GB2402708A - Selectable two-stroke/four-stroke lost-motion valve actuation system for i.c. engines - Google Patents

Selectable two-stroke/four-stroke lost-motion valve actuation system for i.c. engines Download PDF

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Publication number
GB2402708A
GB2402708A GB0314906A GB0314906A GB2402708A GB 2402708 A GB2402708 A GB 2402708A GB 0314906 A GB0314906 A GB 0314906A GB 0314906 A GB0314906 A GB 0314906A GB 2402708 A GB2402708 A GB 2402708A
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United Kingdom
Prior art keywords
engine
stroke
lost
valve
motion
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Granted
Application number
GB0314906A
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GB0314906D0 (en
GB2402708B (en
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Thomas Tsoi Hei Ma
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Individual
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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
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • F01L13/0005—Deactivating valves
    • 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
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/02—Valve drive
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • F01L1/08—Shape of cams
    • 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
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/20—Adjusting or compensating clearance
    • F01L1/22—Adjusting or compensating clearance automatically, e.g. mechanically
    • F01L1/24—Adjusting or compensating clearance automatically, e.g. mechanically by fluid means, e.g. hydraulically
    • 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
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/20—Adjusting or compensating clearance
    • F01L1/22—Adjusting or compensating clearance automatically, e.g. mechanically
    • F01L1/24—Adjusting or compensating clearance automatically, e.g. mechanically by fluid means, e.g. hydraulically
    • F01L1/2405—Adjusting or compensating clearance automatically, e.g. mechanically by fluid means, e.g. hydraulically by means of a hydraulic adjusting device located between the cylinder head and rocker arm
    • 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
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/36—Valve-gear or valve arrangements, e.g. lift-valve gear peculiar to machines or engines of specific type other than four-stroke cycle
    • F01L1/38—Valve-gear or valve arrangements, e.g. lift-valve gear peculiar to machines or engines of specific type other than four-stroke cycle for engines with other than four-stroke cycle, e.g. with two-stroke cycle
    • 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
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • 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
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • F01L13/0015—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
    • F01L9/02—
    • 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
    • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
    • F01L9/10—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic
    • 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
    • F02B69/00—Internal-combustion engines convertible into other combustion-engine type, not provided for in F02B11/00; Internal-combustion engines of different types characterised by constructions facilitating use of same main engine-parts in different types
    • F02B69/06—Internal-combustion engines convertible into other combustion-engine type, not provided for in F02B11/00; Internal-combustion engines of different types characterised by constructions facilitating use of same main engine-parts in different types for different cycles, e.g. convertible from two-stroke to four stroke
    • 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
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/14—Tappets; Push rods
    • F01L1/16—Silencing impact; Reducing wear
    • 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
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/12—Transmitting gear between valve drive and valve
    • F01L1/18—Rocking arms or levers
    • F01L1/185—Overhead end-pivot rocking arms
    • 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
    • F01L2301/00—Using particular materials
    • 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
    • F01L2820/00—Details on specific features characterising valve gear arrangements
    • F01L2820/03—Auxiliary actuators
    • F01L2820/031—Electromagnets

Abstract

The intake and exhaust poppet valves are opened/ closed by respective camshafts via hydraulic elements transmitting the actuating force from the cams to the associated valves. Each camshaft is driven at engine speed and each cam has an actuating profile of duration at least the same in numerical value as the intended valve opening duration for the engine in four-stroke mode. The lost-motion system comprises a hydraulic tappet 22 in a cylinder 24 and a fast-acting solenoid valve 30 for opening and closing an oil release path from the cylinder 24 to a reservoir 26. In four-stroke mode the lost-motion is controlled to deactivate one cam event in every two revolutions of the camshaft while in two-stroke mode the lost-motion is controlled to permit activation of every cam event on the camshaft and at the same time modify the duration of each cam event to produce a shorter valve opening duration. An electromagnetic percussion hammer unit 50, having coils 48, armature 46 and hammer 44 with resilient striking pad 42, is provided to impart a shock pulse of pressure to the tappet 22 to arrest the closing velocity of the valve 12 as it approaches its seat.

