EP0925427A1 - Dispositif automatique de decompression - Google Patents

Dispositif automatique de decompression

Info

Publication number
EP0925427A1
EP0925427A1 EP97944826A EP97944826A EP0925427A1 EP 0925427 A1 EP0925427 A1 EP 0925427A1 EP 97944826 A EP97944826 A EP 97944826A EP 97944826 A EP97944826 A EP 97944826A EP 0925427 A1 EP0925427 A1 EP 0925427A1
Authority
EP
European Patent Office
Prior art keywords
valve
cam
bracket
decompression
automatic decompression
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.)
Granted
Application number
EP97944826A
Other languages
German (de)
English (en)
Other versions
EP0925427B1 (fr
Inventor
Günter Kampichler
Udo Griebl
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.)
Motorenfabrik Hatz GmbH and Co KG
Original Assignee
Motorenfabrik Hatz GmbH and Co KG
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 Motorenfabrik Hatz GmbH and Co KG filed Critical Motorenfabrik Hatz GmbH and Co KG
Publication of EP0925427A1 publication Critical patent/EP0925427A1/fr
Application granted granted Critical
Publication of EP0925427B1 publication Critical patent/EP0925427B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • F01L13/08—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for decompression, e.g. during starting; for changing compression ratio
    • F01L13/085—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for decompression, e.g. during starting; for changing compression ratio the valve-gear having an auxiliary cam protruding from the main cam profile

