| 摘要 |
<p>COOLANT/REFRIGERANT TEMPERATURE CONTROL SYSTEM A variable speed fan drive (46), operated in response to the sensed coolant temperature in an internal combustion engine for a vehicle, blows a controlled amount of air through the engine's radiator (48) to maintain the coolant temperature in a desired narrow operating range. The air pulled in by the fan also cools the refrigerant flowing through the condenser (49) of the vehicle's air conditioning system, the condenser (49) being positioned in front of the coolant radiator (48). If insufficient condenser cooling occurs, even though the coolant may be adequately cooled, the refrigerant temperature rises and causes the compressor discharge pressure in the air conditioning system to increase. That pressure is monitored or sensed (52) and if it exceeds a predetermined maximum allowable level the normal operation of the control system is overridden and the fan (46) is driven at its maximum speed to maximize the air blown through the condenser (49) and radiator, (48) thereby decreasing the refrigerant temperature and thus the discharge pressure.</p> |
