Patent US4084568A successfully refreshed from Google Patents.
US4084568A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Decompression-type internal-combustion engine and method of improving the characteristics of such engine
Assignee: Honda Motor Co Ltd
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Filing: 1976-01-02
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Granted: 1978-04-18
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Expires: 1996-01-02
Abstract
Abstract Improved decompression-type, four-cycle internal-combustion engine which has the conventional compression chamber, reciprocable piston, and intake valve therein; comprising, in accordance with the invention, means for delaying the closing time of the valve, in the course of the compression stroke, with the piston moving upwards, for obtaining reduced compression pressure; and means for closing the valve to its at least nearly closed condition within the closing delay period. The inventive delaying and closing means is preferably embodied in a specifically shaped cam for controlling the operation of the intake valve, with respective depressed, slightly protruding as well as flat portions at preferred, predetermined crank angle positions.
Inventors
- 👤 Kazunobu Sato
- 👤 Takanori Suzuki
- 👤 Tadataka Kobayashi
- 👤 Takeshi Miyazawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:11
CPC Classifications
F; F02; F02N; F02N19/00; F02N19/004; F01; F01L; F01L13/00; F01L13/08; F02B; F02B75/00; F02B75/02; F02B2075/022; F02B2075/027
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
123 words
A four-cycle internal-combustion engine having a compression chamber, a reciprocable piston, at least one intake valve therefor and a cam for controlling the opening and closing of said intake valve, said cam being shaped to open said intake valve to a maximum degree of lift during the intake stroke and then gradually close said valve to momentarily effect substantial closure of the intake valve in the compression stroke at a crank angle of 240° and then to partially re-open said valve from said crank angle of 240° in gradually increasing amount up to 270° and thereafter to gradually close said valve and effect full closure at 330° whereby compression pressure at engine starting is reduced and at maximum operating speed is substantially unaffected.
Claim 2
Dependent Claim
123 words
A four-cycle internal-combustion engine having a compression chamber, a reciprocable piston, at least one intake valve therefor and a cam for controlling the opening and closing of said intake valve, said cam being shaped to open said intake valve to a maximum degree of lift during the intake stroke and then gradually close said valve to momentarily effect substantial closure of the intake valve in the compression stroke at a crank angle of 240° and then to partially re-open said valve from said crank angle of 240° in gradually increasing amount up to 270° and thereafter to gradually close said valve and effect full closure at 330° whereby compression pressure at engine starting is reduced and at maximum operating speed is substantially unaffected.
Claim 3
Dependent Claim
25 words
An engine as claimed in claim 1 wherein said intake valve is lifted at 270° to be re-opened by about 6% of the maximum lift.
Claim 4
Independent Claim
108 words
A method of controlling engine compression in a four-cycle internal combustion engine having a cylinder and an intake valve, said method comprising opening the intake valve to a maximum degree of lift during the intake stroke, gradually closing the intake valve to effect substantially complete and momentary closure during the compression stroke at a crank angle of 240°, then partially re-opening said intake valve in gradually increasing amount from 240° up to at an angle of 270° and thereafter gradually closing said valve to effect full closure at an angle of 330° whereby compression pressure at engine starting is reduced and at maximum operating speed is substantially unaffected.
Claim 5
Independent Claim
108 words
A method of controlling engine compression in a four-cycle internal combustion engine having a cylinder and an intake valve, said method comprising opening the intake valve to a maximum degree of lift during the intake stroke, gradually closing the intake valve to effect substantially complete and momentary closure during the compression stroke at a crank angle of 240°, then partially re-opening said intake valve in gradually increasing amount from 240° up to at an angle of 270° and thereafter gradually closing said valve to effect full closure at an angle of 330° whereby compression pressure at engine starting is reduced and at maximum operating speed is substantially unaffected.
Claim 6
Dependent Claim
25 words
A method as claimed in claim 3 wherein said intake valve is lifted at 270° to be re-opened by about 6% of the maximum lift.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-17 | 1981-10-17 | 1982-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-17 | 1985-10-17 | 1986-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-17 | 1989-10-17 | 1990-04-18 | $7700.00 | Window Closed / Lapsed |