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
  • F01L13/0015—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
  • 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
  • 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
  • F01L2800/13—Throttleless
• • 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
  • F01L2820/00—Details on specific features characterising valve gear arrangements
  • F01L2820/03—Auxiliary actuators
  • F01L2820/032—Electric motors

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 1 01 23 1 86 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 output member in its position when the valve is closed.
• the center of rotation is formed by a roller provided on the intermediate member, which is non-positively supported on an arc-shaped track in the housing, which is also concentric with the role of the output member, that is forms an aquidistante to the path of the turning center and which is called 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.
• the roller attached to the intermediate link only bears against the link if the gas and ace forces of the valve train are directed accordingly and the role is actually supported on the link. If this is not the case, which can happen at overspeed, the frictional connection is lost and lifting takes place, which can lead to noise and even damage when it is replaced. Added to this are the relatively difficult machining of the scenes as segments of an inner cylinder, which cannot be processed continuously, and the inadequate hardness of common housing materials for the roller-scenery contact. With regard to assembly, there is a disadvantage that the control housing cannot be completely pre-assembled on the cylinder head.
• the solution provides that the centers of rotation of the intermediate elements driven by the cam are guided by positive guides, that is to say in a form-fitting manner on the adjustment curve. This ensures that the center of rotation of an intermediate link cannot leave the adjustment curve, so that noises and damage that could be attributed to leaving are avoided.
• this feature is preferably realized in that one or more intermediate links are mounted on a cylindrical bolt, on the axis of which the centers of rotation lie, and that the axis of the bolt is inevitably guided on the adjustment curve.
• the active surface on the output member, to which the control cam of the intermediate member transmits its movement is circular-cylindrical, e.g. is formed by a roller, a circular arc-shaped adjustment curve can be assumed, the center of which coincides with the center of the circular cylindrical active surface or the roller.
• Such an adjustment curve is realized according to a further proposal according to the invention by pendulum supports which are connected via their respective first joint to the cylinder head or the control housing and with their respective second joint to the bolt.
• the cylinder head side the joints common axis coincides with the axis of said cylindrical active surfaces ⁇ on the driven member along which the bolt-side joints with the Pin axis.
• the bolt or its axis can also be positively guided on the adjustment curve with articulated quadrilaterals formed from pendulum supports.
• the adjustment curve that can be realized in this way comes close to the shape of a circular arc and fulfills this exactly at the design point when the system lines meet at the center of the circular arc.
• the deviations outside the design point are absorbed by hydraulic lash adjusters, which are to be provided on the rocker arm-like or straight-guided output links.
• the pin is guided by a slide that is linearly adjustable in the control housing.
• a slide that is linearly adjustable in the control housing.
• the position of the bolt or its axis on the respective 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 on the one hand, by means of a suitable gear or a connecting element, of an adjusting means, for example an adjusting motor, are rotated or displaced.
• the adjustment can of course also be carried out by hydraulic elements. If the bolt is guided by a linearly adjustable slide, the adjustment can also be made directly from the adjusting motor via a spindle provided with a movement thread.
• a particularly advantageous variant of the three embodiments in terms of installation space and variety of parts is to simultaneously design the bolt on which the intermediate members are mounted as an adjusting shaft by providing cam discs, rotatably mounted in the pendulum supports, the four-bar linkage or the slide and by an adjusting means , for example an adjusting motor, is rotated in accordance with the desired valve lift curve.
• slide pieces for the cam disks made of a material of increased strength must be provided in the control housing. Since the adjustment motor will generally be fixed to the housing, but the bolt or the control shaft moves parallel to itself during the adjustment movement, a connecting element must be arranged between the two, which permits this displacement.
• this can be a cardan shaft, a Schmidt clutch, an Oldham clutch or a gear or chain gear.
• a lever mechanism is also suitable for hydraulic actuation.
• 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.
• two intake valves can be actuated by a cam via an intermediate link which has a control curve for each valve. Since there is only one intermediate link and only one pin, 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 the 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.
• the possibilities of generating different valve lift curves for two intake or exhaust valves of a cylinder are expanded according to the invention in that two different cams and two intermediate links with different control curves are used. Nevertheless, both valves can be adjusted together, since the two intermediate links can be mounted on a common pin.
• variable valve control that is also the device according to the invention, to keep the adjustment performance low and because this is higher in the loaded state of the device or its sliding joints and joints than in the non-energized state which largely closed valve
