التفاصيل البيبلوغرافية
| العنوان: |
Two-stroke internal combustion engine with valves for improved fuel efficiency |
| Document Number: |
20100037876 |
| تاريخ النشر: |
February 18, 2010 |
| Appl. No: |
12/228791 |
| Application Filed: |
August 15, 2008 |
| مستخلص: |
A two-stroke cycle internal combustion engine has a cylinder with a cylinder head closing off an end of the cylinder, a crankshaft and a piston connecting with the crankshaft to move the piston in a reciprocating movement within the cylinder. Intake and exhaust valves move into and out of a combustion chamber for openings and closures of the valves. A mixture of fuel and air is forced into the cylinder during an open interval of the intake valve beginning in the middle of the upstroke and terminating in a range of 20-60 degrees before top dead center to improve efficiency and choice of fuel by minimizing compressive forces of the piston during the upstroke. Timing of the closure of the intake valve may be delayed automatically with a reduction in crankshaft angular speed. |
| Inventors: |
Robinson, Barnett Joel (Newton, MA, US) |
| Claim: |
1. An internal combustion engine comprising: a cylinder with a cylinder head closing off an end of the cylinder; a crankshaft and a piston connecting with the crankshaft, the piston being mounted for reciprocating movement within the cylinder wherein the piston is movable via an upstroke in a direction toward the head and via a downstroke in a direction away from the head, and wherein a single cycle of the crankshaft is accomplished with a piston downstroke and a following piston upstroke, a region within the cylinder being established as a combustion chamber defined by a space between the piston and the cylinder head; a valve assembly including an intake valve and an exhaust valve providing for communication of gasses between the combustion chamber and locations outside of the combustion chamber, and a timing device for synchronizing the valve assembly to rotations of the crankshaft, the valve assembly providing for the opening and the closing of the intake valve and the exhaust valve for a two-stroke operation of the engine; wherein, in said operation of the engine, the valve assembly provides for a closure of both of said valves during a terminal stage of said upstroke to establish an interval for ignition of gasses in the combustion chamber; the valve assembly provides for a closure of both of said valves during an initial stage of said downstroke to establish a power interval for imparting rotation to the crankshaft; the valve assembly provides for an opening of said exhaust valve during a terminal stage of said downstroke to establish an exhaust interval for exhausting products of combustion from the combustion chamber; the valve assembly provides for the closure of said exhaust valve at the end of the exhaust interval and an opening of said intake valve after the closure of the exhaust valve, the opening of the intake valve occurring prior to the terminal stage of said upstroke to establish an intake interval for conduction of fuel and air into the combustion chamber; and the intake interval terminates with a closing of the intake valve prior to an ignition of the gasses in the combustion chamber. |
| Claim: |
2. An engine according to claim 1, wherein said cylinder is a first cylinder, said engine further comprising a plurality of cylinders including said first cylinder, said plurality of valves includes an intake valve and an exhaust valve for each of said plurality of cylinders, and said engine further comprises a driver of the fuel, an impeller of air and an intake manifold, said intake manifold interconnecting said driver and impeller with the intake valves of respective ones of said cylinders, said driver providing an ingress of fuel and said impeller providing an ingress of air into the intake manifold. |
| Claim: |
3. An engine according to claim 1, further comprising a driver of the fuel and an impeller of air via said intake valve into the combustion chamber upon an opening of said intake valve during said upstroke. |
| Claim: |
4. An engine according to claim 2, wherein the fuel is in vapor form during the ingress of the fuel into the combustion chamber from the intake manifold. |
| Claim: |
5. An engine according to claim 4, wherein the fuel vapor is mixed with intake air inside the intake manifold, and said impeller drives a mixture of the fuel and the intake air. |
| Claim: |
6. An engine according to claim 5, wherein the valve assembly includes a camshaft, and wherein the air impeller is drivable by an electric motor or by a mechanical power link from the crankshaft or from the camshaft. |
| Claim: |
7. An engine according to claim 5, wherein the impeller comprises a turbocharger driven by engine exhaust gasses. |
| Claim: |
8. An engine according to claim 1, further comprising a spark plug, operable during said ignition interval in the terminal stage of said upstroke for igniting gasses within the combustion chamber. |
| Claim: |
9. An engine according to claim 8, wherein the timing device operates the valve assembly and the spark plug in synchronism with rotations of the crankshaft to provide for an ignition of fuel-air mixture once during each cycle of the crankshaft. |
| Claim: |
