Automatic choke
US7284522B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 2005 |
| Grant date | Oct 23, 2007 |
| Priority date | — |
| Expiry date | Aug 24, 2025 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF02D2011/104
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A choke valve is controlled finely suited to the running state of an engine. A throttle valve 8 and a choke valve 9 are provided in series on an intake pipe 6, and the opening degree of the choke valve 9 is controlled by a stepping motor 11. A choke valve opening degree upon start of engine (start opening degree) and a driving pulse rate of a stepping motor 11 are determined depending on the engine temperature. When lower than the engine temperature TL, the pulse rate is set at first rate, or the lowest rate in a specified range. Depending on the engine temperature, the pulse rate is set higher gradually up to second rate TH. When releasing the choke gradually in warm-up operation, the pulse rate is lowered so as to obtain a choke opening degree of high precision by a high torque.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.