EP0091804A1 - Formschlüssiges Ventilantriebssystem - Google Patents

Formschlüssiges Ventilantriebssystem Download PDF

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Publication number
EP0091804A1
EP0091804A1 EP83301998A EP83301998A EP0091804A1 EP 0091804 A1 EP0091804 A1 EP 0091804A1 EP 83301998 A EP83301998 A EP 83301998A EP 83301998 A EP83301998 A EP 83301998A EP 0091804 A1 EP0091804 A1 EP 0091804A1
Authority
EP
European Patent Office
Prior art keywords
valve
cam
timing
close
engine
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Withdrawn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
EP83301998A
Other languages
English (en)
French (fr)
Inventor
Jeffrey Robert Parker
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 EP0091804A1 publication Critical patent/EP0091804A1/de
Withdrawn legal-status Critical Current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
    • F01L1/30—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
    • F01L13/0015—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
    • F01L13/0036—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 the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction
    • F01L13/0042—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 the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction with cams being profiled in axial and radial direction
    • 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
    • F02B2075/027—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle four

Definitions

  • This invention relates to a desmodromic valve system for internal combustion engines and liquid or gas fuelled pumps.
  • valve mechanism if a valve mechanism is arranged to operate effectively at a very high engine speed and the valve timing is adjusted to the optimum at that speed then it is found that at speeds other than the optimum the mass of air which can enter the cylinders per cycle decreases.
  • the torque developed at engine speeds other than this optimum speed falls off from that obtainable at the optimum speed very rapidly and may only be a small percentage of the maximum torque at speed only slightly different to optimum speed.
  • an engine although efficient at the particular design speed, is virtually useless when operated away from the speed.
  • valve timing was adjusted to optimise torque at lower speeds then the torque decreases as the speed increases and thus no further useful power can be developed beyond a particular speed.
  • the torque developed by the engine must be such as to be able to readily overcome the road load, which includes a frictional component inherent in the motor vehicle design and also, possibly, a gravity component where the vehicle is working on an incline.
  • the road load which includes a frictional component inherent in the motor vehicle design and also, possibly, a gravity component where the vehicle is working on an incline.
  • the load increases specifically due to the incidence of wind resistance, it is necessary that good torque be available.
  • valve timing is optimised for a particular engine speed
  • valve return springs which provide the biassing action to close the valves each of which is opened by a push rod or cam follower operated by the cam shaft.
  • the percentage of power output used in opening the valves can be of the order of 3 to 4 and, it will be appreciated, this loss can be considered quite significant.
  • the object of the invention is to provide a valve system for internal combustion engines which overcomes these previous disadvantages.
  • the system in its broad sense, comprises a desmodromic valve system in which the valve is both positively opened and closed under the action of at least one cam and having means whereby the valve timing is varied with at least one engine parameter to provide timing which is close to optimum at various speeds and/or loads.
  • a desmodromic valve mechanism in which a cam is used to open the valve and the same or another cam is used to positively close the valve.
  • two cams may be provided on the same cam shaft and in a second arrangement the cams may be provided on different cam shafts each of which is in connection with a cam follower arrangement one cam causing actuation of the valve in a first direction and the other in the second direction.
  • valve timing is achieved by relative transverse movement between each cam and the cam follower and the cam profile is arranged so that, depending upon the speed and or torque being delivered by the engine at any time, so the valve timing is caused to change to be close to the optimum.
  • a rocker shaft 1 carrying a rocker 2 which is provided with two cam followers 20 and 21.
  • Two spaced cam shafts 5 and 6 carry cams 4 and 3 respectively cam 4 acting acting through the rocker 2 to close the valve 7 and cam 3 acting through the rocker 2 to open the valve 7, the rocker 2 having a tappet 22 which acts to open and close the valve.
  • valve 7 is provided with upper 8 and lower 9 contact surfaces which are acted upon by tappet 22 to cause the opening and closing of the valve 7.
