Claims
- 1. A two cycle internal combustion engine comprising three cylinders vertically in-line, a crankcase having a first uppermost reed block opening, a second middle reed block opening, and a third lowermost reed block opening, a single intake manifold covering all of said reed block openings, a single fuel delivery device on said manifold and having a throttle bore at said first reed block opening and spaced above said second and third reed block openings.
- 2. The invention according to claim 1 wherein said throttle bore has a first portion horizontally aligned with a portion of said first reed block opening and a second portion horizontally offset from said first reed block opening.
- 3. The invention according to claim 2 wherein the bottom of said throttle bore is spaced slightly above the bottom of said first reed block opening.
- 4. The invention according to claim 2 wherein said cylinders have center-line axes extending horizontally and parallel to each other and lying in a vertical center-line plane, and wherein fuel from said second portion of said throttle bore flows downwardly and then laterally to said second and third reed block openings along a direction perpendicular to said center-line plane.
- 5. The invention according to claim 2 comprising a flow divider dam in said manifold below said first reed block opening and said first portion of said throttle bore and dividing the flow from said throttle bore and diverting to the upper cylinder a portion of the gravitationally induced vertical fuel flow which would otherwise drain to the lower cylinder during engine idle and cause an overly rich fuel mixture in the lower cylinder and an overly lean fuel mixture in the upper cylinder.
- 6. The invention according to claim 5 wherein said first reed block opening has a horizontally extending width, and said flow divider dam has a horizontally extending width substantially the same as said width of said first reed block opening and extending substantially thereacross.
- 7. The invention according to claim 5 comprising a second flow divider dam in said manifold below said second reed block opening and above said third reed block opening and diverting to the middle cylinder a portion of the gravitationally induced vertical fuel flow which would otherwise drain to the lower cylinder during engine idle and cause an overly rich mixture in the lower cylinder and an overly lean mixture in the middle cylinder.
- 8. The invention according to claim 7 wherein said second flow divider dam is vertically in-line with said first mentioned flow divider dam.
- 9. A two cycle internal combustion engine comprising three cylinders vertically in-line, a crankcase having first, second and third reed block openings having faces lying in a common place, a single intake manifold covering all of said reed block openings and including a plenum horizontally offset from said reed block openings along a direction lying in said common plane, a single fuel delivery device on said manifold and having a throttle bore supplying fuel to said plenum such that fuel from said throttle bore flows downwardly in said plenum and then laterally along said common plane to said second and third reed block openings.
- 10. The invention according to claim 9 comprising a flow divider dam in said manifold vertically in-line with and below the uppermost reed block opening.
- 11. The invention according to claim 10 wherein said flow divider dam is also vertically in-line with and below said throttle bore.
- 12. The invention according to claim 11 wherein said throttle bore has a first portion vertically in-line with and above said flow divider dam and horizontally aligned with said uppermost reed block opening, and wherein said throttle bore has a second portion horizontally aligned with said plenum.
- 13. The invention according to claim 9 wherein the bottom of said throttle bore is spaced slightly above the bottom of the uppermost reed block opening.
- 14. The invention according to claim 9 wherein the top of said throttle bore is substantially horizontally aligned with the top of the uppermost reed block opening.
- 15. A two cycle internal combustion engine comprising three cylinders vertically in-line with each other, a crankcase having three reed block openings vertically in-line with each other, a single manifold servicing all three of said cylinders and covering all three of said reed block openings, a single fuel delivery device on said manifold delivering fuel to each of said cylinders through a respective block opening.
- 16. The invention according to claim 15 wherein said manifold has a plenum portion horizontally between said vertical center-line plane and said reed block openings.
- 17. The invention according to claim 16 wherein said fuel delivery device has a throttle bore with a first portion horizontally aligned with a portion of one of said reed block openings, and a second portion horizontally aligned with a portion of said plenum.
- 18. A two cycle internal combustion engine comprising three cylinders vertically in-line, a crankcase having first, second and third reed block openings, one for each of said cylinders, a reed block adaptor plate, first, second and third reed blocks mounted to said reed block adaptor plate, a single intake manifold mounted to said crankcase and covering all of said reed block openings, said reed block adaptor plate being mounted between said crankcase and said manifold, with said first, second and third reed blocks in said first, second and third reed block openings, respectively, said manifold and said reed block adaptor plate defining a plenum therebetween with a front wall at said manifold and a back wall at said reed block adaptor plate, which plenum is laterally offset from said reed block openings, a single fuel delivery device on said manifold delivering fuel to each of said cylinders.
- 19. The invention according to claim 18 wherein said reed block openings are vertically in-line with each other, and wherein said cylinders have respective center-line axes extending horizontally and parallel to each other and lying in a vertical center-line plane, and wherein said plenum between said manifold and said reed block adaptor plate is laterally offset from said reed block openings along a direction perpendicular to said center-line plane.
CROSS REFERENCE TO RELATED
This application is a continuation in part of application Ser. No. 07/707,706, filed May 30, 1991.
The invention relates to two cycle internal combustion engines with vertically in-line cylinders, and more particularly to simple and significantly cost-reduced fuel delivery structure therefor.
The invention arose during continuing development efforts directed toward two cycle internal combustion marine engines having three cylinders vertically inline. In the prior art, each cylinder has its own carburetor which supplies fuel through a respective reed block into the crankcase. The carburetor throttles are connected to each other by throttle linkage. This system is costly because of the expense of three separate carburetors. Furthermore, tuning requires not only synchronization of all three carburetors through the linkage, but also three sets of adjustments, e.g. three separate idle mixture adjustment screws, three choke linkages, etc.
The invention provides a simple and effective solution to the above noted problems, and provides a significant cost reduction. A single intake manifold services all three cylinders, and a single fuel delivery device on the manifold delivers fuel to all of the cylinders. The invention eliminates the extra carburetors, the complicated linkage system, the extra adjustments, etc.
US Referenced Citations (11)
Non-Patent Literature Citations (1)
| Entry |
| "A Five-Cylinder Outboard Engine", Richard A. Davis, SAE Technical Paper Series, 891751, Small Engine Technology Conf. Milwaukee, WI, Sep. 11-13, 1989. |
Continuation in Parts (1)
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Number |
Date |
Country |
| Parent |
707706 |
May 1991 |
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Patent Grant
5119771
