US 2003/0192326 A1 · Air conditioner for motor vehicles

Abstract

An air conditioner for vehicle has a refrigeration cycle with a variable displacement type compressor; A fuel cut control is carried out in response to a vehicle deceleration. In the fuel cut control, the displacement is first increased so that an evaporator performs as a cold storage. Then, if an engine speed is decreased to a certain level, the displacement is decreased to decrease an engine load. The displacement is kept in the decreased level for a predetermined time period or until the end of the fuel cut control. Even when the displacement is decreased, the evaporator can cool air, since the evaporator performs as the cold storage. Further, the time period for keeping the displacement in the decreased level is limited. Therefore, it is possible to prevent an excessive temperature rise and to keep comfortable air conditioning.

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Claims10

Dependent claims

An air conditioner for motor vehicles, the motor vehicles perform a fuel cut control to cut off fuel supply to a vehicle engine in vehicle deceleration, the air conditioner comprising:

a compressor driven by the vehicle engine, the compressor being a variable displacement type and being component of a refrigeration cycle;
an evaporator which is a component of the refrigeration cycle, and cools air to be supplied to a vehicle compartment;
and
a controller which controls the displacement of the compressor, wherein
the controller controls the displacement on the basis of a cooling degree of the evaporator when the vehicle engine is supplied with fuel,
the controller performs a forced reduction control of the displacement by reducing the displacement to a predetermined small value when the fuel cut control is performed, and
the controller sets a time period for the forced reduction control such that the time period is shortened as a thermal load for cooling is increased.

4 more elements

Dependencies are inferred from the claim text.

Air conditioner for motor vehicles

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