  • the valve 7 is located in a valve guide 10 which is fixed in the cylinder head 11.
  • Valve seat 12 is located relative to the valve guide 10 as is conventional and the valve head 14 moving off and on seat 12 causes port 13 to open into the combustion chamber or to be isolated therefrom.
  • the shafts of the two cams 5 and 6 are interconnected either by gears or chains or belts so that the relative orientation between the cams are maintained on rotation of the engine and the cams are, as is conventional, driven at half crank shaft speed in a four cycle engine.
  • the cams 3 and 4 shown in section in Fig. 1. vary in profile along their length, as can be seen in Figs. 2 to 5. In these Figures it can be seen that the cam profiles vary from a first position at one end where the valve is open for only a relatively small part of the crank shaft movement to a position adjacent the other end where the valve is open for a substantial part of the crank shaft movement.
  • the range of degrees of crankshaft movement generally required for the operation of the valves, suitable to a wide range of engine speeds, are indicated in Figs. 2 and 3.
  • cams 3 and 4 are complementary in operation.
  • cam 3 When cam 3 is located so that the end 25 is operating the valve then the valve is opened and held open through 120 degrees of movement of the cam.
  • cam 4 At the end of this movement cam 4, which is inoperative during this period, operates to close the valve which remains closed until cam 3 commences to operate.
  • the valve When the cams move towards the ends 26 and 28, the valve is open for 170 degrees of movement of the cams, which is equivalent to 340 degrees of movement of the crankshaft, and is non-operative for the rest of the rotation of the cam.
  • valve absolute control of the valve is only provided when the free movement of the cam followers is a minimum. Otherwise the cam followers can bounce within the range of any available movement within the constraints applied to the cam followers by the inter-relationship between the two cams.
  • cam formations illustrated in Figs. 2 to 5, are thus exemplary only but do show the possibility of the length of the valve timing varying substantially with engine speed.
  • Fig.6 illustrates one way in which the variation in timing of the invention can be applied.
  • cams 3 and 4 may be on a slideably mounted cam shaft and may be held in the position illustrated by spring 40 and as the engine speed increases so the cams are moved against the spring pressure, either mechanically or hydraulically, so that, for example, the cam follower 45 contacts the cam 3 profile at axial positions along its length.
  • the other cam follower which is obscured in the Figure, contacts 25 cam 4 in the complementarymanner, as previously described. In this way the required variation in the valve timing controlled by cam operation is achieved.
  • pump 50 which may be an engine gear driven pump provides oil under pressure from sump 51 30to chamber 52 which oil acts on piston 53 which exerts a force on shaft 54.
  • the pressure is less than that provided by the spring 40, which is not shown in Fig. 8, the hydraulic pressure does not cause movement of shaft 54.
  • the fluid from the pump can pass through restriction 55 at all times and as the pressure from the pump output increased so oil in the line containing the restriction 56 increases in pressure valve 57 can open permitting oil to return to the sump and by the use of one or more valves similar to valve 57 so the pressure output from the 0pump can be controlled to control the pressure in chamber 53 and thus the relative movement of the shaft 54 against spring 40.
  • Fig. 7 shows an alternative arrangement of rocker 60 which rotates about rocker shaft 61 and has cam followers 62 and 63 which are located in side by side relationship similar to that of Fig. 6 acting against lobes 64 and 65 respectively.
  • the tappet 66 is formed on the end of the rocker.
  • a lower member 67 having an upper surface against which the tappet 66 operates, which member is threaded and adapted to be screwed over the valve stem Oor extension thereof 72.
  • the member 67 is held in its required position by a lock ring 70 located therebelow.
  • Control of the valve during its closing operation is effected by a sleeve 69 which has an internal thread which is screwed over the valve stem.
  • This sleeve has an extension 68 which comprises the mean which actually acts against the tappet 66. 5
  • the tappet 66 is similar in form to the tappet shown in Fig. 6 and terminates in a yolk so that it passes on either side of the sleeve 69.
  • the positive location of the sleeve 68 is effected by a grub lock screw 71 which is screwed into the sleeve and acts against the upper end of the threaded valve stem 72.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)
  • Valve Device For Special Equipments (AREA)
EP83301998A 1982-04-08 1983-04-08 Formschlüssiges Ventilantriebssystem Withdrawn EP0091804A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AU355182 1982-04-08
AU3551/82 1982-04-08

