Vehicle air conditioning system with expansion valve control during high pressure cycle conditions
US5934094A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 1998 |
| Grant date | Aug 10, 1999 |
| Priority date | — |
| Expiry date | Nov 10, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S62/17
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A control apparatus for a gas injection type air conditioning system that prevents lowering of compressor speed and cycle stoppage under conditions where high pressure is liable to occur. During a system heating mode, a pressure change rate ASP of the high pressure of the refrigerating cycle is calculated. When a pressure change rate .increment.SP rises above a predetermined value, a system electric expansion valve aperture is reduced. Accordingly, by calculation of the pressure change rate .increment.SP, it is possible to control the electric expansion valve in the above manner earlier than in prior art control schemes when there is a sudden rise in the high pressure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.