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WO2008030589B1 - Desmodromic valve system including single cam surface for closing and opening the valve - Google Patents

Desmodromic valve system including single cam surface for closing and opening the valve

Info

Publication number
WO2008030589B1
WO2008030589B1 PCT/US2007/019593 US2007019593W WO2008030589B1 WO 2008030589 B1 WO2008030589 B1 WO 2008030589B1 US 2007019593 W US2007019593 W US 2007019593W WO 2008030589 B1 WO2008030589 B1 WO 2008030589B1
Authority
WO
WIPO (PCT)
Prior art keywords
valve
cam
rocker
desmodromic
opening
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.)
Ceased
Application number
PCT/US2007/019593
Other languages
French (fr)
Other versions
WO2008030589A2 (en
WO2008030589A3 (en
Inventor
Jr Julian A Decuir
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
Publication of WO2008030589A2 publication Critical patent/WO2008030589A2/en
Publication of WO2008030589A3 publication Critical patent/WO2008030589A3/en
Publication of WO2008030589B1 publication Critical patent/WO2008030589B1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

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
    • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
    • F01L1/042—Cam discs
    • 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
    • F01L1/047—Camshafts
    • F01L1/053—Camshafts overhead type
    • 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
    • F01L1/12—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
    • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
    • F01L1/30—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of positively opened and closed valves, i.e. desmodromic 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
    • 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
    • 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
    • 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
    • F01L13/0063—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 by modification of cam contact point by displacing an intermediate lever or wedge-shaped intermediate element, e.g. Tourtelot
    • 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
    • F01L2800/00—Methods of operation using a variable valve timing mechanism
    • F01L2800/06—Timing or lift different for valves of same cylinder

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Abstract

A desmodromic valve and cam system is provided. The system may comprise a cam lobe mounted to a cam shaft and defining an effective cam surface. The system may also comprise a rocker mounted to a valve wherein the rocker pivots up and down in response to an input of the cam lobe to close and open the valve. More particularly, the effective cam surface of the cam lobe pushes up on the rocker follower surface to close the valve and pushes down on the rocker follower surface to open the valve.

Claims

22AMENDED CLAIMS received by the International Bureau on 25 April 2008(25.04.2008)
1. (Amended) A desmodromic valve and cam system for an internal combustion engine comprising an engine block and at least one head which utilizes at least one intake and one exhaust valve per cylinder, the system comprising: a main camshaft assembly adapted to be received within a plurality of journals disposed internally within the engine block, the camshaft assembly including one cam lobe for each intake valve and exhaust valve, the cam lobe having an effective cam surface facing radially outward wherein the effective cam surface has a circular configuration; a rocker pivotable about a rocker pivot axis, the rocker having a valve movement end adapted to be mechanically linked to a valve head such that the rocker can either push down or pull up the valve head as the rocker is respectively pivoted down or up about the rocker pivot axis to respectively open or close the valve, the rocker having closing and opening follower surfaces which are arranged and configured to radially face inward to a central portion of the rocker, the closing and opening follower surfaces being representative of desired valve performance characteristics, wherein the rocker is pivoted upward when the effective cam surface of the cam contacts the closing follower surface and pivoted downward when the effective cam surface of the cam contacts the opening follower surface; wherein the cam lobes rotate such that the effective cam surface reciprocally contacts the closing follower surface and the opening follower surface to respectively close and open the valve without the need to use valve springs to close the valves.
2. The desmodromic valve and cam system of Claim 1 wherein the closing and opening follower surfaces have an oblong circular configuration.
3. (Amended) The desmodromic valve and cam system of Claim 1 wherein the cam surface of the cam lobe has a circular configuration.
4. The desmodromic valve and cam system of Claim 1 wherein the cam lobe defines an effective cam surface which is about one half of the outer periphery of the cam lobe.
5. The desmodromic valve and cam system of Claim 1 wherein a rotating axis of the cam lobe is offset with a center of the cam lobe.
6. The desmodromic valve and cam system of Claim 1 wherein the rocker comprises a first part and a second part which is removeably securable to each other to form the rocker.
7. The desmodromic valve and cam system of Claim 1 wherein the closing and opening follower surfaces define a box shaped configuration.
8. The desmodromic valve and cam system of Claim 1 wherein the rocker has a groove and the cam lobe has a mating protrusion for aligning the cam lobe to the rocker as the cam lobe rotates.
9. The desmodromic valve and cam system of Claim 8 wherein a groove depth varies about a periphery of the rocker to control an amount of time that the valve stays closed, stays opened or both.
10. The desmodromic valve and cam system of Claim 9 wherein a height of the protrusion varies about a periphery of the cam lobe to control the amount of time that the valve stays closed, stays opened, or both.
11. (Amended) A desmodromic valve and cam system for an internal combustion engine comprising an engine block and at least one head which utilizes at least one intake and one exhaust valve per cylinder, the system comprising: a main camshaft assembly adapted to be received within a plurality of journals disposed internally within the engine block, the camshaft assembly including one cam lobe for each intake valve and exhaust valve, each cam lobe having an effective cam surface facing radially outward wherein the effective cam surface has a circular configuration; a rocker pivotable about a rocker pivot axis, the rocker having a valve movement end adapted to be mechanically linked to a valve head such that the rocker can either push down or pull up the valve head as the rocker is respectively pivoted down or up about the rocker pivot axis to respectively open or close the valve, the rocker having a central aperture, the central aperture defining a travel path; a slider sized and configured to slid up and down along the travel path within the central aperture of the rocker, the slider having opening and closing follower surfaces wherein the opening and closing follower surfaces collectively have a circular configuration that matches the circular configuration of the effective cam surface so as to mate with the effective cam 24
surface of the cam lob, the opening and closing follower surfaces being arranged to face radially inward; wherein the cam lobes rotate such that the effective cam surface reciprocally contacts the closing follower surface and the opening follower surface to respectively close and open the valve without the need to use valve springs to close the valves, and an angle of the travel path is representative of desired valve performance characteristics.
12. The desmodromic valve and cam system of Claim 11 wherein a position of the rocker pivot axis in a horizontal direction and vertical direction is representative of desired valve performance characteristics.
13. The desmodromic valve and cam system of Claim 11 further comprising a spring disposed between the rocker and slider to bias the slider to one side of the rocker.
14. The desmodromic valve and cam system of Claim 13 wherein a spring force exerted on the slider by the spring is representative of desired valve performance characteristics.
15. The desmodromic valve and cam system of Claim 11 wherein the opening and closing follower surfaces form a circular configuration.
16. (Amended) A desmodromic valve and cam system retrofit kit for an engine, the kit comprising: at least one cam lobe attachable to a stock cam shaft of the engine, the cam lobe defining an effective cam surface facing radially outward wherein the effective cam surface has a circular configuration; a corresponding rocker defining opening and closing follower surfaces facing radially inward, the opening and closing follower surfaces being representative of desired valve performance characteristics, the effective cam surface being mateable with the opening and closing follower surfaces in a reciprocal manner as the cam lobe rotates to pivot the rocker down and up about a rocker pivot axis to respectively open and close a valve of the engine, the rocker defining a valve moveable end and a lifter end; a valve joint pivotally connected to the valve moveable end of the rocker and connectable to a stem of the valve; 25
a lifter joint pivotally connected to the lifter moveable end of the rocker and connectable to the lifter which is sized and configured to fit within a lifter aperture of the engine.
PCT/US2007/019593 2006-09-08 2007-09-07 Desmodromic valve system including single cam surface for closing and opening the valve Ceased WO2008030589A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US84307406P 2006-09-08 2006-09-08
US60/843,074 2006-09-08

