EP2936511B1 - Electromagnetic actuating apparatus - Google Patents

Description

The present invention relates to an electromagnetic actuator according to the preamble of the main claim. Such a device is known from DE 195 18 056 A1 known. Next is an actuator from the DE 20 2005 011 901 U1 the applicant known.

The purpose of the generic technology is to provide a suitable in particular for adjusting the camshaft on a motor vehicle engine actuator whose anchor (plunger) position or movement is detected in a simple manner. In the generic technology for this purpose, the energized for driving the anchor means coil is additionally used in its de-energized state during this period, a voltage induced by the armature unit or its movement in the coil voltage tapped as a signal from the coil terminal and suitably below by the detection means is evaluated. It is advantageously achieved by this measure that no additional sensors or detector units are required for the armature detection, which, in addition to corresponding component expenditure, would also require more extensive connection and line infrastructure.

However, in the DE 20 2005 011 901 U1 described technology in the practical realization and in particular in connection with dynamically evolved, fast switching actuators in need of improvement. For example, fast-rotating engines produce correspondingly short camshaft circulation times, which means that increasingly shorter shift times are required for electromagnetic actuators engaging in them; in particular the period between the beginning of the energization of the coil means and the Extending the anchor means (with its end-side engagement ram) in a stroke end position is to be made correspondingly short. This is achieved, inter alia, structurally in that the coil means provided with the energization for the purpose of the armature movement are increasingly low-resistance (and also have relatively lower inductances), which is made possible by corresponding wire cross-sections and winding or winding numbers of the winding wire used for the coil means. However, a disadvantage of such low-resistance coils is that the signal detected in the non-energized state ("throw-back signal") is significantly smaller and therefore harder to detect than in the conventional technology.

To the complementary state of the art is on the US 2010/255433 A1 to refer. Again, an electromagnetic actuator with relative to coil means in response to energization of the same drivable anchoring means is disclosed, the movement of which is detectable relative to stationary core means by the coil means associated detection means. The coil means have a first and a second coil winding. The first coil winding is designed for magnetic interaction with the armature means by means of the current supply, the second coil winding is designed to generate a detection signal which is outside the time of energization. Also, the first and the second coil winding form a two-pole parallel connection with an electronic switching means. However, this known technology is structurally different realized than the present invention as a generic identified technology, not least as in the US 2010/255433 A1 the coils are assigned to the armature and designed to be movable with this.

Object of the present invention is to provide a generic electromagnetic actuator, which, for example by low-resistance, Coil means provided with small number of turns is improved in its dynamic properties and has shortened switching times, so that even in the state of non-energization a reliable detection of the movement or setting position of the armature means can be detected from a detection signal applied to the coil means.

The object is achieved by the electromagnetic actuator with the features of the main claim; advantageous developments of the invention are described in the subclaims.

In accordance with the invention advantageously, the coil means are realized in the form of two separate, but to achieve a two-pole parallel coil windings, of which a first in the above, dynamically advantageous manner for driving the armature unit can be provided with the energization and, relative to the second coil winding, by appropriate design of the Spool wire and / or a reduced number of turns, low impedance is realized. In contrast, the second coil winding, designed relative to the first coil winding by appropriate design of the coil wire and / or an increased number of turns high or high resistance, as a sensor or detector winding and is used to generate the detection signal outside the energization (more precisely: the Bestromungszeit) evaluated ,

However, in order not to increase a line and Beschaltungsaufwand for realized in the form of two components or assemblies coil means, the first and the second coil winding is connected in parallel as a two-pole, such that each of the coil windings forms a branch, the respective branch ends together are connected and at these junctions externally (with the power source and the downstream detection means) are connected. The two-pole thus created makes it possible to use a connection or plug infrastructure, which is also already known for the generic technology, without requiring any additional connections or lines; Especially in an automotive environment with corresponding resource constraints, this leads to considerable advantages in the practical realization.

Since the parallel connection according to the invention would generate the problem that in the non-energized state a detection signal of the armature movement generated by the (high-resistance) second coil winding would be short-circuited by the (low-resistance) first coil winding, electronic switching or blocking means are provided according to the invention for the two-pole, which, in particular by selectively blocking or interrupting the path associated with the first coil winding, prevents such a short-circuit effect. In fact, during energization, the first coil winding also generates one of the Ankerbewegung corresponding induction signal, but this is due to the significantly lower number of turns less than the detection signal of the second coil winding, so that corresponding equalizing currents flow, which then no longer give usable signal at the terminals of the two-pole.

In contrast, the parallel connection of the two coil windings during energization is much less problematic because, due to the higher-resistance configuration, only a negligible proportion of current of the energization signal would flow through the second coil winding.

