Evaporative fuel-purging control system for internal combustion engines
US5445132A · kind A · utility
9Cited by
11References
22Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 9, 1994 |
| Grant date | Aug 29, 1995 |
| Priority date | — |
| Expiry date | Nov 9, 2014 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02M25/08
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
An improved evaporative fuel-purging control system for controlling a purging flow rate which is controlled by a solenoid purge control valve regulated with a pulse waveform signal. As for the characteristic of the purge control valve, differing periods of the signal differentiates the control valve linearity of purging flow rate with respect to the signal duty ratio. To improve the linearity, the pulse waveform signal period which creates the substantial linearity is selected among preset periods periods according to the preset duty ratio which works as a threshold value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.