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
• • 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
  • 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
  • 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
  • F01L2013/0068—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 with an oscillating cam acting on the valve of the "BMW-Valvetronic" 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
  • F01L2303/00—Manufacturing of components used in valve arrangements
  • F01L2303/01—Tools for producing, mounting or adjusting, e.g. some part of the distribution
• • 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
  • F01L2305/00—Valve arrangements comprising rollers
• • 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
• • 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
  • F01L2800/08—Timing or lift different for valves of different cylinders
• • 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
  • F01L2800/13—Throttleless

Definitions

• the invention relates to a device for variable actuation of the gas exchange valves of internal combustion engines according to the preamble of claim 1.
• Such devices are used to design the control of gas exchange valves so that it becomes possible to operate reciprocating engines without the otherwise usual throttle valve.
• Such a device is known for example from DE 101 23 186 A1.
• a rotating cam first drives an intermediate link, which carries out an oscillating, pure rotary movement and carries a control cam, which is composed of a latching area and a stroke area.
• the control curve transfers the stroke curve required to actuate the valve to the role of a rocker arm-like output member, which in turn actuates the valve.
• the desired, different valve lift curves are generated in that the center of rotation of the intermediate member is shifted on an arc-shaped path which is concentric with the role of the driven member in its position when the valve is closed.
• the center of rotation is formed by a roller provided on the intermediate link, which is non-positively connected to an arc-shaped track in the housing supports, which is also concentric with the role of the output member, that is, forms an equidistant to the path of the turning center and is referred to as the backdrop.
• the roller attached to the intermediate link is supported on a cam disc, the angular position of which determines the position of the center of rotation on its arc-shaped path.
• DE 101 00 173 describes a fully variable valve train with a drive means, for example a cam, an intermediate element arranged between the drive means and the gas exchange valve, which acts indirectly on the gas exchange valve and the valve lift can be changed by adjusting an adjustable guide element.
• a drive means for example a cam
• an intermediate element arranged between the drive means and the gas exchange valve, which acts indirectly on the gas exchange valve and the valve lift can be changed by adjusting an adjustable guide element.
• the prior art device still has some disadvantages. All known devices have the disadvantage in common that, due to tolerances, the valve strokes for the individual cylinders turn out to be relatively different the further they are reduced for the purpose of load control. Furthermore, the valve lift of the gas exchange valves of the same cylinder cannot be changed independently. A complete shutdown, that is to say constant keeping of gas exchange valves, as well as the possibility of a cylinder shutdown by completely shutting off all intake and / or exhaust valves of individual cylinders, is still not known. Another disadvantage arises from the fact that the valve lift curve is adjusted during the valve lift of at least individual gas exchange valves. This requires a high adjustment force or a high adjustment torque with a high adjustment performance. The object on which the present invention is based is to create a device which avoids the disadvantages of the prior art and offers additional variabilities for mechanically fully variable valve controls.
• Claims 1 1 and 12 describe methods for operating the device according to the invention.
• the shifting of transmission elements, which cause the valve lift curve to change, is carried out in separate units for each gas exchange valve or in separate units for a plurality of adjacent gas exchange valves, these units being adjusted at least temporarily independently of one another.
• the position of the variable transmission element along the adjustment curve is preferably determined by direct or indirect contact with one or more cam disks which are attached in a rotationally fixed manner to one or more adjustment shafts.
• the cams are attached to an axially displaceable adjustment axis.
• the adjusting shaft or the adjusting axis can in turn be rotated or shifted by a adjusting motor via a suitable gear or a connecting element.
• the adjustment can of course also be carried out by hydraulic elements. If the units are guided by a linearly adjustable slide, the adjustment can also be carried out directly from the adjusting motor via a spindle provided with a movement thread.
• All embodiments have in common that the intermediate links or their cam rollers must be kept in contact with the cams by means of special springs. This is immediately apparent from the situation at zero stroke, which occurs when the cylinder is deactivated.
• the device according to the invention including an adjusting motor or an adjusting device, can be provided separately for each valve of an engine, so that any combinations of valve strokes or opening angles of the individual valves of an engine are possible, including the deactivation of individual cylinders.