While in the development of the invention, the blocking means may have almost any (electrical) switching means, in particular semiconductor-based implemented, it is favorable according to a preferred embodiment of the invention to realize the further education switching or blocking means as a diode, which in the first (low-resistance) coil winding associated branch of the parallel circuit is looped. This diode becomes effective when the second coil winding generates the detection signal (that is to say the induction voltage) in a polarity which is opposite to the polarity of the current supply. In such an embodiment of the second coil winding, the detection signal generated therein would then be represented by the diode associated with the first coil winding be blocked and can thus be tapped by the detection means on the dipole and subsequently evaluated.

On the one hand, it is advantageous to realize this reverse polarity (opposite current flow direction) in that the first and the second coil windings are wound in opposite directions relative to each other. Alternatively, in the same direction winding, a corresponding opposite contacting of the windings take place.

In the constructional realization of the invention, there are numerous possibilities for developing the first and the second coil winding - wound or contacted in opposite directions - it being preferred to provide both coil windings adjacent to one another, more preferably on a common coil support. Again, according to further developments, this common coil carrier may advantageously be arranged along an axial direction of the adjusting device, i. parallel to a direction of movement of the armature unit, first with a coil winding section realizing the first coil winding, then with a coil section implementing the second coil winding, or else the reverse axial sequence can be selected. It is also possible (in addition or as an alternative) to provide the coil windings adjacent to one another in the radial direction, it being particularly advantageous here to apply the second coil winding to the first coil winding realizing the drive coil so as to be suitable on the shell side; Such a configuration is particularly suitable for radially symmetric embodiments of the electromagnetic actuator, in which the coil means, more preferably cylindrical, enclose the armature unit and the core unit and define the axis of movement of the armature unit by its central axis.

In the electrotechnical realization, it is preferable to design the first coil winding such that an ohmic resistance of <20 ohms is formed, more preferably this may be 6 ohms or less (for inductors in the range between approximately 25 mH for coils <20) Ohms up to 4 mH and down to 0.8 mH for coils <6 ohms). Accordingly, good dynamic properties can be realized. By contrast, it is preferred according to the invention, the second coil winding with an ohmic resistance above 100 ohms, is preferred in particular, a resistor above 400 ohms and <1500 ohms, so that a well evaluable detection signal can be generated and, in cooperation with the first coil winding, no significant current division takes place during energization. Here are typical inductances between about 1 H (400 ohm sensor coil) and about 7 H (500 ohms).

An additional advantage here brings the additionally provided for further training according to the second diode, looped into the second coil winding associated branch: by the first diode (in the branch of the first coil winding) opposite polarity prevents this second diode (realized as a Zener diode) any current flow during the energization allows at the same time, in the case of the winding direction or the corresponding contacting which is provided in the opposite way according to the invention, a current flow of the detection signal to the terminals of the dipole.

As a result, the present invention thus achieves a significant improvement in the movement or position detection of anchor means in the context of the generic electromagnetic actuator, with significantly improved dynamic characteristics are achieved and the device is still connected only two poles, in other words, for connection with upstream controllers no additional connections or lines are required.

Thus, the present invention is eminently suitable for use as an actuator for camshaft phasers, but is not limited to this preferred use.

Fig. 1 (a),(b),

ein Ersatzschaltbild der erfindungsgemäßen Spulenmittel einer ersten Ausführungsform der Erfindung mit lediglich einer, der ersten Spulenwicklung zugeordneten Diode, im Bestromungszustand (a) bzw. im Rückwurfzustand (b) bei induzierter Rückwurfspannung und unbestromter Hauptspule;

Fig. 2(a), (b)

ein Ersatzschaltbild der Spulenmittel einer zweiten, alternativen Ausführungsform der Erfindung mit einer zusätzlichen zweiten Diode, zugeordnet der zweiten Spulenwicklung, im Bestromungszustand (a) bzw. im Rückwurfzustand (b) bei induzierter Rückwurfspannung und unbestromter Hauptspule;

Fig. 3 bis 5

schematische Längsschnittdarstellungen der elektromagnetischen Stellvorrichtung mit möglichen geometrisch-konstruktiven Realisierungsvarianten der ersten bzw. zweiten Spulenwicklung.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawings; these show in

Fig. 1 (a), (b),

an equivalent circuit diagram of the coil means according to the invention a first embodiment of the invention with only one, the first coil winding associated diode, in the energized state (a) or in the discarded state (b) with induced back-off voltage and de-energized main coil;

Fig. 2 (a), (b)

an equivalent circuit diagram of the coil means of a second alternative embodiment of the invention with an additional second diode, associated with the second coil winding, in the energized state (a) or in the throw-back state (b) with induced back-off voltage and de-energized main coil;

Fig. 3 to 5

schematic longitudinal sectional views of the electromagnetic actuator with possible geometrical-constructive implementation variants of the first and second coil winding.

