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
  • F01L1/02—Valve drive
  • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
  • F01L1/047—Camshafts
• • 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
• • 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
  • F01L2013/0052—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 provided on an axially slidable sleeve

Definitions

• the invention relates to a valve drive device according to the preamble of claim 1.
• valve train devices in particular of internal combustion engines, with a camshaft, with at least one cam element axially displaceable on the camshaft, and with an abutment device intended to limit a travel in an axial direction of the cam element.
• the invention is in particular the object of reducing an internal friction force of the valve drive device, thereby increasing an efficiency of an internal combustion engine with a valve drive device according to the invention. It is achieved according to the invention by the features of claim 1. Further embodiments emerge from the subclaims.
• the invention is based on a valve drive device, in particular an internal combustion engine, with a camshaft, with at least one cam element displaceable axially on the camshaft, and with a stop device which is provided to limit a travel in an axial direction of the cam element.
• the stop device has at least one stop means connected to the camshaft, whereby a relative rotation between the camshaft and the rotating stop means can be avoided.
• an internal friction force of the valve drive device can thereby be reduced, as a result of which an efficiency of the internal combustion engine can be increased.
• An introduction of lubrication grooves can be omitted.
• axially here and below are to be understood as meaning, in particular, axially with respect to an axis of rotation of the camshaft, and the axial direction is also defined by the axis of rotation.
• the stop device has a second stop means, whereby the path in the axial direction of the cam member can be advantageously restricted in two directions.
• a stop device for both cam elements can be easily realized by means of the two stop means.
• the limitation of the path of the at least one cam element takes place in at least one of the two axial directions indirectly via at least one further element and the stop device.
• the at least one further element is a cam element.
• the stop means is designed as an elevation over a camshaft base circle, advantageously a production-technically simple design of the stop means can be achieved, as a result of which the production costs are further reduced.
• a “camshaft base circle” should be understood to mean, in particular, a circle which, in a cross-sectional area, in particular in a cross-sectional area in which the abutment means lies, can be inserted into the camshaft perpendicular to the axis of rotation with a maximum radius.
• At least one stop means of the stop device is designed as a bolt, whereby a production can be particularly simple and inexpensive.
• the second stop means is designed as a bolt.
• the stop means designed as a bolt it is also possible to use other stop means which appear suitable to the person skilled in the art, such as, for example, a camshaft-fixed stop ring.
• the camshaft has a receiving device, which is provided to receive at least the first stop means.
• the stop means can be easily connected to the camshaft, whereby the frictional force between the stop means and the stop surfaces can be avoided because no relative rotation can take place.
• the cam element has at least one stop surface, which is provided so that at least one stop means rests temporarily.
• the stop surface is at least partially formed as an end face of the cam member.
• the term "front side” is to be understood as meaning, in particular, an area which is axially bounded by a component and arranged approximately perpendicular to an axis of rotation of the camshaft. "Approximately” is to be understood in this context as meaning a deviation of not more than 20%, whereby a deviation of 5% is advantageous and a deviation of 0% is particularly advantageous.
• only one of the two end face is at least partially formed as a stop surface for the stop means, while a second end face is provided to produce a positive contact with the second cam member and thus in particular to form a stop surface for the second cam member.
• the cam member has a, a recess forming boundary surface, which is at least partially formed as a stop surface.
• the valve drive device has a latching device, which is provided to exert an axial force on the cam element in at least one switching position.
• a position of the cam element can be advantageously kept and, in particular, stabilized.
• the latching device on Einrastaus traditions which are formed as inclined grooves.
• a "oblique groove” is to be understood in particular as a latching recess which has at least one oblique surface in the axial direction
• the inclined surface preferably includes an angle not equal to zero and less than 90 degrees with the axis of rotation, the angle being in particular on one side
• FIG. 1 is a perspective view of a valve drive device with a camshaft, with two axially displaceable on the camshaft cam elements and with a stop device,
• valve drive device in a cross section along the line U-Il
• FIG. 1 A first figure.
• Fig. 4 is a perspective view of a valve drive device in a second embodiment
• valve drive device in a cross section along the line V-V
• FIGS 1, 2 and 3 show an inventive embodiment of a valve drive device for an internal combustion engine.
• the valve drive device has two cam elements 11a, 12a arranged on a camshaft 10a, each with two cam pairs 28a, 29a, 30a, 31a for different cylinders.
• Each cam pair 28a, 29a, 30a, 31a has two differently configured cams 32a, 33a each with a same base circle radius 34a, the cams 32a, 33a respectively for different operating modes such as a firing mode and an engine braking mode or a low speed range and a high speed Speed range, designed differently.
• the two cam elements 11a, 12a are arranged displaceably on the camshaft 10a in the axial direction 14a.
• a multi-tooth connection 35a By a multi-tooth connection 35a, the camshaft 10a and the two cam elements 11a, 12a are rotatably connected to each other.
• a first switching position see Fig. 1, 2) of the cam elements 11a, 12a
• the respective first cam 32a of Cam pairs 28a, 29a, 30a, 31a make contact with a cam follower not shown here, whereby a corresponding unshown gas exchange valve is then actuated by a rotation of the cam member 11a, 12a about an axis of rotation 36a.
