Patent US5682854A successfully refreshed from Google Patents.
US5682854A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable compression ratio engine
Assignee: Komatsu Ltd
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Filing: 1995-03-03
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Granted: 1997-11-04
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Expires: 2015-03-03
Abstract
Abstract The present invention is a variable compression ratio engine which can operate both in a Miller cycle and a normal cycle, and which can produce a high output, reduce the generation of NOx, and prevent the occurrence of knocking. For this purpose, the engine is provided with an exhaust gas recirculating device equipped with a first cam shaft (10), provided with cams (11, 12, 13) for operating an intake valve (2) and exhaust valves (4, 5), and a second cam shaft (20), provided with cams (21, 22) for operating at least one intake valve (3) and an exhaust valve (5) to thereby recirculate part of exhaust gas into intake gas.
Inventors
- 👤 Godo Ozawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:25
CPC Classifications
F; F02; F02D; F02D13/00; F02D13/02; F02D13/0203; F02D13/0207; F01; F01L; F01L1/00; F01L1/02; F01L1/026; F01L1/12; F01L1/18; F01L1/181; F01L1/182; F01L1/26; F01L1/34; F01L1/344; F01L1/352; F01L13/00; F01L13/0015; F01L13/0036; F01L13/0047; F02B; F02B23/00; F02B23/02; F02B23/06; F02B23/0672; F02D13/0257; F02D13/0269; F02D15/00; F02M; F02M26/00; F02M26/01; F01L1/04; F01L1/047; F01L1/053; F01L1/0532; F01L1/185; F01L2001/0537; F01L2305/00; F01L2800/00; F01L2800/01; F01L2800/10; F01L2820/00; F01L2820/01; F01L2820/02; F01L2820/03; F01L2820/032; F02B2275/00; F02B2275/14; F02B2275/18; F02B2275/32; F02B3/00; F02B3/06; F02F; F02F1/00; F02F1/24; F02F1/42; F02F1/4214; F02F2001/244; F02F2001/247; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
359 words
A variable compression ratio engine for operating in a first condition under a heavy load and in a second condition under a light load, said engine comprising: at least one cylinder chamber; at least one piston, each piston being positioned in a respective cylinder chamber; first and second intake valves per cylinder chamber; at least one exhaust valve per cylinder chamber; a first cam shaft provided with cams for opening and closing said first intake valve and said at least one exhaust valve; a second cam shaft provided with cams for opening and closing said second intake valve and at least one of said at least one exhaust valve; and a device for changing a phase, between cams on said second cam shaft and cams on said first cam shaft, between a first phase for operating in said first condition under a heavy load and a second phase for operating in said second condition under a light load; whereby a compression ratio of said engine can be changed by changing a timing of the opening and closing of said intake valves and/or said at least one exhaust valve; whereby, in an intake stroke during said first condition under a heavy load, said device sets said intake valves to close at a time before the respective piston is at a bottom dead center of its cycle, and said device sets at least one of said at least one exhaust valve to open and close at times when the respective piston is in the vicinity of a top dead center of its cycle; and whereby, in an intake stroke during said second condition under a light load, said device sets at least one of said intake valves to close at a time when the respective piston is in the vicinity of the bottom dead center of its cycle, and said device sets at least one of said at least one exhaust valve to open and close at times before the respective piston is at the bottom dead center of its cycle so as to recirculate part of the exhaust gas from said cylinder chamber into intake gas for said cylinder chamber.
