• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Variable valve train (1) for adjusting intake or exhaust valves (6) of at least two cylinder banks (110, 110 ') of an internal combustion engine (100) with - a cam (2) bearing camshaft (22) - at least two bumpers (3) for transmission one of the cam (2) having profile in a translational movement for actuating intake or exhaust valves (6), wherein between the outer contour of the cam (2) and the bumper (3) a rotatable adjusting member (8) is provided, wherein Rotation of the adjusting member (8), the operating times of the intake or exhaust valves (6) on the at least two cylinder banks are synchronously changed.
    公开号:AT516570A1
    申请号:T835/2014
    申请日:2014-11-20
    公开日:2016-06-15
    发明作者:Michael Hillebrecht
    申请人:Ge Jenbacher Gmbh & Co Og；
    IPC主号:
    专利说明:

    The invention relates to a variable valve train having the features of the preamble of claim 1.
    A variable valve train, so the ability to adjust the timing and / or the valve lift to operating conditions is seen as an essential technology for achieving efficiency and emission targets in internal combustion engines. There are a variety of commercially available mechanical, hydraulic or combined systems.
    An essential goal of variable valve trains is the reduction of gas exchange work through reduced throttling losses.
    A fully variable mechanical valve train for an internal combustion engine is known for example from DE 10006018. Here, between a drive means, such as a cam, a camshaft and the gas exchange valve to be actuated a transmission means is arranged, which makes it possible to change the predetermined by the cam contour stroke via an adjustable control between a minimum and the full stroke in accordance with the operating conditions.
    A common method for operating an internal combustion engine with a high efficiency is the so-called "Miller cycle". The Miller cycle is an early closing of the intake valves. This means that the inlet valve is closed before the piston has reached bottom dead center in the suction stroke. As a result, the internal combustion engine is relieved of compression work, the cylinder filling remains cooler and the engine can deliver more power. The aim is to increase the efficiency. The Miller cycle improves knocking behavior and nitrogen oxide emissions through internal charge cooling.
    The "Atkinson cycle" is the process with extremely late inlet closure. Again, the engine has to do less charge exchange work.
    Since, among other things, the cold start behavior is a limiting factor for the position of the inlet closure, a variable valve train has already been proposed for the exploitation of the potentials of Miller or Atkinson control times. However, fully variable valve trains, ie valve trains in which timing, lift curves and valve lift can be varied, very expensive.
    Object of the present invention is to provide a simple system for varying a valve opening time, which manages without complex hydraulic or mechanical components and without camshaft adjustment.
    This object is achieved by a variable valve train having the features of claim 1. Advantageous embodiments are specified in the dependent claims.
    Characterized in that between the outer contour of the cam and the bumper, a rotatable adjusting member is provided, wherein the operating times of the intake or exhaust valves are changed synchronously on the at least two cylinder banks by rotation of the adjusting, is a mechanical, synchronous, ie simultaneous adjustment of on or Exhaust valves realized.
    The change in the actuation times is effected by, caused by rotation of the adjusting member, change in the angular position of the contact points of the adjusting member on the cam. The adjustment member transmits the movement of the cam via bumpers to the intake or exhaust valves to such an extent that the gas exchange valves opposite the at least two cylinder banks are changed synchronously with respect to their actuation times.
    It can be provided that the at least two bumpers are fixedly connected to the outer contour of the adjusting member. Stationary means that the bumper is engaged with the outer contour of the adjusting member and therefore the contact point moves with a rotation of the adjusting member with this.
    Alternatively it can be provided that the at least two bumpers are mounted on the outer contour of the adjusting sliding or rolling. In this case, the bumpers are decoupled from the adjusting member, that is not connected in a stationary manner. You can either roll or slide over a roller or a sliding contact on the outer contour of the adjusting. The contact point does not have to move with this rotation of the adjusting.
    It is preferably provided that the adjusting member is designed as a two-legged lever whose two legs transmit the movement of the cam via the respective bumpers on the inlet or outlet valves.
    It is preferably provided that a rotation of the adjusting member causes the cam movement is changed over time transferred to the bumper.
    Thus, by the rotation of the adjusting member, a change of the valve actuation in the direction of earlier valve opening or later valve opening can be effected.
    It is preferably provided that the adjusting member has a profile for valve clearance compensation on the surface in engagement with the bumper. The lash adjuster profile causes the bumper contact points to move along such curves as the adjuster is rotated so that the valve lash of the intake or exhaust valves actuated by the respective bumpers remains unchanged.
