Cooling fan device
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsShoichi Akiyama, Dai Okumura, Atsushi Fukuda, Makoto Monya
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Abstract
A cooling fan device uses a cooling fan coupled to an engine via a fan clutch to generate cooling air flow for a radiator. The cooling fan device includes an electronic control unit configured to control an engagement rate of the fan clutch. The electronic control unit is configured to execute a first calculation process, a second calculation process, and an upper limit guarding process, thereby controlling the engagement rate based on a value of a coolant temperature requested engagement rate that has been subjected to an upper limit guarding process. A first upper limit rotation speed is set to a lower speed when a vehicle speed is relatively low than when the vehicle speed is relatively high.
Claims4
A cooling fan device configured to use a cooling fan coupled to an engine via a fan clutch to generate cooling air flow for a radiator, the cooling fan device comprising an electronic control unit configured to control an engagement rate of the fan clutch, wherein
- the electronic control unit is configured to execute:
- a first calculation process that calculates a coolant temperature requested engagement rate, the coolant temperature requested engagement rate being a requested value of the engagement rate in accordance with a cooling request for the engine coolant;
- a second calculation process that calculates, as a first guard value, a value of the engagement rate at which a rotation speed of the cooling fan is a first upper limit rotation speed based on a vehicle speed;
- and
- an upper limit guarding process that sets a value of the coolant temperature requested engagement rate to the first guard value when a calculated value of the coolant temperature requested engagement rate in the first calculation process exceeds the first guard value,
- thereby controlling the engagement rate based on a value of the coolant temperature requested engagement rate after being subjected to the upper limit guarding process, and
- the first upper limit rotation speed is set to a lower speed when the vehicle speed is relatively low than when the vehicle speed is relatively high.
Dependencies are inferred from the claim text.