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
  • F01L13/0036—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
  • 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
  • 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
• • 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
  • F01L2820/04—Sensors
  • F01L2820/041—Camshafts position or phase sensors

Definitions

• the invention relates to a valve drive device according to the preamble of claim 1.
• valve train devices in particular an internal combustion engine, with at least one cam element axially displaceable cam member, which is intended to realize an adjustable valve train, and with a sensor unit, which is intended to determine an axial switching position of the cam member known.
• the invention is in particular the object of increasing a reliability of a determination of the switching position of the cam member. 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 at least one cam element axially displaceable cam element, which is intended to realize an adjustable valve train, and with a sensor unit, which is intended to determine an axial switching position of the cam member , It is proposed that the sensor unit has at least one first sensor element at least partially coupled to an axial movement of the cam element, by means of which the switching position can be determined by a corresponding sensor element.
• the term "axially” should be understood here to mean in particular axially with respect to an axis of rotation of the cam element.
• Determine in this context means in particular that the sensor unit provides a signal that can be evaluated by a computing unit, by means of which the arithmetic unit Can define switching state.
• the switching position of the cam element can be determined directly, whereby in particular a reliability of the determination of the switching position increases.
• the passive first sensor element is connected to the cam element and is sensed by the corresponding active sensor element, which is arranged stationary.
• the senor unit is designed without contact. As a result, a particularly low-wear sensor unit can be realized. In particular, an inductive method is advantageous.
• the sensor unit has at least one second sensor element at least partially coupled to a rotary movement of the cam element, by means of which a phase position can be determined by a corresponding sensor element.
• the sensor unit can be expanded meaningfully.
• the second sensor element is designed as a sensor wheel.
• the phase position can be determined very easily.
• the corresponding sensor element is designed as an active sensor element and integrally with the active sensor element for determining the axial switching position. As a result, an additional active sensor element can be saved, which in particular can reduce construction costs.
• the first sensor element is intended to define a topology.
• a topology should be understood to mean, in particular, a shaping of a surface. Such a configuration can easily generate a detectable signal, in particular by an inductive measuring method. Alternatively, a material property can also be changed, as a result of which an easily sensible sensor element can likewise be switched.
• the topology is clearly assigned to a switching position. This makes it particularly easy to determine the switching position.
• the first sensor element and the second sensor element are at least partially made in one piece.
• the sensor wheel is preferably embodied like a gear, wherein the sensor element is designed as a filled tooth gap.
• the valve drive device preferably has at least two axial sections which are provided to define the switching positions.
• axial sections in particular by axial sections of the cam element with a ner different topology, can be easily distinguished between the different switching positions of the cam member.
• the one sensor element preferably the active sensor element, is preferably stationary, and detects in one switch position the one axial section and in the other switch position the other axial section.
• the first sensor element is arranged completely in one of the sections. This makes it very easy to define the topology of the corresponding section. In particular, a different geometry of the sections can thereby be achieved.
• a circumferential groove is arranged with a flat topology between the axial portions of the sensor wheel, whereby the portions of the sensor wheel are better separable.
• a multi-part design of the sensor wheel is advantageous, wherein preferably the parts of the sensor wheel are designed spaced, resulting in a circumferential groove between the parts of the sensor wheel.
• valve drive device has a switching device which is provided to switch the first sensor element.
• a switchable sensor element can also be easily closed to a switching position, especially when the sensor element is switched in response to the switching position of the cam member.
• the switching device is provided for changing the topology as a function of the axial switching position of the cam element by means of the first sensor element. This makes it particularly easy to Sensible change of the sensor unit, by means of which the switching position can be determined, can be achieved.
• FIG. 1 shows a valve drive device with a first embodiment of a sensor unit
• FIG. 2 shows a sensor element of the valve drive device from FIG. 1, FIG.
• Fig. 3 is another view of the sensor element
• Fig. 4 shows a valve drive device with a second embodiment of a sensor unit
• Fig. 5 the sensor unit from FIG. 4 in a cross section
• Fig. 6 shows a valve drive device with a third embodiment of a sensor unit
• Fig. 7 the sensor unit of Fig. 6 in a cross section.
• FIG. 1 shows a valve drive device of an internal combustion engine with a cam element IIa axially displaceable via a shift gate 10a, which is arranged on a camshaft, not shown here, and by means of which a switchable valve train can be provided for gas exchange valves of the internal combustion engine, not shown Shift gate 10a displaceable cam element is not shown here.
• the valve drive device has a sensor unit 12a, by means of which an axial switching position of the cam element IIa can be determined.
• the axial switching position of the cam element IIa is determined by means of a first sensor element 13a of the sensor unit 12a, which is coupled to an axial movement of the cam element IIa.
• a corresponding sensor element 14a which is designed as an active sensor element 14a, is arranged stationary.
• the sensor unit 12a is designed contactless.
• the sensor unit 12a can determine a phase angle of the cam element IIa by means of the same active sensor element 14a and a second sensor element 15a, which is coupled to a rotational movement of the cam element IIa.