Description

SELECTABLE 2-STROKE/4-STROKE VALVE ACTUATION SYSTEM
Field of the invention
The present invention relates to a valve actuation system for operating an internal combustion engine according to the two-stroke cycle or the four-stroke cycle.
Background of the invention
Conventional internal combustion engines operate according to thermodynamic principles following either the two-stroke cycle or the four-stroke cycle and are commonly classified as two-stroke engines or four-stroke engines respectively. Both type of engines can operate using a range of fuels including gasoline, diesel, alcohol and gaseous fuels; the fuel can be introduced into the engine by a range of devices including carburettors and fuel injectors into the air intake system and fuel injectors aimed directly into the engine cylinder; and the fuel-air mixture can be ignited by a range of methods including spark ignition and compression ignition. Each engine cycle type has different merits and shortcomings making it a subject of continuous debate as to which is more suitable for automotive application taking into account various parameters such as power density, fuel consumption, exhaust emissions, noise, vibration, engine size, weight and cost etc. Currently, the Motive manufacturer moist first decide on the engine cycle type, then design the engine accordingly.
Summary of the invention
With a view of combining the merits of both engine cycle types, there is provided a method of operating a hydraulic lost-motion valve actuation system for a selectable two-stroke/four-stroke internal combustion engine with intake and exhaust poppet valves opened and closed by - 2 respective camshaft via hydraulic elements transmitting directly or indirectly the actuating force from the cams on the camshaft to the associated engine valves, the valve actuation system being characterized in that each camshaft is driven at engine speed, each cam has an actuating profile of duration in cam angle degrees at least the same in numerical value as the intended valve opening duration in crank angle degrees for the engine in 4-stroke mode, and each hydraulic element has a solenoid-controlled oil release lo path for causing lost-motion in the valve actuation system, wherein the method of operating the lost-motion valve actuation system is such that when the engine is operating in 4stroke mode, the lost-motion is controlled to deactivate one cam event in every two revolutions of the camshaft, and when the engine is operating in 2-stroke mode, the lost-motion is controlled to permit activation of every cam event on the camshaft and at the same time modify the duration of each cam event to produce a shorter valve opening duration intended for the engine in 2-stroke mode.
Additionally, each cam has an actuating profile of height corresponding to a valve lift substantially higher than the intended valve lift for the engine in 4-stroke mode. In this case, the method of operating the lostmotion valve actuation system is such that when the engine is operating in 4-stroke mode, the lost-motion is controlled to deactivate one cam event in every two revolutions of the camshaft and at the same time modify the lift of the remaining working cam event to produce a smaller valve lift intended for the engine in 4-stroke mode, and when the engine is operating in 2-stroke mode, the lost-motion is controlled to permit activation of every cam event on the camshaft and at the same time modify the lift of each cam event to produce a smaller valve lift intended for the engine in 2-stroke mode. - 3 -
In the invention, the excess margin of lift on the cam allows the actual valve lift to be trimmed down using lost- motion control and still attain the desired lift intended for the engine even when the duration is reduced. In this way, the valve opening event selected in 4-stroke mode occurs once every two revolutions of the engine crankshaft and the duration and lift of the valve are variable and capable of attaining the intended maximum duration and maximum lift for the engine in 4-stroke mode. Similarly, lo the valve opening event selected in 2-stroke mode occurs once every revolution of the engine crankshaft and the duration and lift of the valve are variable and capable of reducing to substantially half of the crank angle period of the 4-stroke valve event while still attaining the intended i5 maximum lift for the engine in 2-stroke mode.
