GB1444950A - Vehicle air conditioning systems - Google Patents

Abstract

1444950 Control systems for vehicle air conditioning FIAT SpA 17 Dec 1973 [20 Dec 1972] 58294/73 Headings F4V and F4H A vehicle air conditioning unit comprises a flap 30 movable only to positions closing or substantially closing a fresh air inlet 36 and a used air inlet 34, an evaporator 16 of a refrigeration unit having a compressor 202, a heat exchanger 20 supplied with heated water via a valve 146, a flap 40 for directing air into heat exchange contact with the heat exchanger 20 or through a by-pass therefor, a fan 24 a flap 50 for directing the air wholly or substantially wholly to the windscreen or directly into the passenger compartment, a lever 62 for manually positioning the flap 40, a lever 74 for altering the speed of the fan motor, a push-button unit 80, a source of vacuum 92 and vacuum actuators 100, 120, 190, 134 connected to the unit 80 by conduits and electrical relays 214, 224 controlled respectively in response to the position of flaps 30, 50 and controlling respectively the fan motor and an electromagnetic clutch 242 of the compressor 202 and the fan motor, whereby depression of the push-buttons of unit 80 produces predetermined modes of operation of the air conditioning unit, regardless of the positions of levers 62, 74. Depression of any one of the push-buttons releases any one of the other push-buttons previously depressed. The electrical power source is the vehicle battery 76. Upon depression of a push-button 82, a valve 84 is operated to connect actuators 100, 120 and 134 to the vacuum source 92 whereby flap 30 is moved to position 30<SP>1</SP>, flap 40 to position 44 and valve 146 closed; simultaneously movement of flap 30 permits relay 214 to be closed by a spring 222 to start the compressor 202 and the fan motor at full speed. The flap 50 is positioned to direct air directly into the vehicle. Depression of pushbutton 200 closes a switch 90 starting the compressor 202; the flap 30 returns to its initial position, the flap 40 moves to a position 46 and is manually adjustable by lever 62 and valve 146 is opened. Depression of push-button 152 moves flap 40 to position 44 and closes valve 146 to provide unheated fresh air ventilation. Depression of push-button 212 releases any other button previously depressed, and depression of push-button 164 holds or moves the flap 40 to a position 46 and moves flap 50 to position 50<SP>1</SP>, whereupon the relay 224 is closed by a spring 230 to start the fan motor at full speed, to effect demisting of the windscreen.