Diagnostic method for an automotive HVAC compressor
US6381545B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 12, 2000 |
| Grant date | Apr 30, 2002 |
| Priority date | — |
| Expiry date | Jan 12, 2020 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60H2001/327
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An improved method and apparatus for diagnosing the condition of an automotive HVAC refrigerant compressor based on information contained within the signal produced by a high-side pressure sensor provided for system control purposes. The output signal of the pressure sensor is divided into its DC and AC components, with the DC component being used for system control purposes, and the AC component being used for diagnosing the condition of the compressor. Pulsations of the AC component (which conventionally are removed by filtering for control purposes) correspond to individual piston stroke cycles. The pulsations indicate compressor operation and are counted for purposes of determining the actual compressor speed. Since existing pressure sensor information is utilized to verify compressor operation and to determine compressor speed, the system cost impact due to the diagnostic evaluation is minimal. Moreover, the pulsations provide failure information that could not be detected by a speed sensor since the pulsations verify that work is actually being performed by the compressor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.