Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/06—Electromagnets; Actuators including electromagnets
  • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
  • H01F7/18—Circuit arrangements for obtaining desired operating characteristics, e.g. for slow operation, for sequential energisation of windings, for high-speed energisation of windings
  • H01F7/1844—Monitoring or fail-safe circuits
• • 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
  • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
  • F01L9/20—Valve-gear or valve arrangements actuated non-mechanically by electric means
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
  • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
  • G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
  • G01D5/145—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the relative movement between the Hall device and magnetic fields
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F7/00—Magnets
  • H01F7/06—Electromagnets; Actuators including electromagnets
  • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
  • H01F7/18—Circuit arrangements for obtaining desired operating characteristics, e.g. for slow operation, for sequential energisation of windings, for high-speed energisation of windings
  • H01F2007/1894—Circuit arrangements for obtaining desired operating characteristics, e.g. for slow operation, for sequential energisation of windings, for high-speed energisation of windings minimizing impact energy on closure of magnetic circuit

Definitions

• Electromagnetic actuators which essentially consist of at least one electromagnet and an armature connected to the actuator to be actuated, which can be moved against the force of a return spring when the electromagnet is energized, have a high switching speed.
• bouncing processes can occur. H. the anchor first hits the pole face, but then lifts off, at least briefly, until it finally comes to rest. This can impair the function of the actuator, which can lead to considerable malfunctions, particularly in the case of actuators with a high switching frequency.
• the impact speeds are of the order of magnitude below 0.1 m / s. It is important here that such low impact speeds must be ensured under real operating conditions with all the associated stochastic fluctuations. External interference, such as vibrations or the like, can lead to a sudden drop in the final approach phase or even after contacting the pole face.
• an electromagnetic actuator for actuating a gas exchange valve on an internal combustion engine on which a measuring means is provided for contactless determination of the position of the valve, which is an element connected to the valve stem for generating a predetermined magnetic field and at least one contain a magnetic field sensitive sensor, which has an increased magnetoresistive effect layer system with a measuring layer for detecting the magnetic field, the magnetic field generating element is to be guided relative to the magnetic field sensitive sensor such that the components of the magnetic field impinging on the measuring layer with a reference axis in enclose an average angle of the measuring layer plane which is clearly correlated with the respective position of the magnetic field sensitive sensor relative to the magnetic field generating element.
• a measuring means for contactless determination of the position of the valve, which is an element connected to the valve stem for generating a predetermined magnetic field and at least one contain a magnetic field sensitive sensor, which has an increased magnetoresistive effect layer system with a measuring layer for detecting the magnetic field, the magnetic field generating element is to be guided relative to the magnetic field sensitive sensor such that the
• this system requires a large overall height, which is not practical for a series application on internal combustion engines. Furthermore, there is the problem that the changing magnetic field, in particular the stray field of the electromagnet, overlaps with the "predetermined" magnetic field and thus falsifies the measurement.
• the sensor of the previously known system does not react to the changing magnetic field strength, but the superimposition of an interference field changes the resulting direction of the entire magnetic field at the sensor. Accordingly, it is also necessary to provide additional magnetic shielding.
• the invention has for its object a method for
• This object is achieved according to the invention with a method for motion detection, in particular for controlling the armature impact speed on an e-spectral actuator with at least one electromagnet, which at least has a pole face and is connected to a controllable power supply, and which has an armature which is connected to the actuator to be actuated and which, when current is supplied to the electromagnet, against the force of a return spring from a first switching position in the direction of the pole face of the electromagnet is movably guided into a second switching position given by the system on the pole face, with at least one direction detection sensor assigned to the electromagnet detecting the orientation of the magnetic stray field which changes when the armature approaches and an actuating signal for the power supply is triggered in accordance with the change in orientation.
• the method according to the invention does not work with two different magnetic fields but only with one magnetic field, namely the magnetic field of the one acting on the armature
