 
     Here, the air mixing damper generally rotates more frequently than the other dampers at the time of adjustment of the temperature of air to be sent. That is, it is particularly important to reduce a frictional force caused by a sliding motion between the air mixing damper and the unit case. According to the above-described configuration, a frictional force generated between the air mixing damper and the unit case can be reduced, and it is possible to more stably operate the air conditioner for a vehicle. 
     Advantageous Effects of Invention 
     According to the present invention, it is possible to provide an air conditioner for a vehicle that is inexpensive and that has a high durability. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cross-sectional view showing the configuration of an air conditioner for a vehicle according to an embodiment of the present invention. 
         FIG. 2  is a vertical cross-sectional view showing the vicinity of dampers in the air conditioner for a vehicle shown in  FIG. 1 . 
         FIG. 3  is an enlarged cross-sectional view of a main part of  FIG. 2 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     An embodiment of the present invention will be described with reference to the drawings. As shown in  FIG. 1 , an air conditioner  100  for a vehicle according to the present embodiment includes an evaporator  1 , a heater core  2 , a unit case  3  that accommodates the evaporator  1  and the heater core  2 , a plurality of dampers D (air mixing damper  4 , foot switching damper  5 , defroster switching damper  6 , and face damper  9 ) for adjusting the flow of air inside the unit case  3 , a main lever  20  that supports the dampers D with respect to the unit case  3 , and damper levers  24 . Note that  FIG. 1  is a cross-sectional view of the air conditioner  100  for a vehicle as seen in a width direction, which is a direction intersecting a traveling direction of a vehicle into which the air conditioner  100  for a vehicle is installed. 
     As the evaporator  1 , for example, a heat exchanger for cooling for which a vapor compression refrigerating cycle is adopted is used. A low-pressure refrigerant flowing in the evaporator  1  is evaporated through absorption of heat from air flowing around the evaporator  1  so that the air is cooled. In the present embodiment, the evaporator  1  is formed in a thick plate-like shape. 
     As the heater core  2 , a warm water type heat exchanger for heating that heats air with warm water (that is, engine cooling water) from an engine or the like for a vehicle (not shown) is used. An amount of heat from warm water flowing inside the heater core  2  is applied to air flowing around the heater core  2  so that the air is heated. In the present embodiment, the heater core  2  is also formed in a thick plate-like shape as with the evaporator  1 . 
     The unit case  3  accommodates the evaporator  1  and the heater core  2 , and an air flow path is defined inside the unit case  3 . More specifically, inside the unit case  3 , a cooling space  7 , a heating space  8 , a foot discharge flow path  92 , an air mixing space  91 , a relay space  93 , a center discharge flow path  94 A, a side discharge flow path  94 B, and a defroster discharge flow path  95  (defroster discharge flow path) are formed. 
     The evaporator  1  is accommodated in the cooling space  7 . The evaporator  1  divides the cooling space  7  into two spaces. More specifically, the cooling space  7  includes an introduction space  71  and a cold air supply space  72 . A space formed on one side of the evaporator  1  in the traveling direction of the vehicle is the introduction space  71  through which air introduced by a fan or the like (not shown) flows. The space on the other side of the evaporator  1  (that is, the space formed on the side opposite to the introduction space  71  with respect to the evaporator  1 ) is the cold air supply space  72  through which air cooled by the evaporator  1  flows. That is, air in the introduction space  71  is cooled when the air comes into contact with the evaporator  1  by being sent by the fan and flows into the cold air supply space  72  thereafter. 
     The heater core  2  is accommodated in the heating space  8 . The heating space  8  communicates with the cooling space  7  via a portion of the air mixing space  91 , which will be described later. More specifically, the heating space  8  is provided at a position facing the cooling space  7  from the cold air supply space  72  side. The heater core  2  divides the heating space  8  into three spaces. The heating space  8  includes a second introduction space  81 , a warm air supply space  82 , and a return space  83 . A space on one side (that is, the side facing the cooling space  7  from the heater core  2 ) with respect to the heater core  2  in the traveling direction of the vehicle is the second introduction space  81  into which air supplied from the cold air supply space  72  is introduced. A space on the other side with respect to the heater core  2  (the space formed on the side opposite to the second introduction space  81  with respect to the heater core  2 ) is the warm air supply space  82  through which air heated by the heater core  2  flows. That is, air inside the second introduction space  81  is heated when the air comes into contact with the heater core  2  and flows into the warm air supply space  82  thereafter. 
