Patent US5386723A successfully refreshed from Google Patents.
US5386723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for detecting faulty firing in an internal-combustion engine
Assignee: Siemens AG
•
Filing: 1993-07-26
•
Granted: 1995-02-07
•
Expires: 2013-07-26
Abstract
Abstract In a device for detecting faulty firing in an internal-combustion engine, a combustion-chamber pressure is measured at two crankshaft positions before and after each top dead center for each cylinder. At an ignition top dead center, a pressure differential must be greater than a first limiting value for there to be proper firing. At a charge-change top dead center, the pressure differential must be less than a second limiting value for the pressure measurement to be operating properly.
Inventors
- 👤 Manfred Wier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:14
CPC Classifications
F; F02; F02D; F02D35/00; F02D35/02; F02D35/023; F02D33/00; F02D33/02; F02D41/00; F02D41/22; F02D41/222; F02D2200/00; F02D2200/02; F02D2200/10; F02D2200/1015; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/40
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
179 words
A device for detecting faulty firing in an internal-combustion engine, comprising: pressure sensors each being assigned to a respective cylinder for emitting a pressure signal corresponding to a combustion-chamber pressure; a position sensor system generating at least one crankshaft signal and camshaft signal at a particular piston position; and an evaluation section connected to said pressure sensors and to said position sensor for determining faulty firing of a cylinder from the pressure signal and the crankshaft position signal; said evaluation section having means for: inquiring into the pressure signal of each cylinder at two crankshaft positions before and after each top dead center and forming a pressure differential from them, determining that a faulty firing has taken place if the pressure differential at an ignition top dead center between a compression stroke and a power stroke is less than a first limiting value, and determining that an error in the pressure measurement has occurred if the pressure differential at a charge-change top dead center between an exhaust stroke and an induction stroke is greater than a second limiting value.
Claim 2
Independent Claim
179 words
A device for detecting faulty firing in an internal-combustion engine, comprising: pressure sensors each being assigned to a respective cylinder for emitting a pressure signal corresponding to a combustion-chamber pressure; a position sensor system generating at least one crankshaft signal and camshaft signal at a particular piston position; and an evaluation section connected to said pressure sensors and to said position sensor for determining faulty firing of a cylinder from the pressure signal and the crankshaft position signal; said evaluation section having means for: inquiring into the pressure signal of each cylinder at two crankshaft positions before and after each top dead center and forming a pressure differential from them, determining that a faulty firing has taken place if the pressure differential at an ignition top dead center between a compression stroke and a power stroke is less than a first limiting value, and determining that an error in the pressure measurement has occurred if the pressure differential at a charge-change top dead center between an exhaust stroke and an induction stroke is greater than a second limiting value.
Claim 3
Dependent Claim
44 words
The device according to claim 1, wherein a first of the crankshaft positions before each ignition top dead center lies before a respectively set ignition angle and a second of the crankshaft positions after each ignition top dead center is chosen load-dependently and speed-dependently.
Claim 4
Dependent Claim
38 words
The device according to claim 2, wherein said evaluation section takes the second crankshaft position after each ignition top dead center from a performance graph, as a function of a respective load-dependently and speed-dependently formed fuel injection time.
Claim 5
Dependent Claim
47 words
The device according to claim 1, wherein said evaluation section forms a differential signal being a measure of a level of the compression pressure, from one of the pressure signals at a charge-change top dead center and a following pressure signal before an ignition top dead center.
Claim 6
Dependent Claim
46 words
The device according to claim 4, wherein said evaluation section adds up the differential signals for each cylinder formed by said evaluation section, carries out averaging and establishes a worsened compression pressure of a cylinder if the associated average value is less than a reference value.
References Cited (Backward Citations)
US1960158A
Cited
DE2129872A1
Cited
GB2091000A
Cited
DE3212669A1
Cited
JPS58203865A
Cited
US4781059A
Cited
US4744244A
Cited
JPS63271962A
Cited
US4834031A
Cited
DE3833124A1
Cited
US5127262A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-02-06 | 1998-08-08 | 1999-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-02-06 | 2002-08-08 | 2003-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-02-06 | 2006-08-08 | 2007-02-07 | $7700.00 | Window Closed / Lapsed |