GB2191537A - Two-stroke engine with piston and valve controlled exhaust - Google Patents

Two-stroke engine with piston and valve controlled exhaust Download PDF

Info

Publication number
GB2191537A
GB2191537A GB08612997A GB8612997A GB2191537A GB 2191537 A GB2191537 A GB 2191537A GB 08612997 A GB08612997 A GB 08612997A GB 8612997 A GB8612997 A GB 8612997A GB 2191537 A GB2191537 A GB 2191537A
Authority
GB
United Kingdom
Prior art keywords
exhaust port
engine
rotary valve
internal combustion
stroke internal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB08612997A
Other versions
GB8612997D0 (en
Inventor
Josef Petr Prokopius
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to GB08612997A priority Critical patent/GB2191537A/en
Publication of GB8612997D0 publication Critical patent/GB8612997D0/en
Publication of GB2191537A publication Critical patent/GB2191537A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B33/00—Engines characterised by provision of pumps for charging or scavenging
    • F02B33/02—Engines with reciprocating-piston pumps; Engines with crankcase pumps
    • F02B33/28—Component parts, details or accessories of crankcase pumps, not provided for in, or of interest apart from, subgroups F02B33/02 - F02B33/26
    • F02B33/30—Control of inlet or outlet ports
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L7/00—Rotary or oscillatory slide valve-gear or valve arrangements
    • F01L7/12—Rotary or oscillatory slide valve-gear or valve arrangements specially for two-stroke engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/02—Engines characterised by their cycles, e.g. six-stroke
    • F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
    • F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Characterised By The Charging Evacuation (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Abstract

The exhaust port closing and opening is controlled dually by means of the top edge of the engine piston 1 (for the opening) and by an additional device, for example a rotary valve 6, (for the closing), so that an asymmetrical timing of the exhaust port 12 is obtained. The additional device may be a sliding valve and the rotary valve 6 may be driven from the crankshaft through gears, a chain or a belt. <IMAGE>

