Testing compression in engines from starter motor current waveform
US4062232A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 12, 1976 |
| Grant date | Dec 13, 1977 |
| Priority date | — |
| Expiry date | Oct 12, 1996 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L23/085
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The relative compression in the cylinders of an internal combustion engine is tested by analyzing the starter motor current waveform when the engine is cranked with the ignition or the fuel inhibited. In asymmetrical engines, where the compression strokes of individual cylinders are unequally spaced in time, the starter current waveform may contain double-hump cycles. The area under each double-hump cycle is integrated, and the integration peaks are compared. The compression in one or more cylinders is deficient if the minimum integration peak is less than the maximum integration peak by a significant percentage such as 15 percent or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.