• the second sensor element 15a is designed for this purpose as a sensor wheel, which is non-rotatably connected to the cam element IIa. It has two axial sections 17a, 18a. An average distance 29a between the sections 17a, 18a of the second sensor element 15a corresponds to an axial switching path of the cam element IIa (FIG. 2).
• Both parts of the second sensor element 15a designed as a sensor wheel have a gear-like structure, by means of which current pulses are induced in the active sensor element 14a, by means of which the phase position can be determined.
• As the first sensor element 13a one of the tooth spaces 20a between the teeth 21a of the second sensor element 15a designed as a sensor wheel is filled in the first portion of the second sensor element 15a.
• the first sensor element 13a is embodied in one piece with the second sensor element 15a and thus defines a topology 16a sensed by the active sensor element 14a. Each section 17a, 18a is thus clearly assignable to a switching position of the cam element IIa.
• the first section 17a of the second sensor element 15a has an irregularity due to the first sensor element 13a, which is used to determine the switching position of the cam element IIa.
• the second section 18a of the second sensor element 15a has circumferentially regularly arranged tooth gaps 20a and teeth 21a.
• a signal characteristic of the active sensor element 14a has an increased distance between two signals at a constant rotational speed between the other signals. If the cam element IIa is in the second switching position, the signal profile of the active sensor element 14a is regularly at equal intervals between all signals. As a result, both the switching position and the phase position of the cam element IIa can be determined by means of the sensor unit 12a.
• FIGS. 4 and 5 show a further embodiment of a valve drive device with a sensor unit 12b.
• the letter a in the reference numerals of the embodiment in Figures 1 to 3 is replaced by the letters b and c in the reference numerals of the embodiments in Figures 4-7.
• the following description is essentially limited to the differences from the exemplary embodiment in FIGS. 1 to 3, wherein reference can be made to the description of the exemplary embodiment in FIGS. 1 to 3 with regard to components, features and functions remaining the same.
• the exemplary embodiment in FIGS. 4 and 5 has a second sensor element 15b, which has an axial width, which is at least the same size as an axial switching path of a cam element IIb.
• the second sensor element 15b is formed as a sensor wheel and has a gear-like structure.
• One of the teeth 21b of the second sensor element 15b is designed as a first sensor element 13b. By means of the first sensor element 13b, a topology of the second sensor element 15b can be switched.
• the first sensor element 13b In a first switching position of the cam element IIb, the first sensor element 13b is retracted and has a radial height which corresponds approximately to a base circle level of the second sensor element 15b designed as a sensor wheel (FIG. 4). In a second switching position of the cam element IIb, the first sensor element 13b is extended and has a radial height which is in particular greater than the radial height in the first switching position of the cam element IIb and substantially a radial height of the remaining teeth 21b of the second sensor element 15b corresponds (Fig. 5).
• a "radial height” is to be understood in particular as meaning a radial distance of a surface of the first sensor element 13b running in the circumferential direction from a rotation axis 22b of the cam element IIb.
• the sensor unit 12b In order to change a topology 16b of the second sensor element 15b as a function of an axial switching position of the cam element IIb, the sensor unit 12b has a switching device 19b, by means of which the radial height of the first sensor element 13b can be changed.
• the switching device 19b has a recess 23b, which is introduced into a camshaft 26b.
• the recess 23b has at one end a radially outwardly extending bevel 24b.
• a spring unit 25b with a spiral spring exerts on the first sensor element 13b a radially inwardly directed force.
• the first sensor element 13b is pressed radially outward via the bevel 24b.
• the first sensor element 13b, the second sensor element 15b and the cam element IIb are rigidly connected to each other for axial movement.
• the second sensor element 15c is fixedly connected to a camshaft 26c of the valvetrain device.
• the second sensor element 15c is designed as a perforated disc, wherein a main extension plane of the second sensor element 15c runs perpendicular to a rotation axis 22c of a cam element 11c or the camshaft 26c.
• An active sensor element 14c which determines a phase angle of the cam element 11c by means of the second sensor element 15c, is arranged parallel to the rotation axis 22c.
• the sensor unit 12c has a first sensor element 13c which is connected fixedly to the cam element 11c via a holding device 27c and which thus forms a switching element.
• direction 19c forms.
• the first sensor element 13c is arranged on a side of the second sensor element 15c facing away from the active sensor element 14c and has a size which corresponds to a size of a corresponding opening 28c of the second sensor element 15c designed as a perforated disk.
• the first sensor element 13c In a first switching position, the first sensor element 13c is located outside the openings 28c of the second sensor element 15c, whereby the active sensor element 14c detects all openings 28c. In a second switching position of the cam element 11c, the first sensor element 13c fills one of the openings 28c of the second sensor element 15c, as a result of which a signal of the active sensor element 14c changes. Due to the signal of the active sensor element 14c, both the phase position and the switching position of the cam element 11c can thus be determined.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Valve Device For Special Equipments (AREA)
• Valve-Gear Or Valve Arrangements (AREA)
• Gears, Cams (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=40319427

Family Applications (1)

Country Status (6)

Families Citing this family (15)

Family Cites Families (6)

• 2007
  • 2007-11-17 DE DE102007054979A patent/DE102007054979A1/de not_active Withdrawn
• 2008
  • 2008-10-18 WO PCT/EP2008/008843 patent/WO2009062587A1/de not_active Ceased
  • 2008-10-18 JP JP2010533454A patent/JP2011503426A/ja not_active Abandoned
  • 2008-10-18 CN CN200880116162A patent/CN101861449A/zh active Pending
  • 2008-10-18 EP EP08850850A patent/EP2207949A1/de not_active Withdrawn
• 2010
  • 2010-05-14 US US12/800,478 patent/US20100242873A1/en not_active Abandoned

Non-Patent Citations (1)

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