Aerodynamic sound decreasing apparatus

Abstract

Multiple projections are provided at a flow-change portion, which corresponds to such a portion of a wall surface of an A/C casing, at which velocity gradient of air current becomes larger in an area adjacent to the wall surface, in order to decrease aerodynamic sound generated by disturbed air current.

1 . An aerodynamic sound decreasing apparatus comprising:
 an air passage formed by a passage forming member;   an aerodynamic sound decreasing member provided on a wall surface of the passage forming member for decreasing velocity gradient of an air current colliding against a portion of the wall surface,   wherein the aerodynamic sound decreasing member is provided at such a flow-change portion, at which a shape of the wall surface is changed, and at which the velocity gradient of the air current will be increased in an area adjacent to the wall surface.   
     
     
         2 . The aerodynamic sound decreasing apparatus according to the  claim 1 , wherein
 the aerodynamic sound decreasing member is composed of multiple lines of projections formed on the wall surface and projecting from the wall surface.   
     
     
         3 . The aerodynamic sound decreasing apparatus according to the  claim 1 , wherein
 the aerodynamic sound decreasing member is composed of a plate member arranged in the air passage and separated from the wall surface, wherein the plate member has multiple through-holes.   
     
     
         4 . The aerodynamic sound decreasing apparatus according to the  claim 1 , wherein
 the air current collides against the flow-change portion and thereby a flow direction of the air current is changed.   
     
     
         5 . The aerodynamic sound decreasing apparatus according to the  claim 1 , further comprising;
 a blocking plate provided on the wall surface so as to project from the wall surface for blocking a part of the air current flowing through the air passage,   wherein the aerodynamic sound decreasing member is provided at the flow-change portion, which corresponds to a portion of the wall surface at a downstream side of the blocking plate, so that the air current disturbed by the blocking plate collides against the aerodynamic sound decreasing member.   
     
     
         6 . The aerodynamic sound decreasing apparatus according to the  claim 1 , further comprising;
 a guide plate provided on the wall surface so as to project from the wall surface for guiding a part of the air current flowing through the air passage,   wherein the aerodynamic sound decreasing member is provided at the flow-change portion, which corresponds to a portion of the wall surface at a downstream side of the guide plate, so that the air current disturbed by the guide plate collides against the aerodynamic sound decreasing member.   
     
     
         7 . The aerodynamic sound decreasing apparatus according to the  claim 1 , wherein
 the aerodynamic sound decreasing apparatus is applied to an air conditioning apparatus for a vehicle,   the air passage corresponds to a passage for supplying conditioned air into a passenger compartment of the vehicle,   the passage forming member is composed of an A/C casing for forming the air passage in the inside thereof, and   the aerodynamic sound decreasing member is provided at the flow-change portion, which corresponds to a door surface of an air switching door for opening and closing the air passage and/or on a plate surface of a partitioning wall of the A/C casing surrounding and/or neighboring to the air switching door, wherein the air current collides against the door surface and/or the plate surface and thereby a direction the air current is changed.   
     
     
         8 . The aerodynamic sound decreasing apparatus according to the  claim 7 , wherein
 the air switching door corresponds to a door for opening and closing the air passage, which connects an inside space of the A/C casing to the passenger compartment, and   the aerodynamic sound decreasing member is provided at the flow-change portion, which corresponds to the door surface and/or the plate surface, which faces to the inside space of the A/C casing when the air switching door is in its closed condition.   
     
     
         9 . The aerodynamic sound decreasing apparatus according to the  claim 7 , wherein
 air conditioning apparatus includes an evaporator and a heater core in the inside space of the A/C casing, wherein the air current passes through the evaporator and/or the heater core,   the air switching door corresponds to an air-mix door for controlling an air-mix ratio between cold air having passed through the evaporator and hot air having passed through the heater core.   
     
