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US 8,428,817 B2Granted
Vehicle cooling fan control system and vehicle cooling fan control method
AssigneeCalsonic Kansei Corporation
InventorsKazutaka Yamaguchi, Satoshi Kondo
Life of this patent
Estimating the term…
Abstract
Vehicle cooling fan control system and method which prevent an occupant from hearing peculiar sounds from a cooling fan due to a decrease in rotation speed are provided. The vehicle cooling fan control system according to the present invention is configured not to stop the rotation of a fan motor for a predetermined time even upon satisfaction of an air conditioner stoppage condition as long as a vehicle interior is quiet.
Claims5
A vehicle cooling fan control system, comprising:
- a cooling fan including a fan motor and configured to cool a condenser by an air blowing from a rotation of said fan motor, said condenser being configured for cooling down a refrigerant delivered from a compressor in a refrigeration cycle of an air conditioner;
- an evaporator in a refrigeration cycle of the air conditioner;
- a temperature sensor for detecting an actual outlet temperature of said evaporator;
- a setting section for setting a target outlet temperature of said evaporator;
- a compressor control section for controlling a discharge pressure of said compressor via a compressor ON request signal so that the actual outlet temperature of said evaporator as detected by said temperature sensor approaches the target outlet temperature set by said setting section;
- and
- a fan motor control section for receiving the compressor ON request signal from the compressor control section to control said fan motor of said cooling fan so as to maintain a cooling performance of said condenser, said fan motor control section being configured to:
- determine whether or not at least one of a vehicle speed and an engine rotation speed is lower than a predetermined speed;
- decide whether or not the air conditioner is in operation;
- start counting a predetermined time upon satisfaction of a stoppage condition for the air conditioner and upon determining that at least one of the vehicle speed and the engine rotation speed is lower than the predetermined speed;
- control said fan motor to keep operating at a predetermined rotation speed while receiving the compressor ON request signal even when the stoppage condition is satisfied, and to stop operating when the predetermined time has elapsed;
- and
- when the stoppage condition is satisfied, change a difference between the set target outlet temperature and the actual outlet temperature of said evaporator detected by said temperature sensor to a zero value without canceling the compressor ON request signal so as to make the compressor stop or operate at a minimal level.
10 more elements
A vehicle cooling fan control method, comprising:
- determining whether or not at least one of a vehicle speed and an engine rotation speed is lower than a predetermined speed;
- deciding whether or not an air conditioner is in operation;
- starting counting of a predetermined time upon satisfaction of a stoppage condition for the air conditioner and upon determining that at least one of the vehicle speed and the engine rotation speed is lower than the predetermined speed;
- detecting an outlet temperature of an evaporator in a refrigeration cycle of the air conditioner;
- setting a target outlet temperature of the evaporator;
- controlling a discharge pressure of a compressor via a compressor ON request signal so that the detected outlet temperature of the evaporator approaches the set target outlet temperature;
- controlling a fan motor of a cooling fan to keep operating at a predetermined rotation speed while receiving the compressor ON request signal even when the stoppage condition is satisfied, and to stop operating when the predetermined time has elapsed;
- and
- when the stoppage condition for the air conditioner is satisfied, changing a difference between the target outlet temperature and the detected outlet temperature of the evaporator to a zero value without cancelling the compressor ON request signal so as to make the compressor stop or operate at a minimal level.
6 more elements
Dependencies are inferred from the claim text.