1. Field of the Invention
The present invention generally relates to a vehicle air-conditioning system provided with a compressor that can be driven with a motor. More specifically, the present invention relates to suppressing the overheating of the electronic devices inside the inverter of the compressor and the overheating of the battery due to the operation a vehicle air-conditioning system having a motor driven compressor.
An example of a vehicle air-conditioning system is described in Japanese Laid-Open Patent Publication No. 2000-230482. The vehicle air-conditioning system disclosed in this publication has a hybrid compressor that is constructed such that the compression section is driven by two drive sources. In particular, a first driving force is provided by a motor that is driven by the battery, while a second driving force is delivered from the engine through an electromagnetic clutch. The vehicle air-conditioning system executes capacity limiting determination such that the refrigerant compression capacity of the compression section decreases when the compression section is motor driven with the electromagnetic clutch in the OFF state.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved vehicle air-conditioning system. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.
It has been discovered that in vehicle air-conditioning systems, such as the one disclosed in Japanese Laid-Open Patent Publication No. 2000-230482, if operation of the compressor is started while the intake refrigerant temperature of the compressor is high, a large current will occur in the inverter of the compressor because the drive load on the compressor will be high. Consequently, the electronic devices inside the inverter will become excessively hot such that the inverter will rapidly overheat. At the same time, a burden will be placed on the battery that will cause overheating in the battery as well lead to a shortening of service life.
Therefore, one object of the present invention is to provide an improved vehicle air-conditioning system that suppresses overheating of the electronic devices inside the inverter and that suppresses overheating of the battery.
In accordance with one aspect of the present invention, an improved vehicle air-conditioning system is provided with a compressor; a compressor inverter, a passenger compartment-external heat exchanger, a passenger compartment-internal heat exchanger, a thermal load detecting device and an airflow rate correcting device. The compressor inverter is configured to vary the compressor capacity of the compressor to provide a predetermined air-conditioning level inside of a passenger compartment. The passenger compartment-external heat exchanger is configured to exchange heat between outside air and refrigerant pumped by the compressor. The passenger compartment-internal heat exchanger is configured to exchange heat between the refrigerant and the air that is blown into the passenger compartment by an air blowing device. The thermal load detecting device is configured to detect a thermal load of the compressor. The airflow rate correcting device is configured to adjust airflow rate in such a manner that the airflow rate delivered by the air blowing device decreases as the thermal load detected by the thermal load detecting device increases.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.