The required cam profile of the invention can be manufactured quite easily because the long period of the cam will automatically allow a high lift on a relatively small base circle diameter of the cam without introducing concavity on the cam.
In all the operating modes, the energy for actuating the valves is provided by the camshaft, while the control of the valve opening event in frequency, duration and lift to suit either the 4-stroke or 2-stroke cycle is provided by the solenoid-controlled lost-motion valve actuation system.
Preferably, a recuperative hydraulic circuit is JO provided comprising a reservoir, piston and spring for storing hydraulic energy during the lostmotion and releasing hydraulic energy by assisting the return of oil rapidly to the hydraulic element as soon as the lost-motion operation is completed.
Also preferably, a percussion hammer is provided for striking the piston in the recuperative hydraulic circuit - 4 - and imparting a shock pulse of hydraulic pressure at a predetermined time and rate in order to arrest the closing velocity of the valve as the valve approaches its seat.
Finally, a variable cam phasing system or a cam phase switching system is provided for changing the phase of the engine intake and exhaust valve events appropriately relative to the engine crankshaft rotation to suit either 4-stroke or 2-stroke mode.
Brief description of the drawing
The invention will now be described further, by way of example, with reference to the accompanying drawings in which: Figure 1 shows a schematic view of a lost-motion valve actuation system actuated by a long period high lift cam according to the present invention, Figure 2 and 3 are the valve opening events produced by the said valve actuation system for 4 stroke mode and 2-stroke mode respectively.
Detailed description of the preferred embodiment
Figure 1 shows a schematic view of a lost-motion valve actuation system for a selectable two-stroke/four-stroke internal combustion engine. The system has a camshaft with cam 10 driven at engine speed for actuating an engine valve 12 via a finger follower 14. The return spring for closing the valve 12 has not been shown merely for expediency. The cam 10 has a profile corresponding to an opening duration of approximately 240 in cam angle. This cam opening duration is twice as long as that of a typical standard cam for a 4- stroke engine and is at least the same in numerical value as the intended valve opening duration in crank angle degrees for the engine in 4-stroke mode. Because the cam 10 is driven at engine speed, i.e. at twice the speed of the - 5 - standard cam, its opening duration is actually exactly correct for the 4- stroke engine producing a valve opening period of approximately 240 in crank angle. On the other hand, there are two such events in four engine strokes and one of them is surplus to requirement if the engine were to operate as a 4-stroke engine.
Figure 1 also shows a lost-motion control system comprising a housing 20, a hydraulic tappet 22 supporting 0 the finger follower 14 and is moveable within a hydraulic cylinder 24, a fast-acting solenoid controlled valve 30 for opening and closing an oil release path from the cylinder 24 to a reservoir 26 confined by a moveable piston 28 and spring 34. When the control valve 30 is shut, the cylinder 24 is sealed and the incompressibility of the oil makes the tappet 22 immoveable thus acting to transmit the cam actuating force from the finger follower 14 to the engine valve 12. When the control valve 30 is open, oil can escape past the valve 30 to the reservoir 26 allowing the tappet 22 to give way when an actuating force is applied on the finger follower 14 and resulting in lost-motion for the engine valve 12 depending on how long the control valve 30 is open.