    Particularly preferably, it is provided that the cylinder banks of the internal combustion engine are in a V-arrangement. The problem of the same when changing the valve opening times changing valve clearance is given in particular in internal combustion engines with a V-arrangement of the cylinder banks. The angle between the bumper and the rocker arm is usually close to 90 °, whereby changes in the axial position of the contact point of the bumper directly and significantly affect the valve clearance.
    The adjusting member is rotatably mounted via an adjusting mechanism, preferably via an eccentric shaft, and changes during rotation of the adjusting the movement pattern of the bumpers, which the opposite of a cylinder bank gas exchange valves via optionally provided rocker arm the gas exchange valves actuated bumpers. This ensures that only one adjusting each two gas exchange valves are made variable in their control times. The invention is particularly suitable for internal combustion engines with a V arrangement of the cylinders.
    The internal combustion engine is particularly preferably a stationary internal combustion engine, in particular an Otto-powered gas engine. Especially preferably, the internal combustion engine is designed for operation in the Miller or Atkinson cycle.
    The invention will be explained in more detail with the aid of the figures.
    Showing:
    1 a valve train according to the prior art,
    2 is a schematic representation of a variable valve train,
    Fig. 3a, 3b kinematic details of the valve train of Figure 2 Fig. 4 is a schematic representation of a variable valve train in a second embodiment
    5 is a schematic representation of a variable valve train Fig. 6a, 6b Details of Figure 5 upon actuation of the adjusting 8th
    FIG. 1 shows the valve drive of a V-engine according to the prior art. Shown schematically is an internal combustion engine 100 with two cylinder banks 110 and 110 'in V arrangement.
    The bumpers 3 are about bearings 4 in contact with the cam 2 of the camshaft 22. The profile of the cam 2 transmits upon rotation of the camshaft 22 a translational movement on the bumper 3, which actuates the gas exchange valves 6 in further consequence on the rocker arm 5. Because of the symmetrical structure of the internal combustion engine 100, the reference numerals for the on both cylinder banks 110 and 110 'partially awarded only for one side.
    Figure 2 shows a variable valve train 1 according to a first embodiment in a reduced to the kinematics representation.
    The direction of rotation of the camshaft 22 is indicated by an arrow and extends in a clockwise direction.
    Between the bumper side storage 4 (which is for example designed as a support roller), the bumper 3 and the cam 2, an adjusting member 8 is arranged in the form of a two-levered lever. The legs of the adjusting member 8 are denoted by 81 and 82. The adjusting member 8 can be pivoted about an eccentrically mounted actuating shaft 11. The bumpers 3 are fixedly connected in this embodiment with the legs 81 and 82, respectively. Stationary means that the bumpers 3 are connected at their points of contact with the legs 81 and 82, respectively. This can be realized about pans or similar means on the legs 81 and 82, respectively.
    The camshaft 22 transmits by means of cam 2 via the support rollers 9 a hub on the adjusting member 8. The bumpers associated with the bearings 4 touch the adjusting member 8 on the support rollers 9 opposite side.
    Dashed curves show the trajectories of individual points. Thus, it can be seen that, when the actuating shaft 11 is rotated counterclockwise, the support rollers 9 associated with the adjusting member move clockwise on the cam 2.
    The bumper-side bearing 4 may be formed, for example, as a support roller or as a sliding contact.
    In motors in V-arrangement angle often need to be realized between bumper and rocker arm not equal to 90 °. When using an adjusting mechanism according to the first embodiment, such an opening adjustment leads to a reduction of the included angle on the one and an opening (widening) of the angle on the other cylinder bank.
    At high pitch angles, and particularly fixed bumpers, this kinematically results in a relative change in valve lash between the cylinder banks, i. while on the one hand, the valve clearance is greater, it decreases on the opposite cylinder bank. The result is an unacceptably large game on one bank and, at a certain twist angle, jamming on the other bank.
    From the figure 2 it is clear that by the pivoting of the adjusting member 8, the trajectory of the storage 4 on the right side, i. on the side of the lever arm 82, and the path of movement of the bearing 4 facing contour of the adjusting member 8 move away from each other (box "Detail 2").
    Conversely, the distance of this trajectory on the left side, i. on the side of the lever arm 81, see box "Detail 1".