     Furthermore, in the heating space  8 , a space is formed between an upper end portion of the heater core  2  and an inner wall of the unit case  3 . The space is the return space  83  through which air passing through the second introduction space  81  and the warm air supply space  82  in this order returns to the air mixing space  91 , which will be described later. 
     The cooling space  7  and the heating space  8  configured as described above communicate with each other via the air mixing space  91 . In the air mixing space  91 , air cooled in the cooling space  7  (cold air) and air heated in the heating space  8  (warm air) are mixed with each other. More specifically, the air mixing space  91  is a flow path that communicates with the cold air supply space  72  of the cooling space  7  and the warm air supply space  82  of the heating space  8  and extends upward. On the cooling space  7  side in the air mixing space  91 , a guide partition wall portion  10  that guides air flowing through the air mixing space  91  to an upper side is provided. 
     The air mixing space  91  is provided with the air mixing damper  4  that adjusts the mixing ratio (mixing state) between air introduced from the cooling space  7  and air introduced from the heating space  8 . The air mixing damper  4  is a plate-shaped member rotatably supported by the unit case  3  at a boundary between the air mixing space  91  and the heating space  8 . More specifically, the air mixing damper  4  includes a rotary shaft  41  that rotates around a central axis A 1  extending in a vehicle width direction, an air mixing damper main body  42 , and a reheating prevention damper  43 , the air mixing damper main body  42  and the reheating prevention damper  43  extending on a plane intersecting the width direction with the rotary shaft  41  interposed therebetween. 
     In the present embodiment, the rotary shaft  41  is provided on a straight line connecting an upper end portion (first end portion t 1 ) and a lower end portion (second end portion t 2 ) of the boundary between the air mixing space  91  and the heating space  8 . Furthermore, the rotary shaft  41  is provided at a position that coincides with an upper end portion of the heater core  2  in a vertical direction as seen in a cross-sectional view. In addition, a dimension from the rotary shaft  41  to a lower end portion (third end portion t 3 ) of the guide partition wall portion  10  is approximately the same as a dimension from the rotary shaft  41  to the second end portion t 2 . 
     The air mixing damper main body  42  extends by the dimension from the rotary shaft  41  to the second end portion t 2  (similarly, by the dimension from the rotary shaft  41  to the third end portion t 3  of the guide partition wall portion  10 ) as seen in the cross-sectional view. On the other hand, the reheating prevention damper  43  extends in a direction opposite to a direction in which the air mixing damper main body  42  extends with the rotary shaft  41  interposed therebetween. More specifically, the reheating prevention damper  43  extends to be inclined toward the air mixing space  91  side with respect to a plane along which the air mixing damper main body  42  extends. 
     The air mixing damper  4  configured as described above is rotatable between a maximum cooling position shown in  FIG. 1  and a maximum heating position (not shown). At the maximum cooling position, a tip portion of the air mixing damper main body  42  (an end portion on the side opposite to the rotary shaft  41 ) comes into contact with the second end portion t 2  from the air mixing space  91  side. At the same time, the reheating prevention damper  43  is held at a position facing the first end portion t 1  from the rotary shaft  41  in the vertical direction. Accordingly, at the maximum cooling position, the cooling space  7  and the heating space  8  are divided by the air mixing damper main body  42 , and the cooling space  7  and the air mixing space  91  communicate with each other. 
     On the other hand, although not shown in detail, at the maximum heating position, the tip portion of the air mixing damper main body  42  comes into contact with the third end portion t 3  of the guide partition wall portion  10  from the air mixing space  91  side. At the same time, the reheating prevention damper  43  comes into contact with an upper end of the heater core  2  from the return space  83  side. Accordingly, the cooling space  7  and the heating space  8  communicate with each other, and the heating space  8  and the air mixing space  91  communicate with each other via the return space  83 . 
     In the air mixing space  91 , an inner wall of the unit case  3  forms the foot discharge flow path  92  at a region that faces the guide partition wall portion  10  in the traveling direction (that is, above the heating space  8 ). The foot discharge flow path  92  communicates with a foot discharge outlet (not shown) for sending air to the feet of an occupant in the vehicle. 
