GB2403996A - Variable camshaft phase system - Google Patents

Variable camshaft phase system Download PDF

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Publication number
GB2403996A
GB2403996A GB0316729A GB0316729A GB2403996A GB 2403996 A GB2403996 A GB 2403996A GB 0316729 A GB0316729 A GB 0316729A GB 0316729 A GB0316729 A GB 0316729A GB 2403996 A GB2403996 A GB 2403996A
Authority
GB
United Kingdom
Prior art keywords
camshaft
chain
crankshaft
phase
phase system
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Withdrawn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
GB0316729A
Other versions
GB0316729D0 (en
Inventor
David Hostettler Wain
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 GB0316729A priority Critical patent/GB2403996A/en
Publication of GB0316729D0 publication Critical patent/GB0316729D0/en
Publication of GB2403996A publication Critical patent/GB2403996A/en
Withdrawn legal-status Critical Current

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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
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/02—Valve drive
    • F01L1/022—Chain drive
    • 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
    • F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
    • F01L1/344—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
    • F01L1/348—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear by means acting on timing belts or chains
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H7/00—Gearings for conveying rotary motion by endless flexible members
    • F16H7/08—Means for varying tension of belts, ropes, or chains

Abstract

A variable camshaft phase system consists of a method of varying the phase of the camshaft(s) and hence the valves relative to the crankshaft in an internal combustion engine. For example, a variable camshaft phase system comprises a camshaft (in this case working both inlet and outlet valves) linked to the crankshaft via a cam chain. The phase of the camshaft relative to the crankshaft may be changed using a control cog, pressed against one side of the chain. Any slack in the chain is then taken up by a tensioning cog on the other side of the chain.

Description

VARIABLE CAMSHAFT PHASE SYSTEM
This invention relates to a variable camshaft phase system.
A conventional internal combustion engine comprises one or more pistons which convert linear motion into rotational motion via a crankshaft. The linear motion of the pistons is powered by the introduction of fuel air mixture into the cylinders, which when ignited convert chemical energy into linear motion of the piston.
The fuel air mixture is sucked into the cylinder through one or more inlet valves as the piston moves downwards. The fuel air mixture is then compressed as the piston moves upwards. It is then ignited and the resulting combustion pushes the piston downwards again. The burnt mixture is finally pushed out of the cylinder through one or more outlet valves when the piston moves upwards.
The inlet and outlet valves open and close in a synchonised fashion with the crankshaft. This is normally achieved using one or two camshafts. These are shafts that rotate at half the rate of the crankshaft. They are normally connected to the crankshaft using cogs and a chain or belt. These camshafts are cylindrically asymmetrical and open the valves by pushing against the them, once every two revolutions. The camshaft profile determines when and for how long the valves open.
It was noted in the mid 1980's that if the phase of the camshaft is changed relative to the crankshaft, the amount of torque at low revs could be increased. Unfortunately, this also led to reduced power at high revs. This was probably due to the resonances within the inlet manifold and exhaust system.
According to the present invention there is provided a variable camshaft phase system comprising an internal combustion engine such that the phase of the camshaft(s) may be changed relative to the crankshaft, thus varying the valve phase.
A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows, in perspective, a variable camshaft phase system comprising a chain linking the camshaft to the crankshaft. A control cog, whose position may be varied, is pressed against the chain in order to vary the amount of cam chain between the LHS of the camshaft and crankshaft. The slack in the chain is compensated for by a tensioning cog on the RHS.
Referring to the drawing, the variable camshaft valve system comprises a control cog, pressed against the cam chain, used in conjunction with a tensioning cog, that may be used to vary the amount of chain between the camshaft and the crankshaft.
As the position of the control cog is varied, the phase of the camshaft is changed relative to the crankshaft. This varies the phase of the valves, allowing greater torque at low revs, whilst allowing higher power at high revs.

