Active grille shutter

Abstract

An active grille shutter controls opening and closing of a variable duct device which uses movable louvers to open and close an opening provided at the front end of a vehicle to introduce moving air. The active grille shutter includes: thermal load state detection units each configured to detect a thermal load state of the vehicle; and an opening and closing control unit configured to set the variable duct device in a closed state in a normal condition, and to set the variable duct device in an open state when it is determined that the thermal load state of the vehicle is a predetermined high thermal load state.

1 . An active grille shutter for controlling opening and closing of a variable duct device that uses a movable louver to open and close an opening provided at a front end of a vehicle to introduce air, the active grille shutter comprising:
 a thermal load state detection unit configured to detect a thermal load state of the vehicle; and   an opening and closing control unit configured to set the variable duct device in a closed state in a normal condition, and to set the variable duct device in an open state when it is determined that the thermal load state of the vehicle is a predetermined high thermal load state.   
     
     
         2 . The active grille shutter according to  claim 1 ,
 wherein the thermal load state detection unit includes an ambient temperature sensor configured to detect an ambient temperature, and   the opening and closing control unit is configured to maintain the variable duct device in a closed state irrespective of a result of the detection by the thermal load state detection unit when the ambient temperature is substantially below a freezing point.   
     
     
         3 . The active grille shutter according to  claim 1 ,
 wherein the thermal load state detection unit includes a vehicle speed sensor configured to detect a running speed of the vehicle, and   the opening and closing control unit is configured to determine that the vehicle is in the high thermal load state when the vehicle has a low running speed which is lower than or equal to a predetermined value.   
     
     
         4 . The active grille shutter according to  claim 2 ,
 wherein the thermal load state detection unit includes a vehicle speed sensor configured to detect a running speed of the vehicle, and   the opening and closing control unit is configured to determine that the vehicle is in the high thermal load state when the vehicle has a low running speed which is lower than or equal to a predetermined value.   
     
     
         5 . The active grille shutter according  claim 1 ,
 wherein the thermal load state detection unit includes an engine output state detection unit configured to detect an output state of an engine, and   the opening and closing control unit is configured to determine that the vehicle is in the high thermal load state when the engine is in a predetermined high output state.   
     
     
         6 . The active grille shutter according  claim 2 ,
 wherein the thermal load state detection unit includes an engine output state detection unit configured to detect an output state of an engine, and   the opening and closing control unit is configured to determine that the vehicle is in the high thermal load state when the engine is in a predetermined high output state.   
     
     
         7 . The active grille shutter according  claim 1 ,
 wherein the thermal load state detection unit includes a temperature sensor configured to detect at least either one of a coolant temperature and a lubricating oil temperature of the engine, and   the opening and closing control unit is configured to determine that the vehicle is in the high thermal load state when the at least either one of the coolant temperature and the lubricating oil temperature is higher than or equal to a predetermined value.   
     
     
         8 . The active grille shutter according  claim 2 ,
 wherein the thermal load state detection unit includes a temperature sensor configured to detect at least either one of a coolant temperature and a lubricating oil temperature of the engine, and   the opening and closing control unit is configured to determine that the vehicle is in the high thermal load state when the at least either one of the coolant temperature and the lubricating oil temperature is higher than or equal to a predetermined value.   
     
     
         9 . The active grille shutter according  claim 1 ,
 wherein the thermal load state detection unit includes an ambient temperature sensor configured to detect an ambient temperature, and   the opening and closing control unit is configured to determine that the vehicle is in the high thermal load state when the ambient temperature is in a predetermined high temperature state.   
     
     
         10 . The active grille shutter according  claim 2 ,
 wherein the thermal load state detection unit includes an ambient temperature sensor configured to detect an ambient temperature, and   the opening and closing control unit is configured to determine that the vehicle is in the high thermal load state when the ambient temperature is in a predetermined high temperature state.   
     
     
         11 . The active grille shutter according  claim 1 ,
 wherein the thermal load state detection unit includes an air conditioner state detection unit configured to detect an operational state of an air conditioner, and   the opening and closing control unit is configured to determine that the vehicle is in the high thermal load state when the operational state of the air conditioner is in a predetermined high load state.   
     
     
         12 . The active grille shutter according  claim 2 ,
 wherein the thermal load state detection unit includes an air conditioner state detection unit configured to detect an operational state of an air conditioner, and   the opening and closing control unit is configured to determine that the vehicle is in the high thermal load state when the operational state of the air conditioner is in a predetermined high load state.