     An end portion (an end portion on the air mixing space  91  side) of the foot discharge flow path  92  is a foot introduction inlet E 1  for introducing air from the air mixing space  91 . The foot introduction inlet E 1  is an opening that extends in the vertical direction as seen in the cross-sectional view. An upper end of the foot introduction inlet E 1  is a fifth end portion t 5 , and a lower end thereof is a sixth end portion t 6 . 
     The foot switching damper  5  is provided in the foot discharge flow path  92 . The foot switching damper  5  is a plate-shaped member that is rotatably supported in the foot discharge flow path  92 . More specifically, the foot switching damper  5  includes a rotary shaft  51  (second rotary shaft) that rotates around a central axis A 2  (second central axis) extending in the vehicle width direction and a foot switching damper main body  52  (foot damper main body) that extends on a plane intersecting the width direction with the rotary shaft  51  interposed therebetween. The area of the foot switching damper main body  52  is the same as the cross-sectional area of the foot discharge flow path  92 . 
     An accommodation space  5 V for accommodating the foot switching damper  5 , which is recessed upward, is formed on an inner surface of the foot discharge flow path  92 . That is, when the foot switching damper  5  is at an opening position, the foot switching damper  5  is accommodated in the accommodation space  5 V. As seen in a direction in which the foot discharge flow path  92  extends, the foot switching damper  5  accommodated in the accommodation space  5 V does not protrude to the inside of the foot discharge flow path  92 . In other words, in this state, a surface of the foot switching damper  5  is flush with the other inner surface of the foot discharge flow path  92 . 
     Yet another space is formed above the air mixing space  91 . This space is the relay space  93 . The relay space  93  is a space for distributing air supplied from the air mixing space  91  to the defroster discharge flow path  95 , the center discharge flow path  94 A, and the side discharge flow path  94 B, which will be described later. 
     At a region that faces the foot introduction inlet E 1  in the traveling direction, the defroster discharge flow path  95  is formed by an inner wall of the unit case  3 . The defroster discharge flow path  95  extends in the vertical direction and communicates with a defroster discharge outlet (not shown) through which air for defrosting is sent from the inside of the vehicle to a windshield (front window). 
     An end portion (an end portion on the relay space  93  side) of the defroster discharge flow path  95  is a defroster introduction inlet E 2  for introducing air from the relay space  93 . The defroster introduction inlet E 2  is an opening that extends in the vertical direction as seen in the cross-sectional view. An upper end portion of the defroster introduction inlet E 2  is a seventh end portion t 7 , and a lower end portion thereof is an eighth end portion t 8 . 
     The defroster discharge flow path  95  is provided with the defroster switching damper  6 . The defroster switching damper  6  is a plate-shaped member that is rotatably supported above the defroster introduction inlet E 2 . More specifically, the defroster switching damper  6  includes a rotary shaft  61  that rotates around a central axis A 3  extending in the vehicle width direction and a defroster switching damper main body  62  that extends from the rotary shaft  61  on a plane intersecting the width direction. 
     Yet other spaces are formed above the relay space  93 . These spaces are the center discharge flow path  94 A and the side discharge flow path  94 B. The center discharge flow path  94 A is a flow path into which air supplied from the relay space  93  is taken and through which the air is sent to a center discharge outlet (not shown) provided at the center portion of an instrument panel of the vehicle. The side discharge flow path  94 B is a flow path through which air is sent to side discharge outlets (not shown) provided at both end portions of the instrument panel of the vehicle. The center discharge outlet and the side discharge outlets are provided mainly for the purpose of sending cold air or warm air toward the upper part of the body of an occupant. 
     The center discharge flow path  94 A and the side discharge flow path  94 B are arranged to be adjacent to each other in the traveling direction of the vehicle. The center discharge flow path  94 A and the side discharge flow path  94 B extend in different directions. Specifically, the center discharge flow path  94 A extends to an upper side from a lower side in the vertical direction while being closer to the upper side toward a rear side from a front side in the traveling direction of the vehicle. The side discharge flow path  94 B extends in the vertical direction. The center discharge flow path  94 A is provided behind the side discharge flow path  94 B in the traveling direction of the vehicle. 
     The center discharge flow path  94 A is formed by a center discharge flow path forming portion  3 A, which has a tubular shape and is a portion of the unit case  3 . An end portion of the center discharge flow path forming portion  3 A that is on the relay space  93  side is a center opening E 3  that is open toward the relay space  93 . The side discharge flow path  94 B is formed by a side discharge flow path forming portion  3 B, which has a tubular shape and is a portion of the unit case  3 . An end portion of the side discharge flow path forming portion  3 B that is on the relay space  93  side is a side opening E 4  that is open toward the relay space  93 . 
