WO1993001398A1 - Mechanism controlling intake reed valves for two cycle engine - Google Patents

Mechanism controlling intake reed valves for two cycle engine Download PDF

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Publication number
WO1993001398A1
WO1993001398A1 PCT/SE1992/000476 SE9200476W WO9301398A1 WO 1993001398 A1 WO1993001398 A1 WO 1993001398A1 SE 9200476 W SE9200476 W SE 9200476W WO 9301398 A1 WO9301398 A1 WO 9301398A1
Authority
WO
WIPO (PCT)
Prior art keywords
engine
cycle engine
reed valves
mechanism controlling
camdisc
Prior art date
Application number
PCT/SE1992/000476
Other languages
French (fr)
Inventor
Dag Henrik Edlund
Original Assignee
Dag Henrik Edlund
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 Dag Henrik Edlund filed Critical Dag Henrik Edlund
Publication of WO1993001398A1 publication Critical patent/WO1993001398A1/en

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Classifications

    • 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
    • F01L3/00—Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof
    • F01L3/20—Shapes or constructions of valve members, not provided for in preceding subgroups of this group
    • F01L3/205—Reed valves
    • 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
    • F02B75/16—Engines characterised by number of cylinders, e.g. single-cylinder 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

Definitions

  • a well working system which today is used on many high performance engines is a reed valve intake system. It consists of elastic membrane valves which have the function of non-return valves which open due to elasticity when the engine gives a certain negative pressure on the inlet side.
  • the pressure value in the inlet passage changes from negative to positive pressure, closing the membrane valve and obstructing the fresh charge from going backwards and out through the carburator.
  • valve is designed for low force opening gaining charge within a range of low revolutions, problems occur within the higher range of revolutions as the valves can't move fast enough due to low spring force.
  • the durability may be limited as low spring force normally means thin material.
  • the present invention does not have the limitations of todays systems which are described above.
  • the systems also comprises a completely controlled timing of the opening and closing sequenses of the induction period.
  • valveblades 1 are mounted on shafts 2 which are journalled in valve carrier 3. In one end of the shafts 2 lifterarms 4 and returnsprings 5 are situated.
  • the camdisc 6 Against the lifterarms 4 the camdisc 6 is operating.
  • the camdisc 6 rotates with a predetermined number of revolutions in a fixed ratio to the crankshaft of the engine.
  • a gear reduction of for example 1:2 may preferably be choosen for the camdisc.
  • the valve carrier with valves is located in the intake passage.
  • the valvesystem can also be used in supercharged engines when placed in an inletpassage directly connected to inlet ports in the cylinder bore.
  • the camdisc or its transmitting system By designing the camdisc or its transmitting system in a more complicated way the valve can be given a varying opening height and/or duration depending on the engine speed.
  • the camdisc is split in two halves which under influence of centrifugal force move apart from each other when the rotating speed increases.
  • the spring element 21 counteracts this movement to a prefered degree.
  • valve carrier 3 with the inlet pipe 20 is shown separated from the inlet passage 17.
  • crankshaft 7 with the gearwheel 8 transmitts torque to the primary shaft 9 of the gearbox on which the gearwheel 10 is mounted.
  • gear wheel 11 Firmly connected with the gearwheel 10 is the gear wheel 11 which, as one function, has to transmit torque to the crankshaft 7 with the help of gearwheel 12 and the intermediate gear 13 when starting the engine. A kickstarter then actuates the gear wheel 12.
  • the gearwheel 11 also controls the gearwheel 19 via the intermediate gearwheel 14.
  • the shaft 15 is firmly connected to the gearwheel 19 in one end and the camdisc 6 in the other end.
  • the shaft is journalled in the partition wall 16 between the engines transmissionhousing and one side of the inletpassage 17.
  • the shaft 15 rotates half the number of revolutions compared to the crankshaft because the wheels 8 and 10 have the gear ratio 1:3 and the wheels 11 and 19 have the gear ratio 3:2.
  • the cylinder is displayed vertically sectioned.
  • the returnspring ⁇ 5 forces the lifterarms 4 against the camdisc 6, and hence the valveblades also closes the inlet in accordance with the shape of the camdisc in a timesequence when the admission period shall be completed.
  • Fig.6 Like fig.5 but for supercharged engine.
  • camdisc The design of the camdisc is adapted for valveopening at a suitable timeperiod for the engines charging. Inletpassage 22. Inletport 23.