As soon as the lost-motion operation is complete, oil can return to the cylinder 24 via the control valve 30 assisted by the spring 34 and the piston 28 pushing the oil back into the cylinder 24. A non-return valve 32 provides top-up oil to compensate for oil loss due to leakage.
An electro-magnetically percussion hammer unit 50 comprising electric coils 48, armature plate 46 connected to hammer 44 with resilient striking pad 42, is provided for striking the piston 40, 28 and imparting a shock pulse of hydraulic pressure transmitted to the hydraulic tappet 22 at a predetermined time and rate in order to arrest the closing velocity of the valve 12 as the valve approaches its seat. - 6
In Figure 2 which shows the engine valve events during two engine revolutions for the engine operating in 4-stroke mode, one of the two cam events 10 occurring during the two engine revolutions that is surplus to requirement for the 4- - stroke cycle is completely deactivated using the lost-motion e system, represented by the completely shaded profile. This is repeated through consecutive cycles in which alternate events are deactivated thus enabling the engine to run - continuously in 4-stroke mode. In addition, the working - 0 event that is not deactivated may be modified using the lost-motion system, represented by the shaded portion of the profile, to produce the unshaded valve opening profile 10a which could be the optimised intended profile for the engine in 4-stroke mode.
In Figure 3 which shows the engine valve events during c two engine revolution for the engine operating in 2-stroke a mode, both cam events 10 during the two engine revolutions A are required for the 2-stroke cycle at one event per revolution, hence they should always be activated. On the other hand, the cam event 10 is too long for optimum two stroke operation and the lost-motion control is therefore used, represented by the shaded portion of the profile, to produce the unshaded valve opening profile 10b where the 2s event duration is reduced to substantially half of that of I the 4- stroke valve event while still attaining a substantial lift which could be the optimised intended lift for the engine in 2-stroke mode.
In Figures 2 and 3, the opening and closing ramps for the engine valve events have been omitted merely for simplicity. In actual operation, the opening ramp will follow the leading profile of the cam 10 in Figure 1, while the closing ramp at the end of the lost-motion (which no: 3s longer follows the cam 10) may be provided by the percussion hammer unit 50 which imparts a shock pulse of hydraulic pressure at the appropriate time and sufficient rate in - 7 - order to arrest the closing velocity of the valve 12 as the valve approaches its seat.
In all the operating modes, the energy for actuating the engine valve 12 is provided by the cam 10, while the control of the valve opening event in frequency, duration and lift to suit either the 4-stroke or 2-stroke cycle is provided by the solenoid-controlled lost-motion valve actuation system 22, 24, 30, 26, 28.
In the invention, the required cam profile 10 can be manufactured quite easily because the long period of the cam will automatically allow a high lift on a relatively small base circle diameter of the cam without introducing concavity on the cam. This provides an excess margin of lift on the cam 10 and allows the actual valve lift to be trimmed down using lost-motion control and still attain the desired optimised lift intended for the engine even when the duration is reduced.
In Figure 1, although the valve actuation is shown using a cam and finger follower 10 and 14, other cam and follower systems are equally applicable in the present invention such as rocker follower, direct bucket and push rod.
Finally, a variable cam phasing system or a cam phase switching system is provided (not shown) for changing the phase of the engine intake and exhaust valve events appropriately relative to the engine crankshaft rotation to suit either 4-stroke or 2-stroke mode. - 8 -