Definitions

  • the present invention relates to automatic decompression for an internal combustion engine, in particular a single-cylinder diesel engine, with at least one exhaust valve and one intake valve, which are controlled by a camshaft with at least one cam, the exhaust valve being vented to reduce the starting resistance when starting .
  • Devices are known from the prior art which reduce the starting resistance when intake of internal combustion engines. These are primarily semi-automatic devices that release the exhaust valve by a few tenths of a millimeter using a lever that can be operated manually and switch from decompression to compression after a work cycle when reversing or multiple work cycles when cranking by means of a reset or detent mechanism. Furthermore, decompression devices are known from the prior art which, controlled by centrifugal force, only lift a valve (intake or exhaust valve) a few tenths of a millimeter over a certain, short angular range around the ignition TDC and switch from decompressed to compressed state again from a certain crankshaft speed.
  • a fully automatic lifting device is provided for venting the outlet valve below a switching speed for switching from decompression to compression, which causes the outlet valve to be lifted off the valve seat.
  • the lifting device releases the valve as long as the camshaft rotates below a defined switching speed. This advantageously leads to a reduction in the starting resistance during starting, as a result of which the internal combustion engine is started either manually by means of a reversing cable or by a crank or else electrically by means of a small starter motor. Above the switching speed, the lifting device is inactive, ie the valve is not released and full compression is given.
  • the lifting device has an articulated bracket arranged between cams and a control disk with two articulated arms and a crossbar connecting them, which assumes an indented decompression position in the cam plane at speeds below the switching speed, in which it moves over protrudes the cam base circle, and which can be disengaged into a neutral in the control disc level after reaching the switching speed.
  • the bracket is designed such that it is about an axis of rotation arranged parallel to the cam plane can be pivoted in such a way that when the camshaft rotates slowly or is at a standstill, the bracket is engaged in the cam plane with the crossbar arranged transversely to the articulated arms and protrudes beyond the cam base circle.
  • the invention provides that for speed-dependent control of the engagement and disengagement of the bracket for decompression or compression, at least one centrifugal weight held in a defined rest position by a biasing spring and pressurized inward in the radial direction is provided.
  • the mass of the centrifugal weight is dimensioned such that it assumes its outermost radial position against the pressure of the spring at the defined switching speed, ie that it bears against a stop in this position.
  • the biasing spring ensures that the centrifugal weight is held in a defined position in its rest position regardless of the gravitational forces.
  • the preload force of the spring must also be taken into account.
  • an advantageous embodiment of the invention provides that the inner radius of one centrifugal weight is designed as a ramp for engaging the bracket against the resistance of a release spring.
  • the hinge of the bracket is arranged approximately at the level of the longitudinal axis of the camshaft parallel to the cam plane.
  • the articulated arms have a lever arm running to the cross member and a lever arm running from the joint in the direction opposite to the cross member. The lever arm is loaded by the release spring, which keeps the bracket in its disengaged position, provided that the centrifugal weight is in its extreme radial position above the switching speed.
  • the ramp-shaped surface of the inner radius of the flyweight abuts the crossmember and causes the bracket to be held in its engaged position against the pretension of the release spring.
  • the centrifugal weight is coupled to the bracket via a driver arranged on the articulated arm.
  • the driver designed as a lever is directly coupled to a driving arm of the flyweight.
  • the centrifugal weight takes the driver with it so far that the bracket tilts outward into its disengaged position and is positioned in the control disc plane.
  • the driving arm keeps the bracket in siner indented position, in which the traverse is in the cam plane.
  • an advantageous embodiment provides that the ventilation in the decompression division takes place in each case in a defined crank angle range of approximately 90 ° due to the corresponding arc length of the bracket. This is the range that is available after the inlet valve closes and before the ignition TDC is reached or after the ignition TDC and before the exhaust valve is opened. For reasons of valve clearance adjustment, there must be an area in the ignition TDC without valve lift.
  • the switching speed is between 300 and 600 rpm, preferably 400 rpm.
  • gearshift speed selected in this way, manual starting can be carried out even at extremely low temperatures or the engine can be turned with a low-power starter.
  • control cam has a groove for receiving the bracket in the engaged position. This keeps the bracket in its defined position and protects it from deformation.
  • inlet valve can be actuated via the same cam as the outlet valve and is additionally vented in the direction of rotation of the camshaft during the decompression phase after the outlet valve. The advantage here is that, in conjunction with reversing or kickstart devices, the starting resistance is reduced by the proportion of the charge exchange work to be performed for the suction stroke. This also ensures that no unfiltered suction can take place from the outlet tract.
  • a further embodiment of the present invention provides that a valve rocker arm is provided between the cam and the valve. This can control the valve directly or via a push rod.
  • valve rocker arm can be raised by 0.2 mm - 0.6 mm, preferably 0.4 mm, by the lifting device. When implemented accordingly, this causes the valves to lift between 0.3 and 0.8 mm.
  • FIG. 1 shows a front view of a first embodiment of the automatic decompression system according to the invention
  • FIG. 2 shows a sectional side view of the automatic decompression system according to FIG. 1;
  • Fig. 3 is a front view of the automatic decompression system shown in Fig. 1 with the inlet valve vented;
  • FIG. 4 shows an automatic decompression system according to FIG. 1 after the switching speed has been reached
  • FIG. 5 shows a sectional side view of the automatic decompression system according to FIG. 1 after the switching speed has been reached;
  • FIG. 7 shows a further embodiment of the automatic decompression system according to the invention in a sectional side view
  • Fig. 8 is a valve timing diagram with decompression.
  • FIG. 1 shows a front view of a first embodiment of the automatic decompression system according to the invention with cam 1 arranged on camshaft 20 and a control disk 2.
  • a first flyweight 3 which is supported at a point 4 and by a spring 5 in the radial direction inwards is pressed
  • a second flyweight 6 with a further bearing point 7 and the common joint 8 as well as the driving arm 9 and the bracket 22 are mounted.
  • the driver 10, the associated articulated arm 11, the second articulated arm 13 and the cross member 14 form the bracket 22.
  • the toothing 15 of the control disk 2 and the cam base circle 19 are indicated by a dash-dotted line.
  • FIG. 2 shows a sectional side view of the automatic decompression system according to FIG. 1. Only the rocker arm 16 of the exhaust valve is shown. This has a sliding surface 21 which rests on the cam 1 and opens or closes the exhaust valve depending on its stroke movement.
  • the bracket 22 with the cross member 14 and the articulated arm 11 and the driver 10 is pivotally mounted on the two articulated arms in a bearing 23 in the control disc 2. Furthermore, the camshaft 20, the first centrifugal weight 3 and the second centrifugal weight 6 and the toothing 15 of the control disk 2 are shown.
  • the first centrifugal weight 3 is pressed inwards by the spring 5 in the radial direction and the second centrifugal weight 6 is likewise held in the inner radius direction via the articulated connection 8.
  • the driving arm 9 holds the driver 11 in a position distant from the camshaft axis 24, as a result of which the cross member 14 of the bracket 22 is in a moved state in the camshaft plane.
  • the cross member 14 engages in a groove 26 of the cam 1, whereby the cross member 14 of the bracket 22 protrudes a few tenths of a millimeter above the cam base circle N.
  • the engaged bracket first lifts the rocker arm 17 of the intake valve by a few tenths of a millimeter, the effective crank angle range being determined by the arc length of the bracket 22, i.e. is determined by the length of the cross member 14.
  • This state is shown in Fig. 3.
  • the cam 1 When turning further, the cam 1 first opens the outlet valve, then the inlet valve and, after closing, lifts the outlet valve again slightly through the engaged bracket.
  • the engagement and disengagement of the bracket is controlled by centrifugal force, and engagement can only take place when the bracket is not exactly at the level of a rocker arm.
  • 6a to 6c show side views of different embodiments of an inventive Bracket.
  • the driver 10 and a cutting edge 23 serving as a joint are shown.
  • 6b shows a bracket in which the bearing is formed by a ball 60.
  • 6c finally shows the side view of an embodiment of a bracket according to the invention, in which the bearing is formed by an axis 61.
  • FIG. 7 shows a further embodiment of an automatic decompression system according to the invention.
  • the first centrifugal weight 70 has an inner radius formed as a ramp 71 and on the other hand in that the bracket 72 is pivotable about an axis 73 leading through the center line of the camshaft.
  • the bracket 72 has a lever arm 76 which is loaded by a spring 77.
  • the bracket is disengaged above the switching speed and held in this position. Below the switching speed, the bracket is pushed against the spring pressure of the spring 77 by the ramp 71 into its engaged position in the cam plane and held in this position until the centrifugal weight again moves outwards.
  • valve 8 shows a valve control diagram of the decompression, in which the valve lift curve of the exhaust valve is shown at 100, the valve lift curve of the intake valve at 102, the valve lift through automatic decompression at the intake valve at 103 and the valve lift through automatic decompression at the exhaust valve at 104 is pictured. With 105 the ignition TDC is designated and with 106 the over intersection OT. This diagram clearly shows that the valve is not lifted around 40 ° before ignition TDC and 40 ° after ignition TDC.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve Device For Special Equipments (AREA)