    It is immediately obvious that these changes in the trajectories affect the valve clearance 12. While on the right side (side of the lever arm 82), the valve lash 12 is larger, it decreases on the opposite cylinder bank. The result is an unacceptably large valve clearance 12 on one bank and jamming on the other bank.
    Figures 3a and 3b show the details 1 and 2 of Figure 2.
    FIG. 3 a shows by way of example how, when the adjusting element 8 is pivoted after the initial opening, the valve clearance is reduced.
    From Figure 3b shows an example of how the valve clearance increases disproportionately.
    The kinematics of the components involved thus leads to an inequality of the valve clearance on the two cylinder banks of the V-engine.
    FIG. 4 shows a variable valve drive 1 according to a second embodiment.
    The actuation of the adjusting member 8 is carried out as described for Figure 2.
    The adjusting member 8 contacts the cam 2 of the camshaft 22 via the supporting rollers 9 belonging to the adjusting member 8. The direction of rotation of the camshaft 22 is indicated by an arrow and extends in the clockwise direction. The bearings 4 associated with the bumpers contact the adjustment member 8 on the side opposite the support rollers 9, the movement surface being designed as a valve play compensating profile 10.
    The bumpers 3 are guided here by means of guides 7 in the crankcase. The bumpers 3 roll / slide by means of bearings 4 on the outer contour of the legs 81 and 82, respectively. This means that they are not fixedly connected to the adjusting member 8 in this embodiment. The guides 7 essentially allow movement of the bumpers 3 along their longitudinal axis. The guides 7 can also be designed so that they allow a game as a normal movement. To illustrate this additionally allowed pivotal movement, the guides 7 are shown in Figure 4 crowned.
    By rotation of the adjusting member 8, the angular position of the contact point of the adjusting member 8 on the cam 2 is variable. With angular position, the camshaft angle is meant. It is customary to specify control times in degrees of camshaft angle (DE: degree crank angle, CA). For example, if the adjusting member 8 is pivoted to the right by an angle oc, this leads to a shift of the valve lift curves in the direction of a late valve closing, because the angular position of the contact points of the adjusting 8, formed in this embodiment on the support rollers 9, moves in a clockwise direction. Thus, the contact points are detected accordingly later by the cam.
    Due to the valve play compensating profile 10, the negative effect of an asymmetrically changing valve clearance explained with reference to FIGS. 2, 3a, 3b upon actuation of the actuator is avoided here. The profile 10 is geometrically designed such that it compensates for the kinematic change in the valve clearance. Thus, the valve clearance for both cylinder banks remains constant over the adjustment angle of the adjusting 8. The exact shape of the profile of course depends on the geometric relationships of the respective valve train and can be calculated by those skilled in this.
    It can be seen on the embodiment of Figure 4 with decoupled bumpers that compared to the embodiment of Figure 2 with fixed bumpers greater freedom in terms of achievable adjustment angle exists.
    FIG. 5 shows a schematic of a variable valve train 1 in a reduced kinematic representation.
    The bumpers 3 are guided in guides 7, as explained for Figure 4 allow a game. The inner dashed circle is the perimeter of the outer contour of the legs 81,82. The spaced apart second dashed circle shows the constant over the rotation of the adjusting 8 valve clearance 12th
    FIGS. 6 a and 6 b show details of FIG. 5 upon actuation of the adjusting element 8.
    With the proposed solution with decoupled bumpers, it is thus possible to adjust the timing within large angular ranges (for example, up to 12 ° crank angle) and at the same time - by providing a valve clearance compensating profile - to keep the valve clearance constant.
    The bumper ends can be made both as rollers and sliding elements (e.g., ceramic), thus resulting in a simplification of the overall system.
    List of reference numbers used: 1 variable valve train 2 cams 22 camshaft 3 bumper 4 bumper side mounting 5 rocker arm 6 gas exchange valve 7 guide 8 adjusting element 81,82 leg of adjusting element 9 supporting roller on cam side 10 profile 11 actuating shaft 12 valve clearance 100 internal combustion engine 110,110 "cylinder banks
    权利要求:
    Claims (7)
    [1]
    claims
    1. Variable valve train (1) for adjusting intake or exhaust valves (6) of at least two cylinder banks (110, 110 ') of an internal combustion engine (100) with - a cam (2) carrying camshaft (22) - at least two bumpers (3) for transmitting a profile comprising the cam (2) into a translatory movement for actuating inlet or outlet valves (6), characterized in that between the outer contour of the cam (2) and the bumper (3) a rotatable adjusting member (8) is provided, by rotation of the adjusting member (8) the operating times of the intake or exhaust valves (6) on the at least two cylinder banks are synchronously changed.
