Method and apparatus for estimation of relative cylinder compression balance by cranking speed analysis
US6055852A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1998 |
| Grant date | May 2, 2000 |
| Priority date | — |
| Expiry date | Nov 6, 2018 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2200/1015
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention gathers and processes engine speed and position information gathered during cranking, without fuel injection or combustion, in order to derive a set of parameters that are shown to correlate very well with the presence of cylinder compression leakage. Using engine speed and position information from, for example, camshaft gear targets, crankshaft tonewheels, or the flywheel itself, etc., a parameter designated as "metric distance" between adjacent firing cylinder speed fluctuation pulses is determined. For engines with well-balanced cylinder compression, the values of the metric distances measured between all cylinders should be close to each other within a certain threshold. If a cylinder exhibits leakage, the metric distance of the cylinder from its adjacent firing cylinders will significantly exceed the threshold, thereby detecting a leaking cylinder. The method of the present invention also provides a relative estimation of the percentage compression loss from the leaking cylinder. This provides valuable information for service personnel to quickly determine the cause of engine delivering low power. In addition to the service application of the present inv…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.