• a common adjustment of several valves will be provided. This applies particularly to multi-valve engines for the intake and exhaust valves of a cylinder. For example, two intake valves can be actuated by a cam via an intermediate link which has a control curve for each valve.
• both valves are adjusted together and in the same way.
• two different control curves can also be provided on the common intermediate link, with the result of different lift curves on both valves despite common adjustment.
• This variant opens the possibility of opening only one of the two valves, particularly in the lowest load range.
• the particular advantage of this option is that very small cross-sections must be released in the lowest load range and these can be adhered to more precisely if they are only released by a valve.
• variable valve control including the device according to the invention, to keep the adjustment performance low and because this is higher when the device or its sliding joints and joints are under load than when the valve is closed, when the valve is closed largely present, an adjustment is provided according to the invention essentially during the common rest phases of all valves to be adjusted together. These are derived from the signal from the crankshaft and the camshaft and become shorter and shorter the more valves are adjusted together. Their number is therefore limited.
• the joint adjustment of the intake and exhaust valves of only one cylinder results in long, easy-to-adjust rest phases.
• it also enables individual load control of the individual cylinders with an adjustment strategy according to the invention such that the torques of the individual cylinders are regulated for each load state of the overall engine. This is particularly important in the lower load range for quiet engine operation, since the valve lifts do not normally correspond sufficiently due to tolerances.
• the signals required for this adjustment strategy are also supplied by the crankshaft angle encoder and assigned to the individual cylinders by the camshaft angle encoder.
• the shifting of transmission elements which causes the valve lift curve to change, is carried out by means of a common, rotatable adjusting shaft with cam disks.
• a common, rotatable adjusting shaft with cam disks With largely independent adjustment of all or at least several inlet and outlet valves, this offers the possibility of switching off selected valves by means of this continuous adjustment shaft, that is to say no longer opening or at least setting a smaller valve stroke.
• sections of the described cam disks of the adjusting shaft are designed as a catch for the valves which cannot be switched off.
• the latching area is a contour which is formed from a circular arc concentric to the center of rotation of the repelling shaft.
• valve stroke of the displacement units controlled by the cam disks with rest is not changed within the effective range of the rest, while the valve stroke of the displacement units controlled by the cam disks without rest is changed. This change can be made until the valve or valves are completely closed. If all intake valves and / or exhaust valves of the same cylinder are actuated in this way, the charge exchange for selected cylinders is suspended.
• the same function is achieved by using a straight wedge with a corresponding cam contour.
• the latching area is then a contour which is formed from a parallel to the pushing direction of the drawing wedge.
• Fig. 2 shows a cross section using the parts shown in Fig.1 with a pendulum support and adjusting shaft
• Fig. 3 shows a cross section through the device with slide, adjusting shaft and adjusting motor
• FIG. 4 shows a perspective illustration of the device according to the invention with a slide and adjusting shafts in a 4-cylinder in-line engine
• Fig. 5 shows schematically the interaction of engine management, accelerator pedal, angle encoder, adjusting motors and battery
• Fig. 6 is a schematic representation of a continuous adjusting shaft and a section through one of two cams for the positioning of the displacement unit of a cylinder.
• Fig. 1 shows a camshaft 1 which carries a cam 2. This moves the roller 3 in the end region of the intermediate member 4.
• the intermediate member 4 has a control cam 5, which is composed of a latching region 5a and a lifting region 5b.
• the intermediate member 4 is mounted on a bolt 6, the axis 7 of which is guided on an arc-shaped adjusting curve 8.
• the center of the arc-shaped adjustment curve 8 lies on the axis 9 of the roller 10 of the output member 11, which is supported via a joint 12 in the housing (not shown) and actuates the valve 13. It is clearly evident that an adjustment of the axis 7 on the adjustment curve 8 in the direction of the arrow 14 results in a reduction in the opening angle and stroke of the valve 13.
• Fig. 2 shows an embodiment in which the bolt 6 or its axis 7 is guided in a form-fitting manner on the circular-arc-shaped adjustment curve 8 by a pendulum support 15.
• the cylinder head-side joint 16 of the pendulum support 15 or its axis coincides with the axis 9 of the roller 10 of the output member 1 1.
• the adjusting shaft 17 carries cams 18, which determine the position of the bolt 6 or its axis 7 on the adjusting curve 8 via tappets 18a.
• An adjustment of the axis 7 on the adjustment curve 8, as represented by the arrow 14, is caused by a rotation of the cam plate 18 or the adjustment shaft 17 in accordance with the directional arrow 14a.
• the adjustment movement described results in a reduction in the stroke and opening angle of the valve 13.
• FIG. 3 shows a cross section through an embodiment according to the invention using a slide 34 which can be used separately for each valve or pair of valves. Due to the separate application for individual valves, the longest possible rest phases or common rest phases result, so that an adjustment is easily possible only during the rest phases. The separate arrangement is even necessary for the regulation of the individual cylinders according to the invention.