Claim 2
Dependent Claim
359 words
A variable compression ratio engine for operating in a first condition under a heavy load and in a second condition under a light load, said engine comprising: at least one cylinder chamber; at least one piston, each piston being positioned in a respective cylinder chamber; first and second intake valves per cylinder chamber; at least one exhaust valve per cylinder chamber; a first cam shaft provided with cams for opening and closing said first intake valve and said at least one exhaust valve; a second cam shaft provided with cams for opening and closing said second intake valve and at least one of said at least one exhaust valve; and a device for changing a phase, between cams on said second cam shaft and cams on said first cam shaft, between a first phase for operating in said first condition under a heavy load and a second phase for operating in said second condition under a light load; whereby a compression ratio of said engine can be changed by changing a timing of the opening and closing of said intake valves and/or said at least one exhaust valve; whereby, in an intake stroke during said first condition under a heavy load, said device sets said intake valves to close at a time before the respective piston is at a bottom dead center of its cycle, and said device sets at least one of said at least one exhaust valve to open and close at times when the respective piston is in the vicinity of a top dead center of its cycle; and whereby, in an intake stroke during said second condition under a light load, said device sets at least one of said intake valves to close at a time when the respective piston is in the vicinity of the bottom dead center of its cycle, and said device sets at least one of said at least one exhaust valve to open and close at times before the respective piston is at the bottom dead center of its cycle so as to recirculate part of the exhaust gas from said cylinder chamber into intake gas for said cylinder chamber.
Claim 3
Dependent Claim
70 words
A variable compression ratio engine in accordance with claim 1, wherein said at least one exhaust valve comprises first and second exhaust valves; wherein said first cam shaft is provided with cams for opening and closing said first intake valve and said first and second exhaust valves; and wherein said second cam shaft is provided with cams for opening and closing said second intake valve and said second exhaust valve.
Claim 4
Dependent Claim
88 words
A variable compression ratio engine in accordance with claim 1, wherein said device comprises: a planetary gear unit provided with a sun gear, a ring gear, and a planet gear, said sun gear being fixedly attached to said first cam shaft; a gear which is meshed with said ring gear and fixedly attached to said second cam shaft; a support shaft for said planet gear; and a driving device for changing a relative positional relationship between said support shaft for said planet gear and said first cam shaft.
Claim 5
Dependent Claim
55 words
A variable compression ratio engine in accordance with claim 1, wherein said time before the respective piston is at a bottom dead center of its cycle is a time when a crank rotational angle is in the range of 20° to 90° before the respective piston is at the bottom dead center of its cycle.
Claim 6
Dependent Claim
355 words
A variable compression ratio engine for operating in a first condition under a heavy load and in a second condition under a light load, said engine comprising: at least one cylinder chamber; at least one piston, each piston being positioned in a respective cylinder chamber; first and second intake valves per cylinder chamber; at least one exhaust valve per cylinder chamber; a first cam shaft provided with cams for opening and closing said first intake valve and said at least one exhaust valve; a second cam shaft provided with cams for opening and closing said second intake valve and at least one of said at least one exhaust valve; and a device for changing a phase, between cams on said second cam shaft and cams on said first cam shaft, between a first phase for operating in said first condition under a heavy load and a second phase for operating in said second condition under a light load; whereby a compression ratio of said engine can be changed by changing a timing of the opening and closing of said intake valves and/or said at least one exhaust valve; whereby, in an intake stroke during said second condition under a light load, said intake valves are set to close at a time when the respective piston is in the vicinity of a bottom dead center of its cycle, and at least one of said at least one exhaust valve is set to open and close at times before the respective piston is at the bottom dead center of its cycle so as to recirculate part of the exhaust gas from said cylinder chamber into intake gas for said cylinder chamber; and whereby, in an intake stroke during said first condition under a heavy load, at least one of said intake valves is set to close at a time after the respective piston is at the bottom dead center of its cycle, and at least one of said at least one exhaust valve is set to open and close at times when the respective piston is in the vicinity of the bottom dead center of its cycle.