Publications (1)

Publication Number Publication Date
EP0091804A1 true EP0091804A1 (de) 1983-10-19

Family

ID=3694004

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83301998A Withdrawn EP0091804A1 (de) 1982-04-08 1983-04-08 Formschlüssiges Ventilantriebssystem

Country Status (2)

Country Link
EP (1) EP0091804A1 (de)
JP (1) JPS58202318A (de)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2190140A (en) * 1986-05-01 1987-11-11 Chris Walters Valve lift mechanism
EP0384361A2 (de) * 1989-02-22 1990-08-29 Nissan Motor Co., Ltd. Ventiltrieb für Fahrzeugbrennkraftmaschine
EP0429277A1 (de) * 1989-11-24 1991-05-29 Takuya Matsumoto Ventilanordnung für eine Brennkraftmaschine
WO1996037688A1 (de) * 1995-05-23 1996-11-28 Csaba Gyimesi Variierbare ventilsteuerung für verbrennungsmotoren
WO2003040525A1 (en) * 2001-10-17 2003-05-15 Geoffrey Oswald Nevin A grooved-cam valve drive mechanism for internal combustion engines
US6619250B2 (en) * 2001-03-16 2003-09-16 Frank A. Folino Desmodromic valve actuation system
KR100482076B1 (ko) * 2002-05-31 2005-04-13 현대자동차주식회사 엔진의 밸브 개폐장치
US6953014B2 (en) 2001-03-16 2005-10-11 Folino Frank A Thermal compensating desmodromic valve actuation system
EP1679428A1 (de) * 2005-01-11 2006-07-12 Fausto Pontinha Martins Nockenwelle mit variablem Profil zur Betätigung der Ventile in dem Motorbrennraum.
US7082912B2 (en) 2001-03-16 2006-08-01 Folino Frank A System and method for controlling engine valve lift and valve opening percentage
WO2017172570A1 (en) * 2016-03-30 2017-10-05 Duel Steven James Valve train system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016037955A (ja) * 2014-08-10 2016-03-22 義輝 今村 カムシャフト回転トルク軽減システム

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB127613A (en) * 1917-04-30 1919-06-12 Harry Ralph Ricardo Improvements in Regulating the Speed and Power of Internal Combustion Engines.
DE1013115B (de) * 1955-06-15 1957-08-01 Daimler Benz Ag Ventilsteuerung, insbesondere fuer Brennkraftmaschinen
DE2621363A1 (de) * 1976-05-14 1977-11-24 Daimler Benz Ag Lastregelung fuer gemischverdichtende brennkraftmaschinen mit ventilsteuerung
DE3025259A1 (de) * 1973-05-18 1981-01-15 Nissan Motor Ventilbetaetigungsmechanismus
DE3022188A1 (de) * 1980-06-13 1981-12-24 Teodoro 4300 Essen Holtmann Ventilsteuerungseinrichtung eines verbrennungsmotors

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB127613A (en) * 1917-04-30 1919-06-12 Harry Ralph Ricardo Improvements in Regulating the Speed and Power of Internal Combustion Engines.
DE1013115B (de) * 1955-06-15 1957-08-01 Daimler Benz Ag Ventilsteuerung, insbesondere fuer Brennkraftmaschinen
DE3025259A1 (de) * 1973-05-18 1981-01-15 Nissan Motor Ventilbetaetigungsmechanismus
DE2621363A1 (de) * 1976-05-14 1977-11-24 Daimler Benz Ag Lastregelung fuer gemischverdichtende brennkraftmaschinen mit ventilsteuerung
DE3022188A1 (de) * 1980-06-13 1981-12-24 Teodoro 4300 Essen Holtmann Ventilsteuerungseinrichtung eines verbrennungsmotors

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2190140A (en) * 1986-05-01 1987-11-11 Chris Walters Valve lift mechanism
GB2190140B (en) * 1986-05-01 1989-12-06 Chris Walters Valve lift mechanism
EP0384361A2 (de) * 1989-02-22 1990-08-29 Nissan Motor Co., Ltd. Ventiltrieb für Fahrzeugbrennkraftmaschine
EP0384361A3 (de) * 1989-02-22 1991-04-10 Nissan Motor Co., Ltd. Ventiltrieb für Fahrzeugbrennkraftmaschine
US5048474A (en) * 1989-02-22 1991-09-17 Nissan Motor Co., Ltd. Valve train for automotive engine
EP0429277A1 (de) * 1989-11-24 1991-05-29 Takuya Matsumoto Ventilanordnung für eine Brennkraftmaschine
WO1996037688A1 (de) * 1995-05-23 1996-11-28 Csaba Gyimesi Variierbare ventilsteuerung für verbrennungsmotoren
US6619250B2 (en) * 2001-03-16 2003-09-16 Frank A. Folino Desmodromic valve actuation system
US6953014B2 (en) 2001-03-16 2005-10-11 Folino Frank A Thermal compensating desmodromic valve actuation system
US7082912B2 (en) 2001-03-16 2006-08-01 Folino Frank A System and method for controlling engine valve lift and valve opening percentage
WO2003040525A1 (en) * 2001-10-17 2003-05-15 Geoffrey Oswald Nevin A grooved-cam valve drive mechanism for internal combustion engines
KR100482076B1 (ko) * 2002-05-31 2005-04-13 현대자동차주식회사 엔진의 밸브 개폐장치
EP1679428A1 (de) * 2005-01-11 2006-07-12 Fausto Pontinha Martins Nockenwelle mit variablem Profil zur Betätigung der Ventile in dem Motorbrennraum.
WO2017172570A1 (en) * 2016-03-30 2017-10-05 Duel Steven James Valve train system

Also Published As

Publication number Publication date
JPS58202318A (ja) 1983-11-25

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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Effective date: 19840416

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18D Application deemed to be withdrawn

Effective date: 19850813