초록 ▼

A fan cooling system and method are provided to control fan speed for cooling vehicle motor components while minimizing power consumption by the fan and reducing engine fuel consumption for an engine partially powering the fan. The fan cooling system raises engine coolant temperature of a vehicle in

A fan cooling system and method are provided to control fan speed for cooling vehicle motor components while minimizing power consumption by the fan and reducing engine fuel consumption for an engine partially powering the fan. The fan cooling system raises engine coolant temperature of a vehicle in motion to derive a fan speed demand so that fan speed may be reduced. The fan cooling system selects a maximum fan speed demand from one or more fan speed demands to command fan speed based on various sensed inputs, including engine coolant temperatures. The fan cooling system also improves cooling efficiency by incorporating slipheat protection for the fan so as not to overdrive the fan for cooling.

대표청구항 ▼

1. A fan control system for use with a fan cooling system in a vehicle comprising: a fan drive for driving a fan blade to rotate at a particular speed;one or more sensors for sensing engine conditions and transmission conditions;an engine control module coupled to the one or more sensors for receivi

1. A fan control system for use with a fan cooling system in a vehicle comprising: a fan drive for driving a fan blade to rotate at a particular speed;one or more sensors for sensing engine conditions and transmission conditions;an engine control module coupled to the one or more sensors for receiving engine conditions comprising at least an engine coolant temperature, the engine control module coupled to a communication link for transmitting engine information comprising engine conditions;a transmission control module coupled to the one or more sensors for receiving transmission conditions comprising at least a vehicle speed, the transmission control module coupled to the communication link for transmitting transmission information comprising transmission conditions;a power take off control module coupled to the communication link for transmitting power take off status information, wherein the power take off status information comprises whether a power take off unit on the vehicle is engaged or disengaged;a fan control module coupled to the communication link for receiving engine information, transmission information, and power take off status information to process the engine information, the transmission information, and the power take off status information and to generate one or more fan speed demands from the processed information; wherein the fan control module selects from the one or more fan speed demands a maximum fan speed demand to command the fan drive to rotate the fan blade at a commanded rotational fan speed based on the maximum fan speed demand;wherein the fan control module generates at least one of the fan speed demands by processing the engine coolant temperature, the power take off status information, and the vehicle speed;wherein when the vehicle speed of the vehicle is greater than 0 KPH and the power take off unit is engaged, the fan control module raises a set point of the engine coolant temperature to reduce the fan speed demand processed from the engine coolant temperature, the power take off status information, and the vehicle speed; andwherein the communication link connects the engine control module, transmission control module, and power take off control module to the fan control module. 2. The fan control system of claim 1, further comprising a fan speed sensor connected to the fan drive to measure the rotational speed of the fan blade and to communicate the sensed rotational speed of the fan blade to the fan control module. 3. The fan control system of claim 2, wherein the fan control module processes the sensed rotational speed of the fan blade with the engine information, transmission information, and power take off status information to generate the one or more fan speed demands. 4. The fan control system of claim 3, wherein the engine information received by the fan control module comprises ambient air temperature and engine rpm and wherein the fan control module processes a slip heat protection based on the ambient air temperature, the engine rpm, the sensed rotational speed of the fan blade, and the selected fan speed demand. 5. The fan control system of claim 4, wherein the fan control module commands the fan drive to change rotation of the fan blade based on the processed slip heat protection so that the fan drive will not maintain a rotational fan speed of the fan blade so as to overheat beyond design limits of the fan drive. 6. The fan control system of claim 3, wherein the fan control module calculates differences between commanded rotational fan speed and sensed rotational fan speed and modulates the commanded rotational fan speed to reduce the differences. 7. The fan control system of claim 1, wherein the engine information received by the fan control module includes an intake manifold temperature and wherein the fan control module processes the intake manifold temperature to generate the one or more fan speed demands. 8. The fan control system of claim 1, wherein the engine information received by the fan control module includes a catalyst temperature and wherein the fan control module processes the catalyst temperature to generate the one or more fan speed demands. 9. The fan control system of claim 1, wherein the fan control module further comprises a timer that counts to a specified time after the vehicle speed drops below a vehicle speed threshold value. 10. The fan control system of claim 9, wherein the fan control module raises the set point of the engine coolant temperature when the specified time is reached if the power take off unit is engaged. 