Claims (4)

1. A variable camshaft phase system comprising a means to vary the phase of the camshaft(s) relative to the crankshaft, thus varying the phase of the valves.
2. A variable camshaft phase system as claimed in Claim 1 whereby the valves are opened by camshaft(s) that are linked to the crankshaft via a cam chain which is used to vary the phase of the crankshafts.
3. A variable camshaft phase system as claimed in Claim 1 and 2 whereby a control cog, whose position may be varied, is pressed against one part of the cam chain such that the amount of chain on one side is varied.
4. A variable camshaft phase system as claimed in Claim 1, 2 and 3 whereby a tensioner cog is used to take up the slack on the other side of the cam chain.
GB0316729A 2003-07-17 2003-07-17 Variable camshaft phase system Withdrawn GB2403996A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB0316729A GB2403996A (en) 2003-07-17 2003-07-17 Variable camshaft phase system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0316729A GB2403996A (en) 2003-07-17 2003-07-17 Variable camshaft phase system

Publications (2)

Publication Number Publication Date
GB0316729D0 GB0316729D0 (en) 2003-08-20
GB2403996A true GB2403996A (en) 2005-01-19

Family

ID=27763984

Family Applications (1)

Application Number Title Priority Date Filing Date
GB0316729A Withdrawn GB2403996A (en) 2003-07-17 2003-07-17 Variable camshaft phase system

Country Status (1)

Country Link
GB (1) GB2403996A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2437151A (en) * 2006-04-07 2007-10-17 Paul Brian Chatten Mechanism for varying the relative phase angle of pulleys or sprockets connected by a chain or toothed belt

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1024846A (en) * 1962-12-27 1966-04-06 Federico Fornelli Improvements in or relating to valve timing devices
US3441009A (en) * 1966-10-20 1969-04-29 Renzo Rafanelli Device for the automatic regulation of the timing of the inlet and exhaust valves of a four-cycle internal combustion engine
US4862845A (en) * 1988-05-10 1989-09-05 Borg-Warner Transmission And Engine Components Corporation Variable camshaft timing system
US5606941A (en) * 1994-08-17 1997-03-04 Dr.Ing. H.C.F. Porsche Ag Variable timing camshaft drive system
DE19804943A1 (en) * 1998-02-07 1999-08-12 Bosch Gmbh Robert IC engine, especially four stroke engine
GB2339257A (en) * 1998-07-09 2000-01-19 Perkins Engines Co Ltd Variable phase rotary drive apparatus.
US6155218A (en) * 1999-03-22 2000-12-05 The United States Of America As Represented By The Secretary Of The Army Cam advancing and retarding mechanism
US6467446B2 (en) * 1999-12-30 2002-10-22 Hyundai Motor Company Variable valve timing system for vehicle

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1024846A (en) * 1962-12-27 1966-04-06 Federico Fornelli Improvements in or relating to valve timing devices
US3441009A (en) * 1966-10-20 1969-04-29 Renzo Rafanelli Device for the automatic regulation of the timing of the inlet and exhaust valves of a four-cycle internal combustion engine
US4862845A (en) * 1988-05-10 1989-09-05 Borg-Warner Transmission And Engine Components Corporation Variable camshaft timing system
US5606941A (en) * 1994-08-17 1997-03-04 Dr.Ing. H.C.F. Porsche Ag Variable timing camshaft drive system
DE19804943A1 (en) * 1998-02-07 1999-08-12 Bosch Gmbh Robert IC engine, especially four stroke engine
GB2339257A (en) * 1998-07-09 2000-01-19 Perkins Engines Co Ltd Variable phase rotary drive apparatus.
US6155218A (en) * 1999-03-22 2000-12-05 The United States Of America As Represented By The Secretary Of The Army Cam advancing and retarding mechanism
US6220211B1 (en) * 1999-03-22 2001-04-24 The United States Of America As Represented By The Secretary Of The Army Cam advancing and retarding mechanism
US6467446B2 (en) * 1999-12-30 2002-10-22 Hyundai Motor Company Variable valve timing system for vehicle

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2437151A (en) * 2006-04-07 2007-10-17 Paul Brian Chatten Mechanism for varying the relative phase angle of pulleys or sprockets connected by a chain or toothed belt
GB2437151B (en) * 2006-04-07 2011-04-06 Paul Brian Chatten Mechanism for varying the phase angle of pulleys or sprockets when connected by a continuous toothed belt or chain to provide discreet valve timing

Also Published As

Publication number Publication date
GB0316729D0 (en) 2003-08-20

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Legal Events

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