Description

SPECIFICATION Rotary Valve Controlled Exhaust Port of the Two Stroke Internal Combustion Engine Technical Field: This invention relates to two-stroke internal combustion engines, in particular to control of opening and closing of the exhaust port.
Background Art:- Opening and closing of the exhaust port of twostroke internal combustion engines presently designed and manufactured is being controlled buy a top edge of the engine piston. Controlling of exhaust opening and closing by the top edge of the engine piston is in this way fully symmetrical and at each engine cycle part of the fresh mixture charge is lost through the exhaust system. The exhaust port is being closed some 30 of the crankshaft movement after mixture transfer from the crankcase when the transfer ports are being closed, and this 30 late closing of exhaust port allows about 1/6 of the volume of the fresh mixture being pushed out into the exhaust system.A proper design of exhaust system and especially of expansion chambers is desirable to keep fresh mixture losses to the minimum as the exhaust system is controlling the pressures during the transfer and scavenging period in engine cylinder. But the expansion chamber design can be only appropriate in certain, very narrow range of revolutions known as a "power band" and outside these revolutions the exhaust system is inefficient causing loss of the fresh mixture in revolutions below the power band and inadequate discharge of burned gases in high revolutions above the power band. By this inefficiency some power of the engine is lost and emission of unburned gases increased.
This invention introduces a new approach to this problem and enables asymmetrical control of the exhaust port leading to increased efficiency of the engine, higher power output and less emission of unburned gases. Also engines with this asymmetrical exhaust control no longer require the expansion chamber and can run with a straight exhaust system pipe with a silencer. The expansion chamber is sometimes difficult to accommodate on racing motorcycles because of the ground clearance and this invention eliminates this problem also.
Disclosure ofthe Invention:- A two-stroke internal combustion engine having a conventional exhaust port in the engine cylinder, the conventional exhaust port being dually controlled by the top edge of the engine piston and by a rotary valve arrangement. The opening of the said exhaust port is being controlled entirely by the top edge of the engine piston and the closing of the said exhaust port being controlled by the said rotary valve, so that an asymmetrical control of the said exhaust port is possible to obtain. The rotary valve is being driven in the rotary movement in synchronisation with the engine crankshaft by conventional means of sprockets and chain, or timing pulleys and timing belt or by a train of gears.
This invention introduces a new asymmetrical arrangement of exhaust port control eliminating the need for expansion chamber which is generally bulky and the engine can run with higher efficiency and consequently has a higher power output and lower emission of unburned gases than any known symmetrical exhaust port timing arrangement.
A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which:- (1) indicates the engine piston, (2) the engine crankshaft, (3) driving timing pulley or sprocket, (4) the timing belt or chain, (5) the driven timing pulley or sprocket, (6) the rotary valve, (7) the rotary valve body, (8) the exhaust system, (9) the engine cylinder, (10) the engine cylinder head, (11) the crankcase, (12) the exhaust port.
Atwo-stroke internal combustion engine having a conventional exhaust port (12) in the engine cylinder (9), the conventional exhaust port (12) being dually controlled by the top edge of the engine piston (1) and by a rotary valve (6) arrangement, the arrangement being such, that opening of the exhaust port (12) is controlled entirely by the top edge of the engine piston (1) and closing of the said exhaust port (12) being controlled by the rotary valve (6), so that asymmetrical control of opening and closing of the exhaust port (12) is obtained. The rotary valve's rotational movement and the synchronisation of the rotational movement with engine crankshaft (2) is being obtained through a sprocket or timing pulley (3), a chain or timing belt (4), and a sprocket or timing pulley (5).
1. Atwo-stroke internal combustion engine having a conventional exhaust port situated in the engine cylinder and having in addition to the said conventional exhaust port a rotary valve situated in the said exhaust port for asymmetrical control of the said exhaust port.
2. A two-stroke internal combustion engine as claimed in Claim 1 where the rotary valve in the exhaust port is controlling the connection between the engine cylinder and the exhaust system.
3. A two-stroke internal combustion engine as claimed in Claim 1 where the opening of the exhaust port is controlled by the top edge of the engine piston and the closing of the said exhaust port controlled by the rotary valve.
4. A two-stroke internal combustion engine as claimed in Claim 1 where the rotor of the said rotary valve is, in cross section, of segmental shape.
5. A two-stroke internal combustion engine as claimed in Claim 1 where the rotary valve is closing the connection between the engine cylinder and the exhaust system at approximately the same time as transfer ports are being closed by the top edge of the engine piston.
6. A two-stroke internal combustion engine having a conventional exhaust port situated in the engine cylinder and the said exhaust port being dually controlled, in opening by the top edge of the engine piston, and being closed by an additional device as for example sliding valve situated
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Rotary Valve Controlled Exhaust Port of the Two Stroke Internal Combustion Engine Technical Field: This invention relates to two-stroke internal combustion engines, in particular to control of opening and closing of the exhaust port. Background Art:- Opening and closing of the exhaust port of twostroke internal combustion engines presently designed and manufactured is being controlled buy a top edge of the engine piston. Controlling of exhaust opening and closing by the top edge of the engine piston is in this way fully symmetrical and at each engine cycle part of the fresh mixture charge is lost through the exhaust system. The exhaust port is being closed some 30 of the crankshaft movement after mixture transfer from the crankcase when the transfer ports are being closed, and this 30 late closing of exhaust port allows about 1/6 of the volume of the fresh mixture being pushed out into the exhaust system.A proper design of exhaust system and especially of expansion chambers is desirable to keep fresh mixture losses to the minimum as the exhaust system is controlling the pressures during the transfer and scavenging period in engine cylinder. But the expansion chamber design can be only appropriate in certain, very narrow range of revolutions known as a "power band" and outside these revolutions the exhaust system is inefficient causing loss of the fresh mixture in revolutions below the power band and inadequate discharge of burned gases in high revolutions above the power band. By this inefficiency some power of the engine is lost and emission of unburned gases increased. This invention introduces a new approach to this problem and enables asymmetrical control of the exhaust port leading to increased efficiency of the engine, higher power output and less emission of unburned gases. Also engines with this asymmetrical exhaust control no longer require the expansion chamber and can run with a straight exhaust system pipe with a silencer. The expansion chamber is sometimes difficult to accommodate on racing motorcycles because of the ground clearance and this invention eliminates this problem also. Disclosure ofthe Invention:- A two-stroke internal combustion engine having a conventional exhaust port in the engine cylinder, the conventional exhaust port being dually controlled by the top edge of the engine piston and by a rotary valve arrangement. The opening of the said exhaust port is being controlled entirely by the top edge of the engine piston and the closing of the said exhaust port being controlled by the said rotary valve, so that an asymmetrical control of the said exhaust port is possible to obtain. The rotary valve is being driven in the rotary movement in synchronisation with the engine crankshaft by conventional means of sprockets and chain, or timing pulleys and timing belt or by a train of gears. This invention introduces a new asymmetrical arrangement of exhaust port control eliminating the need for expansion chamber which is generally bulky and the engine can run with higher efficiency and consequently has a higher power output and lower emission of unburned gases than any known symmetrical exhaust port timing arrangement. A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which:- (1) indicates the engine piston, (2) the engine crankshaft, (3) driving timing pulley or sprocket, (4) the timing belt or chain, (5) the driven timing pulley or sprocket, (6) the rotary valve, (7) the rotary valve body, (8) the exhaust system, (9) the engine cylinder, (10) the engine cylinder head, (11) the crankcase, (12) the exhaust port. Atwo-stroke internal combustion engine having a conventional exhaust port (12) in the engine cylinder (9), the conventional exhaust port (12) being dually controlled by the top edge of the engine piston (1) and by a rotary valve (6) arrangement, the arrangement being such, that opening of the exhaust port (12) is controlled entirely by the top edge of the engine piston (1) and closing of the said exhaust port (12) being controlled by the rotary valve (6), so that asymmetrical control of opening and closing of the exhaust port (12) is obtained. The rotary valve's rotational movement and the synchronisation of the rotational movement with engine crankshaft (2) is being obtained through a sprocket or timing pulley (3), a chain or timing belt (4), and a sprocket or timing pulley (5). CLAIMS
1. Atwo-stroke internal combustion engine having a conventional exhaust port situated in the engine cylinder and having in addition to the said conventional exhaust port a rotary valve situated in the said exhaust port for asymmetrical control of the said exhaust port.
2. A two-stroke internal combustion engine as claimed in Claim 1 where the rotary valve in the exhaust port is controlling the connection between the engine cylinder and the exhaust system.
3. A two-stroke internal combustion engine as claimed in Claim 1 where the opening of the exhaust port is controlled by the top edge of the engine piston and the closing of the said exhaust port controlled by the rotary valve.
4. A two-stroke internal combustion engine as claimed in Claim 1 where the rotor of the said rotary valve is, in cross section, of segmental shape.
5. A two-stroke internal combustion engine as claimed in Claim 1 where the rotary valve is closing the connection between the engine cylinder and the exhaust system at approximately the same time as transfer ports are being closed by the top edge of the engine piston.
6. A two-stroke internal combustion engine having a conventional exhaust port situated in the engine cylinder and the said exhaust port being dually controlled, in opening by the top edge of the engine piston, and being closed by an additional device as for example sliding valve situated between the engine cylinder in the exhaust port and the exhaust system, so that asymmetrical opening and closing of the exhaust port is being obtained.
7. Atwo-stroke internal combustion engine having the said rotary valve driven in synchronisation with the engine crankshaft by a pair of sprockets and a chain.
8. Atwo-stroke internal combustion engine having the said rotary valve driven in synchronisation with the engine crankshaft by a pair of timing pulleys and by a timing belt.
9. Atwo-stroke internal combustion engine having the said rotary valve driven in synchronisation with the engine crankshaft by a train of gears.
10. Atwo-stroke internal combustion engine as described elsewhere in this invention and as illustrated on the accompanying drawing.
GB08612997A 1986-05-29 1986-05-29 Two-stroke engine with piston and valve controlled exhaust Withdrawn GB2191537A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB08612997A GB2191537A (en) 1986-05-29 1986-05-29 Two-stroke engine with piston and valve controlled exhaust