Claims (5)

1. A method of operating a hydraulic lost-motion valve actuation system for a selectable two-stroke/four stroke internal combustion engine with intake and exhaust poppet valves opened and closed by respective camshaft via hydraulic elements transmitting directly or indirectly the actuating force from the cams on the camshaft to the associated engine valves, the valve actuation system being lo characterized in that each camshaft is driven at crankshaft speed, each cam has an actuating profile of duration in cam angle degrees at least the same in numerical value as the intended valve opening duration in crank angle degrees for the engine in 4-stroke mode, and each hydraulic element has a solenoid-controlled oil release path for causing lost- motion in the valve actuation system, wherein the method of operating the lost-motion valve actuation system is such that when the engine is operating in 4-stroke mode, the lost-motion is controlled to deactivate one cam event in every two revolutions of the camshaft, and when the engine is operating in 2-stroke mode, the lost-motion is controlled to permit activation of every cam event on the camshaft and at the same time modify the duration of each cam event to produce a shorter valve opening duration intended for the engine in 2-stroke mode.
2. A method of operating a hydraulic lost-motion valve actuation system for a selectable two-stroke/folr- stroke internal combustion engine as claimed in claim 1, wherein each cam has an actuating profile of height corresponding to a valve lift substantially higher than the intended valve lift for the engine in 4- stroke mode, and wherein the method of operating the lost-motion valve actuation system is such that when the engine is operating in 4-stroke mode, the lost-motion is controlled to deactivate one cam event in every two revolutions of the camshaft and at the same time modify the lift of the - 9 - remaining working cam event to produce a smaller valve lift intended for the engine in 4-stroke mode, and when the engine is operating in 2-stroke mode, the lost-motion is controlled to permit activation of every cam event on the camshaft and at the same time modify the lift of each cam event to produce a smaller valve lift intended for the engine in 2-stroke mode.
3. A method of operating a hydraulic lost-motion lo valve actuation system for a selectable two-stroke/four- stroke internal combustion engine as claimed in claim 1 and 2, wherein the valve opening event selected in 4-stroke mode is controlled by lost-motion such that it occurs once every two revolutions of the engine crankshaft and the duration and lift of the valve are variable and capable of attaining the intended maximum duration and maximum lift for the engine in 4-stroke mode, and wherein the valve opening event selected in 2-stroke mode is controlled by lost-motion such that it occurs once every revolution of the engine crankshaft and the duration and lift of the valve are variable and capable of reducing to substantially half of the crank angle period of the 4-stroke valve event while still attaining the intended maximum lift for the engine in 2-stroke mode.
4. A method of operating a hydraulic lost-motion valve actuation system for a selectable two-stroke/four- stroke internal combustion engine as claimed in any preceding claim, wherein a variable cam phasing system or a cam phase switching system is provided for changing the phase of the engine intake and exhaust valve events appropriately relative to the engine crankshaft rotation to suit either 4-stroke or 2-stroke mode.
5. A hydraulic lost-motion valve actuation system having a recuperative hydraulic circuit comprising a reservoir, piston and spring for storing hydraulic energy # - 10 during the lost-motion and releasing hydraulic energy after the lost-motion, wherein a percussion hammer is provided for striking the said piston and imparting a shock pulse of hydraulic pressure at a predetermined time and rate in order to arrest the closing velocity of the valve as the valve approaches its seat.
GB0314906A 2003-06-11 2003-06-26 Selectable 2-stroke/4-stroke valve actuation system Expired - Fee Related GB2402708B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GBGB0313435.0A GB0313435D0 (en) 2003-06-11 2003-06-11 Selectable 2-stroke/4-stroke valve actuation system

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GB0314906D0 GB0314906D0 (en) 2003-07-30
GB2402708A true GB2402708A (en) 2004-12-15
GB2402708B GB2402708B (en) 2006-04-26

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GB0314906A Expired - Fee Related GB2402708B (en) 2003-06-11 2003-06-26 Selectable 2-stroke/4-stroke valve actuation system

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006011981A1 (en) * 2006-03-16 2007-09-20 Schaeffler Kg Gas exchanging valves controlling device for reciprocating internal-combustion engine, has cam stroke reducing unit variably reducing stroke of set of cams, and hydrostatic transmission unit varying volume in hydraulic pressure chamber
GB2443690A (en) * 2006-11-09 2008-05-14 Anthony Edgar Blackburn Retractable cam system for an 8-stroke and 4-stroke cycle change engine
GB2470025A (en) * 2009-05-06 2010-11-10 Thomas Tsoi Hei Ma Switchable valve actuation system for a selectable 2-stroke/ 4-stroke i.c engine
EP2299069A1 (en) * 2009-09-02 2011-03-23 Delphi Technologies, Inc. Compact switchable hydraulic lash adjuster with hydraulic lost motion assist
CN101743384B (en) * 2007-06-01 2012-09-05 雅各布斯车辆系统公司 Variabale valve actuation system
CN106968751A (en) * 2015-12-24 2017-07-21 C.R.F.阿西安尼顾问公司 System for the variable actuation of the valve of explosive motor
WO2017213566A1 (en) * 2016-06-07 2017-12-14 Scania Cv Ab Four stroke internal combustion engine and thereto-related method
WO2018182491A1 (en) 2017-03-31 2018-10-04 Scania Cv Ab Four-stroke internal combustion engine thereto related vehicle and method
GB2608166A (en) * 2021-06-24 2022-12-28 Mechadyne Int Ltd Cam switching mechanism

