Refrigeration – Automatic control – Responsive to vehicle body motion or traction
Reexamination Certificate
2000-07-20
2002-03-19
Paik, Sang (Department: 3742)
Refrigeration
Automatic control
Responsive to vehicle body motion or traction
C062S217000, C062S210000
Reexamination Certificate
active
06357242
ABSTRACT:
TECHNICAL FIELD
This invention relates to the control of a motor vehicle air conditioning system, and more particularly to a control that reduces head pressure spikes caused by high compressor acceleration.
BACKGROUND OF THE INVENTION
In a motor vehicle air conditioning system, the refrigerant compressor is customarily driven by the vehicle engine through a mechanical advantage drive such as a belt and pulley system. As a result, engine speed transients produce similar or more severe transients in the air conditioning system. A particularly severe transient occurs during acceleration of the vehicle from standstill, as the compressor speed can rise several thousand revolutions per minute in a matter of seconds. In this case, the transient is manifested by a sharp rise, or spike, in the compressor outlet pressure, which if unchecked, can damage or otherwise degrade the operation of various components, including the compressor itself.
In a conventional system, the high side pressure spike concern is addressed by measuring the high side pressure (with a pressure switch, for example), and de-coupling the compressor from the engine when the measured pressure exceeds a predefined threshold. However, de-coupling the compressor in this manner significantly degrades air conditioning performance and raises durability issues in respect to components such as the compressor clutch. Accordingly, what is needed is an improved way of addressing the transient pressure concern that does not significantly compromise passenger comfort or degrade the system durability.
SUMMARY OF THE INVENTION
The present invention is directed to an improved system and method for suppressing high side pressure transients in a motor vehicle air conditioning system due to engine speed transients during vehicle acceleration through the use of a throttling valve. The throttling valve may be mechanically or electrically activated, and is connected in the low pressure side of the air conditioning system to controllably restrict refrigerant flow in response to one or more parameters that detect or anticipate a high side transient pressure condition. The parameters may include the high side pressure itself, or engine parameters such as engine speed and vehicle speed. In a preferred embodiment, the throttling valve may be controlled to prevent evaporator icing in addition to suppressing high side pressure transients.
REFERENCES:
patent: 3899897 (1975-08-01), Boerger et al.
patent: 4324286 (1982-04-01), Brett
patent: 4531378 (1985-07-01), Nishi et al.
patent: 4578960 (1986-04-01), Nishi et al.
patent: 4756166 (1988-07-01), Tomasov
patent: 4870834 (1989-10-01), Ogawa et al.
patent: 5226472 (1993-07-01), Benevelli et al.
patent: 5924296 (1999-07-01), Takano et al.
patent: 6035652 (2000-03-01), Hashimoto
patent: 6105380 (2000-08-01), Yokomachi et al.
patent: 6119473 (2000-09-01), Kishita et al.
patent: 6145329 (2000-11-01), Brandon et al.
patent: 6148632 (2000-11-01), Kishita et al.
Farley Dennis Lee
Leitzel Lindsey Lee
Wang Mingyu
Dahbour Fadi H.
Delphi Technologies Inc.
Griffin Patrick M.
Paik Sang
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