     
         10 . The aerodynamic sound decreasing apparatus according to the  claim 8 , further comprising;
 a sealing portion provided on the wall surface so as to project from the wall surface for blocking a part of the air current flowing through the air passage, wherein an outer peripheral portion of the air switching door is in contact with the sealing portion when the air switching door is closed,   wherein the aerodynamic sound decreasing member is provided at the flow-change portion, which corresponds to a portion of the wall surface, which is located at a downstream side of the sealing portion and at which the air current disturbed by the sealing portion collides against the aerodynamic sound decreasing member when the air switching door is in its opened condition.   
     
     
         11 . The aerodynamic sound decreasing apparatus according to the  claim 8 , wherein
 the air current disturbed by the outer peripheral portion of the air switching door collides against the aerodynamic sound decreasing member when the air switching door is in its opened condition.   
     
     
         12 . The aerodynamic sound decreasing apparatus according to the  claim 8 , further comprising;
 a sealing portion provided on the wall surface so as to project from the wall surface for blocking apart of the air current flowing through the air passage, wherein an outer peripheral portion of the air switching door is in contact with the sealing portion when the air switching door is closed; and   an elastic lip seal member provided at an outer periphery of the air switching door and in contact with the sealing portion when the air switching door is in its closed condition,   wherein the aerodynamic sound decreasing member is provided at the flow-change portion, which corresponds to a portion of the door surface of the air switching door, which is on a downstream side of the air current.   
     
     
         13 . The aerodynamic sound decreasing apparatus according to the  claim 8 , wherein
 a rib is provided on the door surface of the air switching door for reinforcing the same, wherein the rib projects from the door surface, and   the aerodynamic sound decreasing member is provided at the flow-change portion, which corresponds to a portion of the door surface of the air switching door, at which the air current disturbed by the rib collides against the aerodynamic sound decreasing member.   
     
     
         14 . The aerodynamic sound decreasing apparatus according to the  claim 1 , wherein
 the aerodynamic sound decreasing apparatus is applied to an air conditioning apparatus for a vehicle,   the air passage corresponds to a passage for supplying conditioned air into a passenger compartment of the vehicle,   the passage forming member is composed of an A/C casing for forming the air passage in the inside thereof,   a heat exchanger is provided in the air passage through which the air current passes, and   the aerodynamic sound decreasing member is provided at the flow-change portion, which corresponds to a part of a partitioning wall of the A/C casing, which is located at a downstream side of the heat exchanger and faces to the heat exchanger.   
     
     
         15 . The aerodynamic sound decreasing apparatus according to the  claim 1 , wherein
 the aerodynamic sound decreasing apparatus is applied to an air conditioning apparatus for a vehicle,   the air passage corresponds to a passage for supplying conditioned air into a passenger compartment of the vehicle,   the passage forming member is composed of an A/C casing for forming the air passage in the inside thereof,   a guide plate is provided in the air passage for adjusting a ratio between cold air and hot air,   the aerodynamic sound decreasing member is provided at the flow-change portion, which corresponds to a part of the plate surface of the guide plate.   
     
     
         16 . The aerodynamic sound decreasing apparatus according to the  claim 7 , wherein
 the aerodynamic sound decreasing member is provided on a part of the wall surface of the A/C casing, toward which air from a blower unit is blown out into the inside space of the A/C casing.   
     
     
         17 . The aerodynamic sound decreasing apparatus according to the  claim 1 , wherein
 the air passage formed by the passage forming member includes an air passage through which air is supplied into an inside space of an A/C casing,   the passage forming member includes a scroll casing for forming the air passage in an inside of the scroll casing so as to supply air from a centrifugal type blower unit into the inside space of the A/C casing, and   the aerodynamic sound decreasing member is provided at the flow-change portion, which corresponds to a part of a wall surface of the scroll casing, at which a flow direction of air is changed from an sir drawing direction to a centrifugal direction.   
     
     
         18 . The aerodynamic sound decreasing apparatus according to the  claim 1 , wherein
 the air passage formed by the passage forming member includes an air passage through which air is supplied into an inside space of an A/C casing,   the passage forming member includes a scroll casing for forming the air passage in an inside of the scroll casing so as to supply air from a blower unit into the inside space of the A/C casing, and   the aerodynamic sound decreasing member is provided at the flow-change portion, which corresponds to a part of a wall surface of the scroll casing at its volute tongue.