     The face damper  9  is attached between the center discharge flow path  94 A and the side discharge flow path  94 B. More specifically, the face damper  9  is provided at a ninth end portion t 9  at which an inner surface of the center discharge flow path  94 A and an inner surface of the side discharge flow path  94 B intersect each other. The face damper  9  causes the center discharge flow path  94 A and the side discharge flow path  94 B to switch between an open state and a closed state. 
     The face damper  9  includes a rotary shaft  31  that is rotatable around a central axis A 4  extending in the vehicle width direction and includes a first damper main body  32  and a second damper main body  33  that are provided at the rotary shaft  31  and that extend in different directions from each other toward a radial outer side with respect to the central axis A 4 . The rotary shaft  31  is rotatably supported at the ninth end portion t 9  described above. The first damper main body  32  has a plate-like shape extending toward the center discharge flow path  94 A side from the rotary shaft  31 . The second damper main body  33  has a plate-like shape extending toward the side discharge flow path  94 B side from the rotary shaft  31 . 
     A dimension from the rotary shaft  31  to a tip portion of the first damper main body  32  is equal to a dimension from the ninth end portion t 9  to the fifth end portion t 5 . A dimension from the rotary shaft  31  to a tip portion of the second damper main body  33  is equal to a dimension from the ninth end portion t 9  to the seventh end portion t 7 . Furthermore, when the face damper  9  is at a closing position, the first damper main body  32  extends on a plane orthogonal to a direction in which the center discharge flow path  94 A extends. Furthermore, when the face damper  9  is at the closing position, the second damper main body  33  extends on a plane that is different from the plane on which the first damper main body  32  extends and that is orthogonal to a direction in which the side discharge flow path  94 B extends. That is, the center opening E 3  of the center discharge flow path  94 A and the side opening E 4  of the side discharge flow path  94 B are provided to be closed by the first damper main body  32  and the second damper main body  33  of the face damper  9  when the face damper  9  is at the closing position. Note that the expression “a direction in which a flow path extends” herein means the normal direction of an opening plane of each flow path. Furthermore, “being orthogonal” may not mean being strictly orthogonal, and slight manufacturing errors, tolerances, and the like are allowed as long as the configuration is made to achieve an orthogonal state. 
     According to the above-described configuration, the mixing ratio between cold air from the cooling space  7  and warm air from the heating space  8  is adjusted, and the state of distribution of air to each flow path (foot discharge flow path  92 , defroster discharge flow path  95 , center discharge flow path  94 A, and side discharge flow path  94 B) is switched with the air mixing damper  4 , the foot switching damper  5 , the defroster switching damper  6 , and the face damper  9  rotated. 
     Here, the air mixing damper  4 , the foot switching damper  5 , the defroster switching damper  6 , and the face damper  9  described above are supported at the unit case  3  by means of a configuration as shown in  FIG. 2 . Note that in an example shown in  FIG. 2 , the air mixing damper  4 , the foot switching damper  5 , the defroster switching damper  6 , and the face damper  9  are collectively shown as the dampers D. In other words, a configuration described below can be applied to any combination including any two or more of the air mixing damper  4 , the foot switching damper  5 , the defroster switching damper  6 , and the face damper  9 . In addition, although only two dampers D are shown in  FIG. 2 , it is also possible to apply the configuration described below to three or more dampers D. 
     As shown in  FIG. 2 , each damper D is rotatably supported with respect to the unit case  3  by the damper lever  24 . More specifically, the damper lever  24  includes a damper lever main body  24 A, a pin  24 B, a damper supporting portion  24 C, and a plate-shaped portion  24 D. The damper lever main body  24 A is rotatable around a damper axis Ad that extends in a direction orthogonal to a wall surface (unit case inner surface  3 S or unit case outer surface  3 T) of the unit case  3 . 
