Patent US4834031A successfully refreshed from Google Patents.
US4834031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable compression-ratio control device for an internal combustion engine
Assignee: Toyota Motor Corp
•
Filing: 1988-07-13
•
Granted: 1989-05-30
•
Expires: 2008-07-13
Abstract
Abstract A variable compression ratio control device includes a mechanism for varying a compression ratio of an engine in response to engine driving conditions, at least between a higher stage and a lower stage, a compression ratio detecting sensor for detecting a current compression ratio, a sensor fault detecting unit for detecting a malfunction of the compression ratio detecting sensor, and a fail-safe unit for lowering and fixing the compression ratio when the sensor fault detecting unit detects a malfunction of the compression ratio detecting sensor.
Inventors
- 👤 Kenji Katoh
- 👤 Takao Naruoka
- 👤 Eiji Iwasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:14
CPC Classifications
F; F02; F02D; F02D43/00; F02B; F02B75/00; F02B75/04; F02D15/00; F02D15/04; F02D41/00; F02D41/22; F02D41/222; F02D2041/227
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
93 words
A variable compression ratio control device for an internal combustion engine having a mechanism for varying a compression ratio of the engine in response to engine driving conditions, at least between a first higher stage and a second lower stage, and detecting a current compression ratio; said device comprising; sensor fault detecting means for detecting a malfunction of said compression ratio detecting means, and fail-safe means for varying and fixing a compression ratio to said second lower stage when said sensor fault detecting means detects a malfunction of said compression ratio detecting means.
Claim 2
Dependent Claim
93 words
A variable compression ratio control device for an internal combustion engine having a mechanism for varying a compression ratio of the engine in response to engine driving conditions, at least between a first higher stage and a second lower stage, and detecting a current compression ratio; said device comprising; sensor fault detecting means for detecting a malfunction of said compression ratio detecting means, and fail-safe means for varying and fixing a compression ratio to said second lower stage when said sensor fault detecting means detects a malfunction of said compression ratio detecting means.
Claim 3
Dependent Claim
27 words
A device according to claim 1, wherein said fail-safe means further varies an ignition timing by delaying same, in addition to varying and fixing the compression ratio.
Claim 4
Dependent Claim
42 words
A device according to claim 1, wherein said sensor fault detecting means detects a malfunction of said compression ratio detecting means by comparing a compression ratio calculated from an engine load with an output signal level from said compression ratio detecting means.
Claim 5
Dependent Claim
31 words
A device according to claim 1, wherein said mechanism varies the compression ratio between two stages of a high compression ratio and a low compression ratio in response to driving conditions.
Claim 6
Dependent Claim
25 words
A device according to claim 1, wherein said mechanism varies the compression ratio in a continuous stage or in multistages of more than two stages.
Claim 7
Dependent Claim
36 words
A device according to claim 4, wherein said fail-safe means varies and fixes the compression ratio to the low compression ratio when said sensor fault detecting means detects a malfunction of said compression ratio detecting means.
Claim 8
Dependent Claim
47 words
A device according to claim 5, wherein a compression ratio determined in response to driving conditions is a basic compression ratio, and said basic compression ratio is corrected by a correction factor α having a values derived from an engine driving parameter different from the engine load.
Claim 9
Dependent Claim
43 words
A device according to claim 7, wherein said fail-safe means varies and fixes said correction factor α in such a manner that said basic compression ratio is lowered when said sensor fault detecting means detects a malfunction of said compression ratio detecting means.
Claim 10
Dependent Claim
31 words
A device according to claim 1, wherein said compression ratio detecting means includes a combustion pressure sensor for detecting a combustion pressure which corresponds to a compression ratio of the engine.
Claim 11
Dependent Claim
33 words
A device according to claim 1, wherein said compression ratio detecting means includes piston position sensors for detecting a TDC position of a piston which corresponds to a compression ratio of the engine.
References Cited (Backward Citations)
US4375672A
Cited
JPS58137832A
Cited
JPS58172431A
Cited
US4505152A
Cited
US4687348A
Cited
JPS62142860A
Cited
JPS63105244A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-29 | 1992-11-28 | 1993-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-29 | 1996-11-28 | 1997-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-29 | 2000-11-28 | 2001-05-30 | $7700.00 | Window Closed / Lapsed |