• 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 largely independent adjustment of the inlet and outlet valves offers the possibility of switching off selected valves by means of a continuous adjustment shaft, that is to say no longer opening or at least setting a smaller valve lift.
• sections of the described cam disks of the adjusting shaft are designed as a catch for the valves that cannot be switched off.
• the latching area is a contour which is formed from a circular arc concentric with the center of rotation of the adjusting shaft.
• Fig. 2 shows a cross section using the parts shown in Fig.1 with a pendulum support and adjusting shaft
• Fig. 3 is a perspective view of the device according to the invention with a pendulum support and the bolt as an adjusting shaft
• Fig. 4 shows a cross section through the device with four-bar linkage and adjusting shaft
• FIG. 5 is a perspective view of the device of FIG .. 4
• Fig. 6 shows a cross section through the device with slide, adjusting shaft and adjusting motor
• Fig. 7 shows schematically the interaction of engine management, accelerator pedal, angle encoder, adjusting motors and battery.
• 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 1 1, which is supported via a joint 1 2 in the housing, not shown, and actuates the valve 1 3. 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 1 3.
• 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 1 6 of the pendulum support 1 5 or its axis coincides with the axis 9 of the roller 1 0 of the output member 1 1.
• the adjusting shaft 1 7 carries cams 1 8, which determine the position of the bolt 6 or its axis 7 on the adjusting curve 8 via tappet 1 8a.
• An adjustment of the axis 7 on the adjustment curve 8, as represented by the directional arrow 14, is caused by a rotation of the cam disk 1 8 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 perspective view of the device according to the invention with a pendulum support 15 for inlet valve 19 and outlet valve 20 of a cylinder, picked out from a series of cylinders or valves.
• the cylinder head-side joint 1 6 of the pendulum support 1 5 is clearly visible, the axis of which coincides with the axis 9 of the rollers 10 of the output members 11, so that the bolt 6 is positively guided on an arc-shaped adjustment curve.
• the Bolt 6 according to the invention simultaneously the function of the adjusting shaft. He carries the cams 1 8, which are supported on the attached, hardened sliders 21 and is rotatable in the pendulum support.
• the bolt 6 is connected to the adjusting motor 23 fixed to the housing via a suitable connecting element.
• an articulated shaft 22 serves as a connecting element.
• This embodiment offers considerable advantages with regard to the variety of parts, but also space in the area of the actual valve control. Since other connecting elements, such as Schmitt couplings, Oldham couplings, toothed and chain gears, can also be used in addition to cardan shafts, there is a certain flexibility for accommodating the adjusting motor 23.
• Fig. 4 shows a further embodiment according to the invention for a valve or. Cylinder arrangement as in Fig. 3 in cross section.
• the pin 6 is positively guided by four-bar linkages (24, 25, 26, 27) on an adjustment curve 28 which comes close to a circular arc shape. If the system lines 29 and 30 meet on the axis 9 of the roller 10 of the output member 11, the instantaneous center of rotation of the bolt is even there. The deviations in the remaining area must be absorbed by the game compensation element 31.
• the bolt 6 could assume the function of an adjusting shaft, as shown in FIG. 3. However, as shown, a separate adjusting shaft 17 with cams 18 can also be used.
• the embodiment shown is particularly suitable for a pre-assembly of valves including springs, levers and play compensation elements in the cylinder head as the lower housing part and a complete pre-assembly of all other parts in the control housing as the upper part.
• the bearing blocks 32 for the joints 24 and 26 can be screwed in the same plane as the cover 33 of the camshaft bearing.
• FIG. 5 shows a perspective illustration of the device according to FIG. 4.
• Inlet valve 19 and outlet valve 20 of the cylinder picked out can be seen better, as well as the direct actuation of the pin 6 by the cam. venusionn 1 8. It can be clearly seen that not only the bolt 6 and the camshaft 1 in the upper part of the housing, the control housing, can be preassembled, but also the adjusting shaft 1 7.
• FIG. 6 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, the longest possible rest phases or common rest phases result, so that an adjustment is only possible 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 only approximates a circular arc about the axis 9 of the roller 10 of the stationary output member 11 more or less well. 6, the deviation is exaggerated.
• the adjusting shaft 17 and the cam disc 1 8 rotate according to the arrow 38b and the slide 34 together with the bolt 6 in the direction 38c. Due to the deviation of the straight line 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. 7 schematically shows the interaction of accelerator pedal 40, adjustment 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 actuators 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 will assigned to the individual cylinders with the aid of the low-resolution angle of rotation 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.
• the engine management 44 also takes their phase position from the sensor 43 on the camshaft.

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

Applications Claiming Priority (3)

Publications (2)

Family

ID=33038742

Family Applications (1)

Country Status (5)

Families Citing this family (8)

Family Cites Families (21)

• 2003
  • 2003-03-24 DE DE10312959A patent/DE10312959B4/de not_active Expired - Fee Related
• 2004
  • 2004-03-17 WO PCT/EP2004/002743 patent/WO2004085804A1/fr active IP Right Grant
  • 2004-03-17 AT AT04721181T patent/ATE409801T1/de not_active IP Right Cessation
  • 2004-03-17 US US10/551,540 patent/US7296546B2/en not_active Expired - Lifetime
  • 2004-03-17 EP EP04721181A patent/EP1608851B1/fr not_active Expired - Lifetime
  • 2004-03-17 DE DE502004008152T patent/DE502004008152D1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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