• Electromagnets The fact that the direction of this magnetic field changes due to the changing position of the armature in relation to the pole face of the electromagnet is also advantageously used, the current level being practically irrelevant. Any saturation effects that occur can be eliminated by correcting the sensor signal by correcting the path signal from a previously determined deviation as a function of the current level.
• the field line course of the stray field is oriented essentially parallel to the direction of movement of the armature when the armature is at a great distance from the pole face.
• the field lines are only "bent" directly at the anchor, so that they run at an angle to the direction of movement.
• the direction detection sensor is now assigned to the electromagnet in such a way that, with the armature still removed, it is penetrated essentially by the field lines running parallel to the direction of movement of the armature and is only penetrated essentially transversely by the field lines in the area of proximity of the armature to the pole face, the direction change a corresponding electrical signal can be triggered, which is used to change the power supply to the electromagnet. Due to the axial position of the direction detection sensor relative to the plane of the pole face, the distance between the armature and the pole face can now be specified in which the control intervention for changing the energization of the electromagnet is to be triggered.
• a particular advantage is that changes in the orientation of the magnetic field can be detected over a large distance of the armature movement and, accordingly, the current supply to the electromagnet can be tracked continuously.
• a very sensitive detection of the armature position in relation to the pole face can be achieved, which is given when the directional detection sensor is penetrated by the field lines just perpendicular to the direction of movement of the armature and thus gives the greatest change for the resulting signal is.
• This means that very precise control can take place at the end of the movement - shortly before touchdown - because a very precise, high-resolution path signal is available.
• the field line course of the magnetic stray field is detected laterally next to the pole face via the direction detection sensor.
• At least two direction detection sensors are provided in different orientations to one another and to the electromagnet. This provides the opportunity to form a reference signal and to improve the signal formation.
• 2 schematically shows the course of the magnetic field on one of the electromagnets of the actuator with a large armature distance
• 3 shows the course of the magnetic field on the electromagnet with a small armature distance
• a gas exchange valve GWV for a piston internal combustion engine is shown schematically, which is provided with an electromagnetic actuator EMA as a valve train.
• the actuator EMA consists essentially of a closing magnet 2.1 and an opening magnet 2.2, between which an armature 1 is guided back and forth against the force of return springs RF, which are only schematically indicated here, in accordance with the energization of the electromagnets 2.
• the two possible switching positions of the gas exchange valve GWV forming the actuator are each defined here by the armature being in contact with one of the two electromagnets 2.
• armature In Fig. 1 the armature is shown in its intermediate position after it is moved in the direction of the opening magnet 2.2 by releasing the closing magnet 2.1 by the force of the associated spring RF 1.
• the control method for energizing the opening magnet 2.2 is described below, only identified by reference number 2 below, since the energization of the closing magnet 2.1 takes place analogously.
• the movement process of the Armature 1 is controlled by energizing the magnet 2.
• the current is made available by the current regulator 3, which in turn receives its commands for current supply from a motor control (ECU) 4.
• ECU motor control
• At least the switch-off signals for current 6 are passed to the current controller.
• an operating current-dependent setpoint value 7, which is dependent on the operating point, for example, can be specified by the engine control 4.
• a direction detection sensor 8 is used to change the orientation of the field line course of the control field
• Electromagnet 2 detects a signal in dependence of the fell -1 changing anchor position, after evaluation by the signal conditioning 9 as a displacement signal 10 and / or Geschvindig- is keitssignal a Wegregelungsaku 12 will provide 9 e ⁇ . This generates the control signal 13.
• the signal 10 does not necessarily have to reproduce the path or the speed exactly, for example linearly " , rather a signal is sufficient in each case which provides corresponding information about the path or the speed or also in relation to one contains the given distance of the armature 1 to the pole face of the electromagnet 2.
• a measuring device is also conceivable which provides the path signal non-linearly, that is, when the armature comes very close, it has a greater path dependency than when the armature is further away.
• the data obtained in the signal processing 9 values for the change in orientation of the magnetic field and thus practicing * position control "12" the position of the armature in the block are "processed processes, so that the current supply to the respectively activated electromagnets, here the electromagnet 2.2, can then be regulated via the current regulator 3 and its control via the motor control 4 such that a magnetic force acts on the armature 1 when the pole face is approached, which is dimensioned such that the anchor ultimately hits at a low speed.