Abstract

L'invention concerne un dispositif automatique de décompression pour un moteur à combustion interne, notamment un moteur diesel monocylindre, comportant au moins une soupape d'échappement et une soupape d'admission commandées par un arbre à cames (20) pourvu d'au moins une came (1). Pour réduire la résistance au lancement lors du démarrage, la soupape d'échappement est soulevée, et un dispositif de levée entièrement automatique s'engage dans la came (1) de la soupape d'échappement pour la soulever au-dessous d'un régime permettant le passage de la décompression à la compression. Ce dispositif de levée provoque le décollement de la soupape d'échappement de son siège et présente un étrier (22) monté articulé entre la came (1) et un disque de commande (2) et possédant deux bras articulés (11) reliés par une traverse (14). Cet étrier (22) occupe dans le plan de came, à des régimes inférieurs au régime de passage, une position de décompression engagée, dans laquelle il fait saillie au-dessus du cercle de base de la came, et lorsque le régime de passage est atteint, il peut être désengagé pour revenir dans une position neutre dans le plan du disque de commande. Le dispositif automatique de décompression comprend, pour la commande, en fonction du régime, du processus d'engagement et de désengagement, au moins une masselotte (3) sollicitée en compression en sens radial vers l'intérieur par un ressort (5), cette masselotte étant accouplée de manière flexible avec l'étrier.
EP97944826A 1996-09-11 1997-09-04 Dispositif automatique de decompression Expired - Lifetime EP0925427B1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19636811 1996-09-11
DE19636811A DE19636811C2 (de) 1996-09-11 1996-09-11 Dekompressionsautomatik
PCT/EP1997/004799 WO1998011330A1 (fr) 1996-09-11 1997-09-04 Dispositif automatique de decompression

Publications (2)

Publication Number Publication Date
EP0925427A1 true EP0925427A1 (fr) 1999-06-30
EP0925427B1 EP0925427B1 (fr) 2000-12-13