• Cam elements 11a, 12a, the respective second cam 33a of the cam pairs 28a, 29a, 30a, 31a make contact with another cam follower, not shown, which then by the rotation of the cam member 11a, 12a about the rotation axis 36a a corresponding further unspecified Gas exchange valve is actuated.
• the valve drive device has an actuating device by means of which the cam elements 11a, 12a can be displaced from a first shift position to a second shift position or vice versa.
• the displacement in the axial direction 14a of the cam elements 11a, 12a is defined by a switching path 40a of a shifting gate 37a with two cam tracks 38a, 39a.
• the switching path 40a corresponds to a mean distance between the two cams 32a, 33a of a cam pair 28a, 29a, 30a, 31a.
• the actuating device has two actuating pins 41a, 42a, which can engage in the slide tracks 38a, 39a of the shift gate 37a, whereby the cam elements 11a, 12a can be displaced axially by means of the rotation of the camshaft 10a.
• the valve drive device has a latching device 26a, by means of which the cam elements 11a, 12a engage in the switch positions. Furthermore, an axial force 27a is applied to the cam elements 11a, 12a by the latching device 26a.
• the locking device 26a has two detent ball 43a, 44a, a compression spring 45a and on the inner sides of the two cam elements EinrastausEnglishept 46a, 47a, 48a, 49a, which are formed as helical grooves.
• the compression spring 45a exerts on the detent balls 43a, 44a a radially directed force.
• the axial force 27a is transmitted to the cam elements 11a, 12a.
• two Einrastaus founded ausis 46a, 47a, 48a, 49a are arranged.
• the detent balls 43a, 44a are arranged in the camshaft 10a in a recess 50a which is formed as a bore passing radially through the camshaft 10a.
• the valve drive device has a stop device 13a with two stop means 15a, 16a and stop surfaces 20a, 21a, by means of which the displacement in the axial direction 14a of the two cam elements 11a, 12a is limited.
• the stop means 15a, 16a which have a survey on a camshaft base circle 17a, are designed by means of bolts.
• Two receiving devices 18a, 19a receive the stop means 15a, 16a formed as bolts.
• the receiving devices 18a, 19a are designed as radial, continuous holes in the camshaft.
• a length 51a of the stop means 15a, 16a, which is designed as a bolt, is larger than a diameter 52a of the camshaft 10a, wherein the protuberances formed as projections of the bolt on the camshaft base circle 17a are approximately equal and are arranged diametrically opposite each other (see FIG 3).
• Axially with respect to the shift gate 37a outer end faces 22a, 23a of the two cam elements are partially formed as two abutment surfaces 20a, 21a of the total four abutment surfaces 20a, 21a, 53a, 54a.
• the further abutment surfaces 53a, 54a located axially in relation to the shift gate 37a are arranged between the cam elements 11a, 12a, wherein the one abutment surface 53a is the first cam element 11a and the other abutment surface 54a is the second
• Cam element 12a is assigned.
• the stop surfaces 53a, 54a are formed complementary.
• the displacement of the cam elements 11a, 12a which is performed by means of the shift gate 37a, switches from the first to the second switching position. Starting from the first switching position, first the second cam element 12a is displaced. During the Displacement of the second cam member 12a, the second detent ball 44a is pushed out of the second EinrastausEnglishung 49a and locks after the displacement in the first Einrastausnaturalung 48a.
• the second cam element 12a is now in the second switching position and is clamped between the second stop means 16a and the detent ball 44a by the axial force 27a, which exerts the detent device 26a on the cam element 12a in the direction of the second stop means 16a.
• Cam member 12a by the axial force 27a, which exerts the latching device 26a on the cam member 11a in the direction of the second stop means 16a, clamped. Both cam elements 11a, 12a are located after their displacement in the second switching position.
• FIGS. 4 and 5 show an alternative embodiment of a valve drive device with a stop device 13b.
• the letter a in the reference numerals of the embodiment in Figures 1, 2 and 3 by the letter b in the reference numerals of the embodiments in Figures 4 and 5 is replaced.
• the following description is essentially limited to the differences from the exemplary embodiment in FIGS. 1, 2 and 3, wherein reference can be made to the description of the exemplary embodiment in FIGS. 1, 2 and 3 with regard to components, features and functions remaining the same.
• FIG. 4 shows a first cam element 11b, which is arranged displaceably in the axial direction 14b on a camshaft 10b.
• the camshaft 10b has a stopper 15b made by a bolt.
• the stop means 15b has two elevations via a camshaft base circle 17b and is arranged axially between end face 22b and a stop face 53b of a first cam element 11b.
• the stop means 15b engage in a recess 24b in the cam member 11b.
• a boundary surface 25b forming the recess 24b has a stopper surface 20b defining a path in the axial direction 14b of the cam member 11b.
• the abutment surface 20b is located on a partial surface of the boundary surface 25b of the recess 24b lying in the direction of a shift gate 37b.
• a second partial surface which lies axially opposite the first partial surface can also be formed as a further stop surface.
• a dimension of the recess 24b in the axial direction 14b is greater than a dimension of the stop means 15b, wherein an axial displacement of the first cam member 11b is made possible from a first switching position to a second switching position and vice versa. In the first switching position is the
• Cam element 11b are clamped between the stop surface 20b on the boundary surface 25b and a detent ball 43b. Similarly, the second cam member 12b is clamped in the second switching position.
• the second cam member 12b is configured equivalently. A description and a representation of the second cam member 12b is therefore omitted here.

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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)

Applications Claiming Priority (2)

Publications (1)

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• 2008
  • 2008-01-23 DE DE102008005639.1A patent/DE102008005639B4/de active Active
  • 2008-12-18 EP EP08871243A patent/EP2232020A1/de not_active Withdrawn
  • 2008-12-18 CN CN2008801237040A patent/CN101910569A/zh active Pending
  • 2008-12-18 JP JP2010543385A patent/JP2011510220A/ja active Pending
  • 2008-12-18 WO PCT/EP2008/010807 patent/WO2009092427A1/de not_active Ceased
• 2010
  • 2010-07-19 US US12/804,289 patent/US8387579B2/en not_active Expired - Fee Related

Non-Patent Citations (1)

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