Operation control system for direct injection 2 cycle engine

• US 5,826,557 A
• Filed: 09/22/1997
• Issued: 10/27/1998
• Est. Priority Date: 09/20/1996
• Status: Expired due to Fees

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Inventors: Motoyama, Yu, Ohokubo, Akihiko
• Primary Examiner(s): Okonsky, David A.
• Application Number:
  US08/934,531
• Time in Patent Office: 400 Days
• Field of Search: 123/198 F, 123/73 C, 123/65 PE
• US Class Current: 123/198.00F
• CPC Class Codes: F02B 2075/025 two
• CPC Class Codes: F02D 17/02 Cutting-out cutting-out engines in multiple engine arrangements F02D25/04
• CPC Class Codes: F02D 9/04 concerning exhaust conduits throttle valves, or arrangements thereof in conduits F02D9/08

Abstract

A number of embodiments of two-cycle crankcase compression direct injected internal combustion engines wherein engine speed is controlled under at least some running conditions by cylinder disabling. Exhaust systems including exhaust control valves for precluding the passage of cooler gasses from the disabled cylinders to the operating cylinders through their exhaust ports are illustrated in varying forms and for various types of engines.

Claims

1. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine comprised of an engine body defining at least two combustion chambers, a crankcase chamber associated with each of said combustion chambers, scavenge passage means extending from said crankcase chamber to the respective of said combustion chambers and communicating therewith through a scavenge port opened and closed by a piston reciprocating in the respective combustion chamber, an exhaust port formed in each of said combustion chambers and opened and closed by the reciprocation of said piston for discharging exhaust gasses therefrom, an exhaust system for discharging exhaust gasses from said exhaust ports to the atmosphere comprised of an exhaust manifold having a plurality of branch passages, each extending from a respective one of said exhaust ports to a common collector section, said common collection section communicating with the atmosphere, combustion control means for delivering and igniting a combustible charge in each of said combustion chambers, means for controlling the speed of said engine during at least one running range by periodically disabling the combustion in at least one of said combustion chambers, exhaust control valve means in said exhaust system for controlling the effective flow area therethrough, means for controlling the position of said exhaust control valve means during cylinder disabling for precluding cooler gasses from the disabled combustion chamber from entering an operating combustion chamber through its exhaust port.

2. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 1, wherein the exhaust control valve means includes at least one exhaust control valve interposed in a branch passage of said exhaust system.

3. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 2, wherein the exhaust control valve is positioned in a branch passage of a combustion chamber that is not disabled.

4. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 3, wherein there is an exhaust control valve in all of the branch passages of the exhaust manifold.

5. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 3, wherein there are no exhaust control valves in the branch passages of those combustion chambers that are disabled.

6. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 1, further including means for determining another engine operational condition than combustion chamber disabling and for controlling the position of the exhaust control valve means in response to at least one sensed engine running condition in that other operational condition.

7. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 4, wherein the exhaust control valve is more fully closed during cylinder disabling than during the operational condition when combustion chamber disabling is not practiced.

8. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 1, wherein the combustion control means includes a plurality of fuel injectors, each injecting fuel directly into a respective combustion chamber.

9. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 6, wherein the fuel injectors are covered during at least a portion of the stroke of the piston.

10. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 9, wherein the exhaust control valve means includes at least one exhaust control valve interposed in a branch passage of said exhaust system.

11. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 10, wherein the exhaust control valve is positioned in a branch passage of a combustion chamber that is not disabled.

12. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 11, wherein there is an exhaust control valve in all of the branch passages of the exhaust manifold.

13. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 11, wherein there are no exhaust control valves in the branch passages of those combustion chambers that are disabled.

14. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 10, further including means for determining another engine operational condition than combustion chamber disabling and for controlling the position of the exhaust control valve means in response to at least one sensed engine running condition in that other operational condition.

15. A multiple cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 14, wherein the exhaust control valve is more fully closed during cylinder disabling than during the operational condition when combustion chamber disabling is not practiced.

16. A method of operating a cylinder, two-cycle, crankcase compression, internal combustion engine comprised of an engine body defining at least two combustion chambers, a crankcase chamber associated with each of said combustion chambers, scavenge passage means extending from said crankcase chamber to the respective of said combustion chambers and communicating therewith through a scavenge port opened and closed by a piston reciprocating in the respective combustion chamber, an exhaust port formed in each of said combustion chambers and opened and closed by the reciprocation of said piston for discharging exhaust gasses therefrom, an exhaust system for discharging exhaust gasses from said exhaust ports to the atmosphere comprised of an exhaust manifold having a plurality of branch passages, each extending from a respective one of said exhaust ports to a common collector section, said common collection section communicating with the atmosphere, said method comprising the steps of delivering and igniting a combustible charge in each of said combustion chambers, controlling the speed of said engine during at least one operational running range by periodically disabling the combustion in at least one of said combustion chambers, and controlling the flow of exhaust gasses during cylinder disabling for precluding cooler gasses from the disabled combustion chamber from entering an operating combustion chamber through its exhaust port.

17. A method of operating a cylinder, two-cycle, crankcase compression, internal combustion engine as set forth in claim 16, further including the step of determining another engine operational condition than combustion chamber disabling and controlling the position of the exhaust gas flow in response to at least one sensed engine running condition in that other operational condition.