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08612997A GB2191537A (en) 1986-05-29 1986-05-29 Two-stroke engine with piston and valve controlled exhaust

Publications (2)

Publication Number Publication Date
GB8612997D0 GB8612997D0 (en) 1986-07-02
GB2191537A true GB2191537A (en) 1987-12-16

Family

ID=10598592

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08612997A Withdrawn GB2191537A (en) 1986-05-29 1986-05-29 Two-stroke engine with piston and valve controlled exhaust

Country Status (1)

Country Link
GB (1) GB2191537A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2217783A (en) * 1988-04-30 1989-11-01 Fuji Heavy Ind Ltd Supercharged two-stroke fuel-injected engine
GB2226597A (en) * 1988-12-20 1990-07-04 Mervyn Davies Rotating cylinder valve
DE3937679A1 (en) * 1989-02-22 1990-08-23 Zschopau Motorrad Veb Outlet control for two=stroke IC engine - has piston shaped control member forming part of outlet channel
US5732548A (en) * 1994-10-07 1998-03-31 Platinum Plus, Inc. Method for reducing harmful emissions from two-stroke engines
WO2002025078A1 (en) * 2000-09-22 2002-03-28 Drazen Paut Two-stroke cycle for internal combustion engines
ITAN20100130A1 (en) * 2010-07-28 2012-01-29 E2F Di Esposti Federici Ettore EXHAUST VALVE GROUP FOR TWO-STROKE ENGINE, COOLED WITHOUT CONTACT AND SELF-CLEANING.