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Publication number Priority date Publication date Assignee Title
US5404851A (en) * 1992-08-22 1995-04-11 Man Nutzfahrzeuge Aktiengesellschaft Device for switching a combustion engine from one mode of operation to another mode of operation
US6244257B1 (en) * 1995-08-08 2001-06-12 Diesel Engine Retarders, Inc. Internal combustion engine with combined cam and electro-hydraulic engine valve control
US6257176B1 (en) * 1998-12-08 2001-07-10 Honda Giken Kogyo Kabushiki Kaisha Variable cycle internal combustion engine and controller thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5404851A (en) * 1992-08-22 1995-04-11 Man Nutzfahrzeuge Aktiengesellschaft Device for switching a combustion engine from one mode of operation to another mode of operation
US6244257B1 (en) * 1995-08-08 2001-06-12 Diesel Engine Retarders, Inc. Internal combustion engine with combined cam and electro-hydraulic engine valve control
US6257176B1 (en) * 1998-12-08 2001-07-10 Honda Giken Kogyo Kabushiki Kaisha Variable cycle internal combustion engine and controller thereof

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006011981A1 (en) * 2006-03-16 2007-09-20 Schaeffler Kg Gas exchanging valves controlling device for reciprocating internal-combustion engine, has cam stroke reducing unit variably reducing stroke of set of cams, and hydrostatic transmission unit varying volume in hydraulic pressure chamber
GB2443690A (en) * 2006-11-09 2008-05-14 Anthony Edgar Blackburn Retractable cam system for an 8-stroke and 4-stroke cycle change engine
GB2443690B (en) * 2006-11-09 2011-10-12 Anthony Edgar Blackburn Retractable cam
CN101743384B (en) * 2007-06-01 2012-09-05 雅各布斯车辆系统公司 Variabale valve actuation system
GB2470025A (en) * 2009-05-06 2010-11-10 Thomas Tsoi Hei Ma Switchable valve actuation system for a selectable 2-stroke/ 4-stroke i.c engine
EP2299069A1 (en) * 2009-09-02 2011-03-23 Delphi Technologies, Inc. Compact switchable hydraulic lash adjuster with hydraulic lost motion assist
CN106968751A (en) * 2015-12-24 2017-07-21 C.R.F.阿西安尼顾问公司 System for the variable actuation of the valve of explosive motor
CN106968751B (en) * 2015-12-24 2019-08-13 C.R.F.阿西安尼顾问公司 The system of the variable actuation of valve for internal combustion engine
CN109312643A (en) * 2016-06-07 2019-02-05 斯堪尼亚商用车有限公司 Quartastroke engine and its correlation technique
US20190153906A1 (en) * 2016-06-07 2019-05-23 Scania Cv Ab Four stroke internal combustion engine and thereto-related method
WO2017213566A1 (en) * 2016-06-07 2017-12-14 Scania Cv Ab Four stroke internal combustion engine and thereto-related method
WO2018182492A1 (en) * 2017-03-31 2018-10-04 Scania Cv Ab Four-stroke internal combustion engine thereto related vehicle and method
WO2018182491A1 (en) 2017-03-31 2018-10-04 Scania Cv Ab Four-stroke internal combustion engine thereto related vehicle and method
CN110431287A (en) * 2017-03-31 2019-11-08 斯堪尼亚商用车有限公司 Vehicle relevant to quartastroke engine and method
CN110573700A (en) * 2017-03-31 2019-12-13 斯堪尼亚商用车有限公司 Vehicle and method relating to a four-stroke internal combustion engine
US10837324B2 (en) 2017-03-31 2020-11-17 Scania Cv Ab Four-stroke internal combustion engine thereto related vehicle and method
US10837323B2 (en) 2017-03-31 2020-11-17 Scania Cv Ab Four-stroke internal combustion engine thereto related vehicle and method
EP3601750A4 (en) * 2017-03-31 2020-12-30 Scania CV AB Four-stroke internal combustion engine thereto related vehicle and method
EP3601749A4 (en) * 2017-03-31 2021-02-24 Scania CV AB Four-stroke internal combustion engine thereto related vehicle and method
GB2608166A (en) * 2021-06-24 2022-12-28 Mechadyne Int Ltd Cam switching mechanism

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GB0313435D0 (en) 2003-07-16
GB2402708B (en) 2006-04-26

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