10. An engine according to claim 1, wherein the crankshaft is mounted within main bearings of the engine, and wherein portions of the crankshaft adjacent to the main bearings are formed with cam surfaces to provide a series of cams for driving respective ones of said valves. |
| Claim: |
11. An engine according to claim 1, further comprising a crankcase for holding lubricant below the crankshaft, and a pump for directing the lubricant to the valve assembly. |
| Claim: |
12. An engine according to claim 11, wherein the exhaust and intake valves open into the combustion chamber of the cylinder above the location of the piston at top dead center. |
| Claim: |
13. An engine according to claim 1, wherein closure of the intake valve occurs in the upstroke during an interval of crankshaft rotation from 60 degrees to 30 degrees before top dead center to reduce a compression ratio from the upward movement of the piston with a reduced increase of the temperature of the gasses in the combustion chamber resulting from compression by the piston to enable burning of any one of a range of fuels including gasoline, diesel fuel, kerosene, and heating oil. |
| Claim: |
14. An engine according to claim 13, wherein closure of the intake valve occurs in the upstroke during an interval of crankshaft rotation from 50 degrees to 30 degrees before top dead center. |
| Claim: |
15. An engine according to claim 1, wherein closure of the intake valve occurs in the upstroke during an interval of crankshaft rotation from 60 degrees to 20 degrees before top dead center to reduce a compression ratio from the upward movement of the piston with a reduced increase of the temperature of the gasses in the combustion chamber resulting from compression by the piston to enable burning of any one of a range of fuels including gasoline, diesel fuel, kerosene, and heating oil, and wherein the closure of the intake valve is regulated in accordance with crankshaft rotation rate to provide the value of 20 degree for the closure of the intake valve at a crankshaft rotation rate below 1500 RPM. |
| Claim: |
16. An engine according to claim 1, wherein the valve assembly is capable of advancing and retarding a closing time of the intake valve in accordance with parameters of a vehicle driven by the engine for increasing alternatively efficiency or power output of the engine in response to driving conditions of the vehicle. |
| Claim: |
17. An internal combustion engine comprising: a cylinder with a cylinder head closing off an end of the cylinder; a crankshaft and a piston connecting with the crankshaft, the piston being mounted for reciprocating movement within the cylinder wherein the piston is movable via an upstroke in a direction toward the head and via a downstroke in a direction away from the head, and wherein a single cycle of the crankshaft is accomplished with a piston downstroke and a following piston upstroke, a region within the cylinder being established as a combustion chamber defined by a space between the piston and the cylinder head; a valve assembly including an intake valve and an exhaust valve providing for communication of gasses between the combustion chamber and locations outside of the combustion chamber, and a timing device for synchronizing the valve assembly to rotations of the crankshaft, the valve assembly providing for the opening and the closing of the intake valve and the exhaust valve for a two-stroke operation of the engine; wherein, in said operation of the engine, the valve assembly provides for a closure of both of said valves during a terminal stage of said upstroke to establish an interval for ignition of gasses in the combustion chamber; the valve assembly provides for a closure of both of said valves during an initial stage of said downstroke to establish a power interval for imparting rotation to the crankshaft; the valve assembly provides for an opening of said exhaust valve during a terminal stage of said downstroke to establish an exhaust interval for exhausting products of combustion from the combustion chamber; the valve assembly provides for the closure of said exhaust valve at the end of the exhaust interval and an opening of said intake valve after the closure of the exhaust valve, the opening of the intake valve occurring prior to the terminal stage of said upstroke to establish an intake interval for conduction of fuel into the combustion chamber; and the intake interval terminates with a closing of the intake valve prior to an ignition of the gasses in the combustion chamber; and wherein the timing device is capable of delaying initiation of said ignition and closure of said intake valve at a relatively low rate of said crankshaft rotation for increased efficiency with reduced power of said engine while enabling increased power with reduced efficiency of said engine at a relatively high rate of said crankshaft rotation. |
| Claim: |
18. An engine according to claim 17 wherein said timing device includes a computer with memory for storing engine parameters including optimum camshaft angles relative to crankshaft rotation for opening and closing both the intake valve and the exhaust valve as a function of various engine operating conditions. |
| Current U.S. Class: |
123/65PE |
| Current International Class: |
02 |
| رقم الانضمام: |
edspap.20100037876 |
| قاعدة البيانات: |
USPTO Patent Applications |