11. The fan control system of claim 10, wherein the vehicle speed threshold value comprises any speed value less than or equal to 5 KPH and greater than 0 KPH. 12. The fan control system of claim 1, wherein the set point of the engine coolant temperature comprises a temperature value less than or equal to engine derate temperature. 13. The fan control system of claim 12, wherein the set point of the engine coolant temperature comprises a temperature value approximately 2 degrees Celsius below the engine derate temperature. 14. The fan control system of claim 12, wherein the set point of the engine coolant temperature comprises a temperature value approximately 2 degrees Celsius below engine redline as defined on an instrument cluster. 15. The fan control system of claim 1, further comprising an air conditioning system module for transmitting air conditioning system status information, wherein the air conditioning system status information comprises whether an air conditioning system in the vehicle is turned on or off. 16. The fan control system of claim 15, wherein the fan control module further includes receiving air conditioning status information and an ambient air temperature from the engine information to generate two fan speed demands, wherein the fan control module calculates a first fan speed demand based on a time since the air conditioning system last turned on and generates a second fan speed demand based on the ambient air temperature. 17. The fan control system of claim 1, wherein the communication link is a CAN-bus. 18. The fan control system of claim 1, wherein the fan drive is a viscous fan drive. 19. A method for controlling a speed of a fan blade in a fan cooling system of a vehicle comprising: sensing vehicle motor conditions including engine conditions and transmission conditions at one or more sensors;receiving at an engine control module one or more engine conditions, including at least an engine coolant temperature, from the one or more sensors;transmitting engine information including engine conditions on a communication link from the engine control module to a fan control module;receiving at a transmission control module one or more transmission conditions, including at least a vehicle speed, from the one or more sensors;transmitting transmission information including transmission conditions on the communication link from the transmission control module to the fan control module;transmitting power take off status information from a power take off control module on the communication link from the power take off control module to the fan control module, wherein the power take off status information is whether a power take off unit on the vehicle is engaged or disengaged;receiving engine information, transmission information, and power take off status information at the fan control module;processing the engine information, transmission information, and power take off status information at the fan control module;generating one or more fan speed demands at the fan control module based on the processed engine information, transmission information, and power take off status information, and wherein at least one of the fan speed demands is generated by processing the engine coolant temperature, power take off status information, and vehicle speed;raising a set point of the engine coolant temperature by the fan control module to reduce the fan speed demand processed from the engine coolant temperature, the power take off status information, and the vehicle speed when the vehicle speed of the vehicle is greater than 0 KPH and the power take off unit is engaged;selecting at the fan control module a maximum fan speed demand from the one or more fan speed demands; andcommanding from the fan control module a fan drive to rotate a fan blade connected with the fan drive at a commanded fan speed based on the maximum fan speed demand selected by the fan control module. 20. The method of claim 19, further comprising sensing a rotational fan speed by a fan speed sensor connected with the fan blade and transmitting the sensed speed of the fan to the fan control module from the fan speed sensor. 21. The fan control system of claim 20, wherein the fan control module modifies commanded fan speed based on received sensed fan speed from the fan speed sensor. 22. The method of claim 19, further comprising: sensing a gear selected in the transmission system at the one or more sensors, receiving the gear selected in the transmission system at the transmission control module from the one or more sensors, and transmitting the gear selected in the transmission system on the communication link from the transmission control module to the fan control module. 23. The method of claim 22, wherein generating one or more fan speed demands comprises processing the engine coolant temperature, power take off status information, and the selected gear from the transmission information. 24. The method of claim 19, further comprising reducing heat dissipating from the fan drive beyond fan drive design limits by replacing the fan speed command with a lower or higher speed command to the fan drive from the fan control module. 25. The method of claim 19, wherein the raising a set point of the engine coolant temperature step further comprises counting a time down to zero after the vehicle speed drops below a vehicle speed threshold and raising the set point when the time reaches zero. 26. The method of claim 25, wherein the vehicle speed threshold value may be any speed value greater than 0 KPH and less than or equal to 5 KPH. 27. The method of claim 25, further comprising basing the set point of the engine coolant temperature off an engine torque in the engine information when the time has not reached zero or the power take off unit is disengaged.