So show the Fig. 3 to 5 each in half as a longitudinal section through a radially symmetrically realized electromagnetic actuator according to a first preferred embodiment, three variants, as the first and second coil winding may be provided adjacent to each other: One of a long-armature tappet 10, a disk-shaped, axially magnetized permanent magnet 12 and An armature unit formed on a pair of flux guide disks 14, 16 provided on both sides of the permanent magnet disk 12 is along an axial one Direction 18 (insofar corresponding to the axis of symmetry of Fig. 3 to 5 ) and movably guided relative to a stationary core unit 20. The armature unit cooperates with an engagement-side plunger 22, which is held by the permanent magnetic adhesive force of the permanent magnet 12 at a front end of the armature plunger 12 releasably adhering. At the opposite end of the permanent magnet 12 engagement end 24 of the engagement ram for cooperation with a (not shown) control partner, in particular a parking cam camshaft adjustment for an internal combustion engine is formed, and for this purpose emerges from a front-side housing surface 26 of a unit surrounding the cylindrical housing 28 out. A bottom plate 30 and a frontal flux guide 32 close magnetic circuits over the housing, wherein in the arrangement shown (and in otherwise known manner) in response to the energization of a first coil winding 34, a repulsive force between the core unit 20 and the permanent magnet assembly 14th , 12, 16 arises, which the anchor unit and thus the attaching anchor tappet 22 from its in the Fig. 3 to 5 shown rest position in an engaged position (in the figure direction downwards) drives, so that the engagement end 24 can cooperate with the adjusting groove.

The embodiment shown has, adjacent to the first coil winding 34, a second coil winding 36, which in the implementation of the Fig. 3 the coil winding 34 is axially adjacent in the direction of the permanent magnet unit. Such a form of implementation brings the second coil winding 36, which acts as a detector coil (sensor) for the armature movement in the de-energized state, relatively close to the permanent magnet unit 14, 12, 16, so that high detection quality is ensured.

As a variant to the geometric configuration of Fig. 3 show the Fig. 4 (In the case of identical reference symbols for identical or equivalent components and functional groups) an alternative arrangement of the second coil winding adjacent to the first coil winding; Here, the second coil winding 36, in turn axially adjacent, on the permanent magnet unit opposite end of the first coil unit 36; This variant is particularly easy to contact.

The variant of Fig. 5 , again with otherwise identical or equivalent realization of the other components or assemblies, the second coil winding 40 provides radially outward lying and wound on the first coil winding 34 and thus advantageously allows additional axial space.

All shown embodiments of the Fig. 3 to 5 is common that a (not shown) coil holder, typically realized from a suitable, magnetically non-conductive plastic injection molding material, carries both coil windings in the respective configurations shown.

The Fig. 1 and 2 illustrate as mutually alternative embodiments, the wiring and configuration of the respective coil windings. Thus, as a first exemplary embodiment for realizing the invention, FIG Fig. 1 in the circuit diagram, how the first coil winding (represented by its coil resistance R _main and its inductance L _{main for} compensation purposes) forms a first branch of a dipole, to which a first diode D1 is assigned: the first winding 34 provided for energizing with the purpose of driving the armature unit is energized with a polarity that the falling voltage U _main runs along the flow direction of the diode D1, in other words, while the current is conducting D1.

The first embodiment of the Fig. 1 further illustrates a second, the second coil winding 36 (or 40) corresponding branch in the illustrated equivalent circuit diagram, this second coil winding is shown as a substitute by their ohmic coil resistance R _sensor or its inductance L _sensor . The winding sense of this coil winding is set up so that one of the Bestromungsspannung U _main opposite induction or detector voltage U _sensor (induced by the armature movement in the non-energized state) is formed according to the arrow directions in the Fig. 1 , Is accessed on the two pole by the two terminals A1, A2, so far comparable to a conventional two-pole connection to a control unit. The current flow through the coil winding 36 corresponding branch takes place along the direction of arrow l _sensor .

The Fig. 1 (a) shows the Bestromungszustand the main coil 34 (approximately in a constructive implementation of one of the variants of Fig. 3 to 5 ); it conducts the diode D1. In addition, since the windings 34 and 36 are configured relative to one another such that an ohmic resistance of the winding 36 (with about 400 to 1500 ohms) is significantly greater than an ohmic resistance of the first winding 34 (with about 0.1 to 6 Ohms), the current flow in the branch 36 during energization is negligible. On the other hand leads, after completion of the energization by U _switching according to Fig. 1 (b) and during the discarding or detection operation (upon movement of the armature unit) the diode D1 by its polarity that the detection signal U _sensor can be tapped and processed via the terminals of the two-pole A1, A2 and does not flow through the branch of the first coil winding 34 , as far as the diode D1 locks. This symbolizes the Fig. 1 (b) in that the current flow I _main is blocked by the branch 34; the discard signal is not dissipated over the main coil.