Claim 7
Dependent Claim
355 words
A variable compression ratio engine for operating in a first condition under a heavy load and in a second condition under a light load, said engine comprising: at least one cylinder chamber; at least one piston, each piston being positioned in a respective cylinder chamber; first and second intake valves per cylinder chamber; at least one exhaust valve per cylinder chamber; a first cam shaft provided with cams for opening and closing said first intake valve and said at least one exhaust valve; a second cam shaft provided with cams for opening and closing said second intake valve and at least one of said at least one exhaust valve; and a device for changing a phase, between cams on said second cam shaft and cams on said first cam shaft, between a first phase for operating in said first condition under a heavy load and a second phase for operating in said second condition under a light load; whereby a compression ratio of said engine can be changed by changing a timing of the opening and closing of said intake valves and/or said at least one exhaust valve; whereby, in an intake stroke during said second condition under a light load, said intake valves are set to close at a time when the respective piston is in the vicinity of a bottom dead center of its cycle, and at least one of said at least one exhaust valve is set to open and close at times before the respective piston is at the bottom dead center of its cycle so as to recirculate part of the exhaust gas from said cylinder chamber into intake gas for said cylinder chamber; and whereby, in an intake stroke during said first condition under a heavy load, at least one of said intake valves is set to close at a time after the respective piston is at the bottom dead center of its cycle, and at least one of said at least one exhaust valve is set to open and close at times when the respective piston is in the vicinity of the bottom dead center of its cycle.
Claim 8
Dependent Claim
70 words
A variable compression ratio engine in accordance with claim 5, wherein said at least one exhaust valve comprises first and second exhaust valves; wherein said first cam shaft is provided with cams for opening and closing said first intake valve and said first and second exhaust valves; and wherein said second cam shaft is provided with cams for opening and closing said second intake valve and said second exhaust valve.
Claim 9
Dependent Claim
88 words
A variable compression ratio engine in accordance with claim 5, wherein said device comprises: a planetary gear unit provided with a sun gear, a ring gear, and a planet gear, said sun gear being fixedly attached to said first cam shaft; a gear which is meshed with said ring gear and fixedly attached to said second cam shaft; a support shaft for said planet gear; and a driving device for changing a relative positional relationship between said support shaft for said planet gear and said first cam shaft.
Claim 10
Dependent Claim
55 words
A variable compression ratio engine in accordance with claim 5, wherein said time before the respective piston is at a bottom dead center of its cycle is a time when a crank rotational angle is in the range of 20° to 90° before the respective piston is at the bottom dead center of its cycle.
Claim 11
Dependent Claim
236 words
A variable compression ratio engine for operating under a first condition or under a second condition, said engine comprising: at least one cylinder chamber; at least one piston, each piston being positioned in a respective cylinder chamber; first and second intake valves per cylinder chamber; at least one exhaust valve per cylinder chamber; a first cam shaft provided with cams for opening and closing said first intake valve and said at least one exhaust valve; a second cam shaft provided with a cam for opening and closing said second intake valve; and an intake device for changing a phase, between said cam on said second cam shaft and cams on said first cam shaft, between a first phase for operating in said first condition and a second phase for operating in said second condition; whereby a compression ratio of said engine can be changed by changing a timing of the opening and closing of said intake valves and/or said at least one exhaust valve; whereby, in an intake stroke during said first condition, said intake valves are set to close at a time before the respective piston is at a bottom dead center of its cycle; and whereby, in an intake stroke during said second condition, at least one of said intake valves is set to close at a time when the respective piston is in the vicinity of the bottom dead center of its cycle.
Claim 12
Dependent Claim
236 words
A variable compression ratio engine for operating under a first condition or under a second condition, said engine comprising: at least one cylinder chamber; at least one piston, each piston being positioned in a respective cylinder chamber; first and second intake valves per cylinder chamber; at least one exhaust valve per cylinder chamber; a first cam shaft provided with cams for opening and closing said first intake valve and said at least one exhaust valve; a second cam shaft provided with a cam for opening and closing said second intake valve; and an intake device for changing a phase, between said cam on said second cam shaft and cams on said first cam shaft, between a first phase for operating in said first condition and a second phase for operating in said second condition; whereby a compression ratio of said engine can be changed by changing a timing of the opening and closing of said intake valves and/or said at least one exhaust valve; whereby, in an intake stroke during said first condition, said intake valves are set to close at a time before the respective piston is at a bottom dead center of its cycle; and whereby, in an intake stroke during said second condition, at least one of said intake valves is set to close at a time when the respective piston is in the vicinity of the bottom dead center of its cycle.