Publications (3)

Publication Number Publication Date
WO2008030589A2 WO2008030589A2 (en) 2008-03-13
WO2008030589A3 WO2008030589A3 (en) 2008-06-26
WO2008030589B1 true WO2008030589B1 (en) 2008-08-28

Family

ID=39157880

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2007/019593 Ceased WO2008030589A2 (en) 2006-09-08 2007-09-07 Desmodromic valve system including single cam surface for closing and opening the valve

Country Status (2)

Country Link
US (1) US20080060596A1 (en)
WO (1) WO2008030589A2 (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7878167B2 (en) 2007-08-24 2011-02-01 Decuir Jr Julian A Engine with round lobe
US7870842B2 (en) 2008-04-07 2011-01-18 Decuir Julian A Engine with desmodromically actuated rocker
US8622039B2 (en) * 2010-12-22 2014-01-07 James T. Dougherty Rockerless desmodromic valve system
US9366158B1 (en) 2010-12-22 2016-06-14 James T. Dougherty Unitary cam follower and valve preload spring for a desmodromic valve mechanism
US9175581B2 (en) * 2013-08-20 2015-11-03 Ken Meyer Externally driven interior axial cam
KR101684562B1 (en) * 2015-12-11 2016-12-08 현대자동차 주식회사 Continuous varible vavle duration apparatus and engine provided with the same
KR101684558B1 (en) * 2015-12-14 2016-12-08 현대자동차 주식회사 Continuous varible vavle duration apparatus and engine provided with the same

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4723515A (en) * 1983-05-05 1988-02-09 Investment Rarities Incorporated Mechanism utilizing a single rocker arm for controlling an internal combustion engine valve
US4858573A (en) * 1984-11-13 1989-08-22 Bothwell Peter W Internal combustion engines
US4838114A (en) * 1985-11-29 1989-06-13 Stidworthy Frederick M Arrangements for converting rotary motion to linear motion
US6311659B1 (en) * 1999-06-01 2001-11-06 Delphi Technologies, Inc. Desmodromic cam driven variable valve timing mechanism
US6997152B2 (en) * 2002-04-29 2006-02-14 Delphi Technologies, Inc. Lock-pin cartridge for a valve deactivation rocker arm assembly
US6945206B1 (en) * 2004-04-09 2005-09-20 George Wayne Mobley Lobe-less cam for use in a springless poppet valve system
US6948468B1 (en) * 2004-05-03 2005-09-27 Decuir Engine Technologies, Llc Desmodromic valve and adjustable cam system
US7077088B1 (en) * 2005-05-25 2006-07-18 Decuir Jr Julian A Desmodromic valve retrofit system with replaceable cam lobes for adjusting duration and hydraulic lifters for reliability

Also Published As

Publication number Publication date
WO2008030589A2 (en) 2008-03-13
WO2008030589A3 (en) 2008-06-26
US20080060596A1 (en) 2008-03-13

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