The second embodiment of the Fig. 2 Insofar as a development of the first embodiment (again with identical reference numerals for identical or equivalent units) assigns the branch of the second coil winding 36, a second diode D2, which during the Bestromungsbetriebs (current flow through the first coil winding) blocks, so that no current flow through serving as a sensor coil second coil winding takes place. During the detector operation, D2 opens, so that in this respect the detection signal (with blocked D1) can flow and in turn can be tapped off via A1, A2. The second diode D2 is realized as a Zener diode and is designed such that it blocks _switching in the energizing or switching voltage U, but has a breakdown voltage which is lower than the induced voltage U _sensor . This will, as Fig. 2 (a) symbolizes in the energizing operation I _sensor locked so that no opposing field can arise through the coil branch 36. Similarly, the diode D1 prevents, analogous to the first embodiment of the Fig. 1 in that the discard signal U _{sensor is} removed via the main coil 34; the induced reverse current of the main coil is blocked.

Typical implementation variants of the windings with a setting stroke of 3 mm to 6 mm, a typical setting force in the range of 3 N to 15 N and a typical outer diameter of the housing shell of about 20 mm are between 50 and 500 turns for the first coil winding and between approx. 800 and about 8,000 windings for the second winding, resulting in typical inductances of 0.8 mH to 25 mH and 1 H to 70 H, respectively.

The geometrical-constructive realization forms of the Fig. 3 to 5 show a bistable device; It can be seen that in an extended (engaged) state of the armature unit, the permanent magnet unit 14, 12, 16 at the front end housing end 26, 32 holds (by permanent magnet force), even in a de-energized state of the coil means. A typical provision then takes place in a manner customary for the camshaft adjustment by the action of the adjusting groove cooperating with the engagement ram 22. It is precisely such a bistability preferred for further development that realizes the advantages of the present invention of reliably detecting the movement or setting behavior of the armature unit by means of the second coil winding.

Claims (10)

1. An electromagnetic positioning device having armature means (10, 12, 14, 16, 22) which are drivable relative to stationary coil means (34, 36; 34, 40) in reaction to energizing said coil means (34, 36; 34, 40), the movement (U_Schalten) and/or actuated position of said armature means being detectable via detection means, which are associated to the coil means, relative to stationary core means (20) which interact with the coil means,
   the coil means having a first coil winding (34), which is realized for magnetically interacting with the armature means by means of the energization, as well as a second coil winding (36; 40), which is realized for generating a detection signal temporally outside of the energization for the detection means, the first and the second coil winding forming a parallel circuit for forming a two-terminal circuit, characterized in that
   electronic switching and/or locking means (D1, D2) are assigned to the two-terminal circuit in such a manner that they prevent a short circuit of the detection signal (U_Sensor) via the first coil winding outside of the energization, a ratio of the ohmic resistances of the second coil winding with regard to the first coil winding being > 40, preferably > 100, more preferably > 300, and/or the locking means having a first diode (D1) looped in a branch of the two-terminal circuit associated with the first coil winding.
2. The device according to claim 1, characterized in that each of the first and the second coil winding have a winding direction in the opposite direction to each other and/or have a contacting oriented in the opposite direction and/or that a polarity of the energization is inverse to a polarity of the detection signal.
3. The device according to claim 1 or 2, characterized in that the second coil device is provided adjacent to the first coil device, in particular on a shared coil carrier.
4. The device according to claim 3, characterized in that the second coil winding is provided axially adjacent to the first coil winding.
5. The device according to any of the claims 1 to 4, characterized in that the second coil winding is realized radially adjacent, in particular being seated radially externally, to the first coil winding.
6. The device according to any of the claims 1 to 5, characterized in that the first coil winding has an ohmic resistance of < 20 ohms, preferably < 10 ohms, more preferably < 6 ohms.
7. The device according to any of the claims 1 to 6, characterized in that the second coil winding has an ohmic resistance of > 100 ohms, in particular > 400 ohms, and < 3000 ohms, in particular
   < 1500 ohms.
8. The device according to any of the claims 1 to 7, characterized in that the locking means have a second diode (D2) which is looped in a branch of the two-terminal circuit associated with the second coil winding.
9. The device according to any of the claims 1 to 8, characterized in that permanent magnet means (12) magnetically interacting with the core means are assigned to the armature means, said permanent magnet means (12) generating a repelling force on the core means in reaction to the energization.
10. The device according to any of the claims 1 to 9, characterized in that the armature means formed tappet-like have an engagement end (24), which is formed for interacting with a positioning partner allowing a camshaft displacement of an internal combustion engine, preferably the positioning partner being designed for realizing a resetting of the armature means.

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