• FIGS. 2 and 3 schematically show the electromagnet 2 when it flows through its coil 14, but at different distances from the armature 1 to the pole face 15.
• the magnetic field 16 with its magnetic lines is only shown for the right part of the coil 14 ' .
• the magnetic field 16 has an outward distortion in the form of a stray field 17.
• the orientation of the stray field 17 is significant in the area of the armature 1, since the field lines of the stray field 17 are oriented practically perpendicular to the direction of movement of the armature (arrow 18).
• a direction detection sensor 8 for example a GiantMagnetic Resistance, is attached in the area of the stray field 17 directly next to the movement area of the armature 1
• the direction detection sensor 8 is expediently designed in such a way that a flooding signal in the direction of movement 18 produces a weak signal and in the case of a flooding perpendicular to the direction of movement 18 due to the changed direction of flooding and also due to the increased magnetic flux due to the bundling in this area a stronger signal becomes.
• This signal can then, as shown in FIG. 1, be applied to the signal processor 9 and used accordingly to regulate the energization of the capturing electromagnet 2.
• a control signal can also be triggered as a one-off control intervention when a maximum is reached, depending on the sensitivity of the directional detection sensor used. Or it is also possible to detect the change in the orientation of the magnetic field as a function of time and not only to continuously determine the position or the distance of the armature from the pole face, but also to carry out an evaluation with regard to the respective armature speed.
• two direction detection sensors 8.1 and 8.2 are provided. These sensors are designed so that they emit the strongest signal when they are flooded vertically. Accordingly, the two cattle tion detection sensors 8.1 and 8.2 arranged at a right angle to each other so that the direction detection sensor 8.1 is able to detect the change in the field line course in the approach phase of the armature 1 remote from the pole face and the change in the field line course is detected via the second direction detection sensor 8.2 when the armature 1 is in the last phase of approach to the pole face 15.
• the corresponding actuating signal can then be generated for connection to the path control unit 12. Even a small current dependency can be compensated for by using two sensors by combining the two signals, for example by forming quotients.
• FIG. 7 schematically shows an electromagnet, for example electromagnet 2.2 of the exemplary embodiment according to FIG. 1.
• electromagnets of this type with a W-shaped yoke body 2.3, the arrangement of the yoke body, which is designed as a ring, results in the grooves of the yoke body
• a direction detection sensor 8 into the yoke body 2.3 in the manner shown, namely by arranging it on the pole face 15 or partially recessed into the pole face 15.
• the direction detection sensor 8 projects above the pole face 15. Accordingly, a recess 19 of corresponding size is arranged in the armature 1, which causes the required distortion of the magnetic field in the manner of a stray field, so that when the armature 1 approaches and the direction detection sensor 8 is immersed in the recess 19 the resulting change in direction of the field lines can be detected.
• the direction sensor 8 relative to the plane of symmetry of the yoke body 2.3, and the recess 19 in the armature 1 are arranged correspondingly off-center, so that when the armature 1 approaches the pole face 15 it is also ensured that the direction detection sensor 8 is flooded in every position of the anchor.
• the second switching position assigned to the pole face 15 in accordance with the definition given here can now either be given by the direct contact of the armature 1 on the pole face 15 of the magnet in question.
• the second switch position for the function "close valve” has already been reached when the gas exchange valve rests on its sealing surface, but the armature 1 does not yet Has reached pole surface of the closing magnet 2.1. This can be the case if, as indicated in FIG. 1, the guide pin 1.1 is divided and, as a result of a valve clearance, the armature 1 still moves in the direction of the pole face of the catching electromagnet - here the closing magnet 2.1 - while the gas exchange valve is moving already at rest.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Electromagnetism (AREA)
• Power Engineering (AREA)
• General Physics & Mathematics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Valve Device For Special Equipments (AREA)
• Reciprocating, Oscillating Or Vibrating Motors (AREA)
• Magnetically Actuated Valves (AREA)
• Control Of Linear Motors (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7899438

Family Applications (1)

Country Status (4)

Families Citing this family (6)

Family Cites Families (4)

• 1999
  • 1999-03-03 DE DE19909109A patent/DE19909109A1/de not_active Withdrawn
• 2000
  • 2000-02-25 JP JP2000603054A patent/JP2002538753A/ja not_active Withdrawn
  • 2000-02-25 EP EP00910709A patent/EP1076908A1/de not_active Withdrawn
  • 2000-02-25 WO PCT/EP2000/001546 patent/WO2000052715A1/de not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events