• the bolt 6 is guided in a form-fitting manner in the housing by the slide 34, so that its axis 7 is guided along the adjustment curve 35, a straight line. This straight line approximates as a tangent to an arc around the axis 9 of the roller 10 of the stationary output member 11 more or less well. The deviation is exaggerated in the figure.
• the adjusting shaft 17 rotates and the cam disc 1 8 according to the arrow 38b and the slide 34 together with the bolt 6 shift by Amount 38c. Due to the deviation of the straight adjustment curve 35 from the circular arc shape, the play compensation element 31 must sink in by a certain amount, which is represented by the arrow 38d.
• Fig. 4 shows a perspective view of the device according to the invention using a slide 34 which is used separately for each valve pair of a cylinder.
• the bolt 6 is guided in a form-fitting manner in the valve drive housing (not shown) by the slide 34, so that its axis 7 is guided along the adjustment curve 35, a straight line.
• This straight line only approximates a circular arc about the axis 9 of the roller 10 of the stationary output member 11 more or less well. Due to the deviation of the straight adjustment curve 35 from the circular arc shape, the play compensation element 31 must compensate for a certain amount.
• the axis 7 is adjusted on the adjustment curve 35 by turning the cam 18 or the adjusting shaft 17.
• FIG. 6 The figure shows that in each cylinder a pair of valves by means of a cam 2 and an intermediate member 4, which is mounted in a slide 34 on a pin 6, along its position in the valve drive housing an adjustment curve 35 is positively guided and positioned by means of an adjustment shaft 1 7 over cams 1 8, is actuated. If the adjusting shaft 17 of a cylinder rotates, the position of the slide 34 of this cylinder changes and thus the valve lift curve of both valves of this cylinder. The situation with the other cylinders does not change.
• a common adjusting shaft could position the displacement units of a cylinder group or a cylinder head.
• FIG. 5 schematically shows the interaction of accelerator pedal 40, adjusting motors 23, angle of rotation sensor 42 on the flywheel and angle of rotation sensor 43 on the camshaft with engine management 44.
• a signal emanating from accelerator pedal 40 or a sensor for its position is input by engine management 44 Signal to the adjusting motors 23 converted to increase or decrease the valve lifts.
• the engine management 44 evaluates the signals of the high-resolution rotation angle sensor 42 on the flywheel. These are assigned to the individual cylinders with the aid of the low-resolution rotation angle sensor 43 on the camshaft or on another shaft running at half the crankshaft speed.
• signals are sent to the individual adjusting motors 23 for leveling the torque peaks or the crankshaft speed by correcting the valve strokes of the cylinders with smaller torques upwards and those of the cylinders with larger torques downwards.
• adjustment takes place, with or without compensation, during the common rest phases of the valves operated by an adjustment motor.
• their Engine management 44 takes phase position from sensor 43 on the camshaft.
• FIG. 6 shows a schematic illustration of a continuous adjusting shaft 45 of a 6-cylinder in-line engine, as well as a section through one of two cams for the positioning of the displacement unit of a cylinder.
• the adjusting shaft carries cams 46, 47 for positioning the displacement units for the six cylinders.
• the cam disks 46 for cylinders # 1, # 4 and # 5, and the cam disks 47 for cylinders # 2, # 3 and # 6 are each the same.
• AA shows a cross section through the cam disks 46
• BB shows a cross section through the cam disks 47.
• the sector R of the cam disk 47 is formed by an arc 49 concentric to the center of rotation 48 of the adjusting shaft 45, while in the corresponding sector of the cam disk 46 the adjusting cam curve continuously increases leads to a smaller distance from the center of rotation 48.
• Such a design of the cam disks 46 and 47 ensures that when the adjusting shaft 45 is rotated about its center of rotation 48, the displacement units for the valves of the cylinders # 1, # 4 and # 5 are displaced further in the effective range of the sector R, while the displacement units for the valves of cylinders # 2, # 3 and # 6 remain at rest.
• valve gear By designing the valve gear accordingly, it can be achieved in this way, for example, that the valves of cylinders # 1, # 4 and # 5 remain permanently closed in the subsequent effective range of sector N, while the valves of cylinders # 2, # 3 and # 6 execute another stroke.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Valve Device For Special Equipments (AREA)
• Valve-Gear Or Valve Arrangements (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=33015942

Family Applications (1)

Country Status (8)

Families Citing this family (6)

Family Cites Families (16)

• 2003
  • 2003-03-24 DE DE10312958A patent/DE10312958B4/de not_active Expired - Fee Related
• 2004
  • 2004-03-17 EP EP04721188A patent/EP1608852B1/fr not_active Expired - Lifetime
  • 2004-03-17 AT AT04721188T patent/ATE522704T1/de active
  • 2004-03-17 KR KR1020057017708A patent/KR101059407B1/ko active IP Right Grant
  • 2004-03-17 WO PCT/EP2004/002740 patent/WO2004085802A1/fr active Application Filing
  • 2004-03-17 CN CNB200480007859XA patent/CN100404802C/zh not_active Expired - Fee Related
  • 2004-03-17 US US10/551,539 patent/US7302922B2/en not_active Expired - Lifetime
  • 2004-03-17 JP JP2006504706A patent/JP2006521491A/ja active Pending

Non-Patent Citations (1)

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