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB744248A (en) * 1900-01-01
GB627381A (en) * 1945-10-02 1949-08-08 Twin Coach Co Improvements in and relating to two-stroke internal combustion engines
GB747087A (en) * 1953-11-06 1956-03-28 Sulzer Ag Two-stroke internal combustion engines
GB747788A (en) * 1953-03-06 1956-04-11 Saurer Ag Adolph Improvements in and relating to exhaust control arrangements for two-stroke internalcombustion engines
GB807709A (en) * 1956-07-14 1959-01-21 Sulzer Ag Two-stroke internal combustion engines
GB2145467A (en) * 1983-08-02 1985-03-27 Alexander Macfadzean Two-stroke I.C. engine exhaust ports

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB744248A (en) * 1900-01-01
GB627381A (en) * 1945-10-02 1949-08-08 Twin Coach Co Improvements in and relating to two-stroke internal combustion engines
GB747788A (en) * 1953-03-06 1956-04-11 Saurer Ag Adolph Improvements in and relating to exhaust control arrangements for two-stroke internalcombustion engines
GB747087A (en) * 1953-11-06 1956-03-28 Sulzer Ag Two-stroke internal combustion engines
GB807709A (en) * 1956-07-14 1959-01-21 Sulzer Ag Two-stroke internal combustion engines
GB2145467A (en) * 1983-08-02 1985-03-27 Alexander Macfadzean Two-stroke I.C. engine exhaust ports

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2217783A (en) * 1988-04-30 1989-11-01 Fuji Heavy Ind Ltd Supercharged two-stroke fuel-injected engine
GB2217783B (en) * 1988-04-30 1993-01-13 Fuji Heavy Ind Ltd A system for scavenging in a two-stroke engine
GB2226597A (en) * 1988-12-20 1990-07-04 Mervyn Davies Rotating cylinder valve
DE3937679A1 (en) * 1989-02-22 1990-08-23 Zschopau Motorrad Veb Outlet control for two=stroke IC engine - has piston shaped control member forming part of outlet channel
US5732548A (en) * 1994-10-07 1998-03-31 Platinum Plus, Inc. Method for reducing harmful emissions from two-stroke engines
US5819529A (en) * 1994-10-07 1998-10-13 Clean Diesel Technologies, Inc. Method for reducing emissions from two-stroke engines
WO2002025078A1 (en) * 2000-09-22 2002-03-28 Drazen Paut Two-stroke cycle for internal combustion engines
US6874454B2 (en) 2000-09-22 2005-04-05 Drazen Paut Two-stroke cycle for internal combustion engines
ITAN20100130A1 (en) * 2010-07-28 2012-01-29 E2F Di Esposti Federici Ettore EXHAUST VALVE GROUP FOR TWO-STROKE ENGINE, COOLED WITHOUT CONTACT AND SELF-CLEANING.
WO2012013715A1 (en) * 2010-07-28 2012-02-02 E2F Di Esposti Federici Ettore Discharge valve assembly for two-stroke engine, provided with cooling, non-contacting seal and self-cleaning
CN103038464A (en) * 2010-07-28 2013-04-10 埃托雷埃斯波斯蒂费代里奇的E2F公司 Discharge valve assembly for two-stroke engine, provided with cooling, non-contacting seal and self-cleaning

Also Published As

Publication number Publication date
GB8612997D0 (en) 1986-07-02

Similar Documents

Publication Publication Date Title
US5205251A (en) Rotary valve for internal combustion engine
US4075986A (en) Rotary-poppet valve internal combustion engine
US3945364A (en) Rotary valve for internal combustion engine
US5410996A (en) Rotary valve assembly used with reciprocating engines
KR960000437B1 (en) Reciprocatory machines
JPS6477710A (en) Internal combustion engine
AU638720B2 (en) Reciprocating piston engine with pumping and power cylinders
GB2191537A (en) Two-stroke engine with piston and valve controlled exhaust
EP0767294B1 (en) Internal combustion engine
CA2060203C (en) Reciprocating piston engine with pumping and power cylinders
GB2117047A (en) Intake and exhaust flow control valves in two-stroke engines
US10914205B2 (en) Rotational valve for two stroke engine
KR20080052584A (en) Internal combustion engine
RU2032815C1 (en) Valve gear for internal combustion engine
GB2145467A (en) Two-stroke I.C. engine exhaust ports
RU2139998C1 (en) Two-stroke rotary engine
RU2139431C1 (en) Internal combustion engine
ES527909A0 (en) AN ENGINE DECOMPRESSION DELAY, FOR USE IN AN INTERNAL COMBUSTION ENGINE
SU757757A1 (en) I.c. engine
JPS6214324Y2 (en)
RU2037629C1 (en) Two-stroke internal combustion engine
GB2112060A (en) I.C. engine with rotary valve gear
JP2745310B2 (en) Engine valve gear
SU1019084A1 (en) Two-stroke i.c. engine
GB1592279A (en) Internal combustion rotary engines

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)