Abstract

Reed valves with constrained opening for two cycle engine. A control mechanism for inlet valves on internal combustion engines with the kind of intake which can be used on two cycle engines. The motion on valve blades is controlled by cam supplied control device which is kept in motion in phase with the engine.

Description

MECHANISM CONTROLLING INTAKE REED VALVES FOR TWO CYCLE ENGINE.
To be able to achieve a high power output from a two stroke engine it is essential to design the intake system for highest possible charging ratio of air admitted to the engine. A well working system which today is used on many high performance engines is a reed valve intake system. It consists of elastic membrane valves which have the function of non-return valves which open due to elasticity when the engine gives a certain negative pressure on the inlet side.
When after that, the admission period is completed and the fresh charge shall be scavenged into the combustion chamber, the pressure value in the inlet passage changes from negative to positive pressure, closing the membrane valve and obstructing the fresh charge from going backwards and out through the carburator.
For induction and scavenging of air in a two stroke engine the reciprocating movement of the piston is used as is well known. The aforementioned system allthough contains the following disadvantages:
* The resistibility against valve opening prevents optimal air charging especially within a range of low revolutions.
* If the valve is designed for low force opening gaining charge within a range of low revolutions, problems occur within the higher range of revolutions as the valves can't move fast enough due to low spring force.
Also the durability may be limited as low spring force normally means thin material. The present invention does not have the limitations of todays systems which are described above.
It permits charging without flow resistance caused by valve opening force in the lower as well as the higher range of revolutions. The systems also comprises a completely controlled timing of the opening and closing sequenses of the induction period. la DESCRIPTION
Fig.1-3:
The valveblades 1 are mounted on shafts 2 which are journalled in valve carrier 3. In one end of the shafts 2 lifterarms 4 and returnsprings 5 are situated.
Against the lifterarms 4 the camdisc 6 is operating. The camdisc 6 rotates with a predetermined number of revolutions in a fixed ratio to the crankshaft of the engine.
Depending on the shape of the camdisc and the positioning of the lifterarms a gear reduction of for example 1:2 may preferably be choosen for the camdisc. The valve carrier with valves is located in the intake passage.
The valvesystem can also be used in supercharged engines when placed in an inletpassage directly connected to inlet ports in the cylinder bore. By designing the camdisc or its transmitting system in a more complicated way the valve can be given a varying opening height and/or duration depending on the engine speed.
Assimilar systems are already in use on fourstroke engines and their valve timing control systems. A schematic view of such an example is shown in fig.7.
The camdisc is split in two halves which under influence of centrifugal force move apart from each other when the rotating speed increases. The spring element 21 counteracts this movement to a prefered degree. 2 AN APPLICATION SHOWING AFOREMENTIONED SYSTEM IS SHOWED IN FIG.4-6
Fig.4
Sideview of a motorcycleengine with the transmissioncover removed.
The valve carrier 3 with the inlet pipe 20 is shown separated from the inlet passage 17.
The crankshaft 7 with the gearwheel 8 transmitts torque to the primary shaft 9 of the gearbox on which the gearwheel 10 is mounted.
Firmly connected with the gearwheel 10 is the gear wheel 11 which, as one function, has to transmit torque to the crankshaft 7 with the help of gearwheel 12 and the intermediate gear 13 when starting the engine. A kickstarter then actuates the gear wheel 12.
The gearwheel 11 also controls the gearwheel 19 via the intermediate gearwheel 14.
The shaft 15 is firmly connected to the gearwheel 19 in one end and the camdisc 6 in the other end.
The shaft is journalled in the partition wall 16 between the engines transmissionhousing and one side of the inletpassage 17.
The shaft 15 rotates half the number of revolutions compared to the crankshaft because the wheels 8 and 10 have the gear ratio 1:3 and the wheels 11 and 19 have the gear ratio 3:2.
Fig.5
Sideview of a motorcycleengine with the sidecover over the crankshaftarea and inlet passage removed.
The cylinder is displayed vertically sectioned.
By the upward motion of the piston 18 the camdisc 6 actuates the lifterarms 4 bringing the valveblades 1 to an open state for the engines induction of air or airmixture.
The returnspringε 5 forces the lifterarms 4 against the camdisc 6, and hence the valveblades also closes the inlet in accordance with the shape of the camdisc in a timesequence when the admission period shall be completed.
Fig.6 Like fig.5 but for supercharged engine.
The design of the camdisc is adapted for valveopening at a suitable timeperiod for the engines charging. Inletpassage 22. Inletport 23.