    [2]
    2. Variable valve train (1) according to claim 1, characterized in that the at least two bumpers (3) are fixedly connected to the outer contour of the adjusting member (8).
    [3]
    3. Variable valve train (1) according to claim 1, characterized in that the at least two bumpers (3) on the outer contour of the adjusting member (8) are slidably mounted or rolling.
    [4]
    4. Variable valve train (1) according to at least one of claims 1 to 3, characterized in that the adjusting member (8) is designed as a two-leg lever whose two legs (81, 82) the movement of the cam (2) via the respective bumpers (3, 3 ') transferred to the inlet or outlet valves (6).
    [5]
    5. Variable valve train (1) according to at least one of claims 1 to 4, characterized in that a rotation of the adjusting member (8) causes the cam movement is changed over time to the bumper (3, 3 ') is transmitted.
    [6]
    6. Variable valve train (1) according to at least one of claims 1 to 5, characterized in that the adjusting member (8) on the bumper (3, 3 ') in engagement surface has a profile (10) for valve clearance compensation.
    [7]
    7. Variable valve train (1) according to at least one of claims 1 to 6, characterized in that the cylinder banks (110, 110 ') of the internal combustion engine (100) are in a V-arrangement.
    类似技术:
    公开号 | 公开日 | 专利标题
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    EP1591629B1|2007-03-21|Cam with a groove for controlling the rotation of a tappet
    AT399021B|1995-03-27|VALVE CONTROL FOR INTERNAL COMBUSTION ENGINES
    同族专利:
    公开号 | 公开日
    KR20160060581A|2016-05-30|
    JP2016098832A|2016-05-30|
    CN105649707A|2016-06-08|
    EP3023608A1|2016-05-25|
    US20160146073A1|2016-05-26|
    AT516570B1|2016-11-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE4330913A1|1993-09-11|1995-03-16|Mak Maschinenbau Krupp|Valve gear for internal combustion engines|
    WO2006092312A1|2005-03-03|2006-09-08|Hydraulik-Ring Gmbh|Variable mechanical valve control for an internal combustion engine|
    DE102005047040A1|2005-09-30|2007-04-05|Mtu Friedrichshafen Gmbh|Variable valve controller for V-engine, has lower oscillating arms adjusted around central cam shaft by displacement of guide shafts using actuator that is driven around regulating shaft, where arms are movably coupled with inlet valve|
    DE102014103006A1|2013-03-06|2014-09-11|General Electric Company|Method and systems for variable valve control in a V-engine with central camshaft|US10718238B2|2017-11-03|2020-07-21|Indian Motorcycle International, LLC|Variable valve timing system for an engine|JPH06506749A|1991-04-24|1994-07-28|
    DE10006018B4|2000-02-11|2009-09-17|Schaeffler Kg|Variable valve drive for load control of a spark-ignited internal combustion engine|
    EP2136054B1|2008-06-18|2011-09-07|Caterpillar Motoren GmbH & Co. KG|Device for controlling the operation of an internal combustion engine|
    US9133735B2|2013-03-15|2015-09-15|Kohler Co.|Variable valve timing apparatus and internal combustion engine incorporating the same|
    法律状态:
    2020-08-15| MM01| Lapse because of not paying annual fees|Effective date: 20191120 |
    优先权:
    申请号 | 申请日 | 专利标题
    ATA835/2014A|AT516570B1|2014-11-20|2014-11-20|Variable valve train|ATA835/2014A| AT516570B1|2014-11-20|2014-11-20|Variable valve train|
    US14/944,614| US20160146073A1|2014-11-20|2015-11-18|Variable valve gear|
    KR1020150162673A| KR20160060581A|2014-11-20|2015-11-19|Variable valve gear|
    JP2015226404A| JP2016098832A|2014-11-20|2015-11-19|Variable valve gear|
    EP15195397.3A| EP3023608A1|2014-11-20|2015-11-19|Variable valve drive|
    CN201511005502.4A| CN105649707A|2014-11-20|2015-11-19|Variable valve gear|
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