Family

ID=7805193

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97944826A Expired - Lifetime EP0925427B1 (fr) 1996-09-11 1997-09-04 Dispositif automatique de decompression

Country Status (5)

Country Link
US (1) US6223708B1 (fr)
EP (1) EP0925427B1 (fr)
JP (1) JP2001500209A (fr)
DE (2) DE19636811C2 (fr)
WO (1) WO1998011330A1 (fr)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6782861B2 (en) 2001-02-09 2004-08-31 Briggs & Stratton Corporation Vacuum release mechanism
US6886518B2 (en) * 2000-02-18 2005-05-03 Briggs & Stratton Corporation Retainer for release member
US6539906B2 (en) * 2001-03-30 2003-04-01 Tecumseh Products Company Mechanical compression and vacuum release
DE10253231B3 (de) * 2002-11-15 2004-02-12 Dr.Ing.H.C. F. Porsche Ag Automatische Dekompressionsvorrichtung für ventilgesteuerte Brennkraftmaschinen
FR2884561B1 (fr) 2005-04-14 2010-04-23 Renault Sas Bougie pour vehicule automobile hybride et procede de decompression associe d'un moteur de vehicule hybride.
US7328678B2 (en) * 2005-06-07 2008-02-12 Tecumseh Power Company Mechanical compression and vacuum release mechanism
US7174871B2 (en) * 2005-06-07 2007-02-13 Tecumseh Products Company Mechanical compression and vacuum release mechanism
JP6226787B2 (ja) * 2014-03-19 2017-11-08 本田技研工業株式会社 デコンプ機構付き内燃機関
DE102015204550A1 (de) 2015-03-13 2016-09-15 Bayerische Motoren Werke Aktiengesellschaft Nockenwelle mit einer Dekompressionsvorrichtung
DE102015225727A1 (de) 2015-12-17 2017-07-06 Bayerische Motoren Werke Aktiengesellschaft Dekompressionsvorrichtung für eine Hubkolben-Brennkraftmaschine
RO132154A2 (ro) 2016-03-21 2017-09-29 Schaeffler Technologies AG & Co.KG Aranjament de comutare cu came
DE102019204091A1 (de) * 2019-03-26 2020-10-01 Volkswagen Aktiengesellschaft Verfahren zum Starten eines Verbrennungsmotor und Antriebsanordnung für ein Kraftfahrzeug

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2522725B1 (fr) * 1982-03-04 1985-11-22 Bernard Moteurs Decompresseur a commande centrifuge pour faciliter le demarrage des moteurs a combustion interne
JPS6032507U (ja) * 1983-08-10 1985-03-05 川崎重工業株式会社 エンジンのオ−トデコンプ装置
US4590905A (en) 1984-05-04 1986-05-27 Honda Giken Kogyo Kabushiki Kaisha Process for decompression control in internal combustion engine and apparatus therefor
JPH066888B2 (ja) * 1984-07-10 1994-01-26 富士重工業株式会社 エンジンのデコンプ装置
JPH086574B2 (ja) * 1987-06-05 1996-01-24 本田技研工業株式会社 内燃機関のデコンプ装置
US5150674A (en) * 1991-05-21 1992-09-29 Briggs & Stratton Corporation Centrifugally responsive compressing release mechanism
US5155453A (en) 1991-05-23 1992-10-13 Samsung Semiconductor, Inc. Low-power crystal oscillator
US5301643A (en) 1993-05-05 1994-04-12 Briggs & Stratton Corporation Low oil sensor using compression release to affect engine operation
JP3464715B2 (ja) * 1994-09-07 2003-11-10 本田技研工業株式会社 Ｏｈｃエンジン
JP3366171B2 (ja) * 1995-12-28 2003-01-14 本田技研工業株式会社 エンジンのデコンプ機構

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9811330A1 *

Also Published As

Publication number Publication date
US6223708B1 (en) 2001-05-01
WO1998011330A1 (fr) 1998-03-19
JP2001500209A (ja) 2001-01-09
DE59702768D1 (de) 2001-01-18
EP0925427B1 (fr) 2000-12-13
DE19636811A1 (de) 1998-03-12
DE19636811C2 (de) 2000-06-15

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