     An end portion of the damper lever main body  24 A that is on the unit case inner surface  3 S side is integrally provided with the damper supporting portion  24 C for supporting and fixing the damper D. An end portion of the damper lever main body  24 A that is on the unit case outer surface  3 T side is integrally provided with the plate-shaped portion  24 D that extends within a plane orthogonal to the damper axis Ad. The pin  24 B is provided at a position on the plate-shaped portion  24 D that is eccentric with respect to the damper axis Ad. The pin  24 B has a rod-like shape that protrudes from the plate-shaped portion  24 D in a direction parallel to a rotation axis (damper axis Ad) of the damper D. That is, it is possible to rotate the damper lever  24  and the damper D around the damper axis Ad by applying a force to the pin  24 B. Note that being “parallel” means being substantially parallel, and manufacturing tolerances and errors are allowed. 
     The damper levers  24  are rotated by the main lever  20  via the pins  24 B. The main lever  20  is supported by the unit case  3  at a through-hole (support hole H 1 ) formed in the unit case  3 . Specifically, the main lever  20  includes a main lever main body  21  that has a plate-like shape and that covers each of the damper levers  24  from the unit case outer surface  3 T side and a shaft portion  22  that supports the main lever main body  21  such that the main lever main body  21  can rotate around an axis Ax. 
     Guiding grooves R, into which the pins  24 B of the damper levers  24  described above are fitted, are formed at outer peripheral edges on a surface of the main lever main body  21  that faces the unit case outer surface  3 T side. Although not shown in detail, each guiding groove R extends along the rotation trajectory of the pin  24 B around the damper axis Ad. That is, in a case where the main lever  20  is rotated around the axis Ax, the pins  24 B are guided along the guiding grooves R, and the postures (angles of rotation) of the dampers D are changed. 
     A through-hole H 2  (refer to  FIG. 3 ) that penetrates the main lever main body  21  in a direction along the axis Ax is formed at the center portion of the main lever main body  21 . The shaft portion  22  is fixed at the through-hole H 2 . The shaft portion  22  includes a shaft portion main body  22 A that has a columnar shape centered on the axis Ax, a plurality of claw portions  22 B provided on an outer peripheral side of the shaft portion main body  22 A, and an extension portion  22 P that is provided on a side opposite to the claw portions  22 B of the shaft portion main body  22 A. The plurality of claw portions  22 B have an outer diameter dimension slightly larger than the support hole H 1  formed in the unit case  3 . After the claw portions  22 B are press-fitted into the support hole H 1  by means of elastic deformation, the claw portions  22 B are exposed on the unit case inner surface  3 S side, so that the shaft portion  22  is engaged with the support hole H 1  so as not to fall off from the support hole H 1 . 
     Furthermore, an end portion of the shaft portion  22  that is on a side opposite to the claw portions  22 B is integrally formed with the extension portion  22 P that extends in a radial direction with respect to the axis Ax. The extension portion  22 P is accommodated in an accommodation recess Rs formed to be coaxial with the through-hole H 2  of the main lever main body  21 . Furthermore, the end portion of the shaft portion  22  that is on a side opposite to the claw portions  22 B is integrally provided with a connecting portion C that has a tubular shape centered on the axis Ax. A driving source (actuator) (not shown) is connected to the connecting portion C. That is, the main lever  20  is rotated around the axis Ax by means of a rotational force applied from the driving source. 
     In the above-described configuration, the main lever  20  is rotated in a state of being inserted into the support hole H 1  formed in the unit case  3 . In addition, the guiding grooves R formed in the main lever  20  are in a state of being in sliding contact with the pins  24 B of the damper levers  24 . Therefore, it is necessary to reduce friction generated between the main lever  20 , the damper levers  24 , and the unit case  3 . Here, in the related art, each of the main lever  20  and the damper levers  24  is generally integrally formed of polyacetal (POM) or polybutylene terephthalate (PBT). 
     However, since the main lever  20  and the damper levers  24  slide on each other as described above, in a case where the main lever  20  and the damper levers  24  are formed of the same member, a frictional force generated between the main lever  20  and the damper levers  24  becomes large. As a result, sliding portions between the main lever  20  and the damper levers  24  may be worn or deteriorated at an early stage. As a result, the durability of the air conditioner for a vehicle is limited. 