Claim 13
Dependent Claim
55 words
A variable compression ratio engine in accordance with claim 9, wherein said time before the respective piston is at a bottom dead center of its cycle is a time when a crank rotational angle is in the range of 20° to 90° before the respective piston is at the bottom dead center of its cycle.
Claim 14
Dependent Claim
66 words
A variable compression ratio engine in accordance with claim 9, wherein said at least one exhaust valve comprises first and second exhaust valves; wherein said first cam shaft is provided with cams for opening and closing said first intake valve and said first and second exhaust valves; and wherein said second cam shaft is provided with said cam for opening and closing said second intake valve.
Claim 15
Dependent Claim
88 words
A variable compression ratio engine in accordance with claim 9, wherein said device comprises: a planetary gear unit provided with a sun gear, a ring gear, and a planet gear, said sun gear being fixedly attached to said first cam shaft; a gear which is meshed with said ring gear and fixedly attached to said second cam shaft; a support shaft for said planet gear; and a driving device for changing a relative positional relationship between said support shaft for said planet gear and said first cam shaft.
Claim 16
Dependent Claim
251 words
A variable compression ratio engine for operating in a first condition or in a second condition, said engine comprising: at least one cylinder chamber; at least one piston, each piston being positioned in a respective cylinder chamber; first and second intake valves per cylinder chamber; at least one exhaust valve per cylinder chamber; a first cam shaft provided with cams for opening and closing said first intake valve and said at least one exhaust valve; a second cam shaft provided with cams for opening and closing said second intake valve and at least one of said at least one exhaust valve; a planetary gear unit provided with a sun gear, a ring gear, and a planet gear, said sun gear being fixedly attached to said first cam shaft; a gear which is meshed with said ring gear and fixedly attached to said second cam shaft; a support shaft for said planet gear; and a variable valve timing device which changes valve timing by adjusting a phase, between said first and second cam shafts, between a first phase for operating in said first condition and a second phase for operating in said second condition, by freely changing a relative positional relationship between said support shaft for said planet gear and said first cam shaft, whereby a compression ratio of said engine can be changed by changing said valve timing and a part of exhaust gas from said cylinder chamber is recirculated into intake gas for said cylinder chamber during said second condition.
Claim 17
Dependent Claim
251 words
A variable compression ratio engine for operating in a first condition or in a second condition, said engine comprising: at least one cylinder chamber; at least one piston, each piston being positioned in a respective cylinder chamber; first and second intake valves per cylinder chamber; at least one exhaust valve per cylinder chamber; a first cam shaft provided with cams for opening and closing said first intake valve and said at least one exhaust valve; a second cam shaft provided with cams for opening and closing said second intake valve and at least one of said at least one exhaust valve; a planetary gear unit provided with a sun gear, a ring gear, and a planet gear, said sun gear being fixedly attached to said first cam shaft; a gear which is meshed with said ring gear and fixedly attached to said second cam shaft; a support shaft for said planet gear; and a variable valve timing device which changes valve timing by adjusting a phase, between said first and second cam shafts, between a first phase for operating in said first condition and a second phase for operating in said second condition, by freely changing a relative positional relationship between said support shaft for said planet gear and said first cam shaft, whereby a compression ratio of said engine can be changed by changing said valve timing and a part of exhaust gas from said cylinder chamber is recirculated into intake gas for said cylinder chamber during said second condition.
References Cited (Backward Citations)
JPS5340115A
Cited
JPS54129219A
Cited
JPS5751536B2
Cited
US4552112A
Cited
JPH0580561B2
Cited
JPS6185515A
Cited
JPS63277815A
Cited
US5070824A
Cited
JPH02135604U
Cited
JPH04175453A
Cited
JPH04301172A
Cited
US5253620A
Cited
US5233948A
Cited
US5603292A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-11-03 | 2001-05-05 | 2001-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-11-03 | 2005-05-05 | 2005-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-11-03 | 2009-05-05 | 2009-11-04 | $7700.00 | Window Closed / Lapsed |