Claims

4 PATENT CLAIMS FOR
1. Bladeshaped inletvalves 1, for a two-stroke internal combustion engine, installed on valvecarrier 3 inside inletpassage 17 characterized thereby that their opening is controlled by camsupplied device integrated with the engine.
2. System as set forth in claim 1 characterized thereby that the valveblades are mounted on shafts 2 journalled in the valvecarrier 3.
3. System as set forth in claim 2 characterized thereby that camsupplied controlling device 6 actuates lifterarms 4 mounted on shafts 2.
4. System as set forth in claim 1 or 3 characterized thereby that camsupplied controlling device is journalled in wall in inletpassage 17,22.
5. System as set forth in claim 4 characterized thereby that returnsprings 5 are utilized for closing of valveblades.
PCT/SE1992/000476 1991-07-01 1992-06-29 Mechanism controlling intake reed valves for two cycle engine WO1993001398A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9102025-5 1991-07-01
SE9102025A SE468402B (en) 1991-07-01 1991-07-01 LEAF SHAPED BUTTERFLY VALVES FOR TWO-TASK BURNING ENGINE

Publications (1)

Publication Number Publication Date
WO1993001398A1 true WO1993001398A1 (en) 1993-01-21

Family

ID=20383200

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/SE1992/000476 WO1993001398A1 (en) 1991-07-01 1992-06-29 Mechanism controlling intake reed valves for two cycle engine

Country Status (3)

Country Link
CA (1) CA2107570A1 (en)
SE (1) SE468402B (en)
WO (1) WO1993001398A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996034184A1 (en) * 1995-04-28 1996-10-31 Monika Paszkowska Thermodynamical aspiration valve

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4776305A (en) * 1986-05-20 1988-10-11 Honda Giken Kogyo Kabushiki Kaisha Exhaust timing control device for two-cycle engines
US4920932A (en) * 1985-05-24 1990-05-01 Orbital Engine Company Pty. Ltd. Relating to controlling emissions from two stroke engines
US5063888A (en) * 1989-08-14 1991-11-12 Yamaha Hatsudoki Kabushiki Kaisha Exhaust control valve system for parallel multi-cylinder two-cycle engine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4920932A (en) * 1985-05-24 1990-05-01 Orbital Engine Company Pty. Ltd. Relating to controlling emissions from two stroke engines
US4776305A (en) * 1986-05-20 1988-10-11 Honda Giken Kogyo Kabushiki Kaisha Exhaust timing control device for two-cycle engines
US5063888A (en) * 1989-08-14 1991-11-12 Yamaha Hatsudoki Kabushiki Kaisha Exhaust control valve system for parallel multi-cylinder two-cycle engine

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996034184A1 (en) * 1995-04-28 1996-10-31 Monika Paszkowska Thermodynamical aspiration valve
US5921208A (en) * 1995-04-28 1999-07-13 Paszkowska; Monika Thermodynamical aspiration valve

Also Published As

Publication number Publication date
SE9102025A (en) 1993-01-02
SE9102025D0 (en) 1991-07-01
SE468402B (en) 1993-01-11
CA2107570A1 (en) 1992-10-09

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