     Therefore, in the present embodiment, the main lever  20  is divided into two members (that is, main lever main body  21  and shaft portion  22 ), and these members are formed of different materials. More specifically, the shaft portion  22  has a toughness higher than the main lever main body  21  and is formed of a material different from the unit case  3 . As a specific example of such a material, the shaft portion  22  and the damper levers  24  are formed of one material selected from a group including polyacetal (POM) and polybutylene terephthalate (PBT), and the main lever main body  21  and the unit case  3  are formed of polypropylene (PP). Therefore, slide-contact portions between the shaft portion  22  and the unit case  3 , slide-contact portions between the damper levers  24  and the unit case  3 , and slide-contact portions between the damper levers  24  and the main lever  20  can be formed of different materials from each other. As a result, in comparison with a case where the slide-contact portions are formed of the same material, wear and deterioration of the slide-contact portions can be reduced, for example. 
     As described above, according to the above-described configuration, the main lever  20  includes the main lever main body  21  and the shaft portion  22 . Of these, the shaft portion  22  has a toughness higher than the main lever main body  21  and is formed of a material different from the unit case  3 . Therefore, in comparison with a configuration in which the shaft portion  22  and the unit case  3  are formed of the same material, a frictional force generated between the shaft portion  22  and the unit case  3  can be reduced. Furthermore, since the main lever main body  21  and the shaft portion  22  are formed of different materials from each other, the damper levers  24  sliding on the main lever main body  21  can be formed of the same material (for example, POM) as the shaft portion  22 . In this case as well, a frictional force generated between the damper levers  24  and the main lever main body  21  can be reduced. Furthermore, since the types of materials required can be reduced, cost reduction can be realized. 
     Furthermore, according to the above-described configuration, the shaft portion  22  is engaged with the unit case  3  from one side in a direction along the axis Ax direction via the claw portions  22 B and is fixed to the unit case  3  from the other side by means of the extension portion  22 P provided on the end portion that is on the side opposite to the claw portions  22 B. That is, since the extension portion  22 P is provided, it is possible to eliminate a possibility that the shaft portion  22  falls off toward the other side from the one side. 
     In addition, in the present embodiment, the above-described configuration can be applied to the air mixing damper  4  as the damper D. Here, the air mixing damper  4  generally rotates more frequently than the other dampers at the time of adjustment of the temperature of air to be sent. That is, it is particularly important to reduce a frictional force caused by a sliding motion between the air mixing damper  4  and the unit case  3 . According to the above-described configuration, a frictional force generated between the air mixing damper  4  and the unit case  3  can be reduced, and it is possible to more stably operate the air conditioner  100  for a vehicle. 
     The embodiment of the present invention has been described above. Note that the above-described configuration can be changed and modified in various ways without departing from the gist of the present invention. 
     REFERENCE SIGNS LIST 
       1 : evaporator 
       2 : heater core 
       3 : unit case 
       3 A: center discharge flow path forming portion 
       3 B: side discharge flow path forming portion 
       3 S: unit case inner surface 
       3 T: unit case outer surface 
       4 : air mixing damper 
       5 : foot switching damper 
       6 : defroster switching damper 
       7 : cooling space 
       8 : heating space 
       9 : face damper 
       10 : guide partition wall portion 
       20 : main lever 
       21 : main lever main body 
       22 : shaft portion 
       22 A: shaft portion main body 
       22 B: claw portion 
       22 P: extension portion 
       24 : damper lever 
       24 A: damper lever main body 
       24 B: pin 
       24 C: damper supporting portion 
       24 D: plate-shaped portion 
       31 : rotary shaft 
       32 : first damper main body 
       33 : second damper main body 
       41 : rotary shaft 
       42 : air mixing damper main body 
       43 : reheating prevention damper 
       51 : rotary shaft 
       52 : foot switching damper main body 
       61 : rotary shaft 
       62 : defroster switching damper main body 
       71 : introduction space 
       72 : cold air supply space 
       81 : second introduction space 
       82 : warm air supply space 
       83 : return space 
       91 : air mixing space 
       92 : foot discharge flow path 
       93 : relay space 
       94 A: center discharge flow path 
       94 B: side discharge flow path 
       95 : defroster discharge flow path 
       100 : air conditioner for vehicle 
     Ad: damper axis 
     Ax: axis 
     C: connecting portion 
     D: damper 
     H 1 : support hole 
     H 2 : through-hole 
     R: guiding groove 
     Rs: accommodation recess 
     t 1 : first end portion 
     t 2 : second end portion 
     t 3 : third end portion 
     t 5 : fifth end portion 
     t 6 : sixth end portion 
     t 7 : seventh end portion 
     t